WorldWideScience

Sample records for seabird colony size

  1. Seabird Colonies in Western Greenland

    DEFF Research Database (Denmark)

    Boertmann, D.; Mosbech, A.; Falk, K.

    About 1 million seabirds (indvs) breed in 1032 colonies distributed along the coasts of western Greenland (Fig. 1). However, this figure does not include the little auk colonies in Avanersuaq. These colonies are roughly estimated to hold about 20 mill. pairs. All the basic information on seabird...... colonies in Greenland is compiled in a database maintained by NERI-AE. This report presents data on distribution, population numbers and population trends of 19 species of breeding colonial seabirds in western Greenland. Distributions are depicted on maps in Fig. 18-39. It is apparent that the major...... colonies are found in the northern part of the region, viz. Upernavik and Avanersuaq. The numbers of birds recorded in the database for each species are presented in Tab. 4, and on the basis of these figures estimates of the populations in western Greenland are given (Tab. 5). The most numerous species...

  2. Vocal activity as a low cost and scalable index of seabird colony size.

    Science.gov (United States)

    Borker, Abraham L; McKown, Matthew W; Ackerman, Joshua T; Eagles-Smith, Collin A; Tershy, Bernie R; Croll, Donald A

    2014-08-01

    Although wildlife conservation actions have increased globally in number and complexity, the lack of scalable, cost-effective monitoring methods limits adaptive management and the evaluation of conservation efficacy. Automated sensors and computer-aided analyses provide a scalable and increasingly cost-effective tool for conservation monitoring. A key assumption of automated acoustic monitoring of birds is that measures of acoustic activity at colony sites are correlated with the relative abundance of nesting birds. We tested this assumption for nesting Forster's terns (Sterna forsteri) in San Francisco Bay for 2 breeding seasons. Sensors recorded ambient sound at 7 colonies that had 15-111 nests in 2009 and 2010. Colonies were spaced at least 250 m apart and ranged from 36 to 2,571 m(2) . We used spectrogram cross-correlation to automate the detection of tern calls from recordings. We calculated mean seasonal call rate and compared it with mean active nest count at each colony. Acoustic activity explained 71% of the variation in nest abundance between breeding sites and 88% of the change in colony size between years. These results validate a primary assumption of acoustic indices; that is, for terns, acoustic activity is correlated to relative abundance, a fundamental step toward designing rigorous and scalable acoustic monitoring programs to measure the effectiveness of conservation actions for colonial birds and other acoustically active wildlife. © 2014 Society for Conservation Biology.

  3. A catalog of Louisiana's nesting seabird colonies

    Science.gov (United States)

    Fontenot, William R.; Cardiff, Steve W.; DeMay, Richard A.; Dittmann, Donna L.; Hartley, Stephen B.; Jeske, Clinton W.; Lorenz, Nicole; Michot, Thomas C.; Purrington, Robert Dan; Seymour, Michael; Vermillion, William G.

    2012-01-01

    Summarizing his colonial nesting waterbird survey experiences along the northern coast of the Gulf of Mexico in a paper presented to the Colonial Waterbird Group of the Waterbird Society (Portnoy 1978), bird biologist John W. Portnoy stated, “This huge concentration of nesting waterbirds, restricted almost entirely to the wetlands and estuaries of southern Louisiana, is unmatched in all of North America; for example, a 1975 inventory of wading birds along the Atlantic Coast from Maine to Florida [Custer and Osborn, in press], tallied 250,000 breeding [waterbirds] of 14 species, in contrast with the 650,000 birds of 15 species just from Sabine Pass to Mobile Bay.” The “650,000 birds” to which Portnoy referred, were tallied by him in a 1976 survey of coastal Louisiana, Mississippi, and Alabama (see below, under “Major Surveys” section). According to the National Atlas of Coastal Waterbird Colonies in the Contiguous United States: 1976-82 (Spendelow and Patton 1988), the percentages of the total U.S. populations of Laughing Gull (11%), Forster's Tern (52%), Royal Tern (16%), Sandwich Tern (77%), and Black Skimmer (44%) which annually nest in Louisiana are significant – perhaps crucially so in the cases of Forster's Tern, Sandwich Tern, and Black Skimmer. Nearly three decades after Spendelow and Patton's determinations above, coastal Louisiana still stands out as the major center of colonial wading bird and seabird nesting in all of the United States. Within those three intervening decades, however, the

  4. The global distribution of ammonia emissions from seabird colonies

    Science.gov (United States)

    Riddick, S. N.; Dragosits, U.; Blackall, T. D.; Daunt, F.; Wanless, S.; Sutton, M. A.

    2012-08-01

    Seabird colonies represent a significant source of atmospheric ammonia (NH3) in remote maritime systems, producing a source of nitrogen that may encourage plant growth, alter terrestrial plant community composition and affect the surrounding marine ecosystem. To investigate seabird NH3 emissions on a global scale, we developed a contemporary seabird database including a total seabird population of 261 million breeding pairs. We used this in conjunction with a bioenergetics model to estimate the mass of nitrogen excreted by all seabirds at each breeding colony. The results combined with the findings of mid-latitude field studies of volatilization rates estimate the global distribution of NH3 emissions from seabird colonies on an annual basis. The largest uncertainty in our emission estimate concerns the potential temperature dependence of NH3 emission. To investigate this we calculated and compared temperature independent emission estimates with a maximum feasible temperature dependent emission, based on the thermodynamic dissociation and solubility equilibria. Using the temperature independent approach, we estimate global NH3 emissions from seabird colonies at 404 Gg NH3 per year. By comparison, since most seabirds are located in relatively cold circumpolar locations, the thermodynamically dependent estimate is 136 Gg NH3 per year. Actual global emissions are expected to be within these bounds, as other factors, such as non-linear interactions with water availability and surface infiltration, moderate the theoretical temperature response. Combining sources of error from temperature (±49%), seabird population estimates (±36%), variation in diet composition (±23%) and non-breeder attendance (±13%), gives a mid estimate with an overall uncertainty range of NH3 emission from seabird colonies of 270 [97-442] Gg NH3 per year. These emissions are environmentally relevant as they primarily occur as "hot-spots" in otherwise pristine environments with low anthropogenic

  5. Seabird Nesting Colonies in Louisiana, Geographic NAD83, LSU (1997) [seabirds_LSU_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is a point dataset for seabird nesting colonies derived from GPS locations in the field. The attributes of the habitat points are based upon visual assessment...

  6. Seabird colonies in the Melville Bay, Northwest Greenland

    DEFF Research Database (Denmark)

    Boertmann, David; Huffeldt, Nicholas Per

    This report describes the results of a survey for breeding and colonial seabirds in a hitherto un-surveyed area of Northwest Greenland - the Melville Bay. The results shall be included as background data for oil spill sensitivity mapping, preparation of environmental impact assessments of petroleum...... activities in Baffin Bay and for the regulation (by the Greenland government) of petroleum activities. The survey showed, that compared to other coasts of West Greenland, the Melville Bay holds only few breeding colonies and low numbers of breeding seabirds. The most widespread and numerous species...... is the black guillemot followed by the glaucous gull. However, one colony is of national significance – Sabine Øer, with high numbers of breeding Arctic terns and Sabine’s gulls. Other noteworthy observations were puffins on Thom Ø and many new Iceland gull colonies that extended the known northern breeding...

  7. Colony mapping: A new technique for monitoring crevice-nesting seabirds

    Science.gov (United States)

    Renner, H.M.; Renner, M.; Reynolds, J.H.; Harping, A.M.A.; Jones, I.L.; Irons, D.B.; Byrd, G.V.

    2006-01-01

    Monitoring populations of auklets and other crevice-nesting seabirds remains problematic, although numerous methods have been attempted since the mid-1960s. Anecdotal evidence suggests several large auklet colonies have recently decreased in both abundance and extent, concurrently with vegetation encroachment and succession. Quantifying changes in the geographical extent of auklet colonies may be a useful alternative to monitoring population size directly. We propose a standardized method for colony mapping using a randomized systematic grid survey with two components: a simple presence/absence survey and an auklet evidence density survey. A quantitative auklet evidence density index was derived from the frequency of droppings and feathers. This new method was used to map the colony on St. George Island in the southeastern Bering Sea and results were compared to previous colony mapping efforts. Auklet presence was detected in 62 of 201 grid cells (each grid cell = 2500 m2) by sampling a randomly placed 16 m2 plot in each cell; estimated colony area = 155 000 m2. The auklet evidence density index varied by two orders of magnitude across the colony and was strongly correlated with means of replicated counts of birds socializing on the colony surface. Quantitatively mapping all large auklet colonies is logistically feasible using this method and would provide an important baseline for monitoring colony status. Regularly monitoring select colonies using this method may be the best means of detecting changes in distribution and population size of crevice-nesting seabirds. ?? The Cooper Ornithological Society 2006.

  8. An isotopic investigation of mercury accumulation in terrestrial food webs adjacent to an Arctic seabird colony

    International Nuclear Information System (INIS)

    Choy, Emily S.; Gauthier, Martine; Mallory, Mark L.; Smol, John P.; Douglas, Marianne S.V.; Lean, David; Blais, Jules M.

    2010-01-01

    At Cape Vera (Devon Island, Nunavut, Canada), a seabird colony of northern fulmars (Fulmarus glacialis) congregates and releases nutrients through the deposition of guano to the coastal terrestrial environment, thus creating nutrient-fertilized habitats important to insects, birds, and mammals. Here we determined whether mercury was similarly enriched in various terrestrial food web components in this High Arctic coastal ecosystem due to seabird inputs. Stable isotopes (δ 15 N, δ 13 C) were used to identify trophic linkages and possible routes of contaminant transfer in the food web. Values of δ 15 N were significantly higher in lichens and certain plants collected closer to the bird colony, demonstrating a gradient of seabird influence, and were higher at Cape Vera than our reference site at Cape Herschel, on eastern Ellesmere Island, an area relatively unaffected by seabirds. In contrast, δ 13 C showed little variation among terrestrial species, suggesting minimal influence by seabirds. Concentrations of total mercury (THg) in primary producers and phyto/zooplankton were not significantly correlated with distance from the seabird colony or δ 15 N values, and were similar to other taxa from the High Arctic. Our results provide novel data on THg in several Arctic taxa where concentrations have not been reported previously. Moreover, the analyses indicate that δ 15 N is significantly enriched in the adjacent environment by guano fertilization, but our study was unable to show an enrichment of THg and δ 13 C in the terrestrial food web near the seabird colony.

  9. Population dynamics of Hawaiian seabird colonies vulnerable to sea-level rise.

    Science.gov (United States)

    Hatfield, Jeff S; Reynolds, Michelle H; Seavy, Nathaniel E; Krause, Crystal M

    2012-08-01

    Globally, seabirds are vulnerable to anthropogenic threats both at sea and on land. Seabirds typically nest colonially and show strong fidelity to natal colonies, and such colonies on low-lying islands may be threatened by sea-level rise. We used French Frigate Shoals, the largest atoll in the Hawaiian Archipelago, as a case study to explore the population dynamics of seabird colonies and the potential effects sea-level rise may have on these rookeries. We compiled historic observations, a 30-year time series of seabird population abundance, lidar-derived elevations, and aerial imagery of all the islands of French Frigate Shoals. To estimate the population dynamics of 8 species of breeding seabirds on Tern Island from 1980 to 2009, we used a Gompertz model with a Bayesian approach to infer population growth rates, density dependence, process variation, and observation error. All species increased in abundance, in a pattern that provided evidence of density dependence. Great Frigatebirds (Fregata minor), Masked Boobies (Sula dactylatra), Red-tailed Tropicbirds (Phaethon rubricauda), Spectacled Terns (Onychoprion lunatus), and White Terns (Gygis alba) are likely at carrying capacity. Density dependence may exacerbate the effects of sea-level rise on seabirds because populations near carrying capacity on an island will be more negatively affected than populations with room for growth. We projected 12% of French Frigate Shoals will be inundated if sea level rises 1 m and 28% if sea level rises 2 m. Spectacled Terns and shrub-nesting species are especially vulnerable to sea-level rise, but seawalls and habitat restoration may mitigate the effects of sea-level rise. Losses of seabird nesting habitat may be substantial in the Hawaiian Islands by 2100 if sea levels rise 2 m. Restoration of higher-elevation seabird colonies represent a more enduring conservation solution for Pacific seabirds. Conservation Biology ©2012 Society for Conservation Biology. No claim to original

  10. Population dynamics of Hawaiian seabird colonies vulnerable to sea-level rise

    Science.gov (United States)

    Hatfield, Jeff S.; Reynolds, Michelle H.; Seavy, Nathaniel E.; Krause, Crystal M.

    2012-01-01

    Globally, seabirds are vulnerable to anthropogenic threats both at sea and on land. Seabirds typically nest colonially and show strong fidelity to natal colonies, and such colonies on low-lying islands may be threatened by sea-level rise. We used French Frigate Shoals, the largest atoll in the Hawaiian Archipelago, as a case study to explore the population dynamics of seabird colonies and the potential effects sea-level rise may have on these rookeries. We compiled historic observations, a 30-year time series of seabird population abundance, lidar-derived elevations, and aerial imagery of all the islands of French Frigate Shoals. To estimate the population dynamics of 8 species of breeding seabirds on Tern Island from 1980 to 2009, we used a Gompertz model with a Bayesian approach to infer population growth rates, density dependence, process variation, and observation error. All species increased in abundance, in a pattern that provided evidence of density dependence. Great Frigatebirds (Fregata minor), Masked Boobies (Sula dactylatra), Red-tailed Tropicbirds (Phaethon rubricauda), Spectacled Terns (Onychoprion lunatus), and White Terns (Gygis alba) are likely at carrying capacity. Density dependence may exacerbate the effects of sea-level rise on seabirds because populations near carrying capacity on an island will be more negatively affected than populations with room for growth. We projected 12% of French Frigate Shoals will be inundated if sea level rises 1 m and 28% if sea level rises 2 m. Spectacled Terns and shrub-nesting species are especially vulnerable to sea-level rise, but seawalls and habitat restoration may mitigate the effects of sea-level rise. Losses of seabird nesting habitat may be substantial in the Hawaiian Islands by 2100 if sea levels rise 2 m. Restoration of higher-elevation seabird colonies represent a more enduring conservation solution for Pacific seabirds.

  11. No evidence of extra-pair paternity in a colonial seabird, the common tern (Sterna hirundo)

    DEFF Research Database (Denmark)

    Griggio, M.; Matessi, Giuliano; Marin, G.

    2004-01-01

    The incidence of extra-pair paternity and egg dumping was investigated in a colony of common terns (Sterna hirundo), a colonial seabird, in the Venetian lagoon. Ten families were sampled and multilocus DNA fingerprinting analysis was performed. No indication of extra-pair paternity or egg dumping...

  12. Estimating population size of a nocturnal burrow-nesting seabird using acoustic monitoring and habitat mapping

    Directory of Open Access Journals (Sweden)

    Steffen Oppel

    2014-04-01

    Full Text Available Population size assessments for nocturnal burrow-nesting seabirds are logistically challenging because these species are active in colonies only during darkness and often nest on remote islands where manual inspections of breeding burrows are not feasible. Many seabird species are highly vocal, and recent technological innovations now make it possible to record and quantify vocal activity in seabird colonies. Here we test the hypothesis that remotely recorded vocal activity in Cory’s shearwater (Calonectris borealis breeding colonies in the North Atlantic increases with nest density, and combined this relationship with cliff habitat mapping to estimate the population size of Cory’s shearwaters on the island of Corvo (Azores. We deployed acoustic recording devices in 9 Cory’s shearwater colonies of known size to establish a relationship between vocal activity and local nest density (slope = 1.07, R2 = 0.86, p < 0.001. We used this relationship to predict the nest density in various cliff habitat types and produced a habitat map of breeding cliffs to extrapolate nest density around the island of Corvo. The mean predicted nest density on Corvo ranged from 6.6 (2.1–16.2 to 27.8 (19.5–36.4 nests/ha. Extrapolation of habitat-specific nest densities across the cliff area of Corvo resulted in an estimate of 6326 Cory’s shearwater nests (95% confidence interval: 3735–10,524. This population size estimate is similar to previous assessments, but is too imprecise to detect moderate changes in population size over time. While estimating absolute population size from acoustic recordings may not be sufficiently precise, the strong positive relationship that we found between local nest density and recorded calling rate indicates that passive acoustic monitoring may be useful to document relative changes in seabird populations over time.

  13. No evidence of extra-pair paternity in a colonial seabird, the common tern (Sterna hirundo)

    DEFF Research Database (Denmark)

    Griggio, M.; Matessi, Giuliano; Marin, G.

    2004-01-01

    The incidence of extra-pair paternity and egg dumping was investigated in a colony of common terns (Sterna hirundo), a colonial seabird, in the Venetian lagoon. Ten families were sampled and multilocus DNA fingerprinting analysis was performed. No indication of extra-pair paternity or egg dumping...... was found in any of the families. The results are discussed in the light of life-history strategies, the benefits of coloniality and the evolution of adoption behaviour in the species.......The incidence of extra-pair paternity and egg dumping was investigated in a colony of common terns (Sterna hirundo), a colonial seabird, in the Venetian lagoon. Ten families were sampled and multilocus DNA fingerprinting analysis was performed. No indication of extra-pair paternity or egg dumping...

  14. Seabird colonies as important global drivers in the nitrogen and phosphorus cycles.

    Science.gov (United States)

    Otero, Xosé Luis; De La Peña-Lastra, Saul; Pérez-Alberti, Augusto; Ferreira, Tiago Osorio; Huerta-Diaz, Miguel Angel

    2018-01-23

    Seabirds drastically transform the environmental conditions of the sites where they establish their breeding colonies via soil, sediment, and water eutrophication (hereafter termed ornitheutrophication). Here, we report worldwide amounts of total nitrogen (N) and total phosphorus (P) excreted by seabirds using an inventory of global seabird populations applied to a bioenergetics model. We estimate these fluxes to be 591 Gg N y -1 and 99 Gg P y -1 , respectively, with the Antarctic and Southern coasts receiving the highest N and P inputs. We show that these inputs are of similar magnitude to others considered in global N and P cycles, with concentrations per unit of surface area in seabird colonies among the highest measured on the Earth's surface. Finally, an important fraction of the total excreted N (72.5 Gg y -1 ) and P (21.8 Gg y -1 ) can be readily solubilized, increasing their short-term bioavailability in continental and coastal waters located near the seabird colonies.

  15. A multi-scale problem arising in a model of avian flu virus in a seabird colony

    International Nuclear Information System (INIS)

    Clancy, C F; O'Callaghan, M J A; Kelly, T C

    2006-01-01

    Understanding the dynamics of epidemics of novel pathogens such as the H5N1 strain of avian influenza is of crucial importance to public and veterinary health as well as wildlife ecology. We model the effect of a new virus on a seabird colony, where no pre-existing Herd Immunity exists. The seabirds in question are so-called K-strategists, i.e. they have a relatively long life expectancy and very low reproductive output. They live in isolated colonies which typically contain tens of thousands of birds. These densely populated colonies, with so many birds competing for nesting space, would seem to provide perfect conditions for the entry and spread of an infection. Yet there are relatively few reported cases of epidemics among these seabirds. We develop a SEIR model which incorporates some of the unusual features of seabird population biology and examine the effects of introducing a pathogen into the colony

  16. Contribution of Arctic seabird-colony ammonia to atmospheric particles and cloud-albedo radiative effect

    Science.gov (United States)

    Croft, B.; Wentworth, G. R.; Martin, R. V.; Leaitch, W. R.; Murphy, J. G.; Murphy, B. N.; Kodros, J. K.; Abbatt, J. P. D.; Pierce, J. R.

    2016-01-01

    The Arctic region is vulnerable to climate change and able to affect global climate. The summertime Arctic atmosphere is pristine and strongly influenced by natural regional emissions, which have poorly understood climate impacts related to atmospheric particles and clouds. Here we show that ammonia from seabird-colony guano is a key factor contributing to bursts of newly formed particles, which are observed every summer in the near-surface atmosphere at Alert, Nunavut, Canada. Our chemical-transport model simulations indicate that the pan-Arctic seabird-influenced particles can grow by sulfuric acid and organic vapour condensation to diameters sufficiently large to promote pan-Arctic cloud-droplet formation in the clean Arctic summertime. We calculate that the resultant cooling tendencies could be large (about −0.5 W m−2 pan-Arctic-mean cooling), exceeding −1 W m−2 near the largest seabird colonies due to the effects of seabird-influenced particles on cloud albedo. These coupled ecological–chemical processes may be susceptible to Arctic warming and industrialization. PMID:27845764

  17. Foraging segregation and genetic divergence between geographically proximate colonies of a highly mobile seabird

    Science.gov (United States)

    Wiley, Anne E.; Welch, Andreanna J.; Ostrom, P.H.; James, Helen F.; Stricker, C.A.; Fleischer, R.C.; Gandhi, H.; Adams, J.; Ainley, D.G.; Duvall, F.; Holmes, N.; Hu, D.; Judge, S.; Penniman, J.; Swindle, K.A.

    2012-01-01

    Foraging segregation may play an important role in the maintenance of animal diversity, and is a proposed mechanism for promoting genetic divergence within seabird species. However, little information exists regarding its presence among seabird populations. We investigated genetic and foraging divergence between two colonies of endangered Hawaiian petrels (Pterodroma sandwichensis) nesting on the islands of Hawaii and Kauai using the mitochondrial Cytochrome b gene and carbon, nitrogen and hydrogen isotope values (?? 13C, ?? 15N and ??D, respectively) of feathers. Genetic analyses revealed strong differentiation between colonies on Hawaii and Kauai, with ?? ST = 0. 50 (p Feather ??D varied from -69 to 53???. This variation cannot be related solely to an isotopically homogeneous ocean water source or evaporative water loss. Instead, we propose the involvement of salt gland excretion. Our data demonstrate the presence of foraging segregation between proximately nesting seabird populations, despite high species mobility. This ecological diversity may facilitate population coexistence, and its preservation should be a focus of conservation strategies. ?? 2011 Springer-Verlag (outside the USA).

  18. Spatial heterogeneity as a genetic mixing mechanism in highly philopatric colonial seabirds.

    Science.gov (United States)

    Cristofari, Robin; Trucchi, Emiliano; Whittington, Jason D; Vigetta, Stéphanie; Gachot-Neveu, Hélène; Stenseth, Nils Christian; Le Maho, Yvon; Le Bohec, Céline

    2015-01-01

    How genetic diversity is maintained in philopatric colonial systems remains unclear, and understanding the dynamic balance of philopatry and dispersal at all spatial scales is essential to the study of the evolution of coloniality. In the King penguin, Aptenodytes patagonicus, return rates of post-fledging chicks to their natal sub-colony are remarkably high. Empirical studies have shown that adults return year after year to their previous breeding territories within a radius of a few meters. Yet, little reliable data are available on intra- and inter-colonial dispersal in this species. Here, we present the first fine-scale study of the genetic structure in a king penguin colony in the Crozet Archipelago. Samples were collected from individual chicks and analysed at 8 microsatellite loci. Precise geolocation data of hatching sites and selective pressures associated with habitat features were recorded for all sampling locations. We found that despite strong natal and breeding site fidelity, king penguins retain a high degree of panmixia and genetic diversity. Yet, genetic structure appears markedly heterogeneous across the colony, with higher-than-expected inbreeding levels, and local inbreeding and relatedness hotspots that overlap predicted higher-quality nesting locations. This points towards heterogeneous population structure at the sub-colony level, in which fine-scale environmental features drive local philopatric behaviour, while lower-quality patches may act as genetic mixing mechanisms at the colony level. These findings show how a lack of global genetic structuring can emerge from small-scale heterogeneity in ecological parameters, as opposed to the classical model of homogeneous dispersal. Our results also emphasize the importance of sampling design for estimation of population parameters in colonial seabirds, as at high spatial resolution, basic genetic features are shown to be location-dependent. Finally, this study stresses the importance of

  19. Spatial heterogeneity as a genetic mixing mechanism in highly philopatric colonial seabirds.

    Directory of Open Access Journals (Sweden)

    Robin Cristofari

    Full Text Available How genetic diversity is maintained in philopatric colonial systems remains unclear, and understanding the dynamic balance of philopatry and dispersal at all spatial scales is essential to the study of the evolution of coloniality. In the King penguin, Aptenodytes patagonicus, return rates of post-fledging chicks to their natal sub-colony are remarkably high. Empirical studies have shown that adults return year after year to their previous breeding territories within a radius of a few meters. Yet, little reliable data are available on intra- and inter-colonial dispersal in this species. Here, we present the first fine-scale study of the genetic structure in a king penguin colony in the Crozet Archipelago. Samples were collected from individual chicks and analysed at 8 microsatellite loci. Precise geolocation data of hatching sites and selective pressures associated with habitat features were recorded for all sampling locations. We found that despite strong natal and breeding site fidelity, king penguins retain a high degree of panmixia and genetic diversity. Yet, genetic structure appears markedly heterogeneous across the colony, with higher-than-expected inbreeding levels, and local inbreeding and relatedness hotspots that overlap predicted higher-quality nesting locations. This points towards heterogeneous population structure at the sub-colony level, in which fine-scale environmental features drive local philopatric behaviour, while lower-quality patches may act as genetic mixing mechanisms at the colony level. These findings show how a lack of global genetic structuring can emerge from small-scale heterogeneity in ecological parameters, as opposed to the classical model of homogeneous dispersal. Our results also emphasize the importance of sampling design for estimation of population parameters in colonial seabirds, as at high spatial resolution, basic genetic features are shown to be location-dependent. Finally, this study stresses the

  20. Incidence of plastic fragments among burrow-nesting seabird colonies on offshore islands in northern New Zealand.

    Science.gov (United States)

    Buxton, Rachel T; Currey, Caitlin A; Lyver, Philip O'B; Jones, Christopher J

    2013-09-15

    Marine plastic pollution is ubiquitous throughout the world's oceans, and has been found in high concentrations in oceanic gyres of both the northern and southern hemispheres. The number of studies demonstrating plastic debris at seabird colonies and plastic ingestion by adult seabirds has increased over the past few decades. Despite the recent discovery of a large aggregation of plastic debris in the South Pacific subtropical gyre, the incidence of plastics at seabird colonies in New Zealand is unknown. Between 2011 and 2012 we surveyed six offshore islands on the northeast coast of New Zealand's North Island for burrow-nesting seabird colonies and the presence of plastic fragments. We found non-research related plastic fragments (0.031 pieces/m(2)) on one island only, Ohinau, within dense flesh-footed shearwater (Puffinus carneipes) colonies. On Ohinau, we found a linear relationship between burrow density and plastic density, with 3.5 times more breeding burrows in areas with plastic fragments found. From these data we conclude that plastic ingestion is a potentially a serious issue for flesh-footed shearwaters in New Zealand. Although these results do not rule out plastic ingestion by other species, they suggest the need for further research on the relationship between New Zealand's pelagic seabirds and marine plastic pollution. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. The use of plastic debris as nesting material by a colonial seabird and associated entanglement mortality.

    Science.gov (United States)

    Votier, Stephen C; Archibald, Kirsten; Morgan, Greg; Morgan, Lisa

    2011-01-01

    Entanglement with plastic debris is a major cause of mortality in marine taxa, but the population-level consequences are unknown. Some seabirds collect marine debris for nesting material, which may lead to entanglement. Here we investigate the use of plastics as nesting material by northern gannets Morus bassanus and assess the associated levels of mortality. On average gannet nests contained 469.91 g (range 0-1293 g) of plastic, equating to an estimated colony total of 18.46 tones (range 4.47-42.34 tones). The majority of nesting material was synthetic rope, which appears to be used preferentially. On average 62.85 ± 26.84 (range minima 33-109) birds were entangled each year, totalling 525 individuals over eight years, the majority of which were nestlings. Although mortality rates are high, they are unlikely to have population-level effects. The use of synthetic fibres as nesting material is a common strategy among seabirds, but the impacts of entanglement warrants further investigation. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

  2. Population regulation in Magellanic penguins: what determines changes in colony size?

    Directory of Open Access Journals (Sweden)

    Luciana M Pozzi

    Full Text Available Seabirds are often studied at individual colonies, but the confounding effects of emigration and mortality processes in open populations may lead to inappropriate conclusions on the mechanisms underlying population changes. Magellanic penguin (Spheniscus magellanicus colonies of variable population sizes are distributed along the Argentine coastline. In recent decades, several population and distributional changes have occurred, with some colonies declining and others newly established or increasing. We integrated data of eight colonies scattered along ∼600 km in Northern Patagonia (from 41°26´S, 65°01´W to 45°11´S, 66°30´W, Rio Negro and Chubut provinces and conducted analysis in terms of their growth rates, production of young and of the dependence of those vital rates on colony age, size, and location. We contrasted population trends estimated from abundance data with those derived from population modeling to understand if observed growth rates were attainable under closed population scenarios. Population trends were inversely related to colony size, suggesting a density dependent growth pattern. All colonies located in the north--which were established during the last decades--increased at high rates, with the smallest, recently established colonies growing at the fastest rate. In central-southern Chubut, where colonies are the oldest, the largest breeding aggregations declined, but smaller colonies remained relatively stable. Results provided strong evidence that dispersal played a major role in driving local trends. Breeding success was higher in northern colonies, likely mediated by favorable oceanographic conditions. However, mean foraging distance and body condition of chicks at fledging were influenced by colony size. Recruitment of penguins in the northern area may have been triggered by a combination of density dependence, likely exacerbated by less favorable oceanographic conditions in the southern sector. Our results

  3. Population structure of the soft tick Ornithodoros maritimus and its associated infectious agents within a colony of its seabird host Larus michahellis

    Directory of Open Access Journals (Sweden)

    Marlene Dupraz

    2017-08-01

    Full Text Available The epidemiology of vector-borne zoonoses depends on the movement of both hosts and vectors, which can differ greatly in intensity across spatial scales. Because of their life history traits and small size, vector dispersal may be frequent, but limited in distance. However, little information is available on vector movement patterns at local spatial scales, and particularly for ticks, transmitting the greatest diversity of recognized infectious agents. To test the degree to which ticks can disperse and disseminate pathogens at local scales, we investigated the temporal dynamics and population structure of the soft tick Ornithodoros maritimus within a colony of its seabird host, the Yellow-legged gull Larus michahellis. Ticks were repeatedly sampled at a series of nests during the host breeding season. In half of the nests, ticks were collected (removal sampling, in the other half, ticks were counted and returned to the nest. A subsample of ticks was screened for known bacteria, viruses and parasites using a high throughput real-time PCR system to examine their distribution within the colony. The results indicate a temporal dynamic in the presence of tick life stages over the season, with the simultaneous appearance of juvenile ticks and hatched chicks, but no among-nest spatial structure in tick abundance. Removal sampling significantly reduced tick numbers, but only from the fourth visit onward. Seven bacterial isolates, one parasite species and one viral isolate were detected but no spatial structure in their presence within the colony was found. These results suggest weak isolation among nests and that tick dispersal is likely frequent enough to quickly recolonize locally-emptied patches and disseminate pathogens across the colony. Vector-mediated movements at local scales may therefore play a key role in pathogen emergence and needs to be considered in conjunction with host movements for predicting pathogen circulation and for establishing

  4. Rats and seabirds: effects of egg size on predation risk and the potential of conditioned taste aversion as a mitigation method.

    Science.gov (United States)

    Latorre, Lucía; Larrinaga, Asier R; Santamaría, Luis

    2013-01-01

    Seabirds nesting on islands are threatened by invasive rodents, such as mice and rats, which may attack eggs, chicks and even adults. The low feasibility of rat eradications on many islands makes the development of alternate control plans necessary. We used a combination of field experiments on a Mediterranean island invaded by black rats (Rattusrattus) to evaluate (1) the predation risk posed to different-sized seabird eggs and (2), the potential of two deterrent methods (electronic and chemical) to reduce its impact. Rats were able to consume eggs of all sizes (12 to 68 g), but survival increased 13 times from the smallest to the largest eggs (which also had more resistant eggshells). Extrapolation to seabird eggs suggests that the smallest species (Hydrobatespelagicus) suffer the most severe predation risk, but even the largest (Larusmichahellis) could suffer >60% mortality. Nest attack was not reduced by the deterrents. However, chemical deterrence (conditioned taste aversion by lithium chloride) slowed the increase in predation rate over time, which resulted in a three-fold increase in egg survival to predation as compared to both control and electronic deterrence. At the end of the experimental period, this effect was confirmed by a treatment swap, which showed that conferred protection remains at least 15 days after cessation of the treatment. Results indicate that small seabird species are likely to suffer severe rates of nest predation by rats and that conditioned taste aversion, but not electronic repellents, may represent a suitable method to protect colonies when eradication or control is not feasible or cost-effective.

  5. Avian cholera, a threat to the viability of an Arctic seabird colony?

    Directory of Open Access Journals (Sweden)

    Sébastien Descamps

    Full Text Available Evidence that infectious diseases cause wildlife population extirpation or extinction remains anecdotal and it is unclear whether the impacts of a pathogen at the individual level can scale up to population level so drastically. Here, we quantify the response of a Common eider colony to emerging epidemics of avian cholera, one of the most important infectious diseases affecting wild waterfowl. We show that avian cholera has the potential to drive colony extinction, even over a very short period. Extinction depends on disease severity (the impact of the disease on adult female survival and disease frequency (the number of annual epidemics per decade. In case of epidemics of high severity (i.e., causing >30% mortality of breeding females, more than one outbreak per decade will be unsustainable for the colony and will likely lead to extinction within the next century; more than four outbreaks per decade will drive extinction to within 20 years. Such severity and frequency of avian cholera are already observed, and avian cholera might thus represent a significant threat to viability of breeding populations. However, this will depend on the mechanisms underlying avian cholera transmission, maintenance, and spread, which are currently only poorly known.

  6. application of ant colony optimisation in distribution transformer sizing

    African Journals Online (AJOL)

    HP

    Keywords: ant colony, optimization, transformer sizing, distribution transformer. 1. INTRODUCTION ... more intensive pheromone and higher probability to be chosen [12]. ..... pp.29-41, 1996. [7] EC global market place, “Technical Parameters”,.

  7. Application of ant colony optimisation in distribution transformer sizing

    African Journals Online (AJOL)

    This study proposes an optimisation method for transformer sizing in power system using ant colony optimisation and a verification of the process by MATLAB software. The aim is to address the issue of transformer sizing which is a major challenge affecting its effective performance, longevity, huge capital cost and power ...

  8. Recruitment strategies and colony size in social insects

    NARCIS (Netherlands)

    Planque, R.; van den Berg, G.J.B.; Franks, N.R.

    2010-01-01

    Ants use a great variety of recruitment methods to forage for food or find new nests, including tandem running, group recruitment and scent trails. It has been known for some time that there is a loose correlation across many taxa between species-specific mature colony size and recruitment method.

  9. Pollen foraging in colonies of Melipona bicolor (Apidae, Meliponini): effects of season, colony size and queen number.

    Science.gov (United States)

    Hilário, S D; Imperatriz-Fonseca, V L

    2009-01-01

    We evaluated the ratio between the number of pollen foragers and the total number of bees entering colonies of Melipona bicolor, a facultative polygynous species of stingless bees. The variables considered in our analysis were: seasonality, colony size and the number of physogastric queens in each colony. The pollen forager ratios varied significantly between seasons; the ratio was higher in winter than in summer. However, colony size and number of queens per colony had no significant effect. We conclude that seasonal differences in pollen harvest are related to the production of sexuals and to the number of individuals and their body size.

  10. Input of seabird-derived nitrogen into rice-paddy fields near a breeding/roosting colony of the Great Cormorant (Phalacrocorax carbo), and its effects on wild grass

    International Nuclear Information System (INIS)

    Kazama, Kentaro; Murano, Hirotatsu; Tsuzuki, Kazuhide; Fujii, Hidenori; Niizuma, Yasuaki; Mizota, Chitoshi

    2013-01-01

    Terrestrial ecosystems near breeding/roosting colonies of piscivorous seabirds can receive a large amount of marine-derived N in the form of bird feces. It has been well demonstrated that N input from seabirds strongly affects plant communities in forests or coastal grasslands. The effects of nutrient input on plant communities in agricultural ecosystems near seabird colonies, however, have rarely been evaluated. This relationship was examined in rice-paddy fields irrigated by a pond system located near a colony of the Great Cormorant Phalacrocorax carbo in Aichi, central Japan. In the present study, spatial variations in N content (N %) and N stable isotope composition (δ 15 N) of soils and wild grass species together with the growth height of plants in paddy fields in early spring (fallow period) were examined. Soils had a higher N % and δ 15 N values in fields associated with an irrigation pond that had N input from cormorants. The δ 15 N values tended to be higher around the inlet of irrigation waters, relative to the outlet. These results indicate that cormorant-derived N was input into the paddy fields via the irrigation systems. Plants growing in soil with higher δ 15 N had higher δ 15 N in the above-ground part of the plants and had luxurious growth. A positive correlation in plant height and δ 15 N of NO 3 –N was observed in soil plough horizons.

  11. Effects of island seabird subsidies and invasive species dynamics on the body size and foraging ecology of the Allen Cays Rock Iguana (Cyclura cychlura inornata)

    OpenAIRE

    Richardson, Kristen Mundie

    2015-01-01

    Island systems have long been valuable to ecological research as they provide natural experiments for the study of ecosystem processes. We examined Allen, Leaf, U and Flat Rock Reef Cays in the Bahamas to study the effects of seabird driven marine subsidies and invasive mice on island food webs on the body size and foraging ecology of the Allen Cays Rock Iguana (Cyclura cychlura inornata). Iguanas on an island with nesting seabirds (Allen Cay) had 6 times the body mass and 1.7 times the snout...

  12. Reduced population size does not affect the mating strategy of a vulnerable and endemic seabird

    Science.gov (United States)

    Nava, Cristina; Neves, Verónica C.; Andris, Malvina; Dubois, Marie-Pierre; Jarne, Philippe; Bolton, Mark; Bried, Joël

    2017-12-01

    Bottleneck episodes may occur in small and isolated animal populations, which may result in decreased genetic diversity and increased inbreeding, but also in mating strategy adjustment. This was evaluated in the vulnerable and socially monogamous Monteiro's Storm-petrel Hydrobates monteiroi, a seabird endemic to the Azores archipelago which has suffered a dramatic population decline since the XVth century. To do this, we conducted a genetic study (18 microsatellite markers) in the population from Praia islet, which has been monitored over 16 years. We found no evidence that a genetic bottleneck was associated with this demographic decline. Monteiro's Storm-petrels paired randomly with respect to genetic relatedness and body measurements. Pair fecundity was unrelated to genetic relatedness between partners. We detected only two cases of extra-pair parentage associated with an extra-pair copulation (out of 71 offspring). Unsuccessful pairs were most likely to divorce the next year, but genetic relatedness between pair mates and pair breeding experience did not influence divorce. Divorce enabled individuals to improve their reproductive performances after re-mating only when the new partner was experienced. Re-pairing with an experienced partner occurred more frequently when divorcees changed nest than when they retained their nest. This study shows that even in strongly reduced populations, genetic diversity can be maintained, inbreeding does not necessarily occur, and random pairing is not risky in terms of pair lifetime reproductive success. Given, however, that we found no clear phenotypic mate choice criteria, the part played by non-morphological traits should be assessed more accurately in order to better understand seabird mating strategies.

  13. Queen-worker caste ratio depends on colony size in the pharaoh ant (Monomorium pharaonis)

    DEFF Research Database (Denmark)

    Schmidt, Anna Mosegaard; Linksvayer, Timothy Arnold; Boomsma, Jacobus Jan

    2011-01-01

    The success of an ant colony depends on the simultaneous presence of reproducing queens and nonreproducing workers in a ratio that will maximize colony growth and reproduction. Despite its presumably crucial role, queen–worker caste ratios (the ratio of adult queens to workers) and the factors...... affecting this variable remain scarcely studied. Maintaining polygynous pharaoh ant (Monomorium pharaonis) colonies in the laboratory has provided us with the opportunity to experimentally manipulate colony size, one of the key factors that can be expected to affect colony level queen–worker caste ratios...... species with budding colonies may adaptively adjust caste ratios to ensure rapid growth....

  14. Colony Size of Phaeocystis Antarctica (Prymnesiophyceae) as Influenced by Zooplankton Grazers

    Science.gov (United States)

    The haptophyte Phaeocystis antarctica is a dominant phytoplankton species in the Ross Sea, Antarctica, and exists as solitary cells and mucilaginous colonies that differ by several orders of magnitude in size. Recent studies with P. globosa suggested that colony formation and enl...

  15. Aerial estimation of the size of gull breeding colonies

    Science.gov (United States)

    Kadlec, J.A.; Drury, W.H.

    1968-01-01

    Counts on photographs and visual estimates of the numbers of territorial gulls are usually reliable indicators of the number of gull nests, but single visual estimates are not adequate to measure the number of nests in individual colonies. To properly interpret gull counts requires that several islands with known numbers of nests be photographed to establish the ratio of gulls to nests applicable for a given local census. Visual estimates are adequate to determine total breeding gull numbers by regions. Neither visual estimates nor photography will reliably detect annual changes of less than about 2.5 percent.

  16. Colony size evolution and the origin of eusociality in corbiculate bees (Hymenoptera: Apinae.

    Directory of Open Access Journals (Sweden)

    Enrique Rodriguez-Serrano

    Full Text Available Recently, it has been proposed that the one of the main determinants of complex societies in Hymenoptera is colony size, since the existence of large colonies reduces the direct reproductive success of an average individual, given a decreased chance of being part of the reproductive caste. In this study, we evaluate colony size evolution in corbiculate bees and their relationship with the sociality level shown by these bees. Specifically i the correlation between colony size and level of sociality considering the phylogenetic relationship to evaluate a general evolutionary tendency, and ii the hypothetical ancestral forms of several clades within a phylogeny of corbiculate bees, to address idiosyncratic process occurring at important nodes. We found that the level of social complexity in corbiculate bees is phylogenetically correlated with colony size. Additionally, another process is invoked to propose why colony size evolved concurrently with the level of social complexity. The study of this trait improves the understanding of the evolutionary transition from simple to complex societies, and highlights the importance of explicit probabilistic models to test the evolution of other important characters involved in the origin of eusociality.

  17. The Mediterranean stony coral Cladocora caespitosa (Linnaeus, 1767) as habitat provider for molluscs: colony size effect

    Science.gov (United States)

    Pitacco, Valentina; Crocetta, Fabio; Orlando-Bonaca, Martina; Mavrič, Borut; Lipej, Lovrenc

    2017-11-01

    The stony coral Cladocora caespitosa (Linnaeus, 1767) is an important Mediterranean habitat builder, whose survival is now being threatened by human activities and possibly natural events such as mass mortality and bleaching. We characterized the mollusc assemblage associated with colonies in the Gulf of Trieste (northern Adriatic Sea) and then tested whether the number of mollusc species increases in relation with colony size, following a Species-Area Relationship (SAR) model. At least 62 taxa were found in association with coral colonies, with bivalves constituting the dominant group. More than half of the 3034 specimens encountered were juveniles. Mollusc taxa richness increased with increasing C. caespitosa colony size according to the power-function model, whilst the analyses of trophic and functional groups supports the hypothesis of at least two factors underlying SAR (area per se and habitat diversity). Our results confirmed the importance of C. caespitosa for benthic communities, indicating that larger colonies support higher biodiversity, and suggesting that C. caespitosa is the most important habit builder among Mediterranean cnidarians, having also an influential function as a natural nursery ground. These results underline the necessity of new investigations aimed at filling gaps in our knowledge and planning new measures to protect the species.

  18. Colony size distributions according to in vitro aging in human skin fibroblasts

    International Nuclear Information System (INIS)

    Kim, Jun Sang; Kim, Jae Sung; Cho, Moon June; Park, Jeong Kyu; Paik, Tae Hyun

    1999-01-01

    To investigate the percentage of colonies with 16 or more cells distribution of human skin fibroblast according to in vitro aging, and to evaluate the relationship between percentage of colonies with 16 or more cells and in vivo donor age in human skin fibroblast culture. C1, C2, C3a, and C3b human skin fibroblast samples from three breast cancer patients were used as subjects. The C1, C2, and C3a donor were 44, 54, and 55 years old, respectively. C3a and C3b cells were isolated from the same person. Single cell suspension of skin fibroblasts was prepared with primary explant technique. One hundred cells are plated into 100ml tissue culture flask and cultured for two weeks. The colony size was defined as colonies with 16 or more cells. The cultured cell was stained with crystal violet, and number of cells in each colony was determined with stereo microscope at x 10 magnification. Passage number of C1, C2, C3a and C3b skin fibroblast were 12th, 17th, and 14th, respectively. Percentage of colonies with 16 or more cells of skin fibroblast samples decreased with increasing in vitro passage number. In contrast, cumulative population doublings of skin fibroblast sample increased with increasing in vitro passage number. Percentage of colonies with 16 or more cells also decreased with increasing population doublings in human skin fibroblast culture. There was strong correlation with percentage of colonised with 16 or more cells and population doublings in C3a skin fibroblast sample. At the same point of population doublings, the percentage of colonies with 16 or more cells of the young C1 donor was higher level than the old C3a donor. The population doublings increased with increasing in vitro passage number but percentage of colonies with 16 or more cells decreased. The results of this study imply that percentage of colonies with 16 or more cells is useful as a indicator of in vitro human skin fibroblast aging and may estimate the in vivo donor age

  19. Colony size measurement of the yeast gene deletion strains for functional genomics

    Directory of Open Access Journals (Sweden)

    Mir-Rashed Nadereh

    2007-04-01

    Full Text Available Abstract Background Numerous functional genomics approaches have been developed to study the model organism yeast, Saccharomyces cerevisiae, with the aim of systematically understanding the biology of the cell. Some of these techniques are based on yeast growth differences under different conditions, such as those generated by gene mutations, chemicals or both. Manual inspection of the yeast colonies that are grown under different conditions is often used as a method to detect such growth differences. Results Here, we developed a computerized image analysis system called Growth Detector (GD, to automatically acquire quantitative and comparative information for yeast colony growth. GD offers great convenience and accuracy over the currently used manual growth measurement method. It distinguishes true yeast colonies in a digital image and provides an accurate coordinate oriented map of the colony areas. Some post-processing calculations are also conducted. Using GD, we successfully detected a genetic linkage between the molecular activity of the plant-derived antifungal compound berberine and gene expression components, among other cellular processes. A novel association for the yeast mek1 gene with DNA damage repair was also identified by GD and confirmed by a plasmid repair assay. The results demonstrate the usefulness of GD for yeast functional genomics research. Conclusion GD offers significant improvement over the manual inspection method to detect relative yeast colony size differences. The speed and accuracy associated with GD makes it an ideal choice for large-scale functional genomics investigations.

  20. A framework for analysis of abortive colony size distributions using a model of branching processes in irradiated normal human fibroblasts.

    Science.gov (United States)

    Sakashita, Tetsuya; Hamada, Nobuyuki; Kawaguchi, Isao; Ouchi, Noriyuki B; Hara, Takamitsu; Kobayashi, Yasuhiko; Saito, Kimiaki

    2013-01-01

    Clonogenicity gives important information about the cellular reproductive potential following ionizing irradiation, but an abortive colony that fails to continue to grow remains poorly characterized. It was recently reported that the fraction of abortive colonies increases with increasing dose. Thus, we set out to investigate the production kinetics of abortive colonies using a model of branching processes. We firstly plotted the experimentally determined colony size distribution of abortive colonies in irradiated normal human fibroblasts, and found the linear relationship on the log-linear or log-log plot. By applying the simple model of branching processes to the linear relationship, we found the persistent reproductive cell death (RCD) over several generations following irradiation. To verify the estimated probability of RCD, abortive colony size distribution (≤ 15 cells) and the surviving fraction were simulated by the Monte Carlo computational approach for colony expansion. Parameters estimated from the log-log fit demonstrated the good performance in both simulations than those from the log-linear fit. Radiation-induced RCD, i.e. excess probability, lasted over 16 generations and mainly consisted of two components in the early (probability over 5 generations, whereas abortive colony size distribution was robust against it. These results suggest that, whereas short-term RCD is critical to the abortive colony size distribution, long-lasting RCD is important for the dose response of the surviving fraction. Our present model provides a single framework for understanding the behavior of primary cell colonies in culture following irradiation.

  1. Quantifying the effect of colony size and food distribution on harvester ant foraging.

    Directory of Open Access Journals (Sweden)

    Tatiana P Flanagan

    Full Text Available Desert seed-harvester ants, genus Pogonomyrmex, are central place foragers that search for resources collectively. We quantify how seed harvesters exploit the spatial distribution of seeds to improve their rate of seed collection. We find that foraging rates are significantly influenced by the clumpiness of experimental seed baits. Colonies collected seeds from larger piles faster than randomly distributed seeds. We developed a method to compare foraging rates on clumped versus random seeds across three Pogonomyrmex species that differ substantially in forager population size. The increase in foraging rate when food was clumped in larger piles was indistinguishable across the three species, suggesting that species with larger colonies are no better than species with smaller colonies at collecting clumped seeds. These findings contradict the theoretical expectation that larger groups are more efficient at exploiting clumped resources, thus contributing to our understanding of the importance of the spatial distribution of food sources and colony size for communication and organization in social insects.

  2. Reduction of feral cat (Felis catus Linnaeus 1758) colony size following hysterectomy of adult female cats.

    Science.gov (United States)

    Mendes-de-Almeida, Flavya; Remy, Gabriella L; Gershony, Liza C; Rodrigues, Daniela P; Chame, Marcia; Labarthe, Norma V

    2011-06-01

    The size of urban cat colonies is limited only by the availability of food and shelter; therefore, their population growth challenges all known population control programs. To test a new population control method, a free-roaming feral cat colony at the Zoological Park in the city of Rio de Janeiro was studied, beginning in 2001. The novel method consisted of performing a hysterectomy on all captured female cats over 6 months of age. To estimate the size of the colony and compare population from year to year, a method of capture-mark-release-recapture was used. The aim was to capture as many individuals as possible, including cats of all ages and gender to estimate numbers of cats in all population categories. Results indicated that the feral cat population remained constant from 2001 to 2004. From 2004 to 2008, the hysterectomy program and population estimates were performed every other year (2006 and 2008). The population was estimated to be 40 cats in 2004, 26 in 2006, and 17 cats in 2008. Although pathogens tend to infect more individuals as the population grows older and maintains natural behavior, these results show that free-roaming feral cat colonies could have their population controlled by a biannual program that focuses on hysterectomy of sexually active female cats. Copyright © 2011 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.

  3. GPS tracking for mapping seabird mortality induced by light pollution.

    Science.gov (United States)

    Rodríguez, Airam; Rodríguez, Beneharo; Negro, Juan J

    2015-06-02

    Light pollution and its consequences on ecosystems are increasing worldwide. Knowledge on the threshold levels of light pollution at which significant ecological impacts emerge and the size of dark refuges to maintain natural nocturnal processes is crucial to mitigate its negative consequences. Seabird fledglings are attracted by artificial lights when they leave their nest at night, causing high mortality. We used GPS data-loggers to track the flights of Cory's shearwater Calonectris diomedea fledglings from nest-burrows to ground, and to evaluate the light pollution levels of overflown areas on Tenerife, Canary Islands, using nocturnal, high-resolution satellite imagery. Birds were grounded at locations closer than 16 km from colonies in their maiden flights, and 50% were rescued within a 3 km radius from the nest-site. Most birds left the nests in the first three hours after sunset. Rescue locations showed radiance values greater than colonies, and flight distance was positively related to light pollution levels. Breeding habitat alteration by light pollution was more severe for inland colonies. We provide scientific-based information to manage dark refuges facilitating that fledglings from inland colonies reach the sea successfully. We also offer methodological approaches useful for other critically threatened petrel species grounded by light pollution.

  4. External immunity in ant societies: sociality and colony size do not predict investment in antimicrobials

    Science.gov (United States)

    Halawani, Omar; Pearson, Bria; Mathews, Stephanie; López-Uribe, Margarita M.; Dunn, Robert R.; Smith, Adrian A.

    2018-01-01

    Social insects live in dense groups with a high probability of disease transmission and have therefore faced strong pressures to develop defences against pathogens. For this reason, social insects have been hypothesized to invest in antimicrobial secretions as a mechanism of external immunity to prevent the spread of disease. However, empirical studies linking the evolution of sociality with increased investment in antimicrobials have been relatively few. Here we quantify the strength of antimicrobial secretions among 20 ant species that cover a broad spectrum of ant diversity and colony sizes. We extracted external compounds from ant workers to test whether they inhibited the growth of the bacterium Staphylococcus epidermidis. Because all ant species are highly social, we predicted that all species would exhibit some antimicrobial activity and that species that form the largest colonies would exhibit the strongest antimicrobial response. Our comparative approach revealed that strong surface antimicrobials are common to particular ant clades, but 40% of species exhibited no antimicrobial activity at all. We also found no correlation between antimicrobial activity and colony size. Rather than relying on antimicrobial secretions as external immunity to control pathogen spread, many ant species have probably developed alternative strategies to defend against disease pressure. PMID:29515850

  5. Colony size-frequency distribution of pocilloporid juvenile corals along a natural environmental gradient in the Red Sea

    KAUST Repository

    Lozano-Corté s, Diego; Berumen, Michael L.

    2015-01-01

    Coral colony size-frequency distributions can be used to assess population responses to local environmental conditions and disturbances. In this study, we surveyed juvenile pocilloporids, herbivorous fish densities, and algal cover in the central

  6. 77 FR 73989 - Takes of Marine Mammals Incidental to Specified Activities; Seabird and Pinniped Research...

    Science.gov (United States)

    2012-12-12

    ... National Seashore, plan to conduct the proposed activities for one year. We determined the application... colonies; observing seabird nesting habitat; restoring nesting burrows; observing breeding elephant seals... (Zalophus californianus), Pacific harbor seals (Phoca vitulina), northern elephant seals (Mirounga...

  7. Colony Size Affects the Efficacy of Bait Containing Chlorfluazuron Against the Fungus-Growing Termite Macrotermes gilvus (Blattodea: Termitidae).

    Science.gov (United States)

    Lee, Ching-Chen; Neoh, Kok-Boon; Lee, Chow-Yang

    2014-12-01

    The efficacy of chitin synthesis inhibitors (CSIs) against fungus-growing termites is known to vary. In this study, 0.1% chlorfluazuron (CFZ) cellulose bait was tested against medium and large field colonies of Macrotermes gilvus (Hagen). The termite mounds were dissected to determine the health of the colony. Individual termites (i.e., workers and larvae) and fungus combs were subjected to gas chromatography-mass spectrometry (GC-MS) analysis to detect the presence of CFZ. In this study, 540.0 ± 25.8 g (or equivalent to 540.0 ± 25.8 mg active ingredient) and 680.0 ± 49.0 g (680.0 ± 49.0 mg active ingredient) of bait matrix were removed by the medium- and large-sized colonies, respectively, after baiting. All treated medium-sized colonies were moribund. The dead termites were scattered in the mound, larvae were absent, population size had decreased by 90%, and the queens appeared unhealthy. In contrast, no or limited effects were found in large-sized colonies. Only trace amounts of CFZ were detected in workers, larvae, and fungus combs, and the population of large-sized colonies had declined by only up to 40%. This might be owing to the presence of large amount of basidiomycete fungus and a drastic decrease of CFZ content per unit fungus comb (a main food source of larvae) in the large-sized colonies, and hence reduced the toxic effect and longer time is required to accumulate the lethal dose in larvae. Nevertheless, we do not deny the possibility of CSI bait eliminating or suppressing the higher termite if the test colonies could pick up adequate lethal dose by installing more bait stations and prolonging the baiting period. © 2014 Entomological Society of America.

  8. Colony size-frequency distribution of pocilloporid juvenile corals along a natural environmental gradient in the Red Sea

    KAUST Repository

    Lozano-Cortes, Diego

    2015-10-29

    Coral colony size-frequency distributions can be used to assess population responses to local environmental conditions and disturbances. In this study, we surveyed juvenile pocilloporids, herbivorous fish densities, and algal cover in the central and southern Saudi Arabian Red Sea. We sampled nine reefs with different disturbance histories along a north–south natural gradient of physicochemical conditions (higher salinity and wider temperature fluctuations in the north, and higher turbidity and productivity in the south). Since coral populations with negatively skewed size-frequency distributions have been associated with unfavorable environmental conditions, we expected to find more negative distributions in the southern Red Sea, where corals are potentially experiencing suboptimal conditions. Although juvenile coral and parrotfish densities differed significantly between the two regions, mean colony size and size-frequency distributions did not. Results suggest that pocilloporid colony size-frequency distribution may not be an accurate indicator of differences in biological or oceanographic conditions in the Red Sea.

  9. The influence of fire-coral colony size and agonistic behaviour of territorial damselfish on associated coral reef fish communities.

    Science.gov (United States)

    Leal, Isabela Carolina Silva; de Araújo, Maria Elisabeth; da Cunha, Simone Rabelo; Pereira, Pedro Henrique Cipresso

    2015-07-01

    Branching hydrocorals from the genus Millepora play an important ecological role in South Atlantic reefs, where branching scleractinian corals are absent. Previous studies have shown a high proportion of reef fish species using branching fire-coral colonies as shelter, breeding, and feeding sites. However, the effects of Millepora spp. colony size and how the agonistic behaviour of a competitive damselfish affect the associated reef fish community are still unknown. The present study examined how fire-coral colony volume and the presence of a highly territorial and aggressive damselfish (Brazilian endemic Stegastes fuscus) affects the reef fish community associated with the fire-coral Millepora alcicornis. M. alcicornis colonies were surveyed from September 2012 to April 2013 at Tamandaré Reefs off Northeast Brazil. Our results show that the abundance and richness of coral associated fish was positively correlated with M. alcicornis coral colony volume. Additionally, behaviour of S. fuscus, the most abundant reef fish species found associated with fire-coral colonies (almost 57% of the fish community), was also influenced by fire-coral colony volume. There was a clear trend of increased agonistic behaviour and feeding on coral polyps as colony volume increased. This trend was reversed for the non-occupational swimming category, which decreased as M. alcicornis colony volume increased. Behavioural ontogenetic changes were also detected for S. fuscus individuals. Juveniles mainly showed two distinct behaviours: sheltered on coral branches and feeding on coral polyps. In contrast, adults presented greater equitability among the behavioural categories, mostly non-occupational swimming around coral colonies and agonistic behaviour. Lastly, S. fuscus individuals actively defended fire-coral colonies from intruders. A large number of agonistic interactions occurred against potential food competitors, which were mainly roving herbivores, omnivores, and sessile

  10. Effects of within-colony competition on body size asymmetries and reproductive skew in a social spider

    DEFF Research Database (Denmark)

    Grinsted, Lena; Bilde, Trine

    2013-01-01

    Reproductive partitioning is a key component of social organization in groups of cooperative organisms. In colonies of permanently social spiders of the genus Stegodyphus less than half of the females reproduce, while all females, including nonreproducers, perform suicidal allo-maternal care. Some...... not increase over the course of the experiment, suggesting that body size variation is shaped at an early stage. This might facilitate task specialization within colonies and ensure colony-level reproductive output by early allocation of reproductive roles. We suggest that reproductive skew in social spiders...

  11. Genetic Susceptibility, Colony Size, and Water Temperature Drive White-Pox Disease on the Coral Acropora palmata

    OpenAIRE

    Muller, Erinn M.; van Woesik, Robert

    2014-01-01

    Outbreaks of coral diseases are one of the greatest threats to reef corals in the Caribbean, yet the mechanisms that lead to coral diseases are still largely unknown. Here we examined the spatial-temporal dynamics of white-pox disease on Acropora palmata coral colonies of known genotypes. We took a Bayesian approach, using Integrated Nested Laplace Approximation algorithms, to examine which covariates influenced the presence of white-pox disease over seven years. We showed that colony size, g...

  12. The relationship between canopy cover and colony size of the wood ant Formica lugubris--implications for the thermal effects on a keystone ant species.

    Directory of Open Access Journals (Sweden)

    Yi-Huei Chen

    Full Text Available Climate change may affect ecosystems and biodiversity through the impacts of rising temperature on species' body size. In terms of physiology and genetics, the colony is the unit of selection for ants so colony size can be considered the body size of a colony. For polydomous ant species, a colony is spread across several nests. This study aims to clarify how climate change may influence an ecologically significant ant species group by investigating thermal effects on wood ant colony size. The strong link between canopy cover and the local temperatures of wood ant's nesting location provides a feasible approach for our study. Our results showed that nests were larger in shadier areas where the thermal environment was colder and more stable compared to open areas. Colonies (sum of nests in a polydomous colony also tended to be larger in shadier areas than in open areas. In addition to temperature, our results supported that food resource availability may be an additional factor mediating the relationship between canopy cover and nest size. The effects of canopy cover on total colony size may act at the nest level because of the positive relationship between total colony size and mean nest size, rather than at the colony level due to lack of link between canopy cover and number of nests per colony. Causal relationships between the environment and the life-history characteristics may suggest possible future impacts of climate change on these species.

  13. The transboundary nature of seabird ecology: Chapter 8

    Science.gov (United States)

    Jodice, Patrick G.R.; Suryan, Robert M.

    2015-01-01

    The term ‘seabird’ is generally applied to avian species that forage in the marine environment over open water. Seabirds typically nest in colonies and are long-lived species with low annual reproductive rates. Seabird breeding sites typically occur on islands or along coasts and as such are often at the boundaries of ecological or political zones. During the breeding season, seabirds cross a very distinct terrestrial/marine ecological boundary on a regular basis to forage. Even relatively ‘local’ species cross multiple jurisdictions within a day (e.g., state lands and waters, and federal waters) while pelagic species may transit through international waters on a daily, weekly, or monthly time-frame. Seabird life-histories expose individuals and populations to environmental conditions affecting both terrestrial and marine habitats. The wide-ranging and transboundary nature of seabird ecology also exposes these species to various environmental and anthropogenic forces such as contamination, commercial fisheries and climate forcing that also are transboundary in nature. Therefore, wherever conservation of seabirds or the management of their populations is the goal, consideration must be given to ecosystem dynamics on land and at sea. Because the jurisdiction of agencies does not cross the land-sea boundary in the same manner as the seabirds they are managing, these efforts are facilitated by multi-agency communication and collaboration. By their very nature and by the nature of the systems that they must function within, seabirds embody the complexity of wildlife ecology and conservation in the twenty-first century.

  14. Seabirds as a subsistence and cultural resource in two remote Alaskan communities

    Directory of Open Access Journals (Sweden)

    Rebecca C. Young

    2014-12-01

    Full Text Available Small rural Alaskan communities face many challenges surrounding rapid social and ecological change. The role of local subsistence resources may change over time because of changes in social perception, economic need, and cultural patterns of use. We look at the Bering Sea's Pribilof Islands, comprising two very small communities, and investigate the relationship between the local residents and seabirds as a natural resource. Seabirds may strengthen ties to older ways of life and have potential for future economic opportunities, or modernization may direct interest away from seabirds as a cultural and economic resource. We conducted a survey and interviews of residents of the two Pribilof Island communities, St. Paul and St. George, to assess opinions toward seabirds and harvest levels. Seabirds were generally regarded as important both to individuals and the wider community. However, current levels of subsistence harvest are low, and few people continue to actively harvest or visit seabird colonies. Respondents expressed desire for greater knowledge about seabirds and also concerns about the current economy of the islands and a lack of future development prospects. Despite the challenging economic conditions, the villages retain a strong sense of community and place value on their environment and on seabirds. Surveys indicated an interest in developing eco-tourism based around local resources, including seabirds, as a way to improve the economy.

  15. Can cat predation help competitors coexist in seabird communities?

    Science.gov (United States)

    Pontier, Dominique; Fouchet, David; Bried, Joël

    2010-01-07

    On oceanic islands, nest site availability can be an important factor regulating seabird population dynamics. The potential for birds to secure a nest to reproduce can be an important component of their life histories. The dates at which different seabird species arrive at colonies to breed will have important consequences for their relative chances of success. Early arrival on the island allows birds to obtain nests more easily and have higher reproductive success. However, the presence of an introduced predator may reverse this situation. For instance, in the sub-Antarctic Kerguelen archipelago, early arriving birds suffer heavy predation from introduced cats. Cats progressively switch from seabirds to rabbits, since the local rabbit population starts to peak after early arriving seabird species have already returned to the colony. When late-arriving birds arrive, cat predation pressure on seabirds is thus weaker. In this paper, we investigate the assumption that the advantage of early nest mnopolization conferred to early arriving birds may be counterbalanced by the cost resulting from predation. We develop a mathematical model representing a simplified situation in which two insular seabird species differ only in their arrival date at the colony site and compete for nesting sites. We conclude that predation may ensure the coexistence of the two bird species or favor the late-arriving species, but only when seasonal variations in predation pressure are large. Interestingly, we conclude that arriving early is only favorable until a given level where high reproductive success no longer compensates for the long exposure to strong predation pressure. Our work suggests that predation can help to maintain the balance between species of different phenologies.

  16. Warring arthropod societies: Social spider colonies can delay annihilation by predatory ants via reduced apparency and increased group size.

    Science.gov (United States)

    Keiser, Carl N; Wright, Colin M; Pruitt, Jonathan N

    2015-10-01

    Sociality provides individuals with benefits via collective foraging and anti-predator defense. One of the costs of living in large groups, however, is increased apparency to natural enemies. Here, we test how the individual-level and collective traits of spider societies can increase the risk of discovery and death by predatory ants. We transplanted colonies of the social spider Stegodyphus dumicola into a habitat dense with one of their top predators, the pugnacious ant Anoplolepis custodiens. With three different experiments, we test how colony-wide survivorship in a predator-dense habitat can be altered by colony apparency (i.e., the presence of a capture web), group size, and group composition (i.e., the proportion of bold and shy personality types present). We also test how spiders' social context (i.e., living solitarily vs. among conspecifics) modifies their behaviour toward ants in their capture web. Colonies with capture webs intact were discovered by predatory ants on average 25% faster than colonies with the capture web removed, and all discovered colonies eventually collapsed and succumbed to predation. However, the lag time from discovery by ants to colony collapse was greater for colonies containing more individuals. The composition of individual personality types in the group had no influence on survivorship. Spiders in a social group were more likely to approach ants caught in their web than were isolated spiders. Isolated spiders were more likely to attack a safe prey item (a moth) than they were to attack ants and were more likely to retreat from ants after contact than they were after contact with moths. Together, our data suggest that the physical structures produced by large animal societies can increase their apparency to natural enemies, though larger groups can facilitate a longer lag time between discovery and demise. Lastly, the interaction between spiders and predatory ants seems to depend on the social context in which spiders reside

  17. Field evidence for colony size and aseasonality of breeding and in ...

    African Journals Online (AJOL)

    Ansell's mole-rat, Fukomys anselli, is a cooperatively breeding bathyergid endemic to the Lusaka Province of Zambia. During a 12-month field study involving the capture of 33 colonies of mole-rats, the number of occupants, breeding females and sex ratio within colonies were recorded. While thirty of these social groups ...

  18. Genetic susceptibility, colony size, and water temperature drive white-pox disease on the coral Acropora palmata.

    Science.gov (United States)

    Muller, Erinn M; van Woesik, Robert

    2014-01-01

    Outbreaks of coral diseases are one of the greatest threats to reef corals in the Caribbean, yet the mechanisms that lead to coral diseases are still largely unknown. Here we examined the spatial-temporal dynamics of white-pox disease on Acropora palmata coral colonies of known genotypes. We took a Bayesian approach, using Integrated Nested Laplace Approximation algorithms, to examine which covariates influenced the presence of white-pox disease over seven years. We showed that colony size, genetic susceptibility of the coral host, and high-water temperatures were the primary tested variables that were positively associated with the presence of white-pox disease on A. palmata colonies. Our study also showed that neither distance from previously diseased individuals, nor colony location, influenced the dynamics of white-pox disease. These results suggest that white-pox disease was most likely a consequence of anomalously high water temperatures that selectively compromised the oldest colonies and the most susceptible coral genotypes.

  19. Genetic susceptibility, colony size, and water temperature drive white-pox disease on the coral Acropora palmata.

    Directory of Open Access Journals (Sweden)

    Erinn M Muller

    Full Text Available Outbreaks of coral diseases are one of the greatest threats to reef corals in the Caribbean, yet the mechanisms that lead to coral diseases are still largely unknown. Here we examined the spatial-temporal dynamics of white-pox disease on Acropora palmata coral colonies of known genotypes. We took a Bayesian approach, using Integrated Nested Laplace Approximation algorithms, to examine which covariates influenced the presence of white-pox disease over seven years. We showed that colony size, genetic susceptibility of the coral host, and high-water temperatures were the primary tested variables that were positively associated with the presence of white-pox disease on A. palmata colonies. Our study also showed that neither distance from previously diseased individuals, nor colony location, influenced the dynamics of white-pox disease. These results suggest that white-pox disease was most likely a consequence of anomalously high water temperatures that selectively compromised the oldest colonies and the most susceptible coral genotypes.

  20. Colony size-frequency distribution of pocilloporid juvenile corals along a natural environmental gradient in the Red Sea.

    Science.gov (United States)

    Lozano-Cortés, Diego F; Berumen, Michael L

    2016-04-30

    Coral colony size-frequency distributions can be used to assess population responses to local environmental conditions and disturbances. In this study, we surveyed juvenile pocilloporids, herbivorous fish densities, and algal cover in the central and southern Saudi Arabian Red Sea. We sampled nine reefs with different disturbance histories along a north-south natural gradient of physicochemical conditions (higher salinity and wider temperature fluctuations in the north, and higher turbidity and productivity in the south). Since coral populations with negatively skewed size-frequency distributions have been associated with unfavorable environmental conditions, we expected to find more negative distributions in the southern Red Sea, where corals are potentially experiencing suboptimal conditions. Although juvenile coral and parrotfish densities differed significantly between the two regions, mean colony size and size-frequency distributions did not. Results suggest that pocilloporid colony size-frequency distribution may not be an accurate indicator of differences in biological or oceanographic conditions in the Red Sea. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. A branching process model for the analysis of abortive colony size distributions in carbon ion-irradiated normal human fibroblasts

    International Nuclear Information System (INIS)

    Sakashita, Tetsuya; Kobayashi, Yasuhiko; Hamada, Nobuyuki; Kawaguchi, Isao; Hara, Takamitsu; Saito, Kimiaki

    2014-01-01

    A single cell can form a colony, and ionizing irradiation has long been known to reduce such a cellular clonogenic potential. Analysis of abortive colonies unable to continue to grow should provide important information on the reproductive cell death (RCD) following irradiation. Our previous analysis with a branching process model showed that the RCD in normal human fibroblasts can persist over 16 generations following irradiation with low linear energy transfer (LET) γ-rays. Here we further set out to evaluate the RCD persistency in abortive colonies arising from normal human fibroblasts exposed to high-LET carbon ions (18.3 MeV/u, 108 keV/μm). We found that the abortive colony size distribution determined by biological experiments follows a linear relationship on the log–log plot, and that the Monte Carlo simulation using the RCD probability estimated from such a linear relationship well simulates the experimentally determined surviving fraction and the relative biological effectiveness (RBE). We identified the short-term phase and long-term phase for the persistent RCD following carbon-ion irradiation, which were similar to those previously identified following γ-irradiation. Taken together, our results suggest that subsequent secondary or tertiary colony formation would be invaluable for understanding the long-lasting RCD. All together, our framework for analysis with a branching process model and a colony formation assay is applicable to determination of cellular responses to low- and high-LET radiation, and suggests that the long-lasting RCD is a pivotal determinant of the surviving fraction and the RBE. (author)

  2. A hybrid of ant colony optimization and artificial bee colony algorithm for probabilistic optimal placement and sizing of distributed energy resources

    International Nuclear Information System (INIS)

    Kefayat, M.; Lashkar Ara, A.; Nabavi Niaki, S.A.

    2015-01-01

    Highlights: • A probabilistic optimization framework incorporated with uncertainty is proposed. • A hybrid optimization approach combining ACO and ABC algorithms is proposed. • The problem is to deal with technical, environmental and economical aspects. • A fuzzy interactive approach is incorporated to solve the multi-objective problem. • Several strategies are implemented to compare with literature methods. - Abstract: In this paper, a hybrid configuration of ant colony optimization (ACO) with artificial bee colony (ABC) algorithm called hybrid ACO–ABC algorithm is presented for optimal location and sizing of distributed energy resources (DERs) (i.e., gas turbine, fuel cell, and wind energy) on distribution systems. The proposed algorithm is a combined strategy based on the discrete (location optimization) and continuous (size optimization) structures to achieve advantages of the global and local search ability of ABC and ACO algorithms, respectively. Also, in the proposed algorithm, a multi-objective ABC is used to produce a set of non-dominated solutions which store in the external archive. The objectives consist of minimizing power losses, total emissions produced by substation and resources, total electrical energy cost, and improving the voltage stability. In order to investigate the impact of the uncertainty in the output of the wind energy and load demands, a probabilistic load flow is necessary. In this study, an efficient point estimate method (PEM) is employed to solve the optimization problem in a stochastic environment. The proposed algorithm is tested on the IEEE 33- and 69-bus distribution systems. The results demonstrate the potential and effectiveness of the proposed algorithm in comparison with those of other evolutionary optimization methods

  3. Colony size, cell number, carbon and nitrogen contents of Phaeocystis pouchetii from western Norway

    NARCIS (Netherlands)

    Verity, Peter G.; Whipple, S. J.; Nejstgaard, J. C.; Alderkamp, A.-C.

    Phaeocystis pouchetii is an ecologically important colony-forming marine phytoplankton species in northern hemisphere cold waters. It plays a central role in the processing of biogeochemically important elements in the upper ocean during spring blooms. Here, we report highly significant quantitative

  4. Seabird tissue archival and monitoring project: Protocol for collecting and banking seabird eggs

    Science.gov (United States)

    Weston-York, Geoff; Porter, Barbara J.; Pugh, Rebecca S.; Roseneau, David G.; Simac, Kristin S.; Becker, Paul R.; Thorsteinson, Lyman K.; Wise, Stephen A.

    2001-01-01

    Archiving biological and environmental samples for retrospective analysis is a major component of systematic environmental monitoring. The long-term storage of carefully selected, representative samples in an environmental specimen bank is an important complement to the real-time monitoring of the environment. These archived samples permit:The use of subsequently developed innovative analytical technology that was not available at the time the samples were archived, for clear state-of-art identification an~ quantification of analytes of interest,The identification and quantification of analytes that are of subsequent interest but that were not of interest at the time the samples were archived, andThe comparison of present and past analytical techniques and values, providing continued credibility of past analytical values, and allowing flexibility in environmental monitoring programs.Seabirds, including albatrosses, pelicans, cormorants, terns, kittiwakes, murres, guillemots, and puffins spend most of their lives at sea and have special adaptations for feeding in the marine environment, including the ability to excrete the excess salt obtained from ingesting seawater. Many species nest in dense groups (colonies) on steep, precipitous sea-cliffs and headlands.Seabirds are long-lived and slow to mature. They occupy high positions in the marine food web and are considered sensitive indicators for the marine environment (prey includes krill, small fish, and squid). Breeding success, timing of nesting, diets, and survival rates may provide early indications of changing environmental conditions (e.g., see Hatch et aI., 1993). Chemical analysis of seabird tissues, including egg contents, can be particularly useful in determining whether contaminants (and potential biological effects) associated with human industrial activities, such as offshore petroleum and mineral exploration and development, are accumulating in marine environments. The collection and archival of seabird

  5. Both natural selection and isolation by distance explain phenotypic divergence in bill size and body mass between South Australian little penguin colonies.

    Science.gov (United States)

    Colombelli-Négrel, Diane

    2016-11-01

    Morphological variation between populations of the same species can arise as a response to genetic variation, local environmental conditions, or a combination of both. In this study, I examined small-scale geographic variation in bill size and body mass in little penguins ( Eudyptula minor ) across five breeding colonies in South Australia separated by penguin colonies.

  6. Effects of loading frequency on fatigue crack growth mechanisms in α/β Ti microstructure with large colony size

    International Nuclear Information System (INIS)

    Sansoz, F.; Ghonem, H.

    2003-01-01

    This paper deals with crack tip/microstructure interactions at 520 deg. C in lamellar Ti-6Al-2Sn-4Zr-2Mo-0.1Si (Ti6242) alloy under different fatigue loading frequencies. A series of heat treatments were performed in order to produce large colony microstructures that vary in their lamellar and colony size. Fatigue crack growth (FCG) experiments were conducted on these microstructures at loading frequencies of 10 and 0.05 Hz. The lower frequency was explored with and without imposing a 5 min hold-time at the peak stress level during each loading cycle. Results show that the crack growth behavior is sensitive to the loading frequency. For the same microstructure, the crack growth rate is found to be lower at 10 than at 0.05 Hz. The addition of a hold-time, however, did not alter the FCG rate indicating that creep strain during one loading cycle does not contribute significantly in the crack growth process. It is also shown that variations in lamella and colony size have no effects on the FCG rate except for the early stage of crack propagation. Scanning Electron Microscope examinations are performed on the fracture surface in order to identify the relevant crack growth mechanisms with respect to the loading frequency and the microstructure details. Quasi-cleavage of the α/β colonies along strong planar shear bands is shown to be a major mode of failure under all test condition. At a loading frequency of 10 Hz, the crack path proceeds arbitrary along planes either perpendicular or parallel to the long axis of α lamellae, while at 0.05 Hz, parallel-to-lamellae crack paths become favored. Corresponding differences of crack growth behavior are examined in terms of slip emission at the crack tip and interactions with the microstructure details

  7. The human influence on seabird nesting success: Conservation implications

    Science.gov (United States)

    Anderson, D.W.; Keith, J.O.

    1980-01-01

    Based on studies of brown pelicans Pelecanus occidentalis californicus and Heermann's gulls Larus heermanni, disturbances by recreationists, educational groups, local fishermen and scientists alike can be seriously disruptive and damaging to breeding seabirds in the Gulf of California and off the west coast of Baja California. Similar instances have been identified throughout the world?the problem is not difficult to document, but it is difficult to eliminate. The increasing human-seabird contacts on islands in the Gulf of California and along the west coast of Baja California raise serious questions and immediate concern about the continued preservation of nesting colonies of marine birds in those areas. Conservation measures must consider the extreme sensitivity of many seabirds to the inter- and intraspecific behavioural imbalances created by human disturbances. In some cases, total exclusion of humans may be required; in others, limited access might be possible under closely managed conditions at certain times of the year. A symbiotic relationship between seabird conservation, legitimate research and tourism should be the desired goal.

  8. Seabird mortality from longline fishing in the Mediterranean Sea and Macaronesian waters: a review and a way forward

    Directory of Open Access Journals (Sweden)

    John Cooper

    2003-07-01

    Full Text Available A country-by-country review of seabird mortality from longline fishing in the Mediterranean Sea and in Macaronesian waters shows a paucity of data. Of 12 Mediterranean countries known to undertake longlining, seabird mortality is only reported for six: France, Greece, Italy, Malta, Spain and Tunisia. Seabird mortality from longlining has been reported from the Azores (Portugal but not from the other Macaronesian Islands. Only for one country, Spain, is information on the levels of mortality available, suggesting that 4-6% of the local breeding population of Cory´s shearwater Calonectris diomedea may be killed annually, a level considered unsustainable for the long-term persistence of colonies. Cory´s shearwater is the most commonly affected species, although a number of Larus gull species are also being caught. There is insufficient knowledge to conclude whether any seabird species is at conservation risk within the region, but concern is expressed for Cory´s shearwater. It is recommended that Mediterranean and Macaronesian countries conduct assessments of their longline fisheries and seabird mortality in terms of the Food and Agriculture Organization´s International Plan of Action - Seabirds. Regional fishery organisations, such as ICCAT and GFCM, should commence the collection of seabird mortality data. A longline action plan for the affected seabird species should be produced.

  9. Stress hormones link food availability and population processes in seabirds

    Science.gov (United States)

    Kitaysky, A.S.; Piatt, John F.; Wingfield, J.C.

    2007-01-01

    Catastrophic population declines in marine top predators in the northern Pacific have been hypothesized to result from nutritional stress affecting reproduction and survival of individuals. However, empirical evidence for food-related stress in wild animals is frequently lacking or inconclusive. We used a field endocrinology approach to measure stress, identify its causes, and examine a link between stress and population processes in the common murre Uria aalge. We tested the empirical relationship between variations in the stress hormone corticosterone (CORT) and food abundance, reproduction, and persistence of individuals at declining and increasing colonies in Cook Inlet, Alaska, from 1996 to 2001. We found that CORT secretion in murres is independent of colony, reproductive stage effects, and gender of individuals, but is directly negatively correlated with abundance of their food. Baseline CORT reflected current food abundance, whereas acute stress-induced CORT reflected food abundance in the previous month. As food supply diminished, increased CORT secretion predicted a decrease in reproductive performance. At a declining colony, increased baseline levels of CORT during reproduction predicted disappearance of individuals from the population. Persistence of individuals in a growing colony was independent of CORT during reproduction. The obtained results support the hypothesis that nutritional stress during reproduction affects reproduction and survival in seabirds. This study provides the first unequivocal evidence for CORT secretion as a mechanistic link between fluctuations in food abundance and population processes in seabirds. ?? Inter-Research 2007.

  10. Nest initiation in three North American bumble bees (Bombus): gyne number and presence of honey bee workers influence establishment success and colony size.

    Science.gov (United States)

    Strange, James P

    2010-01-01

    Three species of bumble bees, Bombus appositus Cresson, Bombus bifarius, Cresson and Bombus centralis Cresson (Hymenoptera: Apidae) were evaluated for nest initiation success under three sets of initial conditions. In the spring, gynes of each species were caught in the wild and introduced to nest boxes in one of three ways. Gynes were either introduced in conspecific pairs, singly with two honey bees, Apis mellifera L. (Hymenoptera: Apidae) workers, or alone. Nesting success and colony growth parameters were measured to understand the effects of the various treatments on nest establishment. Colonies initiated from pairs of conspecific gynes were most successful in producing worker bees (59.1%), less successful were colonies initiated with honey bee workers (33.3%), and least successful were bumble bee gynes initiating colonies alone (16.7%). There was a negative correlation between the numbers of days to the emergence of the first worker in a colony to the attainment of ultimate colony size, indicating that gynes that have not commenced oviposition in 21 days are unlikely to result in colonies exceeding 50 workers. B. appositus had the highest rate of nest establishment followed by B. bifarius and B. centralis. Nest establishment rates in three western bumble bee species can be increased dramatically by the addition of either honey bee workers or a second gyne to nesting boxes at colony initiation.

  11. Strict monandry in the ponerine army ant genus Simopelta suggests that colony size and complexity drive mating system evolution in social insects

    DEFF Research Database (Denmark)

    Kronauer, Daniel J C; O'Donnell, Sean; Boomsma, Jacobus J

    2011-01-01

    -ratios have convergently shaped these mating systems. Here we show that ponerine army ants of the genus Simopelta, which are distantly related but similar in general biology to other army ants, have strictly monandrous queens. Preliminary data suggest that workers reproduce in queenright colonies, which...... is in sharp contrast to other army ants. We hypothesize that differences in mature colony size and social complexity may explain these striking discrepancies....

  12. Cormorants as visitors in the Vorsø colony

    DEFF Research Database (Denmark)

    Bregnballe, Thomas; Vinas, Marta Mas; Gregersen, Jens

    2011-01-01

    Like other seabirds Great Cormorants Phalacrocorax carbo sinensis are known to prospect in potential breeding colonies during their first years of life before they settle to breed. Based on daily resightings of colour-ringed cormorants in the old Vorsø colony we examined the difference between...

  13. Effects of founder population size on the performance of Orius laevigatus (Hemiptera: Anthocoridae) colonies

    NARCIS (Netherlands)

    Castañe, C.; Bueno, V.H.P.; Carvalho, L.M.; Lenteren, van J.C.

    2014-01-01

    Orius laevigatus (Hemiptera: Anthocoridae) is a key predator of thrips and is mass reared in large numbers for use in biological control. The aim of this study was to evaluate the effect of founder population size on the biological and behavioral performance of O. laevigatus over time. Laboratory

  14. A hybrid artificial bee colony algorithm and pattern search method for inversion of particle size distribution from spectral extinction data

    Science.gov (United States)

    Wang, Li; Li, Feng; Xing, Jian

    2017-10-01

    In this paper, a hybrid artificial bee colony (ABC) algorithm and pattern search (PS) method is proposed and applied for recovery of particle size distribution (PSD) from spectral extinction data. To be more useful and practical, size distribution function is modelled as the general Johnson's ? function that can overcome the difficulty of not knowing the exact type beforehand encountered in many real circumstances. The proposed hybrid algorithm is evaluated through simulated examples involving unimodal, bimodal and trimodal PSDs with different widths and mean particle diameters. For comparison, all examples are additionally validated by the single ABC algorithm. In addition, the performance of the proposed algorithm is further tested by actual extinction measurements with real standard polystyrene samples immersed in water. Simulation and experimental results illustrate that the hybrid algorithm can be used as an effective technique to retrieve the PSDs with high reliability and accuracy. Compared with the single ABC algorithm, our proposed algorithm can produce more accurate and robust inversion results while taking almost comparative CPU time over ABC algorithm alone. The superiority of ABC and PS hybridization strategy in terms of reaching a better balance of estimation accuracy and computation effort increases its potentials as an excellent inversion technique for reliable and efficient actual measurement of PSD.

  15. Inverse estimation of the spheroidal particle size distribution using Ant Colony Optimization algorithms in multispectral extinction technique

    Science.gov (United States)

    He, Zhenzong; Qi, Hong; Wang, Yuqing; Ruan, Liming

    2014-10-01

    Four improved Ant Colony Optimization (ACO) algorithms, i.e. the probability density function based ACO (PDF-ACO) algorithm, the Region ACO (RACO) algorithm, Stochastic ACO (SACO) algorithm and Homogeneous ACO (HACO) algorithm, are employed to estimate the particle size distribution (PSD) of the spheroidal particles. The direct problems are solved by the extended Anomalous Diffraction Approximation (ADA) and the Lambert-Beer law. Three commonly used monomodal distribution functions i.e. the Rosin-Rammer (R-R) distribution function, the normal (N-N) distribution function, and the logarithmic normal (L-N) distribution function are estimated under dependent model. The influence of random measurement errors on the inverse results is also investigated. All the results reveal that the PDF-ACO algorithm is more accurate than the other three ACO algorithms and can be used as an effective technique to investigate the PSD of the spheroidal particles. Furthermore, the Johnson's SB (J-SB) function and the modified beta (M-β) function are employed as the general distribution functions to retrieve the PSD of spheroidal particles using PDF-ACO algorithm. The investigation shows a reasonable agreement between the original distribution function and the general distribution function when only considering the variety of the length of the rotational semi-axis.

  16. Estimating the population size and colony boundary of subterranean termites by using the density functions of directionally averaged capture probability.

    Science.gov (United States)

    Su, Nan-Yao; Lee, Sang-Hee

    2008-04-01

    Marked termites were released in a linear-connected foraging arena, and the spatial heterogeneity of their capture probabilities was averaged for both directions at distance r from release point to obtain a symmetrical distribution, from which the density function of directionally averaged capture probability P(x) was derived. We hypothesized that as marked termites move into the population and given sufficient time, the directionally averaged capture probability may reach an equilibrium P(e) over the distance r and thus satisfy the equal mixing assumption of the mark-recapture protocol. The equilibrium capture probability P(e) was used to estimate the population size N. The hypothesis was tested in a 50-m extended foraging arena to simulate the distance factor of field colonies of subterranean termites. Over the 42-d test period, the density functions of directionally averaged capture probability P(x) exhibited four phases: exponential decline phase, linear decline phase, equilibrium phase, and postequilibrium phase. The equilibrium capture probability P(e), derived as the intercept of the linear regression during the equilibrium phase, correctly projected N estimates that were not significantly different from the known number of workers in the arena. Because the area beneath the probability density function is a constant (50% in this study), preequilibrium regression parameters and P(e) were used to estimate the population boundary distance 1, which is the distance between the release point and the boundary beyond which the population is absent.

  17. Recovery of seabirds following the Exxon Valdez oil spill

    International Nuclear Information System (INIS)

    Wiens, J.A.

    1993-01-01

    Following the Exxon Valdez oil spill in 1989, over 35,000 dead birds were retrieved and overall mortality was estimated in the hundreds of thousands. These observations led to concerns about persistent impacts on seabirds, especially murres (Uria spp.). Surveys of attendance by murres at breeding colonies in the spill path in 1991, however, indicated no overall differences from prespill attendance levels. Investigations of habitat occupancy conducted shortly after the spill in 1989 showed that, of the 47 bird species examined, the majority were using areas of oil-affected habitats by late 1991, although a few species did not show clear signs of recovery at the end of the study. These species were primarily wintering and resident forms. Because habitat use by other ecologically similar species was not affected by the spill or they recovered rapidly, prospects for recovery of the species that continued to show evidence of oiling impacts on habitat use in late 1991 would seem to be good. Collectively, these studies indicate that concerns about long-term impacts of the Exxon Valdez oil spill on seabirds may not be justified, and that recovery in the use of habitats by many bird species and in colony attendance by murres appeared to be well advanced by late 1991

  18. Celestial moderation of tropical seabird behavior.

    Directory of Open Access Journals (Sweden)

    Patrick Pinet

    Full Text Available Most animals, including birds, have cyclic life histories and numerous studies generally conducted on captive animals have shown that photoperiod is the main factor influencing this periodicity. Moon cycles can also affect periodic behavior of birds. Few studies have investigated the influence of these environmental cues in natural settings, and particularly in tropical areas where the change in photoperiod is slight and some bird species keep cyclic behaviors. Using miniaturized light sensors, we simultaneously investigated under natural conditions the influence of photoperiod and moon phases on the migration dates and at-sea activity of a tropical seabird species, the Barau's petrel, throughout its annual cycle. Firstly, we found that birds consistently started their pre- and post-breeding migrations at precise dates corresponding in both cases to a day-duration of 12.5 hours, suggesting a strong influence of the photoperiod in the regulation of migration behavior. We also found that mean population arrival dates to the colony changed from year to year and they were influenced by moon phases. Returns at their colonies occurred around the last full moon of the austral winter, suggesting that moon cycle is used by birds to synchronize their arrival. Secondly, variations of day-time activity were sinusoidal and correlated to seasonal changes of daylength. We thus hypothesize that the photoperiod could directly affect the behavior of the birds at sea. Night-time at-sea activity exhibited a clear cycle of 29.2 days, suggesting that nocturnal foraging was highly regulated by moon phase, particularly during the non-breeding season. To our knowledge, this is the first study to document a mixed regulation of the behavior of a wild bird by photoperiod and moon phases throughout its annual cycle.

  19. Biogeography of seabirds within a high-latitude ecosystem: Use of a data-assimilative ocean model to assess impacts of mesoscale oceanography

    Science.gov (United States)

    Santora, Jarrod A.; Eisner, Lisa B.; Kuletz, Kathy J.; Ladd, Carol; Renner, Martin; Hunt, George L., Jr.

    2018-02-01

    We assessed the biogeography of seabirds within the Bering Sea Large Marine Ecosystem (LME), a highly productive and extensive continental shelf system that supports important fishing grounds. Our objective was to investigate how physical ocean conditions impact distribution of seabirds along latitudinal gradients. We tested the hypothesis that seabird biogeographic patterns reflect differences in ocean conditions relating to the boundary between northern and southern shelf ecosystems. We used a grid-based approach to develop spatial means (1975-2014) of summertime seabird species' abundance, species' richness, and a multivariate seabird assemblage index to examine species composition. Seabird indices were linked to ocean conditions derived from a data-assimilative oceanographic model to quantify relationships between physics (e.g., temperature, salinity, and current velocity), bathymetry and seabirds along latitudinal gradients. Species assemblages reflected two main sources of variation, a mode for elevated richness and abundance, and a mode related to partitioning of inner/middle shelf species from outer shelf-slope species. Overall, species richness and abundance increased markedly at higher latitudes. We found that latitudinal changes in species assemblages, richness and abundance indicates a major shift around 59-60°N within inner and middle shelf regions, but not in the outer shelf. Within the middle shelf, latitudinal shifts in seabird assemblages strongly related to hydrographic structure, as opposed to the inner and outer shelf waters. As expected, elevated species richness and abundance was associated with major breeding colonies and within important coastal foraging areas. Our study also indicates that seabird observations supported the conclusion that the oceanographic model captured mesoscale variability of ocean conditions important for understanding seabird distributions and represents an important step for evaluating modeling and empirical studies

  20. Will the Effects of Sea-Level Rise Create Ecological Traps for Pacific Island Seabirds?

    Directory of Open Access Journals (Sweden)

    Michelle H Reynolds

    Full Text Available More than 18 million seabirds nest on 58 Pacific islands protected within vast U.S. Marine National Monuments (1.9 million km2. However, most of these seabird colonies are on low-elevation islands and sea-level rise (SLR and accompanying high-water perturbations are predicted to escalate with climate change. To understand how SLR may impact protected islands and insular biodiversity, we modeled inundation and wave-driven flooding of a globally important seabird rookery in the subtropical Pacific. We acquired new high-resolution Digital Elevation Models (DEMs and used the Delft3D wave model and ArcGIS to model wave heights and inundation for a range of SLR scenarios (+0.5, +1.0, +1.5, and +2.0 m at Midway Atoll. Next, we classified vegetation to delineate habitat exposure to inundation and identified how breeding phenology, colony synchrony, and life history traits affect species-specific sensitivity. We identified 3 of 13 species as highly vulnerable to SLR in the Hawaiian Islands and quantified their atoll-wide distribution (Laysan albatross, Phoebastria immutabilis; black-footed albatross, P. nigripes; and Bonin petrel, Pterodroma hypoleuca. Our models of wave-driven flooding forecast nest losses up to 10% greater than passive inundation models at +1.0 m SLR. At projections of + 2.0 m SLR, approximately 60% of albatross and 44% of Bonin petrel nests were overwashed displacing more than 616,400 breeding albatrosses and petrels. Habitat loss due to passive SLR may decrease the carrying capacity of some islands to support seabird colonies, while sudden high-water events directly reduce survival and reproduction. This is the first study to simulate wave-driven flooding and the combined impacts of SLR, groundwater rise, and storm waves on seabird colonies. Our results highlight the need for early climate change planning and restoration of higher elevation seabird refugia to prevent low-lying protected islands from becoming ecological traps in the

  1. Growth dynamics of the threatened Caribbean staghorn coral Acropora cervicornis: influence of host genotype, symbiont identity, colony size, and environmental setting.

    Science.gov (United States)

    Lirman, Diego; Schopmeyer, Stephanie; Galvan, Victor; Drury, Crawford; Baker, Andrew C; Baums, Iliana B

    2014-01-01

    The drastic decline in the abundance of Caribbean acroporid corals (Acropora cervicornis, A. palmata) has prompted the listing of this genus as threatened as well as the development of a regional propagation and restoration program. Using in situ underwater nurseries, we documented the influence of coral genotype and symbiont identity, colony size, and propagation method on the growth and branching patterns of staghorn corals in Florida and the Dominican Republic. Individual tracking of> 1700 nursery-grown staghorn fragments and colonies from 37 distinct genotypes (identified using microsatellites) in Florida and the Dominican Republic revealed a significant positive relationship between size and growth, but a decreasing rate of productivity with increasing size. Pruning vigor (enhanced growth after fragmentation) was documented even in colonies that lost 95% of their coral tissue/skeleton, indicating that high productivity can be maintained within nurseries by sequentially fragmenting corals. A significant effect of coral genotype was documented for corals grown in a common-garden setting, with fast-growing genotypes growing up to an order of magnitude faster than slow-growing genotypes. Algal-symbiont identity established using qPCR techniques showed that clade A (likely Symbiodinium A3) was the dominant symbiont type for all coral genotypes, except for one coral genotype in the DR and two in Florida that were dominated by clade C, with A- and C-dominated genotypes having similar growth rates. The threatened Caribbean staghorn coral is capable of extremely fast growth, with annual productivity rates exceeding 5 cm of new coral produced for every cm of existing coral. This species benefits from high fragment survivorship coupled by the pruning vigor experienced by the parent colonies after fragmentation. These life-history characteristics make A. cervicornis a successful candidate nursery species and provide optimism for the potential role that active propagation

  2. Growth dynamics of the threatened Caribbean staghorn coral Acropora cervicornis: influence of host genotype, symbiont identity, colony size, and environmental setting.

    Directory of Open Access Journals (Sweden)

    Diego Lirman

    Full Text Available BACKGROUND: The drastic decline in the abundance of Caribbean acroporid corals (Acropora cervicornis, A. palmata has prompted the listing of this genus as threatened as well as the development of a regional propagation and restoration program. Using in situ underwater nurseries, we documented the influence of coral genotype and symbiont identity, colony size, and propagation method on the growth and branching patterns of staghorn corals in Florida and the Dominican Republic. METHODOLOGY/PRINCIPAL FINDINGS: Individual tracking of> 1700 nursery-grown staghorn fragments and colonies from 37 distinct genotypes (identified using microsatellites in Florida and the Dominican Republic revealed a significant positive relationship between size and growth, but a decreasing rate of productivity with increasing size. Pruning vigor (enhanced growth after fragmentation was documented even in colonies that lost 95% of their coral tissue/skeleton, indicating that high productivity can be maintained within nurseries by sequentially fragmenting corals. A significant effect of coral genotype was documented for corals grown in a common-garden setting, with fast-growing genotypes growing up to an order of magnitude faster than slow-growing genotypes. Algal-symbiont identity established using qPCR techniques showed that clade A (likely Symbiodinium A3 was the dominant symbiont type for all coral genotypes, except for one coral genotype in the DR and two in Florida that were dominated by clade C, with A- and C-dominated genotypes having similar growth rates. CONCLUSION/SIGNIFICANCE: The threatened Caribbean staghorn coral is capable of extremely fast growth, with annual productivity rates exceeding 5 cm of new coral produced for every cm of existing coral. This species benefits from high fragment survivorship coupled by the pruning vigor experienced by the parent colonies after fragmentation. These life-history characteristics make A. cervicornis a successful candidate

  3. Tufted puffins (Fratercula cirrhata) respond to predation danger during colony approach flights

    NARCIS (Netherlands)

    Addison, B.; Ydenberg, R.C.; Smith, B.D.

    2007-01-01

    In spite of their putative importance in the evolution of certain traits (e.g., nocturnality, coloniality, cliff nesting), the effects of aerial predators on behavior of adult seabirds at colonies have been poorly investigated. We hypothesized that Tufted Puffins (Fratercula cirrhata) respond to

  4. Evidence that tufted puffins Fratercula cirrhata use colony overflights to reduce kleptoparasitism risk

    NARCIS (Netherlands)

    Blackburn, G.S.; Hipfner, J.M.; Ydenberg, R.C.

    2009-01-01

    Predation, foraging and mating costs are critical factors shaping life histories. Among colonial seabirds, colony overflights may enhance foraging or mating success, or diminish the risk of predation and kleptoparasitism. The latter possibility is difficult to test because low predation or

  5. Best practices for assessing forage fish fisheries-seabird resource competition

    Science.gov (United States)

    Sydeman, William J.; Thompson, Sarah Ann; Anker-Nilssen, Tycho; Arimitsu, Mayumi L.; Bennison, Ashley; Bertrand, Sophie; Boersch-Supan, Philipp; Boyd, Charlotte; Bransome, Nicole C.; Crawford, Robert J.M.; Daunt, Francis; Furness, Robert W.; Gianuca, Dimas; Gladics, Amanda; Koehn, Laura; Lang, Jennifer W.; Loggerwell, Elizabeth; Morris, Taryn L.; Phillips, Elizabeth M.; Provencher, Jennifer; Punt, André E..; Saraux, Claire; Shannon, Lynne; Sherley, Richard B.; Simeone, Alejandro; Wanless, Ross M.; Wanless, Sarah; Zador, Stephani

    2017-01-01

    Worldwide, in recent years capture fisheries targeting lower-trophic level forage fish and euphausiid crustaceans have been substantial (∼20 million metric tons [MT] annually). Landings of forage species are projected to increase in the future, and this harvest may affect marine ecosystems and predator-prey interactions by removal or redistribution of biomass central to pelagic food webs. In particular, fisheries targeting forage fish and euphausiids may be in competition with seabirds, likely the most sensitive of marine vertebrates given limitations in their foraging abilities (ambit and gape size) and high metabolic rate, for food resources. Lately, apparent competition between fisheries and seabirds has led to numerous high-profile conflicts over interpretations, as well as the approaches that could and should be used to assess the magnitude and consequences of fisheries-seabird resource competition. In this paper, we review the methods used to date to study fisheries competition with seabirds, and present “best practices” for future resource competition assessments. Documenting current fisheries competition with seabirds generally involves addressing two major issues: 1) are fisheries causing localized prey depletion that is sufficient to affect the birds? (i.e., are fisheries limiting food resources?), and 2) how are fisheries-induced changes to forage stocks affecting seabird populations given the associated functional or numerical response relationships? Previous studies have been hampered by mismatches in the scale of fisheries, fish, and seabird data, and a lack of causal understanding due to confounding by climatic and other ecosystem factors (e.g., removal of predatory fish). Best practices for fisheries-seabird competition research should include i) clear articulation of hypotheses, ii) data collection (or summation) of fisheries, fish, and seabirds on matched spatio-temporal scales, and iii) integration of observational and experimental

  6. Costs of task allocation with local feedback: Effects of colony size and extra workers in social insects and other multi-agent systems.

    Science.gov (United States)

    Radeva, Tsvetomira; Dornhaus, Anna; Lynch, Nancy; Nagpal, Radhika; Su, Hsin-Hao

    2017-12-01

    Adaptive collective systems are common in biology and beyond. Typically, such systems require a task allocation algorithm: a mechanism or rule-set by which individuals select particular roles. Here we study the performance of such task allocation mechanisms measured in terms of the time for individuals to allocate to tasks. We ask: (1) Is task allocation fundamentally difficult, and thus costly? (2) Does the performance of task allocation mechanisms depend on the number of individuals? And (3) what other parameters may affect their efficiency? We use techniques from distributed computing theory to develop a model of a social insect colony, where workers have to be allocated to a set of tasks; however, our model is generalizable to other systems. We show, first, that the ability of workers to quickly assess demand for work in tasks they are not currently engaged in crucially affects whether task allocation is quickly achieved or not. This indicates that in social insect tasks such as thermoregulation, where temperature may provide a global and near instantaneous stimulus to measure the need for cooling, for example, it should be easy to match the number of workers to the need for work. In other tasks, such as nest repair, it may be impossible for workers not directly at the work site to know that this task needs more workers. We argue that this affects whether task allocation mechanisms are under strong selection. Second, we show that colony size does not affect task allocation performance under our assumptions. This implies that when effects of colony size are found, they are not inherent in the process of task allocation itself, but due to processes not modeled here, such as higher variation in task demand for smaller colonies, benefits of specialized workers, or constant overhead costs. Third, we show that the ratio of the number of available workers to the workload crucially affects performance. Thus, workers in excess of those needed to complete all tasks

  7. Costs of task allocation with local feedback: Effects of colony size and extra workers in social insects and other multi-agent systems.

    Directory of Open Access Journals (Sweden)

    Tsvetomira Radeva

    2017-12-01

    Full Text Available Adaptive collective systems are common in biology and beyond. Typically, such systems require a task allocation algorithm: a mechanism or rule-set by which individuals select particular roles. Here we study the performance of such task allocation mechanisms measured in terms of the time for individuals to allocate to tasks. We ask: (1 Is task allocation fundamentally difficult, and thus costly? (2 Does the performance of task allocation mechanisms depend on the number of individuals? And (3 what other parameters may affect their efficiency? We use techniques from distributed computing theory to develop a model of a social insect colony, where workers have to be allocated to a set of tasks; however, our model is generalizable to other systems. We show, first, that the ability of workers to quickly assess demand for work in tasks they are not currently engaged in crucially affects whether task allocation is quickly achieved or not. This indicates that in social insect tasks such as thermoregulation, where temperature may provide a global and near instantaneous stimulus to measure the need for cooling, for example, it should be easy to match the number of workers to the need for work. In other tasks, such as nest repair, it may be impossible for workers not directly at the work site to know that this task needs more workers. We argue that this affects whether task allocation mechanisms are under strong selection. Second, we show that colony size does not affect task allocation performance under our assumptions. This implies that when effects of colony size are found, they are not inherent in the process of task allocation itself, but due to processes not modeled here, such as higher variation in task demand for smaller colonies, benefits of specialized workers, or constant overhead costs. Third, we show that the ratio of the number of available workers to the workload crucially affects performance. Thus, workers in excess of those needed to

  8. A new technique based on Artificial Bee Colony Algorithm for optimal sizing of stand-alone photovoltaic system

    OpenAIRE

    Mohamed, Ahmed F.; Elarini, Mahdi M.; Othman, Ahmed M.

    2013-01-01

    One of the most recent optimization techniques applied to the optimal design of photovoltaic system to supply an isolated load demand is the Artificial Bee Colony Algorithm (ABC). The proposed methodology is applied to optimize the cost of the PV system including photovoltaic, a battery bank, a battery charger controller, and inverter. Two objective functions are proposed: the first one is the PV module output power which is to be maximized and the second one is the life cycle cost (LCC) whic...

  9. The distribution of seabirds and fish in relation to ocean currents in the southeastern Chukchi Sea

    Science.gov (United States)

    Piatt, John F.; Wells, John L.; MacCharles, Andrea; Fadely, Brian S.; Montevecchi, W.A.; Gaston, A.J.

    1991-01-01

    In late August 1988, we studied the distribution of seabirds in the southeastern Chukchi Sea, particularly in waters near a major seabird colony at Cape Thompson. Foraging areas were characterized using hydrographic data obtained from hydroacoustic surveys for fish. Murres (Uria spp.) and Black-legged Kitttiwakes Rissa tridactyla breeding at Cape Thompson fed mostly on Arctic cod, which are known from previous studies to be the most abundant pelagic fish in the region. Our hydroacoustic surveys revealed that pelagic fish were distributed widely, but densities were estimated to be low (e.g., 0.1-10 g∙m-3) throughout the study area and a few schools were recorded. Large feeding flocks of murres and kittiwakes were observed over fish schools with densities estimated to exceed 15 g∙m-3. Fish densities were higher in shallow Alaska Coastal Current waters than offshore in Bering Sea waters, and most piscivorous seabirds foraged in coastal waters. Poor kittiwake breeding success and a low frequency of fish in murre and kittiwake stomachs in late August suggested that fish densities were marginal for sustaining breeding seabirds at that time. Planktivorous Least Auklets Aethia pusilla and Parakeet Auklets Cyclorrhynchus psittacula foraged almost exclusively in Bering Sea waters. Short-tailed Shearwaters Puffinus tenuirostris and Tufted Puffins Fratercula cirrhata foraged in transitional waters at the front between Coastal and Bering Sea currents.

  10. Validating growth and development of a seabird as an indicator of food availability: captive-reared Caspian Tern chicks fed ad libitum and restricted diets

    Science.gov (United States)

    Lyons, Donald E.; Roby, Daniel D.

    2011-01-01

    For seabirds raising young under conditions of limited food availability, reducing chick provisioning and chick growth rates are the primary means available to avoid abandonment of a breeding effort. For most seabirds, however, baseline data characterizing chick growth and development under known feeding conditions are unavailable, so it is difficult to evaluate chick nutritional status as it relates to foraging conditions near breeding colonies. To address this need, we examined the growth and development of young Caspian Terns (Hydroprogne caspia), a cosmopolitan, generalist piscivore, reared in captivity and fed ad libitum and restricted (ca. one-third lower caloric intake) diets. Ad libitum-fed chicks grew at similar rates and achieved a similar size at fledging as previously documented for chicks in the wild and had energetic demands that closely matched allometric predictions. We identified three general characteristics of food-restricted Caspian Tern chicks compared to ad libitum chicks: (1) lower age-specific body mass, (2) lower age-specific skeletal and feather size, such as wing chord length, and (3) heightened levels of corticosterone in blood, both for baseline levels and in response to acute stress. Effects of diet restriction on feather growth (10-11% slower growth in diet-restricted chicks) were less pronounced than effects on structural growth (37-52% slower growth) and body mass (24% lower at fledging age), apparently due to preferential allocation of food resources to maintain plumage growth. Our results suggest that measurements of chick body mass and feather development (e.g., wing chord or primary length) or measurement of corticosterone levels in the blood would allow useful evaluation of the nutritional status of chicks reared in the wild and of food availability in the foraging range of adults. Such evaluations could also inform demography studies (e.g., predict future recruitment) and assist in evaluating designated piscivorous waterbird

  11. Gulf-Wide Information System, Environmental Sensitivity Index Bird Nesting Colonies Database, Geographic NAD83, LDWF (2001) [esi_nests_LDWF_2001

    Data.gov (United States)

    Louisiana Geographic Information Center — This data set contains sensitive biological resource data for seabird and wading bird nesting colonies in coastal Louisiana. Vector points in this data set represent...

  12. Tracking Cairns: Biologging Improves the Use of Seabirds as Sentinels of the Sea

    Directory of Open Access Journals (Sweden)

    Emile Brisson-Curadeau

    2017-11-01

    Full Text Available In 1987, David Cairns proposed that a gradient of colony-based measures on seabirds could be used to assess food supply in the ocean. Measures closely tied to the ocean, such as foraging trip duration, would be sensitive to small declines in food supply while measures more closely tied with the nest site, such as reproductive success, would be sensitive to large declines in food supply. The continual refinement of tracking devices holds the potential to clearly link variables measured via seabirds to food supply, possibly extending Cairns' hypothesis. Here, we review the various tests of Cairns' hypothesis, and demonstrate that those tests have had variable success, partly because of the complex and nonlinear relationships between food supply and colony-based measures. We summarize the metrics available from biologgers and argue that such devices can provide a more direct proxy of food supply. We conclude that Cairns' hypothesis can be extended to biologger-derived parameters and that seabird behavior can be used as an early warning signal for declining food supply.

  13. Seabird transfer of nutrients and trace elements from the north water polynya to land during the mid-holocene warm period, carey islands, northwest Greenland

    DEFF Research Database (Denmark)

    Outridge, Peter M.; Goodsite, Michael Evan; Bennike, Ole

    2016-01-01

    Seabird guano from large nesting colonies is known to increase trace metal levels in adjacent terrestrial environments today, when global oceans are contaminated with Hg, Cd, and other metals. But the effect of seabird guano in the pre-industrial period has rarely been studied. We used stable C...... and N isotopic and trace element analyses of a peat core that represents ca. 2000 years of organic matter accumulation to examine the effect on trace elements and nutrients of a seabird colony that existed in northern Baffin Bay during the Holocene Thermal Maximum (ca. 8000-5000 yr BP). Although C and N......, in which guano markedly increased environmental Hg concentrations. It could be a consequence of Hg concentrations in Arctic marine food webs in the pre-industrial period that were an order of magnitude lower than those of today....

  14. Monitoring of populations and productivity of seabirds at St. George Island, Cape Peirce, and Bluff, Alaska, 1989. Final report

    International Nuclear Information System (INIS)

    Mendenhall, V.M.

    1991-04-01

    In recent years, although descriptive studies have continued, the emphasis on population monitoring of seabirds has increased. Commercial uses of the Continental Shelf of the Bering and Chukchi Seas, including oil and gas development, subsurface placer mining, and commercial fishing, carry the potential for adverse pressures on seabird populations. Populations and productivity of seabirds were monitored in 1989 at three Bering Sea colonies: St. George, Cape Peirce, and Bluff. Murres and black-legged kittiwakes were monitored at all colonies to facilitate intercolony comparisons. These species were selected because they are relatively easy to study, numerous, sensitive to potential impacts of development, and widely distributed. Red legged kittiwakes also were monitored at St. George because of concern for the world status of the species. Methods were standardized among the three colonies to facilitate comparisons among colonies and years. Observations of productivity began at the time nests were established and continued until most young had fledged. Kittiwake nests and murre breeding sites used for estimation of productivity were mapped on photographs or sketches and the fate of each was recorded

  15. AFSC/REFM: Seabird Necropsy dataset of North Pacific

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The seabird necropsy dataset contains information on seabird specimens that were collected under salvage and scientific collection permits primarily by...

  16. Contamination of an arctic terrestrial food web with marine-derived persistent organic pollutants transported by breeding seabirds

    International Nuclear Information System (INIS)

    Choy, Emily S.; Kimpe, Linda E.; Mallory, Mark L.; Smol, John P.; Blais, Jules M.

    2010-01-01

    At Cape Vera, Devon Island (Nunavut, Canada), a colony of northern fulmars (Fulmarus glacialis) concentrates and releases contaminants through their guano to the environment. We determined whether persistent organic pollutants (POPs) from seabirds were transferred to coastal food webs. Snow buntings (Plectrophenax nivalis) were the most contaminated species, with ΣPCB and ΣDDT (mean: 168, 106 ng/g ww) concentrations surpassing environmental guidelines for protecting wildlife. When examined collectively, PCB congeners and DDT in jewel lichen (Xanthoria elegans) were lower in samples taken farther from the seabird colony, and increased with increasing δ 15 N values. However, only concentrations of p'p-DDE:ΣDDT and PCB-95 were significantly correlated inversely with distance from the seabird cliffs. Linkages between marine-derived POPs and their concentrations in terrestrial mammals were less clear. Our study provides novel contaminant data for these species and supports biovector transport as a source of organic contaminants to certain components of the terrestrial food web. - This study provides evidence of contaminant transport by seabirds to a coastal Arctic food web.

  17. Contamination of an arctic terrestrial food web with marine-derived persistent organic pollutants transported by breeding seabirds

    Energy Technology Data Exchange (ETDEWEB)

    Choy, Emily S., E-mail: echoy087@uottawa.c [Program for Chemical and Environmental Toxicology, Department of Biology, University of Ottawa, Ottawa, ON, K1N 6N5 (Canada); Kimpe, Linda E., E-mail: linda.kimpe@uottawa.c [Program for Chemical and Environmental Toxicology, Department of Biology, University of Ottawa, Ottawa, ON, K1N 6N5 (Canada); Mallory, Mark L., E-mail: mark.mallory@ec.gc.c [Canadian Wildlife Service, Environment Canada, Iqaluit, NU, X0A 0H0 (Canada); Smol, John P., E-mail: smolj@queensu.c [Paleoecological Environmental Assessment and Research Lab (PEARL), Department of Biology, Queen' s University, Kingston, ON, K7L 3N6 (Canada); Blais, Jules M., E-mail: jules.blais@uottawa.c [Program for Chemical and Environmental Toxicology, Department of Biology, University of Ottawa, Ottawa, ON, K1N 6N5 (Canada)

    2010-11-15

    At Cape Vera, Devon Island (Nunavut, Canada), a colony of northern fulmars (Fulmarus glacialis) concentrates and releases contaminants through their guano to the environment. We determined whether persistent organic pollutants (POPs) from seabirds were transferred to coastal food webs. Snow buntings (Plectrophenax nivalis) were the most contaminated species, with {Sigma}PCB and {Sigma}DDT (mean: 168, 106 ng/g ww) concentrations surpassing environmental guidelines for protecting wildlife. When examined collectively, PCB congeners and DDT in jewel lichen (Xanthoria elegans) were lower in samples taken farther from the seabird colony, and increased with increasing {delta}{sup 15}N values. However, only concentrations of p'p-DDE:{Sigma}DDT and PCB-95 were significantly correlated inversely with distance from the seabird cliffs. Linkages between marine-derived POPs and their concentrations in terrestrial mammals were less clear. Our study provides novel contaminant data for these species and supports biovector transport as a source of organic contaminants to certain components of the terrestrial food web. - This study provides evidence of contaminant transport by seabirds to a coastal Arctic food web.

  18. Colony size-frequency distributions among different populations of the scleractinan coral Siderastrea stellata in Southwestern Atlantic: implications for life history patterns

    Directory of Open Access Journals (Sweden)

    Monica Moraes Lins de Barros

    2006-12-01

    Full Text Available Colony size-frequency distributions of reef corals may be used to infer growth potential and population responses upon environmental changes. The present paper compares the size structure of colonies of Siderastrea stellata Verrill, 1868,among 11 sites, six of them distributed along a gradient of sediment deposition in Abrolhos, Bahia, Brazil (18º S. Results indicated that the population structure is likely to be influenced by local conditions, rather than large scale factors, such as latitude. The 11 distributions, however, showed higher frequencies of small size classes. Class 1 (up to 2.5 cm diameter was always present and the frequency of colonies from size class 3 (10 cm diameter tended to decrease in all sites. Comparison among the six Abrolhos sites showed that S. stellata has advantages at sites with intermediate sedimentation, where colonies attain larger sizes, probably, reflecting a higher survivorship over time. The present study showed that, despite the influence of environmental conditions on parameters of the populations such as size of colony, the life history strategy of S. stellata reflects a local adaptation that allows its development and survivorship in shallow waters and horizontal substrates, sites characterized by high mortality rates.Distribuições de freqüências de classes de tamanho de colônias de corais recifais, associadas a dados de fecundidade e crescimento, podem ser utilizadas para inferir o potencial de crescimento e respostas da população frente às variações ambientais. Apresentamos análise da estrutura de tamanho de colônias do coral Siderastrea stellata Verrill, 1868, em 11 locais, seis desses distribuídos ao longo de um gradiente de sedimentação em Abrolhos, Bahia, Brasil (18ºS. Os resultados demonstraram ausência de um padrão latitudinal, indicando maior influência de fatores locais. Em Abrolhos, locais com taxas de deposição de sedimento intermediárias apresentaram os maiores

  19. Winter temperature affects the prevalence of ticks in an Arctic seabird.

    Directory of Open Access Journals (Sweden)

    Sébastien Descamps

    Full Text Available The Arctic is rapidly warming and host-parasite relationships may be modified by such environmental changes. Here, I showed that the average winter temperature in Svalbard, Arctic Norway, explained almost 90% of the average prevalence of ticks in an Arctic seabird, the Brünnich's guillemot Uria lomvia. An increase of 1°C in the average winter temperature at the nesting colony site was associated with a 5% increase in the number of birds infected by these ectoparasites in the subsequent breeding season. Guillemots were generally infested by only a few ticks (≤5 and I found no direct effect of tick presence on their body condition and breeding success. However, the strong effect of average winter temperature described here clearly indicates that tick-seabird relationships in the Arctic may be strongly affected by ongoing climate warming.

  20. Plastic debris in great skua (Stercorarius skua) pellets corresponds to seabird prey species.

    Science.gov (United States)

    Hammer, S; Nager, R G; Johnson, P C D; Furness, R W; Provencher, J F

    2016-02-15

    Plastic is a common item in marine environments. Studies assessing seabird ingestion of plastics have focused on species that ingest plastics mistaken for prey items. Few studies have examined a scavenger and predatory species that are likely to ingest plastics indirectly through their prey items, such as the great skua (Stercorarius skua). We examined 1034 regurgitated pellets from a great skua colony in the Faroe Islands for plastics and found approximately 6% contained plastics. Pellets containing remains of Northern fulmars (Fulmarus glacialis) had the highest prevalence of plastic. Our findings support previous work showing that Northern fulmars have higher loads of plastics than other sympatric species. This study demonstrates that marine plastic debris is transferred from surface feeding seabird species to predatory great skuas. Examination of plastic ingestion in species that do not ingest plastics directly can provide insights into how plastic particles transfer vertically within the food web. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. A new technique based on Artificial Bee Colony Algorithm for optimal sizing of stand-alone photovoltaic system.

    Science.gov (United States)

    Mohamed, Ahmed F; Elarini, Mahdi M; Othman, Ahmed M

    2014-05-01

    One of the most recent optimization techniques applied to the optimal design of photovoltaic system to supply an isolated load demand is the Artificial Bee Colony Algorithm (ABC). The proposed methodology is applied to optimize the cost of the PV system including photovoltaic, a battery bank, a battery charger controller, and inverter. Two objective functions are proposed: the first one is the PV module output power which is to be maximized and the second one is the life cycle cost (LCC) which is to be minimized. The analysis is performed based on measured solar radiation and ambient temperature measured at Helwan city, Egypt. A comparison between ABC algorithm and Genetic Algorithm (GA) optimal results is done. Another location is selected which is Zagazig city to check the validity of ABC algorithm in any location. The ABC is more optimal than GA. The results encouraged the use of the PV systems to electrify the rural sites of Egypt.

  2. A new technique based on Artificial Bee Colony Algorithm for optimal sizing of stand-alone photovoltaic system

    Directory of Open Access Journals (Sweden)

    Ahmed F. Mohamed

    2014-05-01

    Full Text Available One of the most recent optimization techniques applied to the optimal design of photovoltaic system to supply an isolated load demand is the Artificial Bee Colony Algorithm (ABC. The proposed methodology is applied to optimize the cost of the PV system including photovoltaic, a battery bank, a battery charger controller, and inverter. Two objective functions are proposed: the first one is the PV module output power which is to be maximized and the second one is the life cycle cost (LCC which is to be minimized. The analysis is performed based on measured solar radiation and ambient temperature measured at Helwan city, Egypt. A comparison between ABC algorithm and Genetic Algorithm (GA optimal results is done. Another location is selected which is Zagazig city to check the validity of ABC algorithm in any location. The ABC is more optimal than GA. The results encouraged the use of the PV systems to electrify the rural sites of Egypt.

  3. An updated assessment of the seabird populations breeding at ...

    African Journals Online (AJOL)

    The Príncipe Autonomous Region is recognised as a marine biodiversity hotspot, although little is known about the status of its marine fauna. It holds most breeding seabirds of the tropical eastern Atlantic Ocean. Based on anecdotal accounts of increased fishing and seabird harvesting, regular monitoring of seabird ...

  4. Ocean-wide Drivers of Migration Strategies and Their Influence on Population Breeding Performance in a Declining Seabird.

    Science.gov (United States)

    Fayet, Annette L; Freeman, Robin; Anker-Nilssen, Tycho; Diamond, Antony; Erikstad, Kjell E; Fifield, Dave; Fitzsimmons, Michelle G; Hansen, Erpur S; Harris, Mike P; Jessopp, Mark; Kouwenberg, Amy-Lee; Kress, Steve; Mowat, Stephen; Perrins, Chris M; Petersen, Aevar; Petersen, Ib K; Reiertsen, Tone K; Robertson, Gregory J; Shannon, Paula; Sigurðsson, Ingvar A; Shoji, Akiko; Wanless, Sarah; Guilford, Tim

    2017-12-18

    Which factors shape animals' migration movements across large geographical scales, how different migratory strategies emerge between populations, and how these may affect population dynamics are central questions in the field of animal migration [1] that only large-scale studies of migration patterns across a species' range can answer [2]. To address these questions, we track the migration of 270 Atlantic puffins Fratercula arctica, a red-listed, declining seabird, across their entire breeding range. We investigate the role of demographic, geographical, and environmental variables in driving spatial and behavioral differences on an ocean-basin scale by measuring puffins' among-colony differences in migratory routes and day-to-day behavior (estimated with individual daily activity budgets and energy expenditure). We show that competition and local winter resource availability are important drivers of migratory movements, with birds from larger colonies or with poorer local winter conditions migrating further and visiting less-productive waters; this in turn led to differences in flight activity and energy expenditure. Other behavioral differences emerge with latitude, with foraging effort and energy expenditure increasing when birds winter further north in colder waters. Importantly, these ocean-wide migration patterns can ultimately be linked with breeding performance: colony productivity is negatively associated with wintering latitude, population size, and migration distance, which demonstrates the cost of competition and migration on future breeding and the link between non-breeding and breeding periods. Our results help us to understand the drivers of animal migration and have important implications for population dynamics and the conservation of migratory species. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. The impact of seabirds on the content of various forms of phosphorus in organic soils of the Bellsund coast, western Spitsbergen

    Directory of Open Access Journals (Sweden)

    Marta Ziółek

    2014-10-01

    Full Text Available In areas isolated from direct human impact, such as Spitsbergen, environmental changes result mainly from natural processes, which include nutrient enrichment caused by seabirds. The objective of this study was to evaluate the degree of nutrient enrichment of organic soils fertilized by seabirds, indicated by the phosphorus content and transformations. This study encompassed two areas on the Bellsund coast. A profile without the influence of seabirds and profiles located at different distances from the colony of birds (0–150 m were analysed. A sequential phosphorus fractionation method was used, and three inorganic P (Pi fractions were obtained as a result: Pi-L (labile P, Pi-FeAl (P associated with Fe and Al and Pi-CaMg (P associated with Ca and Mg; and two fractions of organic P (Po: Po-HuAc (P associated with humic acids and Po-Res (residual P. Polar organic soils not subjected to the direct seabird impact contained amounts of total phosphorus (Pt similar to organic soils in other climate zones. The presence of the seabird colony increased the Pt content and changed the distribution between the ratio of organic and inorganic P fractions. Within the inorganic P fraction, the Pi–CaMg component was dominant and its distribution was modified by the fertilizing effect of bird droppings. The nutrient enrichment of organic soils by birds in the polar zone was therefore very strong.

  6. Mapping seabird sensitivity to offshore wind farms.

    Directory of Open Access Journals (Sweden)

    Gareth Bradbury

    Full Text Available We present a Geographic Information System (GIS tool, SeaMaST (Seabird Mapping and Sensitivity Tool, to provide evidence on the use of sea areas by seabirds and inshore waterbirds in English territorial waters, mapping their relative sensitivity to offshore wind farms. SeaMaST is a freely available evidence source for use by all connected to the offshore wind industry and will assist statutory agencies in assessing potential risks to seabird populations from planned developments. Data were compiled from offshore boat and aerial observer surveys spanning the period 1979-2012. The data were analysed using distance analysis and Density Surface Modelling to produce predicted bird densities across a grid covering English territorial waters at a resolution of 3 km×3 km. Coefficients of Variation were estimated for each grid cell density, as an indication of confidence in predictions. Offshore wind farm sensitivity scores were compiled for seabird species using English territorial waters. The comparative risks to each species of collision with turbines and displacement from operational turbines were reviewed and scored separately, and the scores were multiplied by the bird density estimates to produce relative sensitivity maps. The sensitivity maps reflected well the amassed distributions of the most sensitive species. SeaMaST is an important new tool for assessing potential impacts on seabird populations from offshore development at a time when multiple large areas of development are proposed which overlap with many seabird species' ranges. It will inform marine spatial planning as well as identifying priority areas of sea usage by marine birds. Example SeaMaST outputs are presented.

  7. Mapping seabird sensitivity to offshore wind farms.

    Science.gov (United States)

    Bradbury, Gareth; Trinder, Mark; Furness, Bob; Banks, Alex N; Caldow, Richard W G; Hume, Duncan

    2014-01-01

    We present a Geographic Information System (GIS) tool, SeaMaST (Seabird Mapping and Sensitivity Tool), to provide evidence on the use of sea areas by seabirds and inshore waterbirds in English territorial waters, mapping their relative sensitivity to offshore wind farms. SeaMaST is a freely available evidence source for use by all connected to the offshore wind industry and will assist statutory agencies in assessing potential risks to seabird populations from planned developments. Data were compiled from offshore boat and aerial observer surveys spanning the period 1979-2012. The data were analysed using distance analysis and Density Surface Modelling to produce predicted bird densities across a grid covering English territorial waters at a resolution of 3 km×3 km. Coefficients of Variation were estimated for each grid cell density, as an indication of confidence in predictions. Offshore wind farm sensitivity scores were compiled for seabird species using English territorial waters. The comparative risks to each species of collision with turbines and displacement from operational turbines were reviewed and scored separately, and the scores were multiplied by the bird density estimates to produce relative sensitivity maps. The sensitivity maps reflected well the amassed distributions of the most sensitive species. SeaMaST is an important new tool for assessing potential impacts on seabird populations from offshore development at a time when multiple large areas of development are proposed which overlap with many seabird species' ranges. It will inform marine spatial planning as well as identifying priority areas of sea usage by marine birds. Example SeaMaST outputs are presented.

  8. Optimal Sizing of a Stand-Alone Hybrid Power System Based on Battery/Hydrogen with an Improved Ant Colony Optimization

    Directory of Open Access Journals (Sweden)

    Weiqiang Dong

    2016-09-01

    Full Text Available A distributed power system with renewable energy sources is very popular in recent years due to the rapid depletion of conventional sources of energy. Reasonable sizing for such power systems could improve the power supply reliability and reduce the annual system cost. The goal of this work is to optimize the size of a stand-alone hybrid photovoltaic (PV/wind turbine (WT/battery (B/hydrogen system (a hybrid system based on battery and hydrogen (HS-BH for reliable and economic supply. Two objectives that take the minimum annual system cost and maximum system reliability described as the loss of power supply probability (LPSP have been addressed for sizing HS-BH from a more comprehensive perspective, considering the basic demand of load, the profit from hydrogen, which is produced by HS-BH, and an effective energy storage strategy. An improved ant colony optimization (ACO algorithm has been presented to solve the sizing problem of HS-BH. Finally, a simulation experiment has been done to demonstrate the developed results, in which some comparisons have been done to emphasize the advantage of HS-BH with the aid of data from an island of Zhejiang, China.

  9. Use of social information in seabirds: compass rafts indicate the heading of food patches.

    Science.gov (United States)

    Weimerskirch, Henri; Bertrand, Sophie; Silva, Jaime; Marques, Jose Carlos; Goya, Elisa

    2010-03-29

    Ward and Zahavi suggested in 1973 that colonies could serve as information centres, through a transfer of information on the location of food resources between unrelated individuals (Information Centre Hypothesis). Using GPS tracking and observations on group movements, we studied the search strategy and information transfer in two of the most colonial seabirds, Guanay cormorants (Phalacrocorax bougainvillii) and Peruvian boobies (Sula variegata). Both species breed together and feed on the same prey. They do return to the same feeding zone from one trip to the next indicating high unpredictability in the location of food resources. We found that the Guanay cormorants use social information to select their bearing when departing the colony. They form a raft at the sea surface whose position is continuously adjusted to the bearing of the largest returning columns of cormorants. As such, the raft serves as a compass signal that gives an indication on the location of the food patches. Conversely, Peruvian boobies rely mainly on personal information based on memory to take heading at departure. They search for food patches solitarily or in small groups through network foraging by detecting the white plumage of congeners visible at long distance. Our results show that information transfer does occur and we propose a new mechanism of information transfer based on the use of rafts off colonies. The use of rafts for information transfer may be common in central place foraging colonial seabirds that exploit short lasting and/or unpredictably distributed food patches. Over the past decades Guanay cormorants have declined ten times whereas Peruvian boobies have remained relatively stable. We suggest that the decline of the cormorants could be related to reduced social information opportunities and that social behaviour and search strategies have the potential to play an important role in the population dynamics of colonial animals.

  10. Use of social information in seabirds: compass rafts indicate the heading of food patches.

    Directory of Open Access Journals (Sweden)

    Henri Weimerskirch

    Full Text Available Ward and Zahavi suggested in 1973 that colonies could serve as information centres, through a transfer of information on the location of food resources between unrelated individuals (Information Centre Hypothesis. Using GPS tracking and observations on group movements, we studied the search strategy and information transfer in two of the most colonial seabirds, Guanay cormorants (Phalacrocorax bougainvillii and Peruvian boobies (Sula variegata. Both species breed together and feed on the same prey. They do return to the same feeding zone from one trip to the next indicating high unpredictability in the location of food resources. We found that the Guanay cormorants use social information to select their bearing when departing the colony. They form a raft at the sea surface whose position is continuously adjusted to the bearing of the largest returning columns of cormorants. As such, the raft serves as a compass signal that gives an indication on the location of the food patches. Conversely, Peruvian boobies rely mainly on personal information based on memory to take heading at departure. They search for food patches solitarily or in small groups through network foraging by detecting the white plumage of congeners visible at long distance. Our results show that information transfer does occur and we propose a new mechanism of information transfer based on the use of rafts off colonies. The use of rafts for information transfer may be common in central place foraging colonial seabirds that exploit short lasting and/or unpredictably distributed food patches. Over the past decades Guanay cormorants have declined ten times whereas Peruvian boobies have remained relatively stable. We suggest that the decline of the cormorants could be related to reduced social information opportunities and that social behaviour and search strategies have the potential to play an important role in the population dynamics of colonial animals.

  11. Monitoring polycyclic aromatic hydrocarbon pollution in the marine environment after the Prestige oil spill by means of seabird blood analysis.

    Science.gov (United States)

    Pérez, Cristóbal; Velando, Alberto; Munilla, Ignacio; López-Alonso, Marta; Oro, Daniel

    2008-02-01

    In this study we tested the use of seabird blood as a bioindicator of polycyclic aromatic hydrocarbon (PAH) pollution in the marine environment. Blood cells of breeding yellow-legged gulls (Larus michahellis) were able to track spatial and temporal changes consistent with the massive oil pollution pulse that resulted from the Prestige oil spill. Thus, in 2004, blood samples from yellow-legged gulls breeding in colonies that were in the trajectory of the spill doubled in theirtotal PAH concentrations when compared to samples from unoiled colonies. Furthermore, PAH levels in gulls from an oiled colony decreased by nearly a third in two consecutive breeding seasons (2004 and 2005). Experimental evidence was gathered by means of an oil-ingestion field experiment. The total concentration of PAHs in the blood of gulls given oil supplements was 30% higher compared to controls. This strongly suggested that measures of PAHs in the blood of gulls are sensitive to the ingestion of small quantities of oil. Our study provides evidence that seabirds were exposed to residual Prestige oil 17 months after the spill commenced and gives support to the nondestructive use of seabirds as biomonitors of oil pollution in marine environments.

  12. UNUSUAL BREEDING BY SEABIRDS AT MARION ISLAND ...

    African Journals Online (AJOL)

    In 1997/98, breeding at subantarctic Marion Island was exceptionally good for five species of seabirds capable of foraging over wide areas and for a tern. The number of king penguin Aptenodytes patagonicus chicks surviving to the start of spring in 1997 was considerably more than previously recorded. Greater numbers of ...

  13. Care of oiled seabirds: A veterinary perspective

    International Nuclear Information System (INIS)

    Tseng, F.S.

    1993-01-01

    The primary effects of oil contamination on seabirds include hypothermia, dehydration, gastrointestinal problems, pneumonia, and hemolytic anemia. Other direct effects include skin and corneal irritation as well as an impact on reproductive organs. Secondary problem related to prolonged captive husbandry include various infectious diseases, pododermatitis, joint swellings, and keel lesions. Current methods of prevention and treatment of these effects, including nutritional support, are presented

  14. Differential effects of a local industrial sand lance fishery on seabird breeding performance

    DEFF Research Database (Denmark)

    Frederiksen, M.; Jensen, Henrik; Daunt, F.

    2008-01-01

    fluctuations. We evaluated the effects of an industrial sand lance (Ammodytes marinus) fishery off the North Sea coast of the United Kingdom, which has been opened and closed in a quasi-experimental fashion, on sand-lance-dependent breeding seabirds. Controlling for environmental variation ( sea surface...... tridactyla), but not for four diving species. Analyzing Kittiwake data from 12 colonies inside and outside the closure zone in a replicated before-after control impact design, we again found that breeding productivity was significantly depressed in the closure zone when the fishery was active, whereas...

  15. Differential effects of a local industrial sand lance fishery on seabird breeding performance

    DEFF Research Database (Denmark)

    Frederiksen, M.; Jensen, Henrik; Daunt, F.

    2008-01-01

    fluctuations. We evaluated the effects of an industrial sand lance (Ammodytes marinus) fishery off the North Sea coast of the United Kingdom, which has been opened and closed in a quasi-experimental fashion, on sand-lance-dependent breeding seabirds. Controlling for environmental variation ( sea surface...... or to the fact that only one study colony in the control zone was exposed to high fishery effort within the typical foraging range of Kittiwakes during the breeding season. The strong impact on Kittiwakes, but not on diving species, could result from ( 1) inherently high sensitivity to reduced prey availability...

  16. Threat of plastic pollution to seabirds is global, pervasive, and increasing

    Science.gov (United States)

    Wilcox, Chris; Van Sebille, Erik; Hardesty, Britta Denise

    2015-01-01

    Plastic pollution in the ocean is a global concern; concentrations reach 580,000 pieces per km2 and production is increasing exponentially. Although a large number of empirical studies provide emerging evidence of impacts to wildlife, there has been little systematic assessment of risk. We performed a spatial risk analysis using predicted debris distributions and ranges for 186 seabird species to model debris exposure. We adjusted the model using published data on plastic ingestion by seabirds. Eighty of 135 (59%) species with studies reported in the literature between 1962 and 2012 had ingested plastic, and, within those studies, on average 29% of individuals had plastic in their gut. Standardizing the data for time and species, we estimate the ingestion rate would reach 90% of individuals if these studies were conducted today. Using these results from the literature, we tuned our risk model and were able to capture 71% of the variation in plastic ingestion based on a model including exposure, time, study method, and body size. We used this tuned model to predict risk across seabird species at the global scale. The highest area of expected impact occurs at the Southern Ocean boundary in the Tasman Sea between Australia and New Zealand, which contrasts with previous work identifying this area as having low anthropogenic pressures and concentrations of marine debris. We predict that plastics ingestion is increasing in seabirds, that it will reach 99% of all species by 2050, and that effective waste management can reduce this threat. PMID:26324886

  17. Threat of plastic pollution to seabirds is global, pervasive, and increasing.

    Science.gov (United States)

    Wilcox, Chris; Van Sebille, Erik; Hardesty, Britta Denise

    2015-09-22

    Plastic pollution in the ocean is a global concern; concentrations reach 580,000 pieces per km(2) and production is increasing exponentially. Although a large number of empirical studies provide emerging evidence of impacts to wildlife, there has been little systematic assessment of risk. We performed a spatial risk analysis using predicted debris distributions and ranges for 186 seabird species to model debris exposure. We adjusted the model using published data on plastic ingestion by seabirds. Eighty of 135 (59%) species with studies reported in the literature between 1962 and 2012 had ingested plastic, and, within those studies, on average 29% of individuals had plastic in their gut. Standardizing the data for time and species, we estimate the ingestion rate would reach 90% of individuals if these studies were conducted today. Using these results from the literature, we tuned our risk model and were able to capture 71% of the variation in plastic ingestion based on a model including exposure, time, study method, and body size. We used this tuned model to predict risk across seabird species at the global scale. The highest area of expected impact occurs at the Southern Ocean boundary in the Tasman Sea between Australia and New Zealand, which contrasts with previous work identifying this area as having low anthropogenic pressures and concentrations of marine debris. We predict that plastics ingestion is increasing in seabirds, that it will reach 99% of all species by 2050, and that effective waste management can reduce this threat.

  18. Semivarying coefficient models for capture-recapture data: colony size estimation for the little penguin Eudyptula minor.

    Science.gov (United States)

    Stoklosa, Jakub; Dann, Peter; Huggins, Richard

    2014-09-01

    To accommodate seasonal effects that change from year to year into models for the size of an open population we consider a time-varying coefficient model. We fit this model to a capture-recapture data set collected on the little penguin Eudyptula minor in south-eastern Australia over a 25 year period using Jolly-Seber type estimators and nonparametric P-spline techniques. The time-varying coefficient model identified strong changes in the seasonal pattern across the years which we further examined using functional data analysis techniques. To evaluate the methodology we also conducted several simulation studies that incorporate seasonal variation. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Regionalizing indicators for marine ecosystems: Bering Sea–Aleutian Island seabirds, climate, and competitors

    Science.gov (United States)

    Sydeman, William J.; Thompson, Sarah Ann; Piatt, John F.; García-Reyes, Marisol; Zador, Stephani; Williams, Jeffrey C.; Romano, Marc; Renner, Heather

    2017-01-01

    Seabirds are thought to be reliable, real-time indicators of forage fish availability and the climatic and biotic factors affecting pelagic food webs in marine ecosystems. In this study, we tested the hypothesis that temporal trends and interannual variability in seabird indicators reflect simultaneously occurring bottom-up (climatic) and competitor (pink salmon) forcing of food webs. To test this hypothesis, we derived multivariate seabird indicators for the Bering Sea–Aleutian Island (BSAI) ecosystem and related them to physical and biological conditions known to affect pelagic food webs in the ecosystem. We examined covariance in the breeding biology of congeneric pelagic gulls (kittiwakes Rissa tridactyla and R. brevirostris) andauks (murres Uria aalge and U. lomvia), all of whichare abundant and well-studiedinthe BSAI. At the large ecosystem scale, kittiwake and murre breeding success and phenology (hatch dates) covaried among congeners, so data could be combined using multivariate techniques, but patterns of responsedifferedsubstantially betweenthe genera.Whiledata fromall sites (n = 5)inthe ecosystemcould be combined, the south eastern Bering Sea shelf colonies (St. George, St. Paul, and Cape Peirce) provided the strongest loadings on indicators, and hence had the strongest influence on modes of variability. The kittiwake breeding success mode of variability, dominated by biennial variation, was significantly related to both climatic factors and potential competitor interactions. The murre indicator mode was interannual and only weakly related to the climatic factors measured. The kittiwake phenology indicator mode of variability showed multi-year periods (“stanzas”) of late or early breeding, while the murre phenology indicator showed a trend towards earlier timing. Ocean climate relationships with the kittiwake breeding success indicator suggestthat early-season (winter–spring) environmental conditions and the abundance of pink salmon affect the

  20. Predation threats to the Red-billed Tropicbird breeding colony of Saba: focus on cats

    NARCIS (Netherlands)

    Debrot, A.O.; Ruijter, M.; Endarwin, W.; Hooft, van P.; Wulf, K.

    2014-01-01

    Feral domestic cats (Felis catus) are recognized as one of the most devastating alien predator species in the world and are a major threat to nesting colonies of the Red-billed Tropicbird (Phaethon aethereus), on Saba island, Dutch Caribbean. Cats and rats are both known to impact nesting seabirds

  1. Adding the ocean to the study of seabirds: A brief history of at-sea seabird research

    Science.gov (United States)

    Ainley, David G.; Ribic, Christine A.; Woehler, Eric J.

    2012-01-01

    We review the history of how research directed towards marine ornithology has led to an appreciation of seabirds as highly specialized marine organisms. Beginning with R. C. Murphy (Pacific), V. C. Wynne-Edwards (Atlantic), and associates in the early 1900s, the research approach grew from an emphasis on seabird single-species ecology to an appreciation of interacting species assemblages and finally to seabirds being considered as important components of marine food webs. After a slow, drawn-out beginning, the initial main impetus for developing the field was a need to map seabird abundance and distribution tied to understanding impacts of continental shelf resource exploitation. Coalescing during the 1970s to 1980s to facilitate this line of research were 6 factors: (1) ability to identify birds at sea; (2) standardization of techniques to quantify abundance; (3) resources and techniques for mapping; (4) appreciation of how scale affects seabird relationships to hydrographic features and patchy prey; (5) development of computing power and appropriate statistics; and (6) seabird biologists becoming embedded in, as well as organizing, multidisciplinary marine research projects. Future advances in understanding the role of seabirds in marine food webs will be made by seabird biologists participating in multidisciplinary projects using grid-like surveys relative to oceanographic features in combination with instrumentation that reveals the finer details of seabird foraging behaviors.

  2. GPS-tracking and colony observations reveal variation in offshore habitat use and foraging ecology of breeding Sandwich Terns

    Science.gov (United States)

    Fijn, R. C.; de Jong, J.; Courtens, W.; Verstraete, H.; Stienen, E. W. M.; Poot, M. J. M.

    2017-09-01

    Breeding success of seabirds critically depends on their foraging success offshore. However, studies combining at-sea tracking and visual provisioning observations are scarce, especially for smaller species of seabirds. This study is the first in which breeding Sandwich Terns were tracked with GPS-loggers to collect detailed data on foraging habitat use in four breeding seasons. The maximum home range of individual Sandwich Terns comprised approximately 1900 km2 and the average foraging range was 27 km. Trip durations were on average 135 min with average trip lengths of 67 km. Actual foraging behaviour comprised 35% of the time budget of a foraging trip. Substantial year-to-year variation was found in habitat use and trip variables, yet with the exception of 2012, home range size remained similar between years. Food availability, chick age and environmental conditions are proposed as the main driving factors between inter- and intra-annual variations in trip variables. Our multi-method approach also provided geo-referenced information on prey presence and we conclude that future combining of colony observations and GPS-loggers deployments can potentially provide a near complete insight into the feeding ecology of breeding Sandwich Terns, including the behaviour of birds at sea.

  3. Foraging areas, offshore habitat use, and colony overlap by incubating Leach's storm-petrels Oceanodroma leucorhoa in the Northwest Atlantic.

    Directory of Open Access Journals (Sweden)

    April Hedd

    Full Text Available Despite their importance in marine food webs, much has yet to be learned about the spatial ecology of small seabirds. This includes the Leach's storm-petrel Oceanodroma leucorhoa, a species that is declining throughout its Northwest Atlantic breeding range. In 2013 and 2014, we used global location sensors to track foraging movements of incubating storm-petrels from 7 eastern Canadian breeding colonies. We determined and compared the foraging trip and at-sea habitat characteristics, analysed spatial overlap among colonies, and determined whether colony foraging ranges intersected with offshore oil and gas operations. Individuals tracked during the incubation period made 4.0 ± 1.4 day foraging trips, travelling to highly pelagic waters over and beyond continental slopes which ranged, on average, 400 to 830 km from colonies. Cumulative travel distances ranged from ~900 to 2,100 km among colonies. While colony size did not influence foraging trip characteristics or the size of areas used at sea, foraging distances tended to be shorter for individuals breeding at the southern end of the range. Core areas did not overlap considerably among colonies, and individuals from all sites except Kent Island in the Bay of Fundy foraged over waters with median depths > 1,950 m and average chlorophyll a concentrations ≤ 0.6 mg/m3. Sea surface temperatures within colony core areas varied considerably (11-23°C, coincident with the birds' use of cold waters of the Labrador Current or warmer waters of the Gulf Stream Current. Offshore oil and gas operations intersected with the foraging ranges of 5 of 7 colonies. Three of these, including Baccalieu Island, Newfoundland, which supports the species' largest population, have experienced substantial declines in the last few decades. Future work should prioritize modelling efforts to incorporate information on relative predation risk at colonies, spatially explicit risks at-sea on the breeding and wintering grounds

  4. A changing distribution of seabirds in South Africa – the possible impact of climate and its consequences

    Directory of Open Access Journals (Sweden)

    Robert James Minchin Crawford

    2015-02-01

    Full Text Available In the southern Benguela ecosystem off South Africa, there were recent shifts to the south and east in the distributions of three forage resources (anchovy, sardine, rock lobster, which probably were influenced by environmental change although fishing too may have played a part. In this study, we review information on trends in distributions and numbers of eight seabirds breeding in South Africa. For five species that feed predominantly on anchovy, sardine or rock lobster, their populations off northwest South Africa decreased markedly. For three of these species, which exhibit behavioural inertia and have restricted foraging ranges when breeding (African penguin, Cape cormorant, bank cormorant, there were large decreases in their overall populations in South Africa. Conversely, for two showing more plasticity and able to range over wide areas or move between breeding localities (Cape gannet, swift tern there were increases. It is thought that movement of forage resources away from the northern islands led to a mismatch in the distributions of breeding localities and prey of dependent seabirds off western South Africa and to attempts by several species to establish colonies on the southern mainland closer to food resources. There also were shifts to the south and east in the distributions of three seabirds that do not compete with fisheries for prey (crowned cormorant, white-breasted cormorant, kelp gull, suggesting some environmental forcing, but decreases of these species off northwest South Africa were less severe and populations in South Africa remained stable or increased in the long term. It is likely, because many fishing plants are located in the northwest, that there was increased competition between seabirds and fisheries for prey as forage resources moved south and east. Potential interventions to mitigate the adverse impacts of distributional changes for seabirds include allocations of allowable catches of shared forage resources at

  5. Recovery of seabirds following the Exxon Valdez oil spill: An overview

    International Nuclear Information System (INIS)

    Wiens, J.A.

    1995-01-01

    Following the Exxon Valdez oilspill in March 1989, over 35,000 dead birds were retrieved. Model analyses suggested that actual seabird mortality could have been in the hundreds of thousands, prompting concerns about severe and persistent impacts on populations of several species, especially murres (Uria spp.). Recovery for some populations was projected to take decades. The findings of several studies conducted following the oil spill, however, indicate that these concerns may not be justified. These studies examined colony attendance and reproduction of murres as well as habitat utilization for the prevalent species in Prince William Sound and along the Kenai Peninsula. Surveys of attendance by birds at murre breeding colonies in 1991 indicated no overall differences from prespill attendance levels when colonies were grouped by the degree of oiling in the vicinity. At a large colony in the Barren Islands, where damage was described as especially severe, counts of murres were generally similar to historical estimates made in the late 1970s. In 1990 and 1991, murres breeding at the Barren Islands colony also produced young at levels that were within the range of natural (prespill) variation for this site. Incidental observations indicated that several other species reproduced successfully in oiled areas in Prince William Sound and along the Kenai Peninsula following the spill. 161 refs., 2 figs., 2 tabs

  6. Ingested plastic in a diving seabird, the thick-billed murre (Uria lomvia), in the eastern Canadian Arctic.

    Science.gov (United States)

    Provencher, Jennifer F; Gaston, Anthony J; Mallory, Mark L; O'hara, Patrick D; Gilchrist, H Grant

    2010-09-01

    Plastic debris has become ubiquitous in the marine environment and seabirds may ingest debris which can have deleterious effects on their health. In the North Atlantic Ocean, surface feeding seabirds typically ingest high levels of plastic, while the diving auks which feed in the water column typically have much lower levels. We examined 186 thick-billed murres from five colonies in the eastern Canadian Arctic for ingested plastic debris. Approximately 11% of the birds had at least one piece of plastic debris in their gastrointestinal tracts, with debris dominated by user plastics. This is the first report of ingested plastics in an auk species in Canada's Arctic, and the highest incidence of plastic ingestion to date for thick-billed murres (Uria lomvia). Copyright 2010 Elsevier Ltd. All rights reserved.

  7. Colonial Institutions

    DEFF Research Database (Denmark)

    McAtackney, Laura; Palmer, Russell

    2016-01-01

    and the USA which reveal that the study of colonial institutions should not be limited to the functional life of these institutions—or solely those that take the form of monumental architecture—but should include the long shadow of “imperial debris” (Stoler 2008) and immaterial institutions....

  8. Growth Mechanism of Microbial Colonies

    Science.gov (United States)

    Zhu, Minhui; Martini, K. Michael; Kim, Neil H.; Sherer, Nicholas; Lee, Jia Gloria; Kuhlman, Thomas; Goldenfeld, Nigel

    Experiments on nutrient-limited E. coli colonies, growing on agar gel from single cells reveal a power-law distribution of sizes, both during the growth process and in the final stage when growth has ceased. We developed a Python simulation to study the growth mechanism of the bacterial population and thus understand the broad details of the experimental findings. The simulation takes into account nutrient uptake, metabolic function, growth and cell division. Bacteria are modeled in two dimensions as hard circle-capped cylinders with steric interactions and elastic stress dependent growth characteristics. Nutrient is able to diffuse within and between the colonies. The mechanism of microbial colony growth involves reproduction of cells within the colonies and the merging of different colonies. We report results on the dynamic scaling laws and final state size distribution, that capture in semi-quantitative detail the trends observed in experiment. Supported by NSF Grant 0822613.

  9. Contrasted structuring effects of mesoscale features on the seabird community in the Mozambique Channel

    Science.gov (United States)

    Jaquemet, S.; Ternon, J. F.; Kaehler, S.; Thiebot, J. B.; Dyer, B.; Bemanaja, E.; Marteau, C.; Le Corre, M.

    2014-02-01

    of mescoscale features in structuring the tropical seabird community in the Mozambique Channel, in addition to segregating tropical and non-tropical species. The mechanisms underlying the segregation of tropical seabirds seem to partially differ from that of other tropical regions, and this may be a consequence of the strong local mesoscale activity, affecting prey size and availability schemes. Beyond characterising the foraging habitats of the seabird community of the Mozambique Channel, this study highlights the importance of this region as a hot spot for seabirds; especially the southern part, where several endangered sub-Antarctic species over-winter.

  10. Colony Dimorphism in Bradyrhizobium Strains

    Science.gov (United States)

    Sylvester-Bradley, Rosemary; Thornton, Philip; Jones, Peter

    1988-01-01

    Ten isolates of Bradyrhizobium spp. which form two colony types were studied; the isolates originated from a range of legume species. The two colony types differed in the amount of gum formed or size or both, depending on the strain. Whole 7-day-old colonies of each type were subcultured to determine the proportion of cells which had changed to the other type. An iterative computerized procedure was used to determine the rate of switching per generation between the two types and to predict proportions reached at equilibrium for each strain. The predicted proportions of the wetter (more gummy) or larger colony type at equilibrium differed significantly between strains, ranging from 0.9999 (strain CIAT 2383) to 0.0216 (strain CIAT 2469), because some strains switched faster from dry to wet (or small to large) and others switched faster from wet to dry (or large to small). Predicted equilibrium was reached after about 140 generations in strain USDA 76. In all but one strain (CIAT 3030) the growth rate of the wetter colony type was greater than or similar to that of the drier type. The mean difference in generation time between the two colony types was 0.37 h. Doubling times calculated for either colony type after 7 days of growth on the agar surface ranged from 6.0 to 7.3 h. The formation of two persistent colony types by one strain (clonal or colony dimorphism) may be a common phenomenon among Bradyrhizobium strains. Images PMID:16347599

  11. Corticosterone and foraging behavior in a diving seabird: the Adélie penguin, Pygoscelis adeliae.

    Science.gov (United States)

    Angelier, Frédéric; Bost, Charles-André; Giraudeau, Mathieu; Bouteloup, Guillaume; Dano, Stéphanie; Chastel, Olivier

    2008-03-01

    Because hormones mediate physiological or behavioral responses to intrinsic or extrinsic stimuli, they can help us understand how animals adapt their foraging decisions to energetic demands of reproduction. Thus, the hormone corticosterone deserves specific attention because of its influence on metabolism, food intake and locomotor activities. We examined the relationships between baseline corticosterone levels and foraging behavior or mass gain at sea in a diving seabird, the Adélie penguin, Pygoscelis adeliae. Data were obtained from free-ranging penguins during the brooding period (Adélie Land, Antarctica) by using satellite transmitters and time-depth-recorders. The birds were weighed and blood sampled before and after a foraging trip (pre-trip and post-trip corticosterone levels, respectively). Penguins with elevated pre-trip corticosterone levels spent less time at sea and stayed closer to the colony than penguins with low pre-trip corticosterone levels. These short trips were associated with a higher foraging effort in terms of diving activity and a lower mass gain at sea than long trips. According to previous studies conducted on seabird species, these results suggest that penguins with elevated pre-trip corticosterone levels might maximize the rate of energy delivery to the chicks at the expense of their body reserves. Moreover, in all birds, corticosterone levels were lower post-foraging than pre-foraging. This decrease could result from either the restoration of body reserves during the foraging trip or from a break in activity at the end of the foraging trip. This study demonstrates for the first time in a diving predator the close relationships linking foraging behavior and baseline corticosterone levels. We suggest that slight elevations in pre-trip corticosterone levels could play a major role in breeding effort by facilitating foraging activity in breeding seabirds.

  12. The evolution of seabirds in the Humboldt Current: new clues from the Pliocene of Central Chile.

    Directory of Open Access Journals (Sweden)

    Martín Chávez Hoffmeister

    Full Text Available During the last decade, new Neogene fossil assemblages from South America have revealed important clues about the evolution of seabird faunas in one of the major upwelling systems of the world: the Humboldt Current. However, most of this record comes from arid Northern Chile and Southern Peru and, in consequence, our knowledge of the evolutionary history of seabirds in the temperate transitional zone is negligible. A new Late Pliocene assemblage of fossil birds from the coastal locality of Horcon in Central Chile offers a unique opportunity to fill this gap.Isolated bones of a medium-sized penguin are the most abundant bird remains. Morphological and cladistic analyses reveal that these specimens represent a new species of crested penguin, Eudyptes calauina sp. nov. Eudyptes is a penguin genus that inhabit temperate and subantarctic regions and currently absent in central Chile. Additionally, a partial skeleton of a small species of cormorant and a partial tarsometatarsus of a sooty shearwater have been identified.The Horcon fossils suggest the existence of a mixed avifauna in central Chile during the Pliocene in concordance with the latitudinal thermal gradient. This resembles the current assemblages from the transitional zone, with the presence of species shared with Northern Chile and Southern Peru and a previously unrecorded penguin currently absent from the Humboldt System but present in the Magellanic region. Comparison of Pliocene seabird diversity across the Pacific coast of South America shows that the Horcon avifauna represents a distinctive assemblage linking the living faunas with the Late Miocene ones. A comparison with the fossil record near the Benguela Current (west coast of southern Africa suggests that the thermic gradient could play an important role in the preservation of a higher diversity of cold/temperate seabirds in the Humboldt Current.

  13. Periodic matrix models for seasonal dynamics of structured populations with application to a seabird population.

    Science.gov (United States)

    Cushing, J M; Henson, Shandelle M

    2018-02-03

    For structured populations with an annual breeding season, life-stage interactions and behavioral tactics may occur on a faster time scale than that of population dynamics. Motivated by recent field studies of the effect of rising sea surface temperature (SST) on within-breeding-season behaviors in colonial seabirds, we formulate and analyze a general class of discrete-time matrix models designed to account for changes in behavioral tactics within the breeding season and their dynamic consequences at the population level across breeding seasons. As a specific example, we focus on egg cannibalism and the daily reproductive synchrony observed in seabirds. Using the model, we investigate circumstances under which these life history tactics can be beneficial or non-beneficial at the population level in light of the expected continued rise in SST. Using bifurcation theoretic techniques, we study the nature of non-extinction, seasonal cycles as a function of environmental resource availability as they are created upon destabilization of the extinction state. Of particular interest are backward bifurcations in that they typically create strong Allee effects in population models which, in turn, lead to the benefit of possible (initial condition dependent) survival in adverse environments. We find that positive density effects (component Allee effects) due to increased adult survival from cannibalism and the propensity of females to synchronize daily egg laying can produce a strong Allee effect due to a backward bifurcation.

  14. Effects of oil and oil burn residues on seabird feathers

    DEFF Research Database (Denmark)

    Fritt-Rasmussen, Janne; Linnebjerg, Jannie Fries; Sørensen, Martin X.

    2016-01-01

    It is well known, that in case of oil spill, seabirds are among the groups of animals most vulnerable. Even small amounts of oil can have lethal effects by destroying the waterproofing of their plumage, leading to loss of insulation and buoyancy. In the Arctic these impacts are intensified....... To protect seabirds, a rapid removal of oil is crucial and in situ burning could be an efficient method. In the present work exposure effects of oil and burn residue in different doses was studied on seabird feathers from legally hunted Common eider (Somateria mollissima) by examining changes in total weight...... of the feather and damages on the microstructure (Amalgamation Index) of the feathers before and after exposure. The results of the experiments indicate that burn residues from in situ burning of an oil spill have similar or larger fouling and damaging effects on seabird feathers, as compared to fresh oil....

  15. Seabird tissue archival and monitoring project: Egg collections and analytical results 1999-2002

    Science.gov (United States)

    Vander Pol, Stacy S.; Christopher, Steven J.; Roseneau, David G.; Becker, Paul R.; Day, Russel D.; Kucklick, John R.; Pugh, Rebecca S.; Simac, Kristin S.; Weston-York, Geoff

    2003-01-01

    In 1998, the U.S. Geological Survey Biological Resources Division (USGS-BRD), the U.S. Fish and Wildlife Service (USFWS) Alaska Maritime National Wildlife Refuge (AMNWR), and the National Institute of Standards and Technology (NIST) began the Seabird Tissue Archival and Monitoring Project (STAMP) to collect and cryogenically bank tissues from seabirds in Alaska for future retrospective analysis of anthropogenic contaminants. The approach of STAMP was similar to that of the Alaska Marine Mammal Tissue Archival Project (AMMTAP). AMMTAP was started in 1987 by NIST and the National Oceanic and Atmospheric Administration (NOAA) as part of the Outer Continental Shelf Environmental Assessment Program sponsored by the Minerals Management Service. Presently sponsored by the USGS-BRD, AMMTAP continues its work as part of a larger national program, the Marine Mammal Health and Stranding Response Program. AMMTAP developed carefully designed sampling and specimen banking protocols. Since 1987, AMMTAP has collected tissues from marine mammals taken in Alaska Native subsistence hunts and has cryogenically banked these tissues at the NIST National Biomonitoring Specimen Bank (NBSB). Through its own analytical work and working in partnership with other researchers both within and outside Alaska, AMMTAP has helped to develop a substantial database on contaminants in Alaska marine mammals. In contrast, data and information is limited on contaminants in Alaska seabirds, which are similar to marine mammals in that they feed near the top of the food chain and have the potential for accumulating anthropogenic contaminants. During its early planning stages, STAMP managers identified the seabird egg as the first tissue of choice for study by the project. There is a relatively long history of using bird eggs for environmental monitoring and for investigating the health status of bird populations. Since 1998, protocols for collecting and processing eggs, and cryogenically banking egg samples

  16. Spatial variation in age structure among colonies of a marine snake: the influence of ectothermy.

    Science.gov (United States)

    Bonnet, Xavier; Brischoux, François; Pinaud, David; Michel, Catherine Louise; Clobert, Jean; Shine, Richard; Fauvel, Thomas

    2015-07-01

    Several tetrapod lineages that have evolved to exploit marine environments (e.g. seals, seabirds, sea kraits) continue to rely upon land for reproduction and, thus, form dense colonies on suitable islands. In birds and mammals (endotherms), the offspring cannot survive without their parents. Terrestrial colonies contain all age classes. In reptiles (ectotherms), this constraint is relaxed, because offspring are independent from birth. Hence, each age class has the potential to select sites with characteristics that favour them. Our studies of sea snakes (sea kraits) in the lagoon of New Caledonia reveal marked spatial heterogeneity in age structure among colonies. Sea krait colonies exhibit the endothermic 'seal-seabird' pattern (mixed-age classes within populations) only where the lagoon is narrow. Where the lagoon is wide, most snake colonies are comprised primarily of a single age cohort. Nurseries are located near the coast, adult colonies offshore and mixed colonies in-between. We suggest that ectothermy allows individuals to utilize habitats that are best suited to their own ecological requirements, a flexibility not available to endothermic marine taxa with obligate parental care. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

  17. Seabirds and marine plastic debris in the northeastern Atlantic: A synthesis and recommendations for monitoring and research.

    Science.gov (United States)

    O'Hanlon, Nina J; James, Neil A; Masden, Elizabeth A; Bond, Alexander L

    2017-12-01

    Marine plastic pollution is an increasing, and global, environmental issue. Numerous marine species are affected by plastic debris through entanglement, nest incorporation, and ingestion, which can lead to lethal and sub-lethal impacts. However, in the northeastern Atlantic Ocean, an area of international importance for seabirds, there has been little effort to date to assess information from studies of wildlife and plastic to better understand the spatiotemporal variation of how marine plastic affects different seabird species. To improve our understanding of seabirds and marine plastic in this region, we completed a synthesis of the published and grey literature to obtain information on all known documented cases of plastic ingestion and nest incorporation by this group. We found that of 69 seabird species that commonly occur in the northeastern Atlantic, 25 had evidence of ingesting plastic. However, data on plastic ingestion was available for only 49% of all species, with 74% of investigated species recorded ingesting plastic. We found only three published studies on nest incorporation, for the Northern Gannet (Morus bassanus) and Black-legged Kittiwake (Rissa tridactyla). For many species, sample sizes were small or not reported, and only 39% of studies were from the 21st century, whilst information from multiple countries and years was only available for 11 species. This indicates that we actually know very little about the current prevalence of plastic ingestion and nest incorporation for many species, several of them globally threatened. Furthermore, in the majority of studies, the metrics reported were inadequate to carry out robust comparisons among locations and species or perform meta-analyses. We recommend multi-jurisdictional collaboration to obtain a more comprehensive and current understanding of how marine plastic is affecting seabirds in the northeastern Atlantic Ocean. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  18. Population Change in a Marine Bird Colony is Driven By Changes in Recruitment

    Directory of Open Access Journals (Sweden)

    Anthony J. Gaston

    2011-12-01

    Full Text Available The population dynamics of long-lived birds are thought to be very sensitive to changes in adult survival. However, where natal philopatry is low, recruitment from the larger metapopulation may have the strongest effect on population growth rate even in long-lived species. Here, we illustrate such a situation where changes in a seabird colony size appeared to be the consequence of changes in recruitment. We studied the population dynamics of a declining colony of Ancient Murrelets (Synthliboramphus antiquus at East Limestone Island, British Columbia. During 1990-2010, Ancient Murrelet chicks were trapped at East Limestone Island while departing to sea, using a standard trapping method carried on throughout the departure period. Adult murrelets were trapped while departing from the colony during 1990-2003. Numbers of chicks trapped declined during 1990-1995, probably because of raccoon predation, increased slightly from 1995-2000 and subsequently declined again. Reproductive success was 30% lower during 2000-2003 than in earlier years, mainly because of an increase in desertions. The proportion of nonbreeders among adult birds trapped at night also declined over the study period. Mortality of adult birds, thought to be mainly prebreeders, from predators more than doubled over the same period. Apparent adult survival of breeders remained constant during 1991-2002 once the first year after banding was excluded, but the apparent survival rates in the first year after banding fell and the survival of birds banded as chicks to age three halved over the same period. A matrix model of population dynamics suggested that even during the early part of the study immigration from other breeding areas must have been substantial, supporting earlier observations that natal philopatry in this species is low. The general colony decline after 2000 probably was related to diminished recruitment, as evidenced by the lower proportion of nonbreeders in the trapped

  19. AFSC/REFM: Seabird food habits dataset of the North Pacific

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The seabird food habits dataset contains information on the stomach contents from seabird specimens that were collected under salvage and scientific collection...

  20. Environmental Predictors of Seabird Wrecks in a Tropical Coastal Area.

    Directory of Open Access Journals (Sweden)

    Davi Castro Tavares

    Full Text Available Beached bird surveys have been widely used to monitor the impact of oil pollution in the oceans. However, separating the combined effects of oil pollution, environmental variables and methodological aspects of beach monitoring on seabird stranding patterns is a challenging task. The effects of a comprehensive set of oceanographic and climatic variables and oil pollution on seabird strandings in a tropical area of Brazil were investigated herein, using two robust and innovative methods: Generalized Linear Mixed Models and Structural Equation Modeling. We assessed strandings of four resident seabird species along 480 km of beaches divided into 11 sampling areas, between November 2010 and September 2013. We found that increasing the distance from the nearest breeding island reduce the seabird stranding events. Storm activity and biological productivity were the most important factors affecting the stranding events of brown boobies Sula leucogaster, Cabot's terns Thalasseus acuflavidus and kelp gulls Larus dominicanus. These species are also indirectly affected by warm tropical waters, which reduce chlorophyll-a concentrations. Beach surveys are, thus, useful to investigate the mortality rates of resident species near breeding sites, where individuals are more abundant and exposed to local factors associated with at-sea mortality. In contrast, conservation actions and monitoring programs for far-ranging seabird species are needed in more distant foraging areas. Furthermore, beach monitoring programs investigating the impact of oil pollution on seabirds need to account for the effects of environmental factors on stranding patterns. The present study also demonstrated that seabirds inhabiting tropical coastal waters are sensitive to climate conditions such as adverse weather, which are expected to increase in frequency and intensity in next decades.

  1. Water masses, ocean fronts, and the structure of Antarctic seabird communities: putting the eastern Bellingshausen Sea in perspective

    Science.gov (United States)

    Ribic, Christine A.; Ainley, David G.; Ford, R. Glenn; Fraser, William R.; Tynan, Cynthia T.; Woehler, Eric J.

    2015-01-01

    dominated by Adélie penguins, a Low Antarctic group dominated by petrels, and a Subantarctic group dominated by albatross were evident. In eastern Bellingshausen waters during summer, groups were inconsistent. With regard to frontal features, Antarctic-wide in winter, distance to the ice edge was an important explanatory factor for nine of 14 species, distance to the Antarctic Polar Front for six species and distance to the Shelf Break Front for six species; however, these Antarctic-wide models could not successfully predict spatial relationships of winter seabird density (individual species or total) and biomass in the eastern Bellingshausen. Antarctic-wide in summer, distance to land/Antarctic continent was important for 10 of 18 species, not a surprising result for these summer-time Antarctic breeders, as colonies are associated with ice-free areas of coastal land. Distance to the Shelf Break Front was important for 8 and distance to the southern boundary of the ACC was important for 7 species. These summer models were more successful in predicting eastern Bellingshausen species density and species diversity but failed to predict total seabird density or biomass. Antarctic seabirds appear to respond to fronts in a way similar to that observed along the well-studied upwelling front of the California Current. To understand fully the seabird patterns found in this synthesis, multi-disciplinary at-sea investigations, including a quantified prey field, are needed.

  2. Sexual Size Dimorphism and Body Condition in the Australasian Gannet.

    Directory of Open Access Journals (Sweden)

    Lauren P Angel

    Full Text Available Sexual size dimorphism is widespread throughout seabird taxa and several drivers leading to its evolution have been hypothesised. While the Australasian Gannet (Morus serrator has previously been considered nominally monomorphic, recent studies have documented sexual segregation in diet and foraging areas, traits often associated with size dimorphism. The present study investigated the sex differences in body mass and structural size of this species at two colonies (Pope's Eye, PE; Point Danger, PD in northern Bass Strait, south-eastern Australia. Females were found to be 3.1% and 7.3% heavier (2.74 ± 0.03, n = 92; 2.67 ± 0.03 kg, n = 43 than males (2.66 ± 0.03, n = 92; 2.48 ± 0.03 kg, n = 43 at PE and PD, respectively. Females were also larger in wing ulna length (0.8% both colonies but smaller in bill depth (PE: 2.2%; PD: 1.7% than males. Despite this dimorphism, a discriminant function provided only mild accuracy in determining sex. A similar degree of dimorphism was also found within breeding pairs, however assortative mating was not apparent at either colony (R2 < 0.04. Using hydrogen isotope dilution, a body condition index was developed from morphometrics to estimate total body fat (TBF stores, where TBF(% = 24.43+1.94*(body mass/wing ulna length - 0.58*tarsus length (r2 = 0.84, n = 15. This index was used to estimate body composition in all sampled individuals. There was no significant difference in TBF(% between the sexes for any stage of breeding or in any year of the study at either colony suggesting that, despite a greater body mass, females were not in a better condition than males. While the driving mechanism for sexual dimorphism in this species is currently unknown, studies of other Sulids indicate segregation in foraging behaviour, habitat and diet may be a contributing factor.

  3. Estimating Regions of Oceanographic Importance for Seabirds Using A-Spatial Data.

    Directory of Open Access Journals (Sweden)

    Grant Richard Woodrow Humphries

    Full Text Available Advances in GPS tracking technologies have allowed for rapid assessment of important oceanographic regions for seabirds. This allows us to understand seabird distributions, and the characteristics which determine the success of populations. In many cases, quality GPS tracking data may not be available; however, long term population monitoring data may exist. In this study, a method to infer important oceanographic regions for seabirds will be presented using breeding sooty shearwaters as a case study. This method combines a popular machine learning algorithm (generalized boosted regression modeling, geographic information systems, long-term ecological data and open access oceanographic datasets. Time series of chick size and harvest index data derived from a long term dataset of Maori 'muttonbirder' diaries were obtained and used as response variables in a gridded spatial model. It was found that areas of the sub-Antarctic water region best capture the variation in the chick size data. Oceanographic features including wind speed and charnock (a derived variable representing ocean surface roughness came out as top predictor variables in these models. Previously collected GPS data demonstrates that these regions are used as "flyways" by sooty shearwaters during the breeding season. It is therefore likely that wind speeds in these flyways affect the ability of sooty shearwaters to provision for their chicks due to changes in flight dynamics. This approach was designed to utilize machine learning methodology but can also be implemented with other statistical algorithms. Furthermore, these methods can be applied to any long term time series of population data to identify important regions for a species of interest.

  4. 50 CFR Table 19 to Part 679 - Seabird Avoidance Gear Codes

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Seabird Avoidance Gear Codes 19 Table 19... ALASKA Pt. 679, Table 19 Table 19 to Part 679—Seabird Avoidance Gear Codes VESSEL LOGBOOK CODE SEABIRD AVOIDANCE GEAR OR METHOD. 1 Paired Streamer Lines: Used during deployment of hook-and-line gear to prevent...

  5. Contrasted patterns of age-specific reproduction in long-lived seabirds.

    Science.gov (United States)

    Berman, M; Gaillard, J-M; Weimerskirch, H

    2009-01-22

    While the number of studies providing evidence of actuarial senescence is increasing, and covers a wide range of taxa, the process of reproductive senescence remains poorly understood. In fact, quite high reproductive output until the last years of life has been reported in several vertebrate species, so that whether or not reproductive senescence is widespread remains unknown. We compared age-specific changes of reproductive parameters between two closely related species of long-lived seabirds: the small-sized snow petrel Pagodroma nivea, and the medium-sized southern fulmar Fulmarus glacialoides. Both are sympatric in Antarctica. We used an exceptional dataset collected over more than 40 years to assess age-specific variations of both breeding probability and breeding success. We found contrasted age-specific reproductive patterns between the two species. Reproductive senescence clearly occurred from 21 years of age onwards in the southern fulmar, in both breeding probability and success, whereas we did not report any decline in the breeding success of the snow petrel, although a very late decrease in the proportion of breeders occurred at 34 years. Such a contrasted age-specific reproductive pattern was rather unexpected. Differences in life history including size or migratory behaviour are the most likely candidates to account for the difference we reported in reproductive senescence between these sympatric seabird species.

  6. Molecular evidence for gender differences in the migratory behaviour of a small seabird.

    Directory of Open Access Journals (Sweden)

    Renata J Medeiros

    Full Text Available Molecular sexing revealed an unexpectedly strong female bias in the sex ratio of pre-breeding European Storm Petrels (Hydrobates pelagicus, attracted to playback of conspecific calls during their northwards migration past SW Europe. This bias was consistent across seven years, ranging from 80.8% to 89.7% female (mean annual sex ratio ± SD = 85.5% female ±4.1%. The sex ratio did not differ significantly from unity (i.e., 50% female among (i Storm Petrel chicks at a breeding colony in NW France, (ii adults found dead on beaches in Southern Portugal, (iii breeding birds attending nest burrows in the UK, captured by hand, and (iv adults captured near a breeding colony in the UK using copies of the same sound recordings as used in Southern Europe, indicating that females are not inherently more strongly attracted to playback calls than males. A morphological discriminant function analysis failed to provide a good separation of the sexes, showing the importance of molecular sexing for this species. We found no sex difference in the seasonal or nocturnal timing of migration past Southern Europe, but there was a significant tendency for birds to be caught in sex-specific aggregations. The preponderance of females captured in Southern Europe suggests that the sexes may differ in migration route or in their colony-prospecting behaviour during migration, at sites far away from their natal colonies. Such differences in migration behaviour between males and females are poorly understood but have implications for the vulnerability of seabirds to pollution and environmental change at sea during the non-breeding season.

  7. Seasonal Variation in Parental Care Drives Sex-Specific Foraging by a Monomorphic Seabird.

    Science.gov (United States)

    Burke, Chantelle M; Montevecchi, William A; Regular, Paul M

    2015-01-01

    Evidence of sex-specific foraging in monomorphic seabirds is increasing though the underlying mechanisms remain poorly understood. We investigate differential parental care as a mechanism for sex-specific foraging in monomorphic Common Murres (Uria aalge), where the male parent alone provisions the chick after colony departure. Using a combination of geolocation-immersion loggers and stable isotopes, we assess two hypotheses: the reproductive role specialization hypothesis and the energetic constraint hypothesis. We compare the foraging behavior of females (n = 15) and males (n = 9) during bi-parental at the colony, post-fledging male-only parental care and winter when parental care is absent. As predicted by the reproductive role specialization hypothesis, we found evidence of sex-specific foraging during post-fledging only, the stage with the greatest divergence in parental care roles. Single-parenting males spent almost twice as much time diving per day and foraged at lower quality prey patches relative to independent females. This implies a potential energetic constraint for males during the estimated 62.8 ± 8.9 days of offspring dependence at sea. Contrary to the predictions of the energetic constraint hypothesis, we found no evidence of sex-specific foraging during biparental care, suggesting that male parents did not forage for their own benefit before colony departure in anticipation of post-fledging energy constraints. We hypothesize that unpredictable prey conditions at Newfoundland colonies in recent years may limit male parental ability to allocate additional time and energy to self-feeding during biparental care, without compromising chick survival. Our findings support differential parental care as a mechanism for sex-specific foraging in monomorphic murres, and highlight the need to consider ecological context in the interpretation of sex-specific foraging behavior.

  8. Seasonal Variation in Parental Care Drives Sex-Specific Foraging by a Monomorphic Seabird.

    Directory of Open Access Journals (Sweden)

    Chantelle M Burke

    Full Text Available Evidence of sex-specific foraging in monomorphic seabirds is increasing though the underlying mechanisms remain poorly understood. We investigate differential parental care as a mechanism for sex-specific foraging in monomorphic Common Murres (Uria aalge, where the male parent alone provisions the chick after colony departure. Using a combination of geolocation-immersion loggers and stable isotopes, we assess two hypotheses: the reproductive role specialization hypothesis and the energetic constraint hypothesis. We compare the foraging behavior of females (n = 15 and males (n = 9 during bi-parental at the colony, post-fledging male-only parental care and winter when parental care is absent. As predicted by the reproductive role specialization hypothesis, we found evidence of sex-specific foraging during post-fledging only, the stage with the greatest divergence in parental care roles. Single-parenting males spent almost twice as much time diving per day and foraged at lower quality prey patches relative to independent females. This implies a potential energetic constraint for males during the estimated 62.8 ± 8.9 days of offspring dependence at sea. Contrary to the predictions of the energetic constraint hypothesis, we found no evidence of sex-specific foraging during biparental care, suggesting that male parents did not forage for their own benefit before colony departure in anticipation of post-fledging energy constraints. We hypothesize that unpredictable prey conditions at Newfoundland colonies in recent years may limit male parental ability to allocate additional time and energy to self-feeding during biparental care, without compromising chick survival. Our findings support differential parental care as a mechanism for sex-specific foraging in monomorphic murres, and highlight the need to consider ecological context in the interpretation of sex-specific foraging behavior.

  9. Using stable isotopes of nitrogen and carbon to study seabird ecology: applications in the Mediterranean seabird community

    Directory of Open Access Journals (Sweden)

    Manuela G. Forero

    2003-07-01

    Full Text Available The application of the stable isotope technique to ecological studies is becoming increasingly widespread. In the case of seabirds, stable isotopes of nitrogen and carbon have been mainly used as dietary tracers. This approach relieson the fact that food web isotopic signatures are reflected in the tissues of the consumer. In addition to the study of trophic ecology, stable isotopes have been used to track the movement of seabirds across isotopic gradients, as individuals moving between isotopically distinct foodwebs can carry with them information on the location of previous feeding areas. Studies applying the stable isotope methodology to the study of seabird ecology show a clear evolution from broad and descriptive approaches to detailed and individual-based analyses. The purpose of this article is to show the different fields of application of stable isotopes to the study of the seabird ecology. Finally, we illustrate the utility of this technique by considering the particularities of the Mediterranean seabird community, suggesting different ecological questions and conservation problems that could be addressed by using the stable isotope approach in this community.

  10. Seabird biomass and food consumption in the North Sea

    Energy Technology Data Exchange (ETDEWEB)

    Furness, R.W.

    1984-07-01

    Calculations presented by Bourne contain some order-of-magnitude errors, and give the misleading impression that estimates of fish consumption by seabirds in the North Sea may be as low as 0.25%, or as high as 48%, of fish production, depending on the method of calculation. It is likely that the true figure is closer to 20% once the errors in Bourne's calculations are corrected, but several areas of uncertainty require further study; particularly seabird diets and foraging ranges, fish distribution and movements. Studies from other parts of the world show that seabird numbers can dramatically alter in response to changes in food abundance. Some changes result from natural perturbations and others from effects of overexploitation of fish stocks by man. Effects of overfishing seem likely to be potentially, at least as serious, as effects of oil or chemical pollution in many regions, possibly including the North Sea. 48 references.

  11. Rock coasts and seabird breeding sites : a common optimization

    Science.gov (United States)

    Marie, Eveillard-Buchoux

    2014-05-01

    The North-West coasts of Europe support a lot of part of Northern hemisphere breeding seabirds. In that context, Scotland has a preponderant place and Brittany has southernmost limit of these species areas, for most of them. Outside the breeding season these species live mainly on the open sea and when they do visit the land to breed, they nest on a specific sites : almost all the time they breed on the rock coasts, often on seacliffs. This specific habitat are defines by geomorphological characteristics which offer special forms of the coast. The forms of rock coasts are originally and different because of several proprieties of geology, of lithology, of structures. Breeding seabird, occupying these sites, reveals, in a new light, the richness of these forms and the originals geographic location of the coastline : seabirds prefer nest in exposed coastline like rock caps, rocky points or islands. Seabirds and rock coasts are research topics in environmental geography since several years. However, these combination studies is a new approach in this field and enlargement in the heritage field allows supplement scientific approach. For example, it show that in most important touristic sites, environmental protection measures focused on landscape, habitat or bird, but much more rarely on rock coasts for these intrinsic values. Indeed, in Brittany or in Scotland, seabirds are often stars species in lot of coastal nature reserves, where they're considered like greater ecological heritage. We could see it in touristic promotion field : bird is everywhere, cliff is mostly kept in the dark, as well in leaflets as in speech visitor's guides - without, for example, as a part of this landscape. In all cases, combination of these two heritages is extremely rare. Yet, this current research illustrates the interest and the issue of development of this comparative approach seabirds / rock coasts for optimization of nature tourism and geotourism.

  12. Effects of food stress on survival and reproductive performance of seabirds

    Science.gov (United States)

    Piatt, John F.; Kitaysky, Sasha

    2001-01-01

    Traditional field methods of assessing effects of fluctuations in food supply on the survival and reproductive performance of seabirds may give equivocal results. In this project we applied an additional tool: The measure of stress hormones in free-ranging seabirds. Food stress can be quantified by measuring base levels of stress hormones such as corticosterone in the blood of seabirds, or the rise in blood levels of corticosterone in response to a standardized stressor: capture, handling and restraint. We applied these techniques to seabirds breeding in Lower Cook Inlet and also used captive birds for controlled experiments. This study provided a unique opportunity for a concurrent field and captive study of the behavioral and physiological consequences of stress in seabirds. Moreover, this study provides the basis for management of seabird populations in the areas affected by the Exxon Valdez oil spill, which will have broader applications for seabird monitoring programs. This year represents production of a synthesis of the project.

  13. Seabird feathers as monitors of the levels and persistence of heavy metal pollution after the Prestige oil spill

    International Nuclear Information System (INIS)

    Moreno, Rocio; Jover, Lluis; Diez, Carmen; Sanpera, Carola

    2011-01-01

    We measured heavy metal concentrations in yellow-legged gulls (n = 196) and European shags (n = 189) in order to assess the temporal pattern of contaminant exposure following the Prestige oil spill in November 2002. We analysed Pb, Cu, Zn, Cr, Ni and V levels in chick feathers sampled at four colonies during seven post-spill years (2003-2009), and compared results with pre-spill levels obtained from feathers of juvenile shag corpses (grown in spring/summer 2002). Following the Prestige wreck, Cu (4.3-10 μg g -1 ) and Pb concentrations (1.0-1.4 μg g -1 ) were, respectively, between two and five times higher than pre-spill levels (1.5-3.6 and 0.1-0.4 μg g -1 ), but returned to previous background concentrations after three years. Our study highlights the suitability of chick feathers of seabirds for assessing the impact of oil spills on heavy metal contamination, and provides the best evidence to date on the persistence of oil pollution after the Prestige incident. - Highlights: → Seabirds as sentinel species of levels and persistence of heavy metal pollution after oil spills. → Pb, Cu, Zn, Cr, Ni, V in chick feathers of Phalacrocorax aristotelis and Larus michahellis. → Chronic oil pollution in the marine food web for at least three years after the Prestige oil spill. - Monitoring heavy metal in seabird feathers indicated chronic oil pollution in the marine food web for at least three years after the Prestige oil spill.

  14. Synchrony in the life-history parameters of different seabirds ...

    African Journals Online (AJOL)

    spamer

    Southern Ocean may elucidate how climatic perturbations operating at a global scale impact seabirds in the region. ... Marine & Coastal Management, Department of Environmental Affairs and Tourism, Private Bag ..... (Harris 1979), dark-rumped petrel Pterodroma phae- ... later were significantly negatively related before the.

  15. Seabird bycatch in the demersal longline fishery off southern Africa ...

    African Journals Online (AJOL)

    Differences in catch rates between trips were investigated and moon phase, area and gear type were all found to be significant. All birds were caught using light gear, which sank significantly slower than heavier gear. The South African hake longline fishery has a relatively small impact on pelagic seabird populations ...

  16. conserving surface-nesting seabirds at the prince edward islands

    African Journals Online (AJOL)

    South Africa's subantarctic Prince Edward Islands support substantial proportions of the global populations of a number of surface-nesting seabirds. Populations of most of these have decreased at the islands since the 1980s and 12 of 16 species are regarded as Threatened or Near Threatened regionally or internationally.

  17. Offshore Seabird Distributions during Summer and Autumn at West Greenland

    DEFF Research Database (Denmark)

    Boertmann, D.; Mosbech, A.

    . During the autumn the numbers of seabirds increase as migrants from local and international populations of mainly thick-billed murre and little auk arrive to spend the winter in West Greenland waters. Huge concentrations of thick-billed murres, common eiders and king-eiders may occur then...

  18. Review of the rescue, rehabilitation and restoration of oiled seabirds ...

    African Journals Online (AJOL)

    Review of the rescue, rehabilitation and restoration of oiled seabirds in South Africa, especially African penguins Spheniscus demersus and Cape gannets Morus capensis , 1983–2005. ... In addition, oiling has a long-term negative impact on the breeding productivity and cost of reproduction in de-oiled birds. The primary ...

  19. Effects of oil and oil burn residues on seabird feathers

    DEFF Research Database (Denmark)

    Fritt-Rasmussen, Janne; Linnebjerg, Jannie Fries; Sørensen, Martin X.

    2016-01-01

    It is well known, that in case of oil spill, seabirds are among the groups of animals most vulnerable. Even small amounts of oil can have lethal effects by destroying the waterproofing of their plumage, leading to loss of insulation and buoyancy. In the Arctic these impacts are intensified...

  20. 50 CFR 665.815 - Pelagic longline seabird mitigation measures.

    Science.gov (United States)

    2010-10-01

    ... stern of the vessel; (ii) The mainline and branch lines must be set from the port or the starboard side... (v) Feathers are dry. (9) Any seabird that is released in accordance with paragraph (b)(8) of this... immediately upon the vessel's return to port. Do not give the bird food or water; and (11) Complete the short...

  1. Spatial variogram estimation from temporally aggregated seabird count data

    NARCIS (Netherlands)

    Perez-Lapena, Blanca; Wijnberg, Kathelijne Mariken; Stein, A.; Hulscher, Suzanne J.M.H.

    2013-01-01

    Seabird abundance is an important indicator for assessing impact of human activities on the marine environment. However, data collection at sea is time consuming and surveys are carried out over several consecutive days for efficiency reasons. This study investigates the validity of aggregating

  2. Monitoring Seabirds and Marine Mammals by Georeferenced Aerial Photography

    Science.gov (United States)

    Kemper, G.; Weidauer, A.; Coppack, T.

    2016-06-01

    to distinguish biological from non-biological signals. Each detected seabird or marine mammal signal is identified to species level or assigned to a species group and automatically saved into a geo-database for subsequent quality assurance, geo-statistical analyses and data export to third-party users. The relative size of a detected object can be accurately measured which provides key information for species-identification. During the development and testing of this system until 2015, more than 40 surveys have produced around 500.000 digital aerial images, of which some were taken in specially protected areas (SPA) of the Baltic Sea and thus include a wide range of relevant species. Here, we present the technical principles of this comparatively new survey approach and discuss the key methodological challenges related to optimizing survey design and workflow in view of the pending regulatory requirements for effective environmental impact assessments.

  3. MONITORING SEABIRDS AND MARINE MAMMALS BY GEOREFERENCED AERIAL PHOTOGRAPHY

    Directory of Open Access Journals (Sweden)

    G. Kemper

    2016-06-01

    purpose-programmed software to distinguish biological from non-biological signals. Each detected seabird or marine mammal signal is identified to species level or assigned to a species group and automatically saved into a geo-database for subsequent quality assurance, geo-statistical analyses and data export to third-party users. The relative size of a detected object can be accurately measured which provides key information for species-identification. During the development and testing of this system until 2015, more than 40 surveys have produced around 500.000 digital aerial images, of which some were taken in specially protected areas (SPA of the Baltic Sea and thus include a wide range of relevant species. Here, we present the technical principles of this comparatively new survey approach and discuss the key methodological challenges related to optimizing survey design and workflow in view of the pending regulatory requirements for effective environmental impact assessments.

  4. Sampling design considerations for demographic studies: a case of colonial seabirds

    Science.gov (United States)

    Kendall, William L.; Converse, Sarah J.; Doherty, Paul F.; Naughton, Maura B.; Anders, Angela; Hines, James E.; Flint, Elizabeth

    2009-01-01

    For the purposes of making many informed conservation decisions, the main goal for data collection is to assess population status and allow prediction of the consequences of candidate management actions. Reducing the bias and variance of estimates of population parameters reduces uncertainty in population status and projections, thereby reducing the overall uncertainty under which a population manager must make a decision. In capture-recapture studies, imperfect detection of individuals, unobservable life-history states, local movement outside study areas, and tag loss can cause bias or precision problems with estimates of population parameters. Furthermore, excessive disturbance to individuals during capture?recapture sampling may be of concern because disturbance may have demographic consequences. We address these problems using as an example a monitoring program for Black-footed Albatross (Phoebastria nigripes) and Laysan Albatross (Phoebastria immutabilis) nesting populations in the northwestern Hawaiian Islands. To mitigate these estimation problems, we describe a synergistic combination of sampling design and modeling approaches. Solutions include multiple capture periods per season and multistate, robust design statistical models, dead recoveries and incidental observations, telemetry and data loggers, buffer areas around study plots to neutralize the effect of local movements outside study plots, and double banding and statistical models that account for band loss. We also present a variation on the robust capture?recapture design and a corresponding statistical model that minimizes disturbance to individuals. For the albatross case study, this less invasive robust design was more time efficient and, when used in combination with a traditional robust design, reduced the standard error of detection probability by 14% with only two hours of additional effort in the field. These field techniques and associated modeling approaches are applicable to studies of most taxa being marked and in some cases have individually been applied to studies of birds, fish, herpetofauna, and mammals.

  5. Attendance of scavenging seabirds at trawler discards off Galicia, Spain

    Directory of Open Access Journals (Sweden)

    Julio Valeiras

    2003-07-01

    Full Text Available The occurrence of scavenger seabirds at fishing trawlers was studied off Galicia, Spain. A total of 9,368 seabirds of 23 species were recorded during 92 fishing operations in 1998 and 1999. The most common species were the yellow-legged and lesser black-backed gull (Larus cachinnans and L. fuscus, Sabine´s gull (L. sabini, the northern gannet (Morus bassanus, the great shearwater (Puffinus gravis, sooty shearwater (P. griseus, the Manx and Balearic shearwater (P. puffinus and P. mauretanicus, the great skua (Catharacta skua and terns (mainly Sterna hirundo and S. paradisaea. Other species occurred in small numbers: Leach´s petrel (Oceanodroma leucorhoa, the storm petrel (Hydrobates pelagicus, the little shearwater (Puffinus assimilis, Cory´s shearwater (Calonectris diomedea, the parasitic skua (Stercorarius parasiticus, the pomarine skua (S. pomarinus, the black-headed gull (Larus ridibundus, the glaucous gull (L. hyperboreus, the kittiwake (Rissa tridactyla, the sandwich tern (Sterna sandvicensis, the black tern (Chlidonias niger, the guillemot (Uria aalge and the little auk (Alle alle. The maximum number of seabirds recorded at a haul was 320. The maximum number of a particular species ranged from 120 great shearwaters to 250 yellow-legged/lesser black-backed gulls during a single haul. The differences in ship-follower species abundance are related to migratory movements but fisheries could also have a strong influence at a smaller scale on the distribution of seabirds off Galicia. The degree to which seabirds rely on fishery discards as food was not quantified, but may be important for several species.

  6. Seabird eggs as bioindicators of chemical contamination in Chile

    Energy Technology Data Exchange (ETDEWEB)

    Cifuentes, Jacqueline Munoz; Becker, Peter H.; Sommer, Ute; Pacheco, Patricia; Schlatter, Roberto

    2003-11-01

    Seabird eggs are proposed as biomonitors of chemical contamination in Chile. - Seabird eggs were used as bioindicators of chemical contamination in Chile. Brown-hooded Gull (Larus maculipennis), Kelp Gull (Larus dominicanus), Trudeau's Tern (Sterna trudeaui), Neotropic Cormorant (Phalacrocorax brasilianus), and Pink-footed Shearwater (Puffinus creatopus) eggs were sampled at different breeding sites during the 1990s. Mercury and organochlorines (PCBs, DDT, HCB, HCH, and PCP) were quantified to reveal the interspecific differences, spatial and temporal trends in contamination levels. Trudeau's Tern displayed the highest levels of mercury (486 ng g{sup -1} wet weight). The highest {sigma}DDT concentrations were measured in Brown-hooded Gulls (726 ng g{sup -1}). PCB levels were similar among the species (102-236 ng g{sup -1}), but the composition of the PCB mixture was different in Pink-footed Shearwaters. With the exception of the Brown-hooded Gull, all species studied presented similar and low levels of organochlorines ({sigma}OHa). Residues of PCB and related compounds were not detected in any of the seabird eggs analyzed in Chile. Geographical variation was low, although levels of industrial chemicals were slightly higher in eggs from Concepcion Bay, and agricultural chemicals in eggs from Valdivia. Also interannual variation was low, but some evidence was found of decreasing levels in gull eggs throughout the time of the study. The causes of the low levels and small variability in space and time of environmental chemicals in Chilean seabirds are discussed. We propose the use of seabirds in future monitoring of the development of chemical contamination in Chile.

  7. Seabird eggs as bioindicators of chemical contamination in Chile

    International Nuclear Information System (INIS)

    Cifuentes, Jacqueline Munoz; Becker, Peter H.; Sommer, Ute; Pacheco, Patricia; Schlatter, Roberto

    2003-01-01

    Seabird eggs are proposed as biomonitors of chemical contamination in Chile. - Seabird eggs were used as bioindicators of chemical contamination in Chile. Brown-hooded Gull (Larus maculipennis), Kelp Gull (Larus dominicanus), Trudeau's Tern (Sterna trudeaui), Neotropic Cormorant (Phalacrocorax brasilianus), and Pink-footed Shearwater (Puffinus creatopus) eggs were sampled at different breeding sites during the 1990s. Mercury and organochlorines (PCBs, DDT, HCB, HCH, and PCP) were quantified to reveal the interspecific differences, spatial and temporal trends in contamination levels. Trudeau's Tern displayed the highest levels of mercury (486 ng g -1 wet weight). The highest ΣDDT concentrations were measured in Brown-hooded Gulls (726 ng g -1 ). PCB levels were similar among the species (102-236 ng g -1 ), but the composition of the PCB mixture was different in Pink-footed Shearwaters. With the exception of the Brown-hooded Gull, all species studied presented similar and low levels of organochlorines (ΣOHa). Residues of PCB and related compounds were not detected in any of the seabird eggs analyzed in Chile. Geographical variation was low, although levels of industrial chemicals were slightly higher in eggs from Concepcion Bay, and agricultural chemicals in eggs from Valdivia. Also interannual variation was low, but some evidence was found of decreasing levels in gull eggs throughout the time of the study. The causes of the low levels and small variability in space and time of environmental chemicals in Chilean seabirds are discussed. We propose the use of seabirds in future monitoring of the development of chemical contamination in Chile

  8. On colonial grounds

    NARCIS (Netherlands)

    Dommelen, Peter Alexander René van

    1998-01-01

    As a study of the colonial situations of first millennium BC Sardinia, this book is as much an investigation into colonialism as a sociological category, as it explores the specific historical conditions of a particular region. Taking a fresh look at colonialism in Mediterranean archaeology from a

  9. An epidemiological model of viral infections in a Varroa-infested bee colony: the case of a bee-dependent mite population size

    OpenAIRE

    Bernardi, Sara; Venturino, Ezio

    2016-01-01

    In recent years the spread of the ectoparasitic mite Varroa destructor has become the most serious threat to worldwide apiculture. In the model presented here we extend the bee population dynamics with mite viral epidemiology examined in an earlier paper by allowing a bee-dependent mite population size. The results of the analysis match field observations well and give a clear explanation of how Varroa affects the epidemiology of certain naturally occurring bee viruses, causing considerable d...

  10. Early Developmental Program Shapes Colony Morphology in Bacteria

    Directory of Open Access Journals (Sweden)

    Gideon Mamou

    2016-03-01

    Full Text Available When grown on a solid surface, bacteria form highly organized colonies, yet little is known about the earliest stages of colony establishment. Following Bacillus subtilis colony development from a single progenitor cell, a sequence of highly ordered spatiotemporal events was revealed. Colony was initiated by the formation of leading-cell chains, deriving from the colony center and extending in multiple directions, typically in a “Y-shaped” structure. By eradicating particular cells during these early stages, we could influence the shape of the resulting colony and demonstrate that Y-arm extension defines colony size. A mutant in ymdB encoding a phosphodiesterase displayed unordered developmental patterns, indicating a role in guiding these initial events. Finally, we provide evidence that intercellular nanotubes contribute to proper colony formation. In summary, we reveal a “construction plan” for building a colony and provide the initial molecular basis for this process.

  11. Potential benefits and shortcomings of marine protected areas for small seabirds revealed using miniature tags

    Directory of Open Access Journals (Sweden)

    Sara M Maxwell

    2016-12-01

    Full Text Available Marine protected areas are considered important tools for protecting marine biodiversity, and animal tracking is a key way to determine if boundaries are effectively placed for protection of key marine species, including seabirds. We tracked chick-rearing brown noddies (Anous stolidus from the Dry Tortugas National Park in Florida USA in 2016 using 1.8 g Nanofix GPS tags (n = 10, making this the first time this species has ever been tracked. We determined movement parameters, such as flight speed, distance traveled and home range, and how birds used a complex of marine protected areas including the Dry Tortugas National Park which is largely no-take (i.e., no fishing or extraction permitted, and the Florida Keys National Marine Sanctuary, of which two Ecological Reserves totaling 517.9 km2 are no-take. Birds remained largely within marine protected areas, with 91.3% of birds’ locations and 58.8% of the birds’ total home range occurring within the MPAs, and 79.2% of birds’ locations and 18.2% of the birds’ total home range within no-take areas. However areas of probable foraging, indicated by locations where birds had high-residence time, were found within one of the MPAs only 64.7% of the time, and only 6.7% of those locations were in no-take areas. Birds traveled a mean straight line distance from the colony of 37.5 km, primarily using the region to the southwest of the colony where the shelf break and Loop Current occur. High-residence-time locations were found in areas of significantly higher sea surface temperature and closer to the shelf break than low residency locations. A sea surface temperature front occurs near the shelf edge, likely indicative of where Sargassum seaweed is entrained, providing habitat for forage species. Much of this region, however, falls outside the boundaries of the marine protected areas, and brown noddies and other species breeding in the Dry Tortugas may interact with fisheries via resource competition

  12. Nocturnal Foraging by Red-Legged Kittiwakes, a Surface Feeding Seabird That Relies on Deep Water Prey During Reproduction.

    Science.gov (United States)

    Kokubun, Nobuo; Yamamoto, Takashi; Kikuchi, Dale M; Kitaysky, Alexander; Takahashi, Akinori

    2015-01-01

    Narrow foraging specialization may increase the vulnerability of marine predators to climate change. The red-legged kittiwake (Rissa brevirostris) is endemic to the Bering Sea and has experienced drastic population fluctuations in recent decades, presumably due to climate-driven changes in food resources. Red-legged kittiwakes are presumed to be a nocturnal surface-foraging seabird that feed almost entirely on deep water Myctophidae fishes. However, there is little empirical evidence confirming their nocturnal foraging activity during the breeding season. This study investigated the foraging behavior of red-legged kittiwakes by combining GPS tracking, accelerometry, and dietary analyses at the world's largest breeding colony of red-legged kittiwakes on St. George I. GPS tracking of 5 individuals revealed that 82.5% of non-flight behavior (including foraging and resting) occurred over the ocean basin (bottom depth >1,000 m). Acceleration data from 4 birds showed three types of behaviors during foraging trips: (1) flight, characterized by regular wing flapping, (2) resting on water, characterized by non-active behavior, and (3) foraging, when wing flapping was irregular. The proportions of both foraging and resting behaviors were higher at night (14.1 ± 7.1% and 20.8 ± 14.3%) compared to those during the day (6.5 ± 3.0% and 1.7 ± 2.7%). The mean duration of foraging (2.4 ± 2.9 min) was shorter than that of flight between prey patches (24.2 ± 53.1 min). Dietary analyses confirmed myctophids as the dominant prey (100% by occurrence and 98.4 ± 2.4% by wet-weight). Although the sample size was limited, these results suggest that breeding red-legged kittiwakes concentrated their foraging on myctophids available at the surface during nighttime in deep water regions. We propose that the diel patterns and ephemeral nature of their foraging activity reflected the availability of myctophids. Such foraging specialization may exacerbate the vulnerability of red

  13. Nocturnal Foraging by Red-Legged Kittiwakes, a Surface Feeding Seabird That Relies on Deep Water Prey During Reproduction.

    Directory of Open Access Journals (Sweden)

    Nobuo Kokubun

    Full Text Available Narrow foraging specialization may increase the vulnerability of marine predators to climate change. The red-legged kittiwake (Rissa brevirostris is endemic to the Bering Sea and has experienced drastic population fluctuations in recent decades, presumably due to climate-driven changes in food resources. Red-legged kittiwakes are presumed to be a nocturnal surface-foraging seabird that feed almost entirely on deep water Myctophidae fishes. However, there is little empirical evidence confirming their nocturnal foraging activity during the breeding season. This study investigated the foraging behavior of red-legged kittiwakes by combining GPS tracking, accelerometry, and dietary analyses at the world's largest breeding colony of red-legged kittiwakes on St. George I. GPS tracking of 5 individuals revealed that 82.5% of non-flight behavior (including foraging and resting occurred over the ocean basin (bottom depth >1,000 m. Acceleration data from 4 birds showed three types of behaviors during foraging trips: (1 flight, characterized by regular wing flapping, (2 resting on water, characterized by non-active behavior, and (3 foraging, when wing flapping was irregular. The proportions of both foraging and resting behaviors were higher at night (14.1 ± 7.1% and 20.8 ± 14.3% compared to those during the day (6.5 ± 3.0% and 1.7 ± 2.7%. The mean duration of foraging (2.4 ± 2.9 min was shorter than that of flight between prey patches (24.2 ± 53.1 min. Dietary analyses confirmed myctophids as the dominant prey (100% by occurrence and 98.4 ± 2.4% by wet-weight. Although the sample size was limited, these results suggest that breeding red-legged kittiwakes concentrated their foraging on myctophids available at the surface during nighttime in deep water regions. We propose that the diel patterns and ephemeral nature of their foraging activity reflected the availability of myctophids. Such foraging specialization may exacerbate the vulnerability of red

  14. Feather corticosterone reveals developmental stress in seabirds.

    Science.gov (United States)

    Will, Alexis P; Suzuki, Yuya; Elliott, Kyle H; Hatch, Scott A; Watanuki, Yutaka; Kitaysky, Alexander S

    2014-07-01

    In nest-bound avian offspring, food shortages typically trigger a release of the stress hormone corticosterone (CORT). Recent studies indicate that CORT is passively deposited in the tissue of growing feathers and thus may provide an integrated measure of stress incurred during development in the nest. The current hypothesis predicts that, assuming a constant rate of feather growth, elevated CORT circulating in the blood corresponds to higher levels of CORT in feather tissue, but experimental evidence for nutritionally stressed chicks is lacking. Here, we examined how food limitation affects feather CORT content in the rhinoceros auklet (Cerorhinca moncerata). We (i) used captive chicks reared on control versus restricted diets, and (ii) applied this technique to free-living chicks with unknown nutritional histories that fledged at three separate colonies. We found that (i) feather growth was not affected by experimentally induced nutritional stress; (ii) captive chicks raised on a restricted diet had higher levels of CORT in their primary feathers; (iii) feather CORT deposition is a sensitive method of detecting nutritional stress; and (iv) free-living fledglings from the colony with poor reproductive performance had higher CORT in their primary feathers. We conclude that feather CORT is a sensitive integrated measure revealing the temporal dynamics of food limitations experienced by rhinoceros auklet nestlings. The use of feather CORT may be a powerful endocrine tool in ecological and evolutionary studies of bird species with similar preferential allocation of limited resources to feather development. © 2014. Published by The Company of Biologists Ltd.

  15. Trophic ecology drives contaminant concentrations within a tropical seabird community.

    Science.gov (United States)

    Sebastiano, Manrico; Bustamante, Paco; Eulaers, Igor; Malarvannan, Govindan; Mendez-Fernandez, Paula; Churlaud, Carine; Blévin, Pierre; Hauselmann, Antoine; Covaci, Adrian; Eens, Marcel; Costantini, David; Chastel, Olivier

    2017-08-01

    To support environmental management programs, there is an urgent need to know about the presence and understand the dynamics of major contaminants in seabird communities of key marine ecosystems. In this study, we investigated the concentrations and trophodynamics of trace elements in six seabird species and persistent organic pollutants (POPs) in three seabird species breeding on Grand Connétable Island (French Guiana), an area where the increase in human population and mining activities has raised concerns in recent years. Red blood cell Hg concentrations in adults were the highest in Magnificent frigatebirds Fregata magnificens (median: 5.6 μg g -1 dw; range: 3.8-7.8 μg g -1 dw) and lowest in Sooty terns Onychoprion fuscatus (median: 0.9 μg g -1 dw; range: 0.6-1.1 μg g -1 dw). Among POPs, dichlorodiphenyldichloroethylene (p,p'-DDE) was the most abundant compound in plasma of Cayenne terns Thalasseus sandvicensis (median: 1100 pg g -1 ww; range: 160 ± 5100 pg g -1 ww), while polychlorinated biphenyls (PCBs) were the most abundant compound class in plasma of Magnificent frigatebirds (median: 640 pg g -1 ww; range 330 ± 2700 pg g -1 ww). While low intensity of POP exposure does not appear to pose a health threat to this seabird community, Hg concentration in several adults Laughing gulls Leucophaeus atricilla and Royal terns Thalasseus maximus, and in all Magnificent frigatebirds was similar or higher than that of high contaminated seabird populations. Furthermore, nestling red blood cells also contained Hg concentrations of concern, and further studies should investigate its potential health impact in this seabird community. Differences in adult trophic ecology of the six species explained interspecific variation in exposure to trace element and POPs, while nestling trophic ecology provides indications about the diverse feeding strategies adopted by the six species, with the consequent variation in exposure to contaminants. Copyright

  16. Differential responses of seabirds to environmental variability over 2 years in the continental shelf and oceanic habitats of southeastern Bering Sea

    Science.gov (United States)

    Yamamoto, Takashi; Kokubun, Nobuo; Kikuchi, Dale M.; Sato, Nobuhiko; Takahashi, Akinori; Will, Alexis P.; Kitaysky, Alexander S.; Watanuki, Yutaka

    2016-04-01

    Seasonal sea-ice cover has been decreasing in the southeastern Bering Sea shelf, which might affect ecosystem dynamics and availability of food resources to marine top predators breeding in the region. In this study, we investigated the foraging responses of two seabird species, surface-foraging red-legged kittiwakes Rissa brevirostris (hereafter, RLKI) and pursuit-diving foraging thick-billed murres Uria lomvia (TBMU) to different marine environmental conditions over 2 years. At-sea distributions of RLKI and TBMU breeding on St. George Island, the largest seabird colony in the region, were recorded using GPS loggers, and blood samples were taken to examine their physiological condition and isotopic foraging niche in a given year. Between the study years, winter ice retreated earlier and summer water temperatures were relatively warmer in 2014 compared to those in 2013. RLKI foraging occurred mostly over the oceanic basin in both years. TBMU, however, foraged mostly over the shelf but showed a relatively higher use of the shelf break and oceanic basin in 2013. The foraging distances from the colony peaked at 250-300 km in 2013 and bimodally at 150-250 and 300-350 km in 2014 for RLKI and tended to be farther in 2013 compared to those in 2014 for TBMU. Plasma levels of corticosterone did not differ between the years in RLKI but differed in TBMU, showing higher levels of physiological stress incurred by murres in 2013, the year of relatively cooler sea surface temperatures with later sea-ice retreat. δ13N (a proxy of trophic level of prey) did not differ between the years in either RLKI or TBMU. These results suggest that the response of ecosystem dynamics to climate variability in the southeastern Bering Sea may differ between the ocean basin and continental shelf regions, which, in turn, may generate differential responses in seabirds relying on those habitats for foraging.

  17. Massive Mortality of a Planktivorous Seabird in Response to a Marine Heatwave

    Science.gov (United States)

    Jones, Timothy; Parrish, Julia K.; Peterson, William T.; Bjorkstedt, Eric P.; Bond, Nicholas A.; Ballance, Lisa T.; Bowes, Victoria; Hipfner, J. Mark; Burgess, Hillary K.; Dolliver, Jane E.; Lindquist, Kirsten; Lindsey, Jacqueline; Nevins, Hannahrose M.; Robertson, Roxanne R.; Roletto, Jan; Wilson, Laurie; Joyce, Trevor; Harvey, James

    2018-04-01

    Climate change has exacerbated the occurrence of large-scale sea surface temperature anomalies, or marine heatwaves (MHWs)—extreme phenomena often associated with mass mortality events of marine organisms. Using a combination of citizen science and federal data sets, we investigated the causal mechanisms of the 2014/2015 die-off of Cassin's Auklets (Ptychoramphus aleuticus), a small zooplanktivorous seabird, during the NE Pacific MHW of 2013-2015. Carcass deposition followed an effective reduction in the energy content of mesozooplankton, coincident with the loss of cold-water foraging habitat caused by the intrusion of the NE Pacific MHW into the nearshore environment. Models examining interannual variability in effort-controlled carcass abundance (2001-2014) identified the biomass of lipid-poor zooplankton as the dominant predictor of increased carcass abundance. In 2014, Cassin's Auklets dispersing from colonies in British Columbia likely congregated into a nearshore band of cooler upwelled water and ultimately died from starvation following the shift in zooplankton composition associated with onshore transport of the NE Pacific MHW. For Cassin's Auklets, already in decline due to ocean warming, large-scale and persistent MHWs might represent a global population precipice.

  18. Modeled distribution and abundance of a pelagic seabird reveal trends in relation to fisheries

    Science.gov (United States)

    Renner, Martin; Parrish, Julia K.; Piatt, John F.; Kuletz, Kathy J.; Edwards, Ann E.; Hunt, George L.

    2013-01-01

    The northern fulmar Fulmarus glacialis is one of the most visible and widespread seabirds in the eastern Bering Sea and Aleutian Islands. However, relatively little is known about its abundance, trends, or the factors that shape its distribution. We used a long-term pelagic dataset to model changes in fulmar at-sea distribution and abundance since the mid-1970s. We used an ensemble model, based on a weighted average of generalized additive model (GAM), multivariate adaptive regression splines (MARS), and random forest models to estimate the pelagic distribution and density of fulmars in the waters of the Aleutian Archipelago and Bering Sea. The most important predictor variables were colony effect, sea surface temperature, distribution of fisheries, location, and primary productivity. We calculated a time series from the ratio of observed to predicted values and found that fulmar at-sea abundance declined from the 1970s to the 2000s at a rate of 0.83% (± 0.39% SE) per annum. Interpolating fulmar densities on a spatial grid through time, we found that the center of fulmar distribution in the Bering Sea has shifted north, coinciding with a northward shift in fish catches and a warming ocean. Our study shows that fisheries are an important, but not the only factor, shaping fulmar distribution and abundance trends in the eastern Bering Sea and Aleutian Islands.

  19. Prevalence of blood parasites in seabirds - a review

    Directory of Open Access Journals (Sweden)

    Quillfeldt Petra

    2011-10-01

    Full Text Available Abstract Introduction While blood parasites are common in many birds in the wild, some groups seem to be much less affected. Seabirds, in particular, have often been reported free from blood parasites, even in the presence of potential vectors. Results From a literature review of hemosporidian prevalence in seabirds, we collated a dataset of 60 species, in which at least 15 individuals had been examined. These data were included in phylogenetically controlled statistical analyses of hemosporidian prevalence in relation to ecological and life-history parameters. Haemoproteus parasites were common in frigatebirds and gulls, while Hepatozoon occurred in albatrosses and storm petrels, and Plasmodium mainly in penguins. The prevalence of Haemoproteus showed a geographical signal, being lower in species with distribution towards polar environments. Interspecific differences in Plasmodium prevalence were explained by variables that relate to the exposure to parasites, suggesting that prevalence is higher in burrow nesters with long fledgling periods. Measures of Plasmodium, but not Haemoproteus prevalences were influenced by the method, with PCR-based data resulting in higher prevalence estimates. Conclusions Our analyses suggest that, as in other avian taxa, phylogenetic, ecological and life-history parameters determine the prevalence of hemosporidian parasites in seabirds. We discuss how these relationships should be further explored in future studies.

  20. Effects of oil pollution on seabirds in the northeast Pacific

    International Nuclear Information System (INIS)

    Burger, A.E.; Fry, D.M.

    1993-01-01

    A review is presented of the sources and impacts of oil pollution affecting seabirds in the eastern North Pacific. The numbers and volume of oil spills in this region increased markedly between 1974 and 1989 along with the increasing industrialization of the Pacific Rim coupled with major oil developments such as the Alaska North Slope. Spills that killed significant numbers of seabirds include those of the Exxon Valdez, the Apex Houston, and the Nestucca. Beached bird surveys have demonstrated that small-volume, chronic oil pollution is an ongoing source of mortality in coastal regions. Experiments and models used in the North Pacific show that ocean currents, wind, seabird distribution, and the persistence of oiled carcasses at sea and ashore can all affect the assessments of mortality from major spills. Experimental releases of carcasses and drift blocks at sea indicate that few birds killed by spills are likely to come ashore. Effects of oil on the plumage and physiology of birds include loss of insulation of the bird's feathers and toxic effects of ingested oil (intestinal irritation, anemia, gland enlargement, liver and kidney damage, reproductive failure, and suppression of immunity). The long-term efficiency of rehabilitation programs is assessed and suggestions for future research are made. 99 refs., 2 figs., 3 tabs

  1. Interspecies and spatial trends in polycyclic aromatic hydrocarbons (PAHs) in Atlantic and Mediterranean pelagic seabirds

    International Nuclear Information System (INIS)

    Roscales, Jose L.; Gonzalez-Solis, Jacob; Calabuig, Pascual; Jimenez, Begona

    2011-01-01

    PAHs were analyzed in the liver of 5 species of pelagic seabirds (Procellariiformes) from the northeast Atlantic and the Mediterranean. The main objective was to assess the trophic and geographic trends of PAHs in seabirds to evaluate their suitability as bioindicators of chronic marine pollution by these compounds. Although higher levels of PAHs have been described in the Mediterranean compared to other oceanic regions, we did not find significant spatial patterns and observed only minor effects of the geographic origin on seabird PAHs. However, we found significant higher PAH levels in petrel compared to shearwater species, which could be related to differences in their exploitation of mesopelagic and epipelagic resources, respectively, and the vertical dynamic of PAHs in the water column. Overall, although this study enhances the need of multi-species approaches to show a more comprehensive evaluation of marine pollution, seabirds emerged as poor indicators of pelagic chronic PAH levels. - Highlights: → PAHs in pelagic seabirds show specific inter-species patterns related to trophic ecology. → Geographic origin shows a minor effect over PAH levels in pelagic seabirds. → Pelagic seabirds seem to be poor indicators of chronic PAH levels. - PAH levels in Atlantic and Mediterranean pelagic seabirds show specific inter-species patterns related to trophic ecology but a minor influence of their geographic origin.

  2. Marine wind farms - seabirds, white-tailed eagles, Eurasian eagle-owl and waders. A screening of potential conflict areas; Offshore vindenergianlegg - sjoefugl, havoern, hubro og vadere. En screening av potensielle konfliktomraader

    Energy Technology Data Exchange (ETDEWEB)

    Christensen-Dalsgaard, S.; Lorentsen, S.-H.; Dahl, E.L.; Follestad, A.; Hanssen, F.O.; Systad, G.H.

    2010-06-15

    The objective of the present study was to develop a decision-relevant, large-scale screening tool for areas that may be suitable for the establishment of offshore wind power plants. The surveyed area ranged from the Swedish border in the south (North Sea/Skagerrak) to the northern tip of Andoeya (North Sea). Marine wind farms are a relatively new element in European waters, and at present there have been few investigations carried out to study their short- and long-term environmental effects. While there have been several studies to identify environmental impacts of wind farms in other countries, there is currently only one such study in Norway, on the island of Smoela. So far, four mechanisms have been emphasized with regard to the impact of wind farms on birds: 1) mortality resulting from collisions with wind turbines (tower and wings), 2) avoidance due to interference from installations in operation and from the activity associated with the construction of the windfarm; 3) loss and change of habitat, through habitat degradation and fragmentation, and 4) barrier effects, which may increase the flight distance and increase the birds' energy demands. In this report, we have chosen to use a methodology that was developed to evaluate seabird vulnerability to marine wind farms in German waters. This method provides a species-specific vulnerability index based on nine factors: flight maneuverability, flight altitude, percentage of time flying, nocturnal flight activity, sensitivity towards disturbance by ship/helicopter traffic, flexibility in habitat use, biogeographical population size, adult survival rate and conservation status. Combined with a measure of density or relative proportion of the relevant species in an area, a wind farm sensitivity index (WSI) is created. The WSI can be summed for all species found in the area at different times of the year to give a total WSI for seabirds. The existing data for seabirds in winter and in the breeding season was of

  3. Surveys of murre colony attendance in the northern Gulf of Alaska following the Exxon Valdez oil spill

    International Nuclear Information System (INIS)

    Erikson, D.E.

    1995-01-01

    Field surveys were conducted in July and August 1991 on 32 of the 36 murre (Uria spp.) colonies in the northern Gulf of Alaska to assess colony attendance (number of birds present at a colony) two years after the exxon Valdez oil spill. The surveys focused on murre colonies because murres represented 74% of the recovered seabird carcasses and because it had claimed that there was large-scale mortality of murres, leading to 60% to 70% decreases at some large colonies and population recovery periods of 20 to 70 years. Murres were present at all 32 colonies, and colony attendance estimates were generally similar to those from historical (prespill) surveys, particularly for those colonies in the direct path of the spill, i.e., the Barren Islands and Chiswell islands. Colony attendance levels in 1991 do not support the contention that murre colony attendance in the study area was drastically lower than historical levels. When colonies were grouped according to risk of oil exposure, the mean changes in attendance between 1991 and historical murre surveys did not differ significantly among the groups. Factors that could account for the observed similarity of 1991 and historical murre counts despite the high estimated mortality are (1) overestimation of mortality or (2) replacement of lost breeders through either recruitment of formerly nonbreeding individuals into the breeding population at spill-affected colonies or immigration of murres form nonaffected colonies. The findings of this study suggest that impacts of the Exxon Valdez oil spill on murre colony attendance in the northern Gulf of alaska were relatively short-term. 118 refs., 5 figs., 8 tabs

  4. The co-distribution of seabirds and their juvenile fish prey in Baffin Bay

    DEFF Research Database (Denmark)

    LeBlanc, Mathieu; Mosbech, Anders; Fortier, Louis

    documented. We test the hypothesis that the abundance and biomass of juvenile fish, especially at the sea-ice edge, influence the distribution and composition of the seabird assemblage. Hydroacoustic data were recorded continuously during the CCGS Amundsen GreenEdge 2016 cruise in southern Baffin Bay, using...... cod (Boreogadus saida), the main pelagic forage fish, plays a key role by transferring energy from the zooplankton to the upper trophic levels, including seabirds. The interactions between fish and seabirds at the sea-ice edge, an environment increasingly common in the warming Arctic, are poorly...... a hull-mounted EK60 multi-frequency echosounder. Pelagic nets were deployed to document the fish assemblage and to validate the acoustic echoes. Seabird observations during transit periods and seabird sampling in Greenland waters were completed. This study will provide insights in the predator...

  5. EROD activity and stable isotopes in seabirds to disentangle marine food web contamination after the Prestige oil spill

    International Nuclear Information System (INIS)

    Velando, Alberto; Munilla, Ignacio; Lopez-Alonso, Marta; Freire, Juan; Perez, Cristobal

    2010-01-01

    In this study, we measured via surgical sampling hepatic EROD activity in yellow-legged gulls from oiled and unoiled colonies, 17 months after the Prestige oil spill. We also analyzed stable isotope composition in feathers of the biopsied gulls, in an attempt to monitor oil incorporation into marine food web. We found that yellow-legged gulls in oiled colonies were being exposed to remnant oil as shown by hepatic EROD activity levels. EROD activity was related to feeding habits of individual gulls with apparent consequences on delayed lethality. Capture-recapture analysis of biopsied gulls suggests that the surgery technique did not affect gull survival, giving support to this technique as a monitoring tool for oil exposure assessment. Our study highlights the combination of different veterinary, toxicological and ecological methodologies as a useful approach for the monitoring of exposure to remnant oil after a large oil spill. - Two years after Prestige oil spill, seabirds were exposed to remnant oil related to their feeding habits with consequences on delayed lethality.

  6. EROD activity and stable isotopes in seabirds to disentangle marine food web contamination after the Prestige oil spill

    Energy Technology Data Exchange (ETDEWEB)

    Velando, Alberto, E-mail: avelando@uvigo.e [Departamento de Ecoloxia e Bioloxia Animal, Facultade de Ciencias, Universidade de Vigo, Campus As Lagoas, 36310 Vigo (Spain); Munilla, Ignacio [Departamento de Botanica, Facultade de Farmacia, Universidade de Santiago de Compostela, Santiago de Compostela (Spain); Lopez-Alonso, Marta [Departamento de Patoloxia Animal, Facultade de Veterinaria, Universidade de Santiago de Compostela, Lugo (Spain); Freire, Juan [Grupo de Recursos Marinos y Pesquerias Universidade da Coruna, A Coruna (Spain); Perez, Cristobal [Departamento de Ecoloxia e Bioloxia Animal, Facultade de Ciencias, Universidade de Vigo, Campus As Lagoas, 36310 Vigo (Spain)

    2010-05-15

    In this study, we measured via surgical sampling hepatic EROD activity in yellow-legged gulls from oiled and unoiled colonies, 17 months after the Prestige oil spill. We also analyzed stable isotope composition in feathers of the biopsied gulls, in an attempt to monitor oil incorporation into marine food web. We found that yellow-legged gulls in oiled colonies were being exposed to remnant oil as shown by hepatic EROD activity levels. EROD activity was related to feeding habits of individual gulls with apparent consequences on delayed lethality. Capture-recapture analysis of biopsied gulls suggests that the surgery technique did not affect gull survival, giving support to this technique as a monitoring tool for oil exposure assessment. Our study highlights the combination of different veterinary, toxicological and ecological methodologies as a useful approach for the monitoring of exposure to remnant oil after a large oil spill. - Two years after Prestige oil spill, seabirds were exposed to remnant oil related to their feeding habits with consequences on delayed lethality.

  7. California gull chicks raised near colony edges have elevated stress levels

    Science.gov (United States)

    Herring, Garth; Ackerman, Joshua T.

    2011-01-01

    Coloniality in nesting birds represents an important life history strategy for maximizing reproductive success. Birds nesting near the edge of colonies tend to have lower reproductive success than individuals nesting near colony centers, and offspring of edge-nesting parents may be impaired relative to those of central-nesting parents. We used fecal corticosterone metabolites in California gull chicks (Larus californicus) to examine whether colony size or location within the colony influenced a chick's physiological condition. We found that chicks being raised near colony edges had higher fecal corticosterone metabolite concentrations than chicks raised near colony centers, but that colony size (ranging from 150 to 11,554 nests) had no influence on fecal corticosterone levels. Fecal corticosterone metabolite concentrations also increased with chick age. Our results suggest that similarly aged California gull chicks raised near colony edges may be more physiologically stressed, as indicated by corticosterone metabolites, than chicks raised near colony centers.

  8. Experimental Study for Automatic Colony Counting System Based Onimage Processing

    Science.gov (United States)

    Fang, Junlong; Li, Wenzhe; Wang, Guoxin

    Colony counting in many colony experiments is detected by manual method at present, therefore it is difficult for man to execute the method quickly and accurately .A new automatic colony counting system was developed. Making use of image-processing technology, a study was made on the feasibility of distinguishing objectively white bacterial colonies from clear plates according to the RGB color theory. An optimal chromatic value was obtained based upon a lot of experiments on the distribution of the chromatic value. It has been proved that the method greatly improves the accuracy and efficiency of the colony counting and the counting result is not affected by using inoculation, shape or size of the colony. It is revealed that automatic detection of colony quantity using image-processing technology could be an effective way.

  9. Organochlorine contaminants in seven species of Arctic seabirds from northern Baffin Bay

    International Nuclear Information System (INIS)

    Buckman, Andrea H.; Norstrom, Ross J.; Hobson, Keith A.; Karnovsky, Nina J.; Duffe, Jason; Fisk, Aaron T.

    2004-01-01

    Organochlorine contaminants (OCs) were determined in liver and fat of seven species of seabirds (Alle alle, Uria lomvia, Cepphus grylle, Rissa tridactyla, Pagophila eburnea, Larus hyperboreus, and Fulmaris glacialis) collected in May/June 1998 from the Northwater Polynya in northern Baffin Bay. OC concentrations ranged over an order of magnitude between seabird species and OC groups, with PCBs having the highest concentrations followed by DDT, chlordane, HCH and ClBz. Positive relationships between δ 15 N (estimator of trophic level) and OC concentrations (lipid basis) were found for all OC groups, showing that trophic position and biomagnification significantly influence OC concentrations in Arctic seabirds. Concentrations of a number of OCs in particular species (e.g., HCH in P. eburnean) were lower than expected based on δ 15 N and was attributed to biotransformation. P. eburnea and F. glacialis, which scavenge, and R. tridactyla, which migrate from the south, were consistently above the δ 15 N-OC regression providing evidence that these variables can elevate OC concentrations. Stable isotope measurements in muscle may not be suitable for identifying past scavenging events by seabirds. OC relative proportions were related to trophic position and phylogeny, showing that OC biotransformation varies between seabird groups. Trophic level, migration, scavenging and biotransformation all play important roles in the OCs found in Arctic seabirds. - Concentrations of organochlorides in high Arctic seabirds are influenced by trophic level, migration, scavenging and biotransformation

  10. JAX Colony Management System (JCMS): an extensible colony and phenotype data management system

    OpenAIRE

    Donnelly, Chuck J.; McFarland, Mike; Ames, Abigail; Sundberg, Beth; Springer, Dave; Blauth, Peter; Bult, Carol J.

    2010-01-01

    The Jackson Laboratory Colony Management System (JCMS) is a software application for managing data and information related to research mouse colonies, associated biospecimens, and experimental protocols. JCMS runs directly on computers that run one of the PC Windows® operating systems, but can be accessed via web browser interfaces from any computer running a Windows, Macintosh®, or Linux® operating system. JCMS can be configured for a single user or multiple users in small- to medium-size wo...

  11. Predation on seabirds by red foxes at Shaiak Island, Alaska

    Science.gov (United States)

    Petersen, M.R.

    1982-01-01

    Two Red Foxes (Vulpes fulva) that invaded Shaiak Island before the 1976 nesting season had a marked impact on the nesting success of five of seven species of seabirds breeding on the island that year. Common Eiders (Somateria mollissima), Glaucous-winged Gulls (Larus glaucescens), and Common Murres (Uria aalge), that nest in areas accessible to foxes, did not raise any young to fledging. Double-crested Cormorants (Phalacrocorax auritus) were only slightly more successful; 13 (4.3%) of 300 pairs raised one or more young to fledging. Evidence suggested that 21 (35.6%) of 62 pairs of Tufted Puffins (Lunda cirrhata) lost eggs or chicks to foxes, and foxes killed at least 13 (8.3%) of 156 adult puffins on ten sample plots. Conversely, Black-Legged Kittiwakes (Rissa tridactyla) and Pelagic Cormorants (Phalacrocorax pelagicus), which nested primarily on cliffs inaccessible to foxes, lost very few nests. There was no apparent change in general nest site selections by seabirds the following year, when foxes were no longer present. Any avoidance by birds of areas vulnerable to fox predation would probably be discernible only after several years of continuous predation.

  12. Trophic signatures of seabirds suggest shifts in oceanic ecosystems

    Science.gov (United States)

    Gagne, Tyler O.; Hyrenbach, K. David; Hagemann, Molly E.; Van Houtan, Kyle S.

    2018-01-01

    Pelagic ecosystems are dynamic ocean regions whose immense natural capital is affected by climate change, pollution, and commercial fisheries. Trophic level–based indicators derived from fishery catch data may reveal the food web status of these systems, but the utility of these metrics has been debated because of targeting bias in fisheries catch. We analyze a unique, fishery-independent data set of North Pacific seabird tissues to inform ecosystem trends over 13 decades (1890s to 2010s). Trophic position declined broadly in five of eight species sampled, indicating a long-term shift from higher–trophic level to lower–trophic level prey. No species increased their trophic position. Given species prey preferences, Bayesian diet reconstructions suggest a shift from fishes to squids, a result consistent with both catch reports and ecosystem models. Machine learning models further reveal that trophic position trends have a complex set of drivers including climate, commercial fisheries, and ecomorphology. Our results show that multiple species of fish-consuming seabirds may track the complex changes occurring in marine ecosystems. PMID:29457134

  13. Migration and opportunistic feeding increase PCB accumulation in Arctic seabirds.

    Science.gov (United States)

    Baert, J M; Janssen, C R; Borgå, K; De Laender, F

    2013-10-15

    It is widely accepted that body concentrations of persistent organic pollutants (POPs) tend to increase with trophic level (TL). Yet, little attention has been paid to the causes in the underlying differences in POP body concentrations between species occupying similar TLs. In this paper we use two modeling approaches to quantify the importance of migration and opportunistic feeding, relative to that of trophic level, in explaining interspecific differences in polychlorinated biphenyl (PCB) body concentrations between 6 Arctic seabird species breeding in the Barents Sea: Little Auk (Alle alle), Black Guillemot (Cepphus grylle), Brünnich's Guillemot (Uria lomvia), Common Eider (Somateria mollissima), Black-legged Kittiwake (Rissa tridactyla), and Glaucous Gull (Larus hyperboreus). As a first approach, we use additive models to analyze two independent data sets (n = 470 and n = 726). We demonstrate that migration, opportunistic feeding, and TL significantly (p < 0.001) increase PCB body concentrations by a factor 3.61-4.10, 2.66-20.95, and 2.38-2.41, respectively. Our second approach, using a mechanistic bioaccumulation model, confirmed these positive effects on the body burdens but suggested lower effects of migration, opportunistic feeding, and TL (1.55, 2.39, and 2.38) than did our statistical analysis. These two independent approaches demonstrate that the effects of migration and opportunistic feeding on seabird body burdens can be similar to that of an increase of one TL and should therefore be accounted for in future analyses.

  14. Global phenological insensitivity to shifting ocean temperatures among seabirds

    Science.gov (United States)

    Keogan, Katharine; Daunt, Francis; Wanless, Sarah; Phillips, Richard A.; Walling, Craig A.; Agnew, Philippa; Ainley, David G.; Anker-Nilssen, Tycho; Ballard, Grant; Barrett, Robert T.; Barton, Kerry J.; Bech, Claus; Becker, Peter; Berglund, Per-Arvid; Bollache, Loïc; Bond, Alexander L.; Bouwhuis, Sandra; Bradley, Russell W.; Burr, Zofia M.; Camphuysen, Kees; Catry, Paulo; Chiaradia, Andre; Christensen-Dalsgaard, Signe; Cuthbert, Richard; Dehnhard, Nina; Descamps, Sébastien; Diamond, Tony; Divoky, George; Drummond, Hugh; Dugger, Katie M.; Dunn, Michael J.; Emmerson, Louise; Erikstad, Kjell Einar; Fort, Jérôme; Fraser, William; Genovart, Meritxell; Gilg, Olivier; González-Solís, Jacob; Granadeiro, José Pedro; Grémillet, David; Hansen, Jannik; Hanssen, Sveinn A.; Harris, Mike; Hedd, April; Hinke, Jefferson; Igual, José Manuel; Jahncke, Jaime; Jones, Ian; Kappes, Peter J.; Lang, Johannes; Langset, Magdalene; Lescroël, Amélie; Lorentsen, Svein-Hâkon; Lyver, Phil O'B.; Mallory, Mark; Moe, Børge; Montevecchi, William A.; Monticelli, David; Mostello, Carolyn; Newell, Mark; Nicholson, Lisa; Nisbet, Ian; Olsson, Olof; Oro, Daniel; Pattison, Vivian; Poisbleau, Maud; Pyk, Tanya; Quintana, Flavio; Ramos, Jaime A.; Ramos, Raül; Reiertsen, Tone Kirstin; Rodríguez, Cristina; Ryan, Peter; Sanz-Aguilar, Ana; Schmidt, Niels M.; Shannon, Paula; Sittler, Benoit; Southwell, Colin; Surman, Christopher; Svagelj, Walter S.; Trivelpiece, Wayne; Warzybok, Pete; Watanuki, Yutaka; Weimerskirch, Henri; Wilson, Peter R.; Wood, Andrew G.; Phillimore, Albert B.; Lewis, Sue

    2018-04-01

    Reproductive timing in many taxa plays a key role in determining breeding productivity1, and is often sensitive to climatic conditions2. Current climate change may alter the timing of breeding at different rates across trophic levels, potentially resulting in temporal mismatch between the resource requirements of predators and their prey3. This is of particular concern for higher-trophic-level organisms, whose longer generation times confer a lower rate of evolutionary rescue than primary producers or consumers4. However, the disconnection between studies of ecological change in marine systems makes it difficult to detect general changes in the timing of reproduction5. Here, we use a comprehensive meta-analysis of 209 phenological time series from 145 breeding populations to show that, on average, seabird populations worldwide have not adjusted their breeding seasons over time (-0.020 days yr-1) or in response to sea surface temperature (SST) (-0.272 days °C-1) between 1952 and 2015. However, marked between-year variation in timing observed in resident species and some Pelecaniformes and Suliformes (cormorants, gannets and boobies) may imply that timing, in some cases, is affected by unmeasured environmental conditions. This limited temperature-mediated plasticity of reproductive timing in seabirds potentially makes these top predators highly vulnerable to future mismatch with lower-trophic-level resources2.

  15. Predictive Modelling to Identify Near-Shore, Fine-Scale Seabird Distributions during the Breeding Season.

    Science.gov (United States)

    Warwick-Evans, Victoria C; Atkinson, Philip W; Robinson, Leonie A; Green, Jonathan A

    2016-01-01

    During the breeding season seabirds are constrained to coastal areas and are restricted in their movements, spending much of their time in near-shore waters either loafing or foraging. However, in using these areas they may be threatened by anthropogenic activities such as fishing, watersports and coastal developments including marine renewable energy installations. Although many studies describe large scale interactions between seabirds and the environment, the drivers behind near-shore, fine-scale distributions are not well understood. For example, Alderney is an important breeding ground for many species of seabird and has a diversity of human uses of the marine environment, thus providing an ideal location to investigate the near-shore fine-scale interactions between seabirds and the environment. We used vantage point observations of seabird distribution, collected during the 2013 breeding season in order to identify and quantify some of the environmental variables affecting the near-shore, fine-scale distribution of seabirds in Alderney's coastal waters. We validate the models with observation data collected in 2014 and show that water depth, distance to the intertidal zone, and distance to the nearest seabird nest are key predictors in the distribution of Alderney's seabirds. AUC values for each species suggest that these models perform well, although the model for shags performed better than those for auks and gulls. While further unexplained underlying localised variation in the environmental conditions will undoubtedly effect the fine-scale distribution of seabirds in near-shore waters we demonstrate the potential of this approach in marine planning and decision making.

  16. Predictive Modelling to Identify Near-Shore, Fine-Scale Seabird Distributions during the Breeding Season.

    Directory of Open Access Journals (Sweden)

    Victoria C Warwick-Evans

    Full Text Available During the breeding season seabirds are constrained to coastal areas and are restricted in their movements, spending much of their time in near-shore waters either loafing or foraging. However, in using these areas they may be threatened by anthropogenic activities such as fishing, watersports and coastal developments including marine renewable energy installations. Although many studies describe large scale interactions between seabirds and the environment, the drivers behind near-shore, fine-scale distributions are not well understood. For example, Alderney is an important breeding ground for many species of seabird and has a diversity of human uses of the marine environment, thus providing an ideal location to investigate the near-shore fine-scale interactions between seabirds and the environment. We used vantage point observations of seabird distribution, collected during the 2013 breeding season in order to identify and quantify some of the environmental variables affecting the near-shore, fine-scale distribution of seabirds in Alderney's coastal waters. We validate the models with observation data collected in 2014 and show that water depth, distance to the intertidal zone, and distance to the nearest seabird nest are key predictors in the distribution of Alderney's seabirds. AUC values for each species suggest that these models perform well, although the model for shags performed better than those for auks and gulls. While further unexplained underlying localised variation in the environmental conditions will undoubtedly effect the fine-scale distribution of seabirds in near-shore waters we demonstrate the potential of this approach in marine planning and decision making.

  17. Geolocation Reveals Year-Round at-Sea Distribution and Activity of a Superabundant Tropical Seabird, the Sooty Tern Onychoprion fuscatus

    Directory of Open Access Journals (Sweden)

    Audrey Jaeger

    2017-12-01

    Full Text Available Migration is a fundamental aspect of the ecology and evolutionary history of many animals, driven by seasonal changes in resource availability and habitat structure. Seabird migration has been investigated extensively in highly seasonal temperate and polar environments. By contrast, the relationships between migration and seasonal environmental changes have rarely been studied in tropical marine habitats. The sooty tern Onychoprion fuscatus is the most abundant tropical seabirds, and has been ranked as the most important tropical species in terms of its annual estimated consumption of marine resources. We used global location sensing (GLS loggers to describe for the first time the year-round at-sea distribution and activity patterns of sooty terns from a large breeding colony in the western Indian Ocean (Bird Island, Seychelles. While breeding, they foraged within 1,074 ± 274 km of the colony. After breeding, birds undertook an extensive post-breeding migration throughout the Indian Ocean; average distances traveled exceeded 50,000 km per individual. Sooty terns used mainly four distinct core oceanic areas during the non-breeding period; in the Bay of Bengal (A, northeast to an area straddling the Chagos-Laccadive plateau (B, southeast to an area on each side of the 90 East Ridge (C and southwest to an area around Comoros (D. Individuals exhibited a high degree of fidelity to these core areas in successive years. We also established that they performed an unusual behavior for a non-Procellariiformes seabird; most individuals undertook a 1-month pre-laying exodus, during which they foraged in a specific area c. 2,000 km to the south-east of the colony. Year-round at-sea activity of sooty terns revealed that they spent only 3.72% of their time in contact with seawater, so indicating that they must sleep in flight. Activity parameters exhibited seasonal (breeding vs. non-breeding periods and daily variations; they notably never land on the water

  18. Link between bird survival and water temperature: the greenhouse effect is a factor in sea-bird killing; Sammenheng mellom fuglenes overlevelse og vanntemperaturen: drivhuseffekten er med paa aa drepe sjoefugl

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    In a joint project between NINA and the University of Tromsoe it has been established that a few degrees warmer sea water may mean win or vanish for Norwegian oceanic birds of the Atlantic Ocean. It is not the warm sea water as such that kills the birds, but rather the lack of food. When capellin and sand eel do not tolerate that the water is getting warmer, food scarcity occurs for the seabirds. Sea temperature has already risen during the last few decades and is predicted by climatologists to rise further in the coming years. A rise in water temperature of just 1 {sup o}C in the winter habitat of the white-breasted guillemot has been shown to reduce its survival by four per cent. In the long term this corresponds to a reduction of the life span by more than 50 per cent, from 25 to 11 years. Similar but less clear trends have been found in some of the other species, notably atlantic puffin and razorbill. The exact cause of the temperature effect is still not completely understood, but the direct effect is probably the impact of climatic change on the chain of food. In 2004, British seabird colonies of the North Sea suffered almost complete breeding collapse when the sand eel came close to disappearing from the sea. British scientists explained this as caused by North Sea water being warmed by the greenhouse effect. Reducing the greenhouse effect by curtailing the emission of carbon dioxide would probably alleviate the situation for the affected seabirds. Urgent steps are not easily taken since the critical phase for survival of the seabirds is the winter, when the birds are distributed all over an enormous sea area.

  19. Seabird, fish, marine mammal and oceanography coordinated investigations (SMMOCI) in the Pribilof Islands, Alaska, July 2005

    Data.gov (United States)

    Department of the Interior — We conducted a survey of seabirds, fishes, marine mammals and oceanographic conditions near the Pribilof Islands, Alaska (Fig. 1) from the M/V Tiˆglaˆx during 20-26...

  20. Marine distribution of arctic seabirds over six decades: changes and conservation applications

    DEFF Research Database (Denmark)

    Wong, SNP; Johansen, Kasper Lambert; Lieske, DJ

    Climate change is causing rapid changes in Arctic marine ecosystems and understanding its impacts on wildlife is critical for conservation management, especially as the decline in sea ice leads to increased development and vessel traffic. The Arctic supports hundreds of millions of seabirds, which...... collected from 1988 to 2015 and covering a combined 185,000 linear km, we examined the marine distribution of seabirds in sub-arctic and Arctic waters between Canada and Greenland, an area covering over 5,000,000 km2. We developed a predictive model to investigate how ice cover and ocean processes influence...... the distribution of arctic seabirds in summer and autumn and identified existing areas of high density. Comparing these results to at-sea surveys conducted in the same waters from 1966 - 1987, we examined how seabird distribution has changed over the last six decades. Understanding how changes in the marine...

  1. Spread of plague among black-tailed prairie dogs is associated with colony spatial characteristics

    Science.gov (United States)

    Johnson, T.L.; Cully, J.F.; Collinge, S.K.; Ray, C.; Frey, C.M.; Sandercock, B.K.

    2011-01-01

    Sylvatic plague (Yersinia pestis) is an exotic pathogen that is highly virulent in black-tailed prairie dogs (Cynomys ludovicianus) and causes widespread colony losses and individual mortality rates >95%. We investigated colony spatial characteristics that may influence inter-colony transmission of plague at 3 prairie dog colony complexes in the Great Plains. The 4 spatial characteristics we considered include: colony size, Euclidean distance to nearest neighboring colony, colony proximity index, and distance to nearest drainage (dispersal) corridor. We used multi-state mark-recapture models to determine the relationship between these colony characteristics and probability of plague transmission among prairie dog colonies. Annual mapping of colonies and mark-recapture analyses of disease dynamics in natural colonies led to 4 main results: 1) plague outbreaks exhibited high spatial and temporal variation, 2) the site of initiation of epizootic plague may have substantially influenced the subsequent inter-colony spread of plague, 3) the long-term effect of plague on individual colonies differed among sites because of how individuals and colonies were distributed, and 4) colony spatial characteristics were related to the probability of infection at all sites although the relative importance and direction of relationships varied among sites. Our findings suggest that conventional prairie dog conservation management strategies, including promoting large, highly connected colonies, may need to be altered in the presence of plague. ?? 2011 The Wildlife Society.

  2. Threat of plastic pollution to seabirds is global, pervasive, and increasing

    OpenAIRE

    Wilcox, C; Van Sebille, E; Hardesty, BD

    2015-01-01

    Plastic pollution in the ocean is a rapidly emerging global environmental concern, with high concentrations (up to 580,000 pieces per km2) and a global distribution, driven by exponentially increasing production. Seabirds are particularly vulnerable to this type of pollution and are widely observed to ingest floating plastic. We used a mixture of literature surveys, oceanographic modeling, and ecological models to predict the risk of plastic ingestion to 186 seabird species globally. Impacts ...

  3. Chlamydiaceae in North Atlantic Seabirds Admitted to a Wildlife Rescue Center in Western France

    OpenAIRE

    Aaziz, R.; Gourlay, P.; Vorimore, F.; Sachse, K.; Siarkou, V. I.; Laroucau, K.

    2015-01-01

    Birds are the primary hosts of Chlamydia psittaci, a bacterium that can cause avian chlamydiosis in birds and psittacosis in humans. Wild seabirds are frequently admitted to wildlife rescue centers (WRC) at European Atlantic coasts, for example, in connection with oil spills. To investigate the extent of chlamydial shedding by these birds and the resulting risk for animals in care and the medical staff, seabirds from a French WRC were sampled from May 2011 to January 2014. By use of a quantit...

  4. Specters of Colonialism

    DEFF Research Database (Denmark)

    Muhr, Sara Louise; Azad, Salam

    2013-01-01

    at the same time they always are bound to fail to become ‘Swedish’ because of the same foreign origins. Although Swedish culture – partly by distancing itself from having a colonial past – has successfully built up an image of openness, we argue that without acknowledging and confronting the role...

  5. Global phenological insensitivity to shifting ocean temperatures among seabirds

    DEFF Research Database (Denmark)

    Keogan, Katharine; Daunt, Francis; Wanless, Sarah

    2018-01-01

    Reproductive timing in many taxa plays a key role in determining breeding productivity 1 , and is often sensitive to climatic conditions 2 . Current climate change may alter the timing of breeding at different rates across trophic levels, potentially resulting in temporal mismatch between...... the resource requirements of predators and their prey 3 . This is of particular concern for higher-trophic-level organisms, whose longer generation times confer a lower rate of evolutionary rescue than primary producers or consumers 4 . However, the disconnection between studies of ecological change in marine...... systems makes it difficult to detect general changes in the timing of reproduction 5 . Here, we use a comprehensive meta-analysis of 209 phenological time series from 145 breeding populations to show that, on average, seabird populations worldwide have not adjusted their breeding seasons over time (−0...

  6. Mortality of seabirds in high-seas salmon gillnets

    Science.gov (United States)

    Ainley, D.G.; DeGange, A.R.; Jones, L.L.; Beach, R.J.

    1981-01-01

    Since 1952, the Japanese have operated a large salmon driftnet.fishery in the northern North Pacific Ocean and Bering Sea. This fishery is divided into two components: the high-seas mothership fleet, which consists of several processing ships and their numerous, smaller catcher boats that remain at sea during the entire fishing season, and the land-based fleet, which consists of independent fishing boats that catch and store their own fish and return to Japan at more frequent intervals (Sanger 1976; Fredin et al. 2 ). A similar fishery in the North Atlantic between 1965 and 1976 was responsible for the deaths of large numbers of the thick-billed murre, Uria lomvia, and significant reductions in its breeding populations (Tull et al. 1972). Recent work in the North Pacific and Bering Sea by Sana (1978) and King et al. (1979) indicated that large numbers of seabirds are killed annually in the Japanese salmon fishery also.

  7. Even at the uttermost ends of the Earth: how seabirds telecouple the Beagle Channel with regional and global processes that affect environmental conservation and social-ecological sustainability

    Directory of Open Access Journals (Sweden)

    Andrea N. Raya Rey

    2017-12-01

    Full Text Available Human-wildlife dynamics exhibit novel characteristics in the Anthropocene, given the unprecedented degree of globalization that has increased the linkages between habitats and people across space and time. This is largely caused by transnational mobility and migration, international labor, resource markets, and trade. Understanding the relationship between humans and wildlife, and their associated telecoupling processes, helps to promote better management practices and governance for reconciling socioeconomic and conservation interests. Even remote places on the globe exhibit these features. For example, in southern Patagonia's coastal and marine ecosystems, seabirds are not only very abundant and charismatic members of the wildlife community, nowadays, their colonies are a main tourism attraction of global significance, and in the past they were used for consumptive and scientific purposes that also linked the "uttermost ends of the Earth" with distant places. Thus, in this study, we review human-seabird interactions in the iconic Beagle Channel (BC in the Argentine portion of the Tierra del Fuego Archipelago. We adapted and employed the coupled human and natural systems (CHANS approach and telecoupling framework to integrate disparate social and biological information and obtain a more holistic understanding of current human-seabird dynamics and trends in the BC. Although our assessment includes the temporal scale of human-seabird relationships, we centered the CHANS and telecoupling analysis on the modern seabird-tourism interaction, focused on the channel's Argentine sector, in which tourism is most intensively developed. Our synthesis of the BC's telecoupled CHANS allowed us to recognize the strong historical local-to-global interactions between both human and natural subsystems and the sharp increase in distance telecoupling during the 20th century. Despite this globalizing trend in seabirds connecting the BC's local ecosystems to distant

  8. Synthetic quorum sensing in model microcapsule colonies

    Science.gov (United States)

    Shum, Henry; Balazs, Anna C.

    2017-08-01

    Biological quorum sensing refers to the ability of cells to gauge their population density and collectively initiate a new behavior once a critical density is reached. Designing synthetic materials systems that exhibit quorum sensing-like behavior could enable the fabrication of devices with both self-recognition and self-regulating functionality. Herein, we develop models for a colony of synthetic microcapsules that communicate by producing and releasing signaling molecules. Production of the chemicals is regulated by a biomimetic negative feedback loop, the “repressilator” network. Through theory and simulation, we show that the chemical behavior of such capsules is sensitive to both the density and number of capsules in the colony. For example, decreasing the spacing between a fixed number of capsules can trigger a transition in chemical activity from the steady, repressed state to large-amplitude oscillations in chemical production. Alternatively, for a fixed density, an increase in the number of capsules in the colony can also promote a transition into the oscillatory state. This configuration-dependent behavior of the capsule colony exemplifies quorum-sensing behavior. Using our theoretical model, we predict the transitions from the steady state to oscillatory behavior as a function of the colony size and capsule density.

  9. A traditional and a less-invasive robust design: choices in optimizing effort allocation for seabird population studies

    Science.gov (United States)

    Converse, S.J.; Kendall, W.L.; Doherty, P.F.; Naughton, M.B.; Hines, J.E.; Thomson, David L.; Cooch, Evan G.; Conroy, Michael J.

    2009-01-01

    For many animal populations, one or more life stages are not accessible to sampling, and therefore an unobservable state is created. For colonially-breeding populations, this unobservable state could represent the subset of adult breeders that have foregone breeding in a given year. This situation applies to many seabird populations, notably albatrosses, where skipped breeders are either absent from the colony, or are present but difficult to capture or correctly assign to breeding state. Kendall et al. have proposed design strategies for investigations of seabird demography where such temporary emigration occurs, suggesting the use of the robust design to permit the estimation of time-dependent parameters and to increase the precision of estimates from multi-state models. A traditional robust design, where animals are subject to capture multiple times in a sampling season, is feasible in many cases. However, due to concerns that multiple captures per season could cause undue disturbance to animals, Kendall et al. developed a less-invasive robust design (LIRD), where initial captures are followed by an assessment of the ratio of marked-to-unmarked birds in the population or sampled plot. This approach has recently been applied in the Northwestern Hawaiian Islands to populations of Laysan (Phoebastria immutabilis) and black-footed (P. nigripes) albatrosses. In this paper, we outline the LIRD and its application to seabird population studies. We then describe an approach to determining optimal allocation of sampling effort in which we consider a non-robust design option (nRD), and variations of both the traditional robust design (RD), and the LIRD. Variations we considered included the number of secondary sampling occasions for the RD and the amount of total effort allocated to the marked-to-unmarked ratio assessment for the LIRD. We used simulations, informed by early data from the Hawaiian study, to address optimal study design for our example cases. We found that

  10. Differential responses of seabirds to inter-annual environmental change in the continental shelf and oceanic habitats of southeastern Bering Sea

    Science.gov (United States)

    Yamamoto, T.; Kokubun, N.; Kikuchi, D. M.; Sato, N.; Takahashi, A.; Will, A.; Kitaysky, A. S.; Watanuki, Y.

    2015-11-01

    Seasonal sea-ice cover has been decreasing in the southeastern Bering Sea shelf, which might affect ecosystem dynamics and availability of food resources to marine top predators breeding in the region. In this study, we investigated the foraging responses of two seabird species, surface-foraging red-legged kittiwakes Rissa brevirostris (hereafter, RLKI) and pursuit-diving foraging thick-billed murres Uria lomvia (TBMU) to the inter-annual change in environmental conditions. Between the study years, winter ice retreated earlier and summer water temperatures were warmer in 2014 compared to those in 2013. At-sea distributions of RLKI and TBMU breeding on St. George Island, the largest seabird colony in the region, were recorded using GPS loggers, and blood samples were taken to examine their physiological condition and isotopic foraging niche in a given year. RLKI foraging occurred mostly over the oceanic basin in both years. TBMU, however, foraged mostly over the shelf, but showed a relatively higher use of the shelf break and oceanic basin in the colder year, 2013. The foraging distances from the colony peaked at 250-300 km in 2013 and, bimodally, at 150-250 and 300-350 km in 2014 for RLKI, and tended to be farther in 2013 compared to those in 2014 for TBMU. Plasma levels of corticosterone did not differ between years in RLKI, but differed in TBMU, showing higher levels of physiological stress incurred by murres during the colder year, 2013. δ13N (a proxy of trophic level of prey) did not differ between the years in either RLKI or TBMU, while δ13C (a proxy of prey origin) were lower in 2014 than in 2013 in both species, suggesting possible differences in influx of oceanic prey items into foraging areas. These results suggest that the response of ecosystem dynamics to climate variability in the southeast Bering Sea may differ between the ocean basin and continental shelf regions, which, in turn, may generate differential responses in seabirds relying on those

  11. Colony formation in the cyanobacterium Microcystis.

    Science.gov (United States)

    Xiao, Man; Li, Ming; Reynolds, Colin S

    2018-02-22

    Morphological evolution from a unicellular to multicellular state provides greater opportunities for organisms to attain larger and more complex living forms. As the most common freshwater cyanobacterial genus, Microcystis is a unicellular microorganism, with high phenotypic plasticity, which forms colonies and blooms in lakes and reservoirs worldwide. We conducted a systematic review of field studies from the 1990s to 2017 where Microcystis was dominant. Microcystis was detected as the dominant genus in waterbodies from temperate to subtropical and tropical zones. Unicellular Microcystis spp. can be induced to form colonies by adjusting biotic and abiotic factors in laboratory. Colony formation by cell division has been induced by zooplankton filtrate, high Pb 2+ concentration, the presence of another cyanobacterium (Cylindrospermopsis raciborskii), heterotrophic bacteria, and by low temperature and light intensity. Colony formation by cell adhesion can be induced by zooplankton grazing, high Ca 2+ concentration, and microcystins. We hypothesise that single cells of all Microcystis morphospecies initially form colonies with a similar morphology to those found in the early spring. These colonies gradually change their morphology to that of M. ichthyoblabe, M. wesenbergii and M. aeruginosa with changing environmental conditions. Colony formation provides Microcystis with many ecological advantages, including adaption to varying light, sustained growth under poor nutrient supply, protection from chemical stressors and protection from grazing. These benefits represent passive tactics responding to environmental stress. Microcystis colonies form at the cost of decreased specific growth rates compared with a unicellular habit. Large colony size allows Microcystis to attain rapid floating velocities (maximum recorded for a single colony, ∼ 10.08 m h -1 ) that enable them to develop and maintain a large biomass near the surface of eutrophic lakes, where they may shade

  12. A new approach to study of seabird-fishery overlap: Connecting chick feeding with parental foraging and overlap with fishing vessels

    Directory of Open Access Journals (Sweden)

    Junichi Sugishita

    2015-07-01

    Full Text Available Incidental fisheries bycatch is recognised as a major threat to albatross populations worldwide. However, fishery discards and offal produced in large quantities might benefit some scavenging seabirds. Here, we demonstrate an integrated approach to better understand the ecological ramifications of fine-scale overlap between seabirds and fisheries. As a case study, we examined whether foraging in association with a fishing vessel is advantageous for chick provisioning in terms of quantity of food delivered to chicks, in northern royal albatross (Diomedea sanfordi at Taiaroa Head, New Zealand. Fine-scale overlap between albatrosses and vessels was quantified by integrating GPS tracking and Vessel Monitoring Systems (VMS. Meal size delivered to chicks was measured using custom-designed nest balances, and monitoring of attendance of adults fitted with radio transmitters was used in conjunction with time-lapse photography at the nest allowed us to allocate each feeding event to a specific parent. The combination of these techniques enabled comparison of meal sizes delivered to chicks with parental foraging trip durations with or without fishing vessels association. A total of 45 foraging trips and associated chick feeding events were monitored during the chick-rearing period in 2012. Differences in the meal size and foraging trip duration relative to foraging overlap with fisheries were examined using a linear mixed-effect model, adjusted for chick age. Our results, based on three birds, suggest that foraging in association with vessels does not confer an advantage for chick feeding for this population that demonstrated low rates of overlap while foraging. The integrated research design presented can be applied to other seabird species that are susceptible to bycatch, and offers a valuable approach to evaluate habitat quality by linking habitat use and foraging success in terms of total amount of food delivered to offspring.

  13. Kant's Second Thoughts on Colonialism

    NARCIS (Netherlands)

    Kleingeld, Pauline; Flikschuh, Katrin; Ypi, Lea

    2014-01-01

    Kant is widely regarded as a fierce critic of colonialism. In Toward Perpetual Peace and the Metaphysics of Morals, for example, he forcefully condemns European conduct in the colonies as a flagrant violation of the principles of right. His earlier views on colonialism have not yet received much

  14. The effects of oil pollution on seabirds off the west coast of Vancouver Island

    International Nuclear Information System (INIS)

    Burger, A.E.

    1992-01-01

    Annual oil shipments off the west coast of Vancouver Island include over 300 tankers carrying 26 million m 3 of crude oil, over 400 loads totalling ca 2 million m 3 of refined petroleum products delivered to local ports, and thousands of smaller fuel deliveries. The incidence and estimated risks of oil spills off the coast of Vancouver Island are reviewed. Large spills of over 1,000 bbl are likely to affect the area every 4-5 y, but several hundred minor spills occur annually. Beached bird surveys yielded densities of 0.72 carcasses/km, of which at least 12% were oiled by small, predominantly unreported spills. Under normal conditions, the incidence of oiled birds on beaches is low relative to beach survey results from other parts of the world, but these data underestimate the actual at-sea mortality because of the characteristics of the beaches and the ocean currents off the island. This has been confirmed by experiments using bird-sized drift blocks released off the island and studies of carcass persistence on beaches. The effects of the Nestucca spill, which killed ca 56,000 seabirds off Vancouver Island and northern Washington in winter 1988-89, are reviewed. 57 refs., 6 figs., 7 tabs

  15. Environmental variability drives shifts in the foraging behaviour and reproductive success of an inshore seabird.

    Science.gov (United States)

    Kowalczyk, Nicole D; Reina, Richard D; Preston, Tiana J; Chiaradia, André

    2015-08-01

    Marine animals forage in areas that aggregate prey to maximize their energy intake. However, these foraging 'hot spots' experience environmental variability, which can substantially alter prey availability. To survive and reproduce animals need to modify their foraging in response to these prey shifts. By monitoring their inter-annual foraging behaviours, we can understand which environmental variables affect their foraging efficiency, and can assess how they respond to environmental variability. Here, we monitored the foraging behaviour and isotopic niche of little penguins (Eudyptula minor), over 3 years (2008, 2011, and 2012) of climatic and prey variability within Port Phillip Bay, Australia. During drought (2008), penguins foraged in close proximity to the Yarra River outlet on a predominantly anchovy-based diet. In periods of heavy rainfall, when water depth in the largest tributary into the bay (Yarra River) was high, the total distance travelled, maximum distance travelled, distance to core-range, and size of core- and home-ranges of penguins increased significantly. This larger foraging range was associated with broad dietary diversity and high reproductive success. These results suggest the increased foraging range and dietary diversity of penguins were a means to maximize resource acquisition rather than a strategy to overcome local depletions in prey. Our results demonstrate the significance of the Yarra River in structuring predator-prey interactions in this enclosed bay, as well as the flexible foraging strategies of penguins in response to environmental variability. This plasticity is central to the survival of this small-ranging, resident seabird species.

  16. Avian disease assessment in seabirds and non-native passerines birds at Midway Atoll NWR

    Science.gov (United States)

    LaPointe, Dennis A.; Atkinson, Carter T.; Klavitter, John L.

    2013-01-01

    Midway Atoll in the Northwestern Hawaiian Islands supports the largest breeding colony of Laysan albatross (Phoebastria immutabilis) in the world and is a proposed site for the translocation of endangered Northwestern Hawaiian Island passerine birds such as the Nihoa finch (Telespiza ultima), Nihoa millerbird (Acrocephalus familiaris kingi), or Laysan finch (Telespiza cantans). On the main Hawaiian Islands, introduced mosquito-borne avian malaria (Plasmodium relictum) and avian pox (Avipoxvirus) have contributed to the extinction and decline of native Hawaiian avifauna. The mosquito vector (Culex quinquefasciatus) is present on Sand Island, Midway Atoll, where epizootics of Avipoxvirus have been reported among nestling Laysan albatross, black-footed albatross (Phoebastria nigripes), and red-tailed tropicbirds (Phaethon rubricauda) since 1963. Two introduced passerines, the common canary (Serinus canaria) and the common myna (Acridotheres tristis), are also present on Sand Island and may serve as reservoirs of mosquito-borne pathogens. Assessing disease prevalence and transmission potential at Midway Atoll National Wildlife Refuge (NWR) is a critical first step to translocation of Nihoa endemic passerines. In May 2010 and April 2012 we surveyed Midway Atoll NWR for mosquitoes and evidence of mosquito-borne disease. Although we did not observe active pox infections on albatross nestlings in May 2010, active infections were prevalent on albatross nestlings in April 2012. Presumptive diagnosis of Avipoxvirus was confirmed by PCR amplification of the Avipoxvirus 4b core protein gene from lesions collected from 10 albatross nestlings. Products were sequenced and compared to 4b core protein sequences from 28 Avipoxvirus isolates from the Hawaiian Islands and other parts of the world. Sequences from all Midway isolates were identical and formed a clade with other Avipoxvirus isolates from seabirds that was distinct from other Avipoxvirus isolates from the Hawaiian Islands

  17. Laser-induced speckle scatter patterns in Bacillus colonies

    Directory of Open Access Journals (Sweden)

    Huisung eKim

    2014-10-01

    Full Text Available Label-free bacterial colony phenotyping technology called BARDOT (BActerial Rapid Detection using Optical scattering Technology provided successful classification of several different bacteria at the genus, species, and serovar level. Recent experiments with colonies of Bacillus species provided strikingly different characteristics of elastic light scatter (ELS patterns, which were comprised of random speckles compared to other bacteria, which are dominated by concentric rings and spokes. Since this laser-based optical sensor interrogates the whole volume of the colony, 3-D information of micro- and macro-structures are all encoded in the far-field scatter patterns. Here, we present a theoretical model explaining the underlying mechanism of the speckle formation by the colonies from Bacillus species. Except for Bacillus polymyxa, all Bacillus spp. produced random bright spots on the imaging plane, which presumably dependent on the cellular and molecular organization and content within the colony. Our scatter model-based analysis revealed that colony spread resulting in variable surface roughness can modify the wavefront of the scatter field. As the center diameter of the Bacillus spp. colony grew from 500 μm to 900 μm, average speckles area decreased 2-fold and the number of small speckles increased 7-fold. In conclusion, as Bacillus colony grows, the average speckle size in the scatter pattern decreases and the number of smaller speckle increases due to the swarming growth characteristics of bacteria within the colony.

  18. Combined bio-logging and stable isotopes reveal individual specialisations in a benthic coastal seabird, the Kerguelen shag.

    Directory of Open Access Journals (Sweden)

    Elodie C M Camprasse

    Full Text Available Individual specialisations, which involve the repetition of specific behaviours or dietary choices over time, have been suggested to benefit animals by avoiding competition with conspecifics and increasing individual foraging efficiency. Among seabirds, resident and benthic species are thought to be good models to study inter-individual variation as they repetitively exploit the same environment. We investigated foraging behaviour, isotopic niche and diet in the Kerguelen shag Phalacrocorax verrucosus during both the incubation and chick-rearing periods for the same individuals to determine the effect of sex, breeding stage, body mass and morphometrics on mean foraging metrics and their consistency. There were large differences between individuals in foraging behaviour and consistency, with strong individual specialisations in dive depths and heading from the colony. Stable isotopes revealed specialisations in feeding strategies, across multiple temporal scales. Specifically, individuals showed medium term specialisations in feeding strategies during the breeding season, as well as long-term consistency. A clustering analysis revealed 4 different foraging strategies displaying significantly different δ15N values and body masses. There were no sex or stage biases to clusters and individuals in different clusters did not differ in their morphology. Importantly, the results suggest that the different strategies emphasized were related to individual prey preferences rather than intrinsic characteristics.

  19. Defining ecologically relevant scales for spatial protection with long-term data on an endangered seabird and local prey availability.

    Science.gov (United States)

    Sherley, Richard B; Botha, Philna; Underhill, Les G; Ryan, Peter G; van Zyl, Danie; Cockcroft, Andrew C; Crawford, Robert J M; Dyer, Bruce M; Cook, Timothée R

    2017-12-01

    Human activities are important drivers of marine ecosystem functioning. However, separating the synergistic effects of fishing and environmental variability on the prey base of nontarget predators is difficult, often because prey availability estimates on appropriate scales are lacking. Understanding how prey abundance at different spatial scales links to population change can help integrate the needs of nontarget predators into fisheries management by defining ecologically relevant areas for spatial protection. We investigated the local population response (number of breeders) of the Bank Cormorant (Phalacrocorax neglectus), a range-restricted endangered seabird, to the availability of its prey, the heavily fished west coast rock lobster (Jasus lalandii). Using Bayesian state-space modeled cormorant counts at 3 colonies, 22 years of fisheries-independent data on local lobster abundance, and generalized additive modeling, we determined the spatial scale pertinent to these relationships in areas with different lobster availability. Cormorant numbers responded positively to lobster availability in the regions with intermediate and high abundance but not where regime shifts and fishing pressure had depleted lobster stocks. The relationships were strongest when lobsters 20-30 km offshore of the colony were considered, a distance greater than the Bank Cormorant's foraging range when breeding, and may have been influenced by prey availability for nonbreeding birds, prey switching, or prey ecology. Our results highlight the importance of considering the scale of ecological relationships in marine spatial planning and suggest that designing spatial protection around focal species can benefit marine predators across their full life cycle. We propose the precautionary implementation of small-scale marine protected areas, followed by robust assessment and adaptive-management, to confirm population-level benefits for the cormorants, their prey, and the wider ecosystem, without

  20. Buying years to extinction: is compensatory mitigation for marine bycatch a sufficient conservation measure for long-lived seabirds?

    Directory of Open Access Journals (Sweden)

    José Manuel Igual

    Full Text Available Along the lines of the 'polluter pays principle', it has recently been proposed that the local long-line fishing industry should fund eradication of terrestrial predators at seabird breeding colonies, as a compensatory measure for the bycatch caused by the fishing activity. The measure is economically sound, but a quantitative and reliable test of its biological efficacy has never been conducted. Here, we investigated the demographic consequences of predator eradication for Cory's shearwater Calonectris diomedea, breeding in the Mediterranean, using a population model that integrates demographic rates estimated from individual life-history information with experimental measures of predation and habitat structure. We found that similar values of population growth rate can be obtained by different combinations of habitat characteristics, predator abundance and adult mortality, which explains the persistence of shearwater colonies in islands with introduced predators. Even so, given the empirically obtained values of survival, all combinations of predator abundance and habitat characteristics projected a decline in shearwater numbers. Perturbation analyses indicated that the value and the sensitivity of shearwater population growth rates were affected by all covariates considered and their interactions. A decrease in rat abundance delivered only a small increase in the population growth rate, whereas a change in adult survival (a parameter independent of rat abundance had the strongest impact on population dynamics. When adult survival is low, rat eradication would allow us to "buy" years before extinction but does not reverse the process. Rat eradication can therefore be seen as an emergency measure if threats on adult survival are eliminated in the medium-term period. For species with low fecundity and long life expectancy, our results suggest that rat control campaigns are not a sufficient, self-standing measure to compensate the biological toll

  1. Scaling of soaring seabirds and implications for flight abilities of giant pterosaurs.

    Directory of Open Access Journals (Sweden)

    Katsufumi Sato

    Full Text Available The flight ability of animals is restricted by the scaling effects imposed by physical and physiological factors. In comparisons of the power available from muscle and the mechanical power required to fly, it is predicted that the margin between the powers should decrease with body size and that flying animals have a maximum body size. However, predicting the absolute value of this upper limit has proven difficult because wing morphology and flight styles varies among species. Albatrosses and petrels have long, narrow, aerodynamically efficient wings and are considered soaring birds. Here, using animal-borne accelerometers, we show that soaring seabirds have two modes of flapping frequencies under natural conditions: vigorous flapping during takeoff and sporadic flapping during cruising flight. In these species, high and low flapping frequencies were found to scale with body mass (mass(-0.30 and mass(-0.18 in a manner similar to the predictions from biomechanical flight models (mass(-1/3 and mass(-1/6. These scaling relationships predicted that the maximum limits on the body size of soaring animals are a body mass of 41 kg and a wingspan of 5.1 m. Albatross-like animals larger than the limit will not be able to flap fast enough to stay aloft under unfavourable wind conditions. Our result therefore casts doubt on the flying ability of large, extinct pterosaurs. The largest extant soarer, the wandering albatross, weighs about 12 kg, which might be a pragmatic limit to maintain a safety margin for sustainable flight and to survive in a variable environment.

  2. All you can eat: is food supply unlimited in a colonially breeding bird?

    OpenAIRE

    Hoi, Herbert; Kri?tof?k, J?n; Darolov?, Al?beta

    2015-01-01

    Food availability is generally considered to determine breeding site selection and therefore plays an important role in hypotheses explaining the evolution of colony formation. Hypotheses trying to explain why birds join a colony usually assume that food is not limited, whereas those explaining variation in colony size suggest that food is under constraint. In this study, we investigate the composition and amount of food items not eaten by the nestlings and found in nest burrows of colonially...

  3. Sanitary and nutritional characterization of honeybee colonies in Eucalyptus grandis plantations

    OpenAIRE

    Invernizzi, C.; Santos, E.; García, E.; Daners, G.; Di Landro, R.; Saadoun, A.; Cabrera, C.

    2011-01-01

    In Uruguay, many beekeepers transport their colonies to Eucalyptus grandis plantations at the end of the summer and autumn, obtaining important honey harvests. However, at the end of the flowering period the colonies become extremely weakened undergoing high levels of mortality. Nutritional and health problems could explain the weakening of colonies. In order to find out the causes for this weakening, colonies of the same size were taken to an E. grandis plantation, split up in three groups d...

  4. Maximum possible age of a petrel breeding colony near Punakaiki (South Island, New Zealand) from radiocarbon and stable isotope analysis of soil

    International Nuclear Information System (INIS)

    Hawke, D.J.

    2004-01-01

    The lifetime of individual petrel colonies is poorly known. This study used radiocarbon, 13 C, and 15 N analysis of soil to determine the maximum possible age of a colony presently occupied by Westland petrels. A sample of Ap horizon soil in lithic contact was selected for analysis, as soil least likely to have been redistributed by petrel burrowing. Chemical removal of mobile organic matter decreased δ 15 N from 14.0 permille (typical of breeding colony soils) to 6.1 permille (within the range of temperate forest soils without sea-bird breeding). δ 13 C values changed little, from -27.1 permille (untreated soil) to -28.4 permille (treated soil), and were typical of forest soil with with C 3 vegetation and no incorporation of marine C. Duplicate AMS radiocarbon analysis of treated sample yielded a combined conventional radiocarbon age of 864 ± 32 BP, indicating that sea-bird breeding could not have occurred at the site for more than 740-960 calendar years. Initial colony occupation may have occurred much later than this, and not been continuous. Sea bird species other than Westland petrels may also have used the site. (author). 30 refs., 2 figs

  5. Effects of protozoan grazing on colony formation in Phaeocystis globosa (Prymnesiophyceae) and the potential costs and benefits

    DEFF Research Database (Denmark)

    Jakobsen, Hans Henrik; Tang, K.W.

    2002-01-01

    . scintillans increased the mean colony size by up to 50 % relative to the controls, whereas grazing by G. dominans enhanced the mean colony size by up to 3-fold. Microscopic observations confirmed that N. scintillans was also able to ingest small colonies. In contrast, G. dominans apparently did not ingest...

  6. Chlamydiaceae in North Atlantic Seabirds Admitted to a Wildlife Rescue Center in Western France.

    Science.gov (United States)

    Aaziz, R; Gourlay, P; Vorimore, F; Sachse, K; Siarkou, V I; Laroucau, K

    2015-07-01

    Birds are the primary hosts of Chlamydia psittaci, a bacterium that can cause avian chlamydiosis in birds and psittacosis in humans. Wild seabirds are frequently admitted to wildlife rescue centers (WRC) at European Atlantic coasts, for example, in connection with oil spills. To investigate the extent of chlamydial shedding by these birds and the resulting risk for animals in care and the medical staff, seabirds from a French WRC were sampled from May 2011 to January 2014. By use of a quantitative PCR (qPCR), 195 seabirds belonging to 4 orders, 5 families and 13 species were examined, of which 18.5% proved to be Chlamydiaceae positive. The highest prevalence of shedders was found in northern gannets (Morus bassanus) (41%), followed by European herring gulls (Larus argentatus) (14%) and common murres (Uria aalge) (7%). Molecular characterization and phylogenetic analysis of qPCR-positive northern gannet samples revealed two variants of a strain closely related to C. psittaci. In European herring gulls and in one common murre, strains showing high sequence similarity to the atypical Chlamydiaceae-like C122 previously found in gulls were detected. Our study shows that seabirds from the northeastern Atlantic Ocean carry several chlamydial organisms, including C. psittaci-related strains. The staff in WRCs should take protective measures, particularly in the case of mass admissions of seabirds. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. HONEY BEE COLONY PHEROMONES

    Directory of Open Access Journals (Sweden)

    M Dražić

    2001-09-01

    Full Text Available ABSTRACT Pheromones are chemicals produced as liquids by specialised cells or glands and transmitted into the environment as liquids or gases. In contrary to hormones, which are excreted in organism and have effect exclusively on organism that produced them, pheromones are excreted outside organism and effect on different individuals of the same species. Pheromones mediate nearly all aspects of honeybee colony life including social defence, brood care, mating, orientation, foraging and reproduction. Pheromone investigation has high economic importance. With use of pheromones it is possible to manipulate with pest insects on crops or to direct honeybees during pollination on target plants.

  8. Seabirds, gyres and global trends in plastic pollution

    International Nuclear Information System (INIS)

    Franeker, Jan A. van; Law, Kara Lavender

    2015-01-01

    Fulmars are effective biological indicators of the abundance of floating plastic marine debris. Long-term data reveal high plastic abundance in the southern North Sea, gradually decreasing to the north at increasing distance from population centres, with lowest levels in high-arctic waters. Since the 1980s, pre-production plastic pellets in North Sea fulmars have decreased by ∼75%, while user plastics varied without a strong overall change. Similar trends were found in net-collected floating plastic debris in the North Atlantic subtropical gyre, with a ∼75% decrease in plastic pellets and no obvious trend in user plastic. The decreases in pellets suggest that changes in litter input are rapidly visible in the environment not only close to presumed sources, but also far from land. Floating plastic debris is rapidly “lost” from the ocean surface to other as-yet undetermined sinks in the marine environment. - Highlights: • Seabirds are effective biological monitors of floating plastic marine debris. • Plastics in fulmar stomachs and in the North Atlantic gyre show similar trends. • Pre-production plastic pellets show strong decreases in fulmars and in the gyre. • These data show that floating plastics rapidly disappear from the ocean surface. - Long term studies give evidence that reduced input of plastic debris into the ocean becomes rapidly visible. Floating plastics disappear to as-yet undetermined sinks

  9. Seabird species vary in behavioural response to drone census.

    Science.gov (United States)

    Brisson-Curadeau, Émile; Bird, David; Burke, Chantelle; Fifield, David A; Pace, Paul; Sherley, Richard B; Elliott, Kyle H

    2017-12-20

    Unmanned aerial vehicles (UAVs) provide an opportunity to rapidly census wildlife in remote areas while removing some of the hazards. However, wildlife may respond negatively to the UAVs, thereby skewing counts. We surveyed four species of Arctic cliff-nesting seabirds (glaucous gull Larus hyperboreus, Iceland gull Larus glaucoides, common murre Uria aalge and thick-billed murre Uria lomvia) using a UAV and compared censusing techniques to ground photography. An average of 8.5% of murres flew off in response to the UAV, but >99% of those birds were non-breeders. We were unable to detect any impact of the UAV on breeding success of murres, except at a site where aerial predators were abundant and several birds lost their eggs to predators following UAV flights. Furthermore, we found little evidence for habituation by murres to the UAV. Most gulls flew off in response to the UAV, but returned to the nest within five minutes. Counts of gull nests and adults were similar between UAV and ground photography, however the UAV detected up to 52.4% more chicks because chicks were camouflaged and invisible to ground observers. UAVs provide a less hazardous and potentially more accurate method for surveying wildlife. We provide some simple recommendations for their use.

  10. Modelling seabird collision risk with off-shore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Mateos, Maria; Arroyo, Gonzalo Munoz; Rosario, Jose Juan Alonso del

    2011-07-01

    Full text: Recent concern about the adverse effects of collision mortality of avian migrants at wind farms has highlighted the need to understand bird-wind turbine interactions. Here, a stochastic collision model, based on data of seabird behaviour collected on- site, is presented, as a flexible and easy to take tool to assess the collisions probabilities of off-shore wind farms in a pre-construction phase. The collision prediction model considering the wind farm area as a risk window has been constructed as a stochastic model for avian migrants, based on Monte Carlo simulation. The model calculates the probable number of birds collided per time unit. Migration volume, wind farm dimensions, vertical and horizontal distribution of the migratory passage, flight direction and avoidance rates, between other variables, are taken into account in different steps of the model as the input variables. In order to assess the weighted importance of these factors on collision probability predictions, collision probabilities obtained from the set of scenarios resulting from the different combinations of the input variables were modelled by using Generalised Additive Models. The application of this model to a hypothetical project for erecting a wind farm at the Strait of Gibraltar showed that collision probability, and consequently mortality rates, strongly depend on the values of the avoidance rates taken into account, and the distribution of birds into the different altitude layers. These parameters should be considered as priorities to be addressed in post-construction studies. (Author)

  11. Analysis of Colonial Currency

    Science.gov (United States)

    Kurkowski, Michael; Cangany, Catherine; Jordan, Louis; Manukyan, Khachatur; Schultz, Zachary; Wiescher, Michael

    2017-09-01

    This project entailed studying the cellulose in paper, the ink, colorants, and other materials used to produce American colonial currency. The technique primarily used in this project was X-Ray Fluorescence Spectroscopy (XRF). XRF mapping was used to provide both elemental analysis of large-scale objects as well as microscopic examination of individual pigment particles in ink, in addition to the inorganic additives used to prepare paper. The combination of elemental mapping with Fourier Transform Infrared (FTIR) and Raman Spectroscopies permits an efficient analysis of the currency. These spectroscopic methods help identify the molecular composition of the pigments. This combination of atomic and molecular analytical techniques provided an in-depth characterization of the paper currency on the macro, micro, and molecular levels. We have identified several of pigments that were used in the preparation of inks and colorants. Also, different inorganic crystals, such as alumina-silicates, have been detected in different papers. The FTIR spectroscopy allowed us to determine the type of cellulose fiber used in the production of paper currency. Our future research will be directed toward revealing important historical relationships between currencies printed throughout the colonies. ISLA Da Vinci Grant.

  12. Tamaño y composición de la colonia de tres especies de hormigas del género Pogonomyrmex (Hymenoptera: Formicidae en la porción central del desierto del Monte, Argentina Colony size and composition in three Pogonomyrmex ant species (Hymenoptera: Formicidae in the central Monte desert, Argentina

    Directory of Open Access Journals (Sweden)

    Beatriz E. Nobua Behrmann

    2010-06-01

    Full Text Available El tamaño de la colonia es un atributo fundamental en la biología de las hormigas ya que está asociado a características ecológicamente relevantes, como sus estrategias de alimentación. Mientras que el tamaño de la colonia de varias especies de hormigas granívoras del género Pogonomyrmex de América del Norte se ha estudiado en detalle, no existe tal información para las especies de América del Sur. En este trabajo, se determinó el tamaño y la composición de la colonia y se describió la estructura del nido de tres especies de Pogonomyrmex que habitan la porción central del desierto del Monte en Argentina: P. mendozanus Cuezzo & Claver, P. inermis Forel y P. rastratus Mayr. Para ello, se excavaron dos nidos de cada especie y se recolectaron todos los individuos encontrados. Las tres especies tienen colonias pequeñas, compuestas por 300-1.100 individuos, de los cuales aproximadamente el 70% son obreras adultas. La estructura de sus nidos es relativamente simple, similar a la de la mayoría de las especies norteamericanas estudiadas, pero con un menor desarrollo en profundidad y un número menor de cámaras; probablemente se deba al menor número de obreras que poseen. Estas características (colonias pequeñas y nidos poco desarrollados son consideradas típicas para las especies del género Pogonomyrmex de América del Sur, lo que las diferencia de la mayoría de sus congéneres estudiados en América del Norte.Colony size in ants is associated with important ecological characteristics such as foraging strategy. Though colony size has been studied with some detail for several North American species of Pogonomyrmex harvester ants, it remains unknown for South American species. We studied colony size, composition, and nest structure of three species of Pogonomyrmex harvester ants inhabiting the central Monte desert in Argentina: P. mendozanus Cuezzo & Claver, P. inermis Forel and P. rastratus Mayr. We excavated two nests of each

  13. Seabird data collected by the Grand Banks offshore hydrocarbon industry 1999-2002 : results, limitations and suggestions for improvement

    International Nuclear Information System (INIS)

    Baillie, S.M.; Robertson, G.J.; Wiese, F.K.

    2005-01-01

    Offshore oil operations attract and concentrate migratory seabirds through an artificially enhanced food supply and lights. In order to understand the vulnerability of seabirds near offshore oil facilities, the degree of association of seabirds with these sites must be determined. Offshore oil and gas exploration on Newfoundland's Grand Banks began in the early 1980s, with first oil produced in 1997 at the Hibernia fixed platform. Additional production followed in 2002 from the Terra Nova Floating Production Storage and Offloading Vessel. As the Grand Banks oil industry grows, seismic surveys continue to be conducted and an estimated 30,000 litres of crude oil and synthetic based drilling fluids have been spilled from exploration drilling, development drilling and production oil operations between 1997 and 2002. Most of the spills occurred in winter when the number of seabirds on the Grand Banks are highest and most vulnerable to oil pollution. This report presents an evaluation of the current Grand Banks offshore oil and gas development seabird monitoring programs. It focuses mostly on seabird monitoring on fixed platforms. The objective was to assess the scientific quality of seabird-related industry programs by compiling and summarizing all available spatial and temporal seabird abundance data and deck stranded birds associated with Grand Banks offshore oil platforms from 1997 to 2002. Data on seabird distributions at sea and stranded bird encounters was collected from 8 offshore hydrocarbon sites on the northeastern Grand Banks. It was recommended that a standardized seabird monitoring and observer training program for the offshore operations in the Grand Banks region be implemented. 43 refs., 5 tabs., 16 figs., 3 appendices

  14. Colony Development and Density-Dependent Processes in Breeding Grey Herons

    Directory of Open Access Journals (Sweden)

    Takeshi Shirai

    2013-01-01

    Full Text Available The density-dependent processes that limit the colony size of colonially breeding birds such as herons and egrets remain unclear, because it is difficult to monitor colonies from the first year of their establishment, and the most previous studies have considered mixed-species colonies. In the present study, single-species colonies of the Grey Heron (Ardea cinerea were observed from the first year of their establishment for 16 years in suburban Tokyo. Colony size increased after establishment, illustrating a saturation curve. The breeding duration (days from nest building to fledging by a pair increased, but the number of fledglings per nest decreased, with colony size. The reproductive season in each year began earlier, and there was greater variation in the timing of individual breeding when the colony size was larger. The prolonged duration until nestling feeding by early breeders of the colony suggests that herons at the beginning of the new breeding season exist in an unsteady state with one another, likely owing to interactions with immigrant individuals. Such density-dependent interference may affect reproductive success and limit the colony size of Grey Herons.

  15. Predicting seasonal variations in coastal seabird habitats in the English Channel and the Bay of Biscay

    Science.gov (United States)

    Virgili, A.; Lambert, C.; Pettex, E.; Dorémus, G.; Van Canneyt, O.; Ridoux, V.

    2017-07-01

    Seabirds, like all animals, have to live in suitable habitats to fulfil their energetic needs for both somatic and reproductive growth and maintenance. Apart from migration trips, all coastal seabirds are linked to the coast, because they need to return daily to land for resting or breeding. Their use of marine habitats strongly depends on their biology, but also on environmental conditions, and can be described using habitat models. This study aimed to: (1) identify the processes that mostly influence seabird distributions along the coasts of the English Channel and the Bay of Biscay; (2) determine seasonal variations of these processes, (3) provide prediction maps that describe the species distributions. We collected data of coastal seabird sightings from aerial surveys carried out in the English Channel and the eastern North Atlantic in the winter 2011-2012 and summer 2012. We classified seabirds into morphological groups and described their habitats using physiographic and oceanographic variables in Generalised Additive Models (GAMs). Finally, we produced maps of predicted distributions by season for each group. The distributions of coastal seabirds were essentially determined by the distance to the nearest coast, with a weaker influence of oceanographic variables. The nature of the substrate, sand or rock, combined with the timing of reproduction, also contributed to determine seasonal at-sea distributions for some species. The highest densities were predicted near the coast, particularly in bays and estuaries for strictly coastal species with possible variations depending on the season. From this study, we were able to predict the seasonal distribution of the studied species according to varying environmental parameters that changed over time, allowing us to understand better their behaviour and ecology.

  16. Using seabird habitat modeling to inform marine spatial planning in central California's National Marine Sanctuaries.

    Directory of Open Access Journals (Sweden)

    Jennifer McGowan

    Full Text Available Understanding seabird habitat preferences is critical to future wildlife conservation and threat mitigation in California. The objective of this study was to investigate drivers of seabird habitat selection within the Gulf of the Farallones and Cordell Bank National Marine Sanctuaries to identify areas for targeted conservation planning. We used seabird abundance data collected by the Applied California Current Ecosystem Studies Program (ACCESS from 2004-2011. We used zero-inflated negative binomial regression to model species abundance and distribution as a function of near surface ocean water properties, distances to geographic features and oceanographic climate indices to identify patterns in foraging habitat selection. We evaluated seasonal, inter-annual and species-specific variability of at-sea distributions for the five most abundant seabirds nesting on the Farallon Islands: western gull (Larus occidentalis, common murre (Uria aalge, Cassin's auklet (Ptychorampus aleuticus, rhinoceros auklet (Cerorhinca monocerata and Brandt's cormorant (Phalacrocorax penicillatus. The waters in the vicinity of Cordell Bank and the continental shelf east of the Farallon Islands emerged as persistent and highly selected foraging areas across all species. Further, we conducted a spatial prioritization exercise to optimize seabird conservation areas with and without considering impacts of current human activities. We explored three conservation scenarios where 10, 30 and 50 percent of highly selected, species-specific foraging areas would be conserved. We compared and contrasted results in relation to existing marine protected areas (MPAs and the future alternative energy footprint identified by the California Ocean Uses Atlas. Our results show that the majority of highly selected seabird habitat lies outside of state MPAs where threats from shipping, oil spills, and offshore energy development remain. This analysis accentuates the need for innovative marine

  17. Wide range of metallic and organic contaminants in various tissues of the Antarctic prion, a planktonophagous seabird from the Southern Ocean

    International Nuclear Information System (INIS)

    Fromant, Aymeric; Carravieri, Alice; Bustamante, Paco; Labadie, Pierre; Budzinski, Hélène; Peluhet, Laurent; Churlaud, Carine; Chastel, Olivier; Cherel, Yves

    2016-01-01

    ABSTRACT: Trace elements (n = 14) and persistent organic pollutants (POPs, n = 30) were measured in blood, liver, kidney, muscle and feathers of 10 Antarctic prions (Pachyptila desolata) from Kerguelen Islands, southern Indian Ocean, in order to assess their concentrations, tissue distribution, and inter-tissue and inter-contaminant relationships. Liver, kidney and feathers presented the highest burdens of arsenic, cadmium and mercury, respectively. Concentrations of cadmium, copper, iron, and zinc correlated in liver and muscle, suggesting that uptake and pathways of metabolism and storage were similar for these elements. The major POPs were 4,4′-DDE, mirex, PCB-153 and PCB-138. The concentrations and tissue distribution patterns of environmental contaminants were overall in accordance with previous results in other seabirds. Conversely, some Antarctic prions showed surprisingly high concentrations of BDE-209. This compound has been rarely observed in seabirds before, and its presence in Antarctic prions could be due to the species feeding habits or to the ingestion of plastic debris. Overall, the study shows that relatively lower trophic level seabirds (zooplankton-eaters) breeding in the remote southern Indian Ocean are exposed to a wide range of environmental contaminants, in particular cadmium, selenium and some emerging-POPs, which merits further toxicological investigations. - Highlights: • Trace elements and POPs were measured in various tissues of 10 Antarctic prions. • Residue diversity was notable given the species' small size and low trophic position. • Cd, Se, BDE 183 and 209 showed noticeably high internal tissue concentrations. • Several POPs showed inter- and intra-tissue correlations, indicating co-exposure. • Blood was validated as a good bioindicator of internal tissue As and Hg levels.

  18. Wide range of metallic and organic contaminants in various tissues of the Antarctic prion, a planktonophagous seabird from the Southern Ocean

    Energy Technology Data Exchange (ETDEWEB)

    Fromant, Aymeric [Centre d' Etudes Biologiques de Chizé, UMR 7372 CNRS—Université de La Rochelle, 79360 Villiers-en-Bois (France); Carravieri, Alice, E-mail: carravieri@cebc.cnrs.fr [Centre d' Etudes Biologiques de Chizé, UMR 7372 CNRS—Université de La Rochelle, 79360 Villiers-en-Bois (France); Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS—Université de la Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle (France); Bustamante, Paco [Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS—Université de la Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle (France); Labadie, Pierre; Budzinski, Hélène; Peluhet, Laurent [Université de Bordeaux, UMR 5805 EPOC (LPTC Research Group), Université Bordeaux, 351 Cours de la Libération, F 33405 Talence Cedex (France); Churlaud, Carine [Littoral Environnement et Sociétés (LIENSs), UMR 7266 CNRS—Université de la Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle (France); Chastel, Olivier; Cherel, Yves [Centre d' Etudes Biologiques de Chizé, UMR 7372 CNRS—Université de La Rochelle, 79360 Villiers-en-Bois (France)

    2016-02-15

    ABSTRACT: Trace elements (n = 14) and persistent organic pollutants (POPs, n = 30) were measured in blood, liver, kidney, muscle and feathers of 10 Antarctic prions (Pachyptila desolata) from Kerguelen Islands, southern Indian Ocean, in order to assess their concentrations, tissue distribution, and inter-tissue and inter-contaminant relationships. Liver, kidney and feathers presented the highest burdens of arsenic, cadmium and mercury, respectively. Concentrations of cadmium, copper, iron, and zinc correlated in liver and muscle, suggesting that uptake and pathways of metabolism and storage were similar for these elements. The major POPs were 4,4′-DDE, mirex, PCB-153 and PCB-138. The concentrations and tissue distribution patterns of environmental contaminants were overall in accordance with previous results in other seabirds. Conversely, some Antarctic prions showed surprisingly high concentrations of BDE-209. This compound has been rarely observed in seabirds before, and its presence in Antarctic prions could be due to the species feeding habits or to the ingestion of plastic debris. Overall, the study shows that relatively lower trophic level seabirds (zooplankton-eaters) breeding in the remote southern Indian Ocean are exposed to a wide range of environmental contaminants, in particular cadmium, selenium and some emerging-POPs, which merits further toxicological investigations. - Highlights: • Trace elements and POPs were measured in various tissues of 10 Antarctic prions. • Residue diversity was notable given the species' small size and low trophic position. • Cd, Se, BDE 183 and 209 showed noticeably high internal tissue concentrations. • Several POPs showed inter- and intra-tissue correlations, indicating co-exposure. • Blood was validated as a good bioindicator of internal tissue As and Hg levels.

  19. Behavioural mapping of a pelagic seabird: combining multiple sensors and a hidden Markov model reveals the distribution of at-sea behaviour

    Science.gov (United States)

    Dean, Ben; Freeman, Robin; Kirk, Holly; Leonard, Kerry; Phillips, Richard A.; Perrins, Chris M.; Guilford, Tim

    2013-01-01

    The use of miniature data loggers is rapidly increasing our understanding of the movements and habitat preferences of pelagic seabirds. However, objectively interpreting behavioural information from the large volumes of highly detailed data collected by such devices can be challenging. We combined three biologging technologies—global positioning system (GPS), saltwater immersion and time–depth recorders—to build a detailed picture of the at-sea behaviour of the Manx shearwater (Puffinus puffinus) during the breeding season. We used a hidden Markov model to explore discrete states within the combined GPS and immersion data, and found that behaviour could be organized into three principal activities representing (i) sustained direct flight, (ii) sitting on the sea surface, and (iii) foraging, comprising tortuous flight interspersed with periods of immersion. The additional logger data verified that the foraging activity corresponded well to the occurrence of diving. Applying this approach to a large tracking dataset revealed that birds from two different colonies foraged in local waters that were exclusive, but overlapped in one key area: the Irish Sea Front (ISF). We show that the allocation of time to each activity differed between colonies, with birds breeding furthest from the ISF spending the greatest proportion of time engaged in direct flight and the smallest proportion of time engaged in foraging activity. This type of analysis has considerable potential for application in future biologging studies and in other taxa. PMID:23034356

  20. Characterization of (241)Pu occurrence, distribution, and bioaccumulation in seabirds from northern Eurasia.

    Science.gov (United States)

    Strumińska-Parulska, Dagmara I; Skwarzec, Bogdan

    2015-05-01

    The paper presents unique data of plutonium (241)Pu study in seabirds from northern Eurasia, permanently or temporally living at the southern Baltic Sea coast. Together, ten marine birds species were examined, as follows: three species that permanently reside at the southern Baltic, four species of wintering birds, and three species of migrating birds; 366 samples were analyzed. The obtained results indicated plutonium was non-uniformly distributed in organs and tissues of analyzed seabirds. The highest (241)Pu content was found in the digestion organs and feathers, the lowest in muscles. Also, the internal radiation doses from (241)Pu were evaluated.

  1. Effects of changes in sandeel availability on the reproductive output of seabirds

    DEFF Research Database (Denmark)

    Rindorf, Anna; Wanless, S.; Harris, M.P.

    2000-01-01

    The lesser sandeel Ammodytes marinus is a key prey species for many marine birds in the North Sea. This fish is currently the target of the largest single species fishery in the area, and this has led to concern about the potential impact of the fishery on seabirds. There are 2 critical issues...... productivity, breeding effort and diet in 3 species of seabird with contrasting foraging and dietary characteristics (common guillemot Uria aalge, black-legged kittiwake Rissa tridactyla, and European shag Phalacrocorax aristotelis) and an index of availability of 1 group and older sandeels derived from catch...

  2. A critical number of workers in a honeybee colony triggers investment in reproduction.

    Science.gov (United States)

    Smith, Michael L; Ostwald, Madeleine M; Loftus, J Carter; Seeley, Thomas D

    2014-10-01

    Social insect colonies, like individual organisms, must decide as they develop how to allocate optimally their resources among survival, growth, and reproduction. Only when colonies reach a certain state do they switch from investing purely in survival and growth to investing also in reproduction. But how do worker bees within a colony detect that their colony has reached the state where it is adaptive to begin investing in reproduction? Previous work has shown that larger honeybee colonies invest more in reproduction (i.e., the production of drones and queens), however, the term 'larger' encompasses multiple colony parameters including number of adult workers, size of the nest, amount of brood, and size of the honey stores. These colony parameters were independently increased in this study to test which one(s) would increase a colony's investment in reproduction via males. This was assayed by measuring the construction of drone comb, the special type of comb in which drones are reared. Only an increase in the number of workers stimulated construction of drone comb. Colonies with over 4,000 workers began building drone comb, independent of the other colony parameters. These results show that attaining a critical number of workers is the key parameter for honeybee colonies to start to shift resources towards reproduction. These findings are relevant to other social systems in which a group's members must adjust their behavior as a function of the group's size.

  3. A critical number of workers in a honeybee colony triggers investment in reproduction

    Science.gov (United States)

    Smith, Michael L.; Ostwald, Madeleine M.; Loftus, J. Carter; Seeley, Thomas D.

    2014-10-01

    Social insect colonies, like individual organisms, must decide as they develop how to allocate optimally their resources among survival, growth, and reproduction. Only when colonies reach a certain state do they switch from investing purely in survival and growth to investing also in reproduction. But how do worker bees within a colony detect that their colony has reached the state where it is adaptive to begin investing in reproduction? Previous work has shown that larger honeybee colonies invest more in reproduction (i.e., the production of drones and queens), however, the term `larger' encompasses multiple colony parameters including number of adult workers, size of the nest, amount of brood, and size of the honey stores. These colony parameters were independently increased in this study to test which one(s) would increase a colony's investment in reproduction via males. This was assayed by measuring the construction of drone comb, the special type of comb in which drones are reared. Only an increase in the number of workers stimulated construction of drone comb. Colonies with over 4,000 workers began building drone comb, independent of the other colony parameters. These results show that attaining a critical number of workers is the key parameter for honeybee colonies to start to shift resources towards reproduction. These findings are relevant to other social systems in which a group's members must adjust their behavior as a function of the group's size.

  4. Integrating population and genetic monitoring to understand changes in the abundance of a threatened seabird

    Science.gov (United States)

    Catalina Vásquez-Carrillo; R. William Henry; Laird Henkel; M. Zachariah. Peery

    2013-01-01

    Population monitoring programs for threatened species are rarely designed to disentangle the effects of movements from changes in birth and death rates on estimated trends in abundance. Here, we illustrate how population and genetic monitoring can be integrated to understand the cause of large changes in the abundance of a threatened species of seabird, the Marbled...

  5. Comparison of trends in abundance of guano-producing seabirds in ...

    African Journals Online (AJOL)

    The abundant guano-producing seabirds in Peru and southern Africa feed mainly on the large populations of anchovy Engraulis spp. and sardine Sardinops sagax supported by the Humboldt and Benguela upwelling systems. Numbers of guanay cormorants Phalacrocorax bougainvillii in Peru and the breeding population ...

  6. Positive Interactions among Foraging Seabirds, Marine Mammals and Fishes and Implications for Their Conservation

    Directory of Open Access Journals (Sweden)

    Richard R. Veit

    2017-10-01

    Full Text Available There is increasing recognition of the importance of “positive interactions” among species in structuring communities. For seabirds, an important kind of positive interaction is the use of birds of the same species, birds of other species, and other marine predators such as cetaceans, seals and fishes as cues to the presence of prey. The process by which a single bird uses, say, a feeding flock of birds as a cue to the presence of prey is called “local enhancement” or “facilitation.” There are subtly different uses of each of these terms, but the issue we address here is the ubiquity of positive interactions between seabirds and other marine predators when foraging at sea, and whether as a result of their associations the feeding success, and therefore presumably the fitness, of individual seabirds is increased. If this contention is true, then it implies that conservation of any one species of seabird must take into consideration the status and possible conservation of those species that the focal species uses as a cue while foraging. For example, conservation of great shearwaters (Ardenna gravis, which often feed over tuna (e.g., Thunnus schools, should take in to consideration conservation of tuna. Ecosystem management depends on understanding the importance of such processes; the loss of biodiversity, and the consequent threat to foraging success, may be a substantial threat to the stability of marine ecosystems.

  7. Increasing frequency of plastic particles ingested by seabirds in the subarctic North Pacific

    Science.gov (United States)

    Robards, Martin D.; Piatt, John F.; Wohl, Kenton D.

    1995-01-01

    We examined gut contents of 1799 seabirds comprising 24 species collected in 1988-1990 to assess the types and quantities of plastic particles ingested by seabirds in the subarctic waters of Alaska. Of the 15 species found to ingest plastic, most were surface-feeders (shearwaters, petrels, gulls) or plankton-feeding divers (auklets, puffins). Of 4417 plastic particles examined, 76% were industrial pellets and 21% were fragments of ‘user’ plastic. Ingestion rates varied geographically, but no trends were evident and rates of plastic ingestion varied far more among species within areas than within species among areas. Comparison with similar data from 1968 seabirds comprising 37 species collected in 1969-1977 revealed that plastic ingestion by seabirds has increased significantly during the 10–15-year interval between studies. This was demonstrated by: (i) an increase in the total number of species ingesting plastic; (ii) an increase in the frequency of occurrence of plastic particles within species that ingested plastic; and, (iii) an increase in the mean number of plastic particles ingested by individuals of those species.

  8. Bibliography of seabirds in the waters of Southern Africa, the Prince Edward and Tristan groups

    CSIR Research Space (South Africa)

    Cooper, J

    1981-12-01

    Full Text Available The titles of 2 088 publications are given which refer to seabirds in the waters of southern Africa, the Prince Edward Islands, the Tristan da Cunha group and Gough Island. An index lists the relevant publications by number for 117 species...

  9. Front affecting the distribution of seabirds in the northern Bering Sea

    OpenAIRE

    Harrison, Nancy M.; L Hunt Jr., George; Cooney, Robert T.

    1990-01-01

    We observed seabirds aggregated at a front marking the boundary between two water masses in the Bering Sea. Least Auklets (Aethia pusilla) were most abundant at the front; surface-feeding species including Northern Fulmars (Fulmarus glacialis), Black-legged Kittiwakes (Rissa tridactyla) and Red Phalaropes (Phalaropusfuscus) were also present.

  10. The most common diet results in low reproduction in a generalist seabird

    NARCIS (Netherlands)

    van Donk, S.; Camphuysen, K.C.J.; Shamoun-Baranes, J.; van der Meer, J.

    2017-01-01

    Dietary specialization has been described across a wide range of taxa in the animal kingdom. Fitness consequences are, however, not well documented. We examined the reproductive consequences of different dietary specializations in the herring gull Larus argentatus, an omnivorous seabird, using an

  11. Seabird aggregative patterns: a new tool for offshore wind energy risk assessment.

    Science.gov (United States)

    Christel, Isadora; Certain, Grégoire; Cama, Albert; Vieites, David R; Ferrer, Xavier

    2013-01-15

    The emerging development of offshore wind energy has raised public concern over its impact on seabird communities. There is a need for an adequate methodology to determine its potential impacts on seabirds. Environmental Impact Assessments (EIAs) are mostly relying on a succession of plain density maps without integrated interpretation of seabird spatio-temporal variability. Using Taylor's power law coupled with mixed effect models, the spatio-temporal variability of species' distributions can be synthesized in a measure of the aggregation levels of individuals over time and space. Applying the method to a seabird aerial survey in the Ebro Delta, NW Mediterranean Sea, we were able to make an explicit distinction between transitional and feeding areas to define and map the potential impacts of an offshore wind farm project. We use the Ebro Delta study case to discuss the advantages of potential impacts maps over density maps, as well as to illustrate how these potential impact maps can be applied to inform on concern levels, optimal EIA design and monitoring in the assessment of local offshore wind energy projects. Copyright © 2012 Elsevier Ltd. All rights reserved.

  12. 78 FR 66686 - Takes of Marine Mammals Incidental to Specified Activities; Seabird and Pinniped Research...

    Science.gov (United States)

    2013-11-06

    .... Researchers would conduct occasional, intermittent visits during the rest of the year. A majority of the... immature seals and adult females return to molt. During the time they are onshore they are fasting (NPS.... Landing--403. ANI Seabird Monitoring 68 1 Other Areas--12...... Other Areas--816. ANI Intermittent...

  13. 76 FR 46724 - Takes of Marine Mammals Incidental to Specified Activities; Seabird and Pinniped Research...

    Science.gov (United States)

    2011-08-03

    ... Nuevo Island, and Point Reyes National Seashore in central California (CA) for one year. PRBO, along... research activities for one year. NMFS reviewed PRBO's application and identified a number of issues...; observing seabird nesting habitat; restoring nesting burrows; observing breeding elephant seals, and...

  14. Pulau Ling: an important seabird hotspot on the east coast of Peninsular Malaysia

    Directory of Open Access Journals (Sweden)

    Abdulmaula Hamza

    2016-12-01

    Full Text Available Pulau Ling is a small rocky island located to the south of Pulau Redang, forming with other southeast small islands, the Redang Archipelago, in the state of Terengganu, Malaysia. The island was highlighted in the early 1950s as an important seabird site, although little was then known on the status of seabirds on the island. Field visits were made between May 2015 and September 2015 to assess the importance of this small island to seabird species. Four tern species were identified: two of them, black-naped tern Sterna sumatrana and bridled tern Onychoprion anaethetus, were found to breed there, while the other two species, great crested tern Thalasseus bergii and roseate tern Sterna dougallii were found to use the island as a stopover site without any evidence of breeding. Furthermore, the Pacific Eastern Reef egret Egretta sacra (the black morph, was also found to breed on the island. Other species encountered included white-bellied sea eagle Haliaeetus leucogaster (recorded once in June 2015, soaring over the island. These preliminary data show the importance of such small rocky outcrops for tropical breeding and migrating seabirds, where food availability and lack of disturbance may be the two main drivers for diversity and survival.

  15. Genetic diversity affects colony survivorship in commercial honey bee colonies

    Science.gov (United States)

    Tarpy, David R.; vanEngelsdorp, Dennis; Pettis, Jeffrey S.

    2013-08-01

    Honey bee ( Apis mellifera) queens mate with unusually high numbers of males (average of approximately 12 drones), although there is much variation among queens. One main consequence of such extreme polyandry is an increased diversity of worker genotypes within a colony, which has been shown empirically to confer significant adaptive advantages that result in higher colony productivity and survival. Moreover, honey bees are the primary insect pollinators used in modern commercial production agriculture, and their populations have been in decline worldwide. Here, we compare the mating frequencies of queens, and therefore, intracolony genetic diversity, in three commercial beekeeping operations to determine how they correlate with various measures of colony health and productivity, particularly the likelihood of queen supersedure and colony survival in functional, intensively managed beehives. We found the average effective paternity frequency ( m e ) of this population of honey bee queens to be 13.6 ± 6.76, which was not significantly different between colonies that superseded their queen and those that did not. However, colonies that were less genetically diverse (headed by queens with m e ≤ 7.0) were 2.86 times more likely to die by the end of the study when compared to colonies that were more genetically diverse (headed by queens with m e > 7.0). The stark contrast in colony survival based on increased genetic diversity suggests that there are important tangible benefits of increased queen mating number in managed honey bees, although the exact mechanism(s) that govern these benefits have not been fully elucidated.

  16. Worker life tables, survivorship, and longevity in colonies of Bombus (Fervidobombus atratus (Hymenoptera: Apidae

    Directory of Open Access Journals (Sweden)

    Eunice Vieira da Silva-Matos

    2000-06-01

    Full Text Available Survivorship curves and longevity of workers were studied in two queenright and two queenless colonies of Bombus (Fervidobombus atratus. Survivorship curves for workers of all colonies were, in general, convex, indicating an increasing mortality rate with increasing age. The mean longevity for the workers from queenright colonies, 24.3 days and 17.6 days, was not significantly different from that in queenless colonies, 21.2 days and 20.2 days. In all colonies workers started foraging activities when aged 0-5 days, and the potential forager rates rose progressively with increasing age. Mortality rates within each age interval were significantly correlated with the foraging worker rates in all colonies. Only in two of the colonies (one queenright and one queenless longevity was significantly correlated with worker size. The duration of brood development period seems to be one of the most important factors influencing adult worker longevity in this bumble bee species.

  17. Colonial Figures: Memories of Street Traders in the Colonial and Early Post-colonial Periods

    Directory of Open Access Journals (Sweden)

    Sheri Lynn Gibbings

    2012-12-01

    Full Text Available This article explores post-colonial memories about street traders among individuals who lived in the former colony of the Dutch East Indies. It argues that these narratives romanticize the relationship between Europeans and indigenous peoples. Street vendors are also used to differentiate between periods within colonial and post-colonial history. The nostalgic representation of interracial contact between Europeans and traders is contrasted with representations of other figures such as the Japanese and the nationalist. A recurring feature of these representations is the ability of Europeans to speak with street traders and imagine what they wanted and needed. The traders are remembered as a social type that transgressed politics and represented the neutrality of the economic sphere as a place for shared communication. The article concludes that the figure of the street vendor contributes to the nostalgic reinvention of the colony but is also used in narratives to differentiate between and mark changes across the colonial and post-colonial periods.

  18. JAX Colony Management System (JCMS): an extensible colony and phenotype data management system.

    Science.gov (United States)

    Donnelly, Chuck J; McFarland, Mike; Ames, Abigail; Sundberg, Beth; Springer, Dave; Blauth, Peter; Bult, Carol J

    2010-04-01

    The Jackson Laboratory Colony Management System (JCMS) is a software application for managing data and information related to research mouse colonies, associated biospecimens, and experimental protocols. JCMS runs directly on computers that run one of the PC Windows operating systems, but can be accessed via web browser interfaces from any computer running a Windows, Macintosh, or Linux operating system. JCMS can be configured for a single user or multiple users in small- to medium-size work groups. The target audience for JCMS includes laboratory technicians, animal colony managers, and principal investigators. The application provides operational support for colony management and experimental workflows, sample and data tracking through transaction-based data entry forms, and date-driven work reports. Flexible query forms allow researchers to retrieve database records based on user-defined criteria. Recent advances in handheld computers with integrated barcode readers, middleware technologies, web browsers, and wireless networks add to the utility of JCMS by allowing real-time access to the database from any networked computer.

  19. The Future Lunar Flora Colony

    Science.gov (United States)

    Goel, E. G.; Guven, U. G.

    2017-10-01

    A constructional design for the primary establishment for a lunar colony using the micrometeorite rich soil is proposed. It highlights the potential of lunar regolith combined with Earth technology for water and oxygen for human outposts on the Moon.

  20. A comparison of two seabird communities on opposite coasts of the Alborán Sea (western Mediterranean

    Directory of Open Access Journals (Sweden)

    Mariano Paracuellos

    2003-07-01

    Full Text Available We compared the seabird communities at two sites of the southern and northern shores of the Alborán Sea in the Western Mediterranean (Melilla and Adra respectively during a whole year. Similarities and differences in environmental characteristics of the two study sites were caused by a set of geographical, physical and socio-economic human factors. Sampling was performed weekly during two-hour periods by counting seabirds crossing a given point of the coast. We found similarities in the composition and seasonality of the species between Melilla and Adra. However, there were differences between the two sites in the number of species and individuals, which were usually higher on the southern shore. In this area, seabirds depending on marine trophic resources were more abundant, whereas on the northern shore the most abundant seabird species were those whose feeding habits were not so dependent on sea resources.

  1. NOAA ESRI Grid - predictions of seabird diversity in the New York offshore planning area made by the NOAA Biogeography Branch

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset represents seabird diversity predictions from spatial models developed for the New York offshore spatial planning area. This raster was derived from...

  2. Parent–offspring resemblance in colony-specific adult survival of cliff swallows

    Science.gov (United States)

    Brown, Charles R.; Roche, Erin A.; Brown, Mary Bomberger

    2015-01-01

    Survival is a key component of fitness. Species that occupy discrete breeding colonies with different characteristics are often exposed to varying costs and benefits associated with group size or environmental conditions, and survival is an integrative net measure of these effects. We investigated the extent to which survival probability of adult (≥1-year old) cliff swallows (Petrochelidon pyrrhonota) occupying different colonies resembled that of their parental cohort and thus whether the natal colony had long-term effects on individuals. Individuals were cross-fostered between colonies soon after hatching and their presence as breeders monitored at colonies in the western Nebraska study area for the subsequent decade. Colony-specific adult survival probabilities of offspring born and reared in the same colony, and those cross-fostered away from their natal colony soon after birth, were positively and significantly related to subsequent adult survival of the parental cohort from the natal colony. This result held when controlling for the effect of natal colony size and the age composition of the parental cohort. In contrast, colony-specific adult survival of offspring cross-fostered to a site was unrelated to that of their foster parent cohort or to the cohort of non-fostered offspring with whom they were reared. Adult survival at a colony varied inversely with fecundity, as measured by mean brood size, providing evidence for a survival–fecundity trade-off in this species. The results suggest some heritable variation in adult survival, likely maintained by negative correlations between fitness components. The study provides additional evidence that colonies represent non-random collections of individuals.

  3. Agar Technique for the Cultivation In Vitro of Bone-Marrow Colonies

    Energy Technology Data Exchange (ETDEWEB)

    Metcalf, D. [Walter and Eliza Hall Institute, Royal Melbourne Hospital, Melbourne, VIC (Australia)

    1969-07-15

    In solid-state agar cultures certain haemopoietic cells proliferate and form discrete colonies of 200 - 4000 cells. Colony formation is dependent on stimulation by the colony-stimulating factor, and this is achieved by (1) the use of a cell feeder layer, (2) the addition of conditioned medium, or (3) the addition of human or mouse serum or urine containing the factor. All colonies initially contain granulocytic cells which differentiate from myeloblasts to polymorphs as colony growth proceeds. Later colonies develop a second population of phagocytic mononuclear cells (macrophages). The colony-forming-system is simple, readily quantitated and highly reproducible. Linear dose responses occur between the dose of colony-stimulating factor and the number and size of colonies developing from a standard number of bone-marrow cells. In-vitro colony formation has been achieved with haemopoietic cells of the following species: mouse, rat, hamster, guinea pig, rabbit and human. In the adult mouse, colony-forming cells are located in the bone marrow, spleen and blood and in the embryo, in the yolk sac, liver and spleen. The colony-forming cell appears to be an early member of the granulocytic series. The colony-forming system has been used as a quantitative assay system: (1) to assay levels of colony-stimulating factor in serum and urine and in the chemical- characterization and purification of the factor; and (2) to enumerate the number of colony-forming cells in haemopoietic tissues in response to a variety of experimental procedures and disease states. Since the system is applicable to human bone-marrow cells, it should prove of value in the quantitative assay of (1) survival of human bone marrow on storage, and (2) bone-marrow content of granulocytic precursor cells in various disease states and following various types of therapy. The system is not suitable for the mass production in vitro of haemopoietic cells for therapeutic use. (author)

  4. A long-term retrospective study on rehabilitation of seabirds in Gran Canaria Island, Spain (2003-2013.

    Directory of Open Access Journals (Sweden)

    Natalia Montesdeoca

    Full Text Available The aims of this study were to analyze the causes of morbidity and mortality in a large population of seabirds admitted to the Tafira Wildlife Rehabilitation Center (TWRC in Gran Canaria Island, Spain, from 2003 to 2013, and to analyze the outcomes of the rehabilitation process.We included 1,956 seabirds (133 dead on admission and 1,823 admitted alive in this study. Causes of morbidity were classified into nine categories: light pollution (fallout, fishing gear interaction, crude oil, poisoning/intoxication, other traumas, metabolic/nutritional disorder, orphaned young birds, other causes, and unknown/undetermined. The crude and stratified (by causes of admission rates of the three final disposition categories (euthanasia Er, unassisted mortality Mr, and release Rr, the time until death, and the length of stay were also studied for the seabirds admitted alive.Yellow-legged Gull (Larus michahellis was the species most frequently admitted (46.52%, followed by Cory's Shearwater (Calonectris diomedea borealis (20.09%. The most frequent causes of morbidity were light pollution (fallout (25.81%, poisoning/intoxication (24.69%, and other traumas (18.14%. The final disposition rates were: Er = 15.35%, Mr = 16.29%, and Rr = 68.34%. The highest Er was observed in the 'other traumas' category (58.08%. Seabirds admitted due to metabolic/nutritional disorder had the highest Mr (50%. The highest Rr was observed in the light pollution (fallout category (99.20%.This survey provides useful information for the conservation of several seabird species. We suggest that at least the stratified analysis by causes of admission of the three final disposition rates, and the parameters time until death and length of stay at the center should be included in the outcome research of the rehabilitation of seabirds. The high release rate for seabirds (68.34% achieved at the TWRC emphasizes the importance of wildlife rehabilitation centers for the conservation of seabirds.

  5. The relevance of the Mediterranean Region to colonial waterbird conservation

    Science.gov (United States)

    Erwin, R.M.; Crivelli, Alain J.; Hafner, Heinz; Fasola, Mauro; Erwin, R. Michael; McCrimmon, Donald A.=

    1996-01-01

    The Mediterranean Sea is the largest partially enclosed sea in the world and provides habitat to more than 100 species of waterbirds from the Palearctic-North African-Middle Eastern regions. Even though the Mediterranean suffers from pollution, has little tidal influence, and is oligotrophic, more than half of the western Palearctic populations of numerous waterfowl species winter in the region. Thirty-three species of colonial waterbirds breed along the 46,000 km Mediterranean coastline with nine species considered threatened or endangered, mostly because of wetland loss and degradation. The long history of human activity and scientific investigations in the region has taught some valuable lessons. In the area of colonial waterbird biology and conservation, we have learned important lessons about the value of long-term monitoring and research on selected populations. From marking studies of Greater Flamingos (Phoenicopterus ruber roseus) and Little Egrets (Egretta garzetta) results have been used to derive useful information about metapopulation dynamics. Involvement of both African and European biologists allowed year-round Studies of these species that yielded valuable spin-offs for training in avian and wetland conservation. We have also learned the value of man-made wetlands as feeding and nesting sites for some colonial waterbirds. Careful evaluations of the habitat quality of different types of wetlands are required, as in contaminant levels such as lead shot and pesticides. Wetland conservationists have also learned from some instructive mistakes. Dam construction and agricultural incentive programs sponsored by the European Community, the World Bank, and others from the past have largely ignored impacts on wetlands and wildlife. In some areas, economic ventures such as aquaculture operations and salt mining have not involved waterbird habitat needs in their planning. Research and conservation needs include: (1) establishing regional monitoring programs and

  6. Bio-Physical Coupling of Seabirds and Prey with a Dynamic River Plume

    Science.gov (United States)

    Phillips, E. M.; Horne, J. K.; Zamon, J. E.; Adams, J.

    2016-02-01

    Freshwater plumes and plume density fronts are important regions of bio-physical coupling. On the west coast of North America, discharge from the Columbia River into the northern California Current creates a large, dynamic plume and multiple plume fronts. These nutrient-rich, productive waters fuel primary and secondary production, supporting a wide variety of small pelagic prey fish, large populations of Pacific salmon, seabirds, and marine mammals. To determine the influence of the Columbia River plume on marine predators, we analyzed at-sea seabird counts, in situ environmental data, surface trawl densities of prey fish, and acoustic backscatter measurements collected from research vessels in May and June 2010-2012. Concurrent distribution patterns of satellite-tagged sooty shearwaters (Puffinus griseus) and common murres (Uria aalge) were compared with seabird counts from ship surveys. To evaluate plume use by satellite-tagged birds, daily surface salinity values from SELFE hindcast models were extracted at each tag location. Both seabird species occurred in plume waters disproportionate to the total surveyed area, concentrating in the river plume when river flow and plume volume decreased. Murres were consistently within 20 km of the geographic mean center of the river plume. In contrast, shearwaters consistently occurred 100 km to the north of the plume center, where high densities of prey fish occur. Although acoustically detected prey also occurred in greater densities within the plume when volume decreased, surface catches of prey in the plume did not vary with changing plume conditions. Geographic indices of colocation (GIC) were low between murres and prey species caught in surface trawls, whereas GICs were >0.5 between shearwaters and prey species including squid (Loligo opalescens), juvenile Chinook salmon (Oncorhynchus tshawytscha), and coho (O. kisutch) salmon. We conclude that the river plume and associated fronts are identifiable, predictable, and

  7. High nutrient concentration and temperature alleviated formation of large colonies of Microcystis: Evidence from field investigations and laboratory experiments.

    Science.gov (United States)

    Zhu, Wei; Zhou, Xiaohua; Chen, Huaimin; Gao, Li; Xiao, Man; Li, Ming

    2016-09-15

    Correlations between Microcystis colony size and environmental factors were investigated in Meiliang Bay and Gonghu Bay of Lake Taihu (China) from 2011 to 2013. Compared with Gonghu Bay, both nutrient concentrations and Microcystis colony sizes were greater in Meiliang Bay. The median colony size (D50: 50% of the total mass of particles smaller than this size) increased from April to August and then decreased until November. In both bays, the average D50 of Microcystis colonies were 500 μm) dominated in summer. The differences in colony size in Meiliang Bay and Gonghu Bay were probably due to horizontal drift driven by the prevailing south wind in summer. Redundancy analysis (RDA) of field data indicated that colony size was negatively related to nutrient concentrations but positively related to air temperature, suggesting that low nutrient concentrations and high air temperature promoted formation of large colonies. To validate the field survey, Microcystis colonies collected from Lake Taihu were cultured at different temperatures (15, 20, 25 and 30 °C) under high and low nutrient concentrations for 9 days. The size of Microcystis colonies significantly decreased when temperature was above 20 °C but had no significant change at 15 °C. The differences in temperature effects on colony formation shown from field and laboratory suggested that the larger colonies in summer were probably due to the longer growth period rather than the higher air temperature and light intensity. In addition, colony size decreased more significantly at high nutrient levels. Therefore, it could be concluded that high nutrient concentration and temperature may alleviate formation of large colonies of Microcystis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Numerical simulation of the vertical migration of Microcystis (cyanobacteria colonies based on turbulence drag

    Directory of Open Access Journals (Sweden)

    Hongru Zhao

    2016-11-01

    Full Text Available The vertical migration and accumulation of Microcystis is an important process in water blooms, and colony migration is influenced by colony size and wind-wave disturbance. The vertical migration of Microcystis colonies in turbulence can be simulated in a numerical model. In this study, we model such migration by coupling the colony size and hydrodynamics, including the gravity, colony buoyancy, and the viscous drag force of turbulence. The turbulence intensity was represented by the turbulent kinetic energy (KZ; the larger the KZ, the stronger the wind-wave disturbance. The simulated vertical distribution of Microcystis well agreed with the measured values in a laboratory experiment indicating that our model can simulate the vertical distribution of Microcystis under different hydrodynamic conditions. We also found a size-dependent critical turbulent kinetic energy (TKZ, such that if the turbulent kinetic energy of water exceeds the critical value (i.e., KZ > TKZ, the colonies sink under the drag forces of turbulence; conversely, if KZ < TKZ, the colonies can overcome the turbulent mixing and float. The TKZ of each colony was linearly related to colony diameter. The model is crucial for prediction and prevention of water blooms. The simulated threshold turbulent kinetic energy, at which water blooms disappear in Lake Taihu (a large freshwater lake in the Yangtze Delta, Jiangsu Province, China, was 55.5 cm2 s−2. 

  9. Status of breeding seabirds on the Northern Islands of the Red Sea, Saudi Arabia.

    Science.gov (United States)

    Shobrak, Mohammed Y; Aloufi, Abdulhadi A

    2014-07-01

    We undertook breeding surveys between 2010 and 2011 to assess the status of breeding birds on 16 islands in the northern Saudi Arabia. Sixteen bird species were found breeding at three different seasons; i.e. winter (Osprey), spring (Caspian and Saunder's Terns), and summer (Lesser Crested, White-cheeked, Bridled Terns). It is postulated that food availability is an important factor influencing the breeding of seabirds in the northern Saudi Arabian Red Sea. Several species laid eggs earlier in northern parts of the Red Sea than in southern parts. The predicted increases in temperatures (Ta ) could have a negative effect on species survival in the future, especially on those whose nests that are in the open. Finally, disturbance, predation and egg collection were probably the main immediate threats affecting the breeding seabird species in the northern Red Sea.

  10. Bioaccumulation of PCBs in Arctic seabirds: influence of dietary exposure and congener biotransformation

    International Nuclear Information System (INIS)

    Borga, Katrine; Wolkers, Hans; Skaare, Janneche U.; Hop, Haakon; Muir, Derek C.G.; Gabrielsen, Geir W.

    2005-01-01

    Four seabird species and their prey (zooplankton or fish) were collected in the Barents Sea to determine how dietary exposure, cytochrome P450 (CYP) enzyme activities and sex influenced their hepatic PCB concentrations and accumulation patterns. Five males and five females from each seabird species (little auk (Alle alle), Bruennich's guillemot (Uria lomvia), black guillemot (Cepphus grylle) and black-legged kittiwake (Rissa tridactyla)) were analysed. PCB concentrations could not be explained directly by carbon source (δ 13 C) or trophic position (δ 15 N), but by a combination of dietary parameters (δ 13 C, δ 15 N, migratory pattern, age) and contaminant metabolism. Contrary to previous studies, the PCB pattern differed among seabirds, with a higher proportion of persistent congeners (% of PCB-153, R PCB-153 ) in black-legged kittiwake than in auks. The PCB pattern also differed among auks, with little auk as the most efficient biotransformer (highest R PCB-153 values of persistent congeners). Based on high R PCB-153 values, Bruennich's guillemot poorly metabolised ortho-meta-unsubstituted congeners, whereas black guillemot poorly metabolised meta-para unsubstituted congeners. Species-specific differences in PCB biotransformation were confirmed by metabolic indices, where PCB patterns in seabirds were adjusted for PCB pattern in prey. The relative contribution of ortho-meta-unsubstituted congeners to ΣPCBsdecreased with increasing EROD activity. There were no differences in PCB concentrations, PCB patterns or cytochrome P450 enzyme activities between males and females. CYP P450 activities (CYP1A- and CYP2B/3A-like: EROD and testosterone 6β-hydroxylation, respectively) were low and did not correlate with concentrations of non- or mono-ortho Cl-substituted PCBs (NO- and MO-PCBs), or with total toxic equivalent concentrations (TEQs) for dioxin-like effects of NO- and MO-PCBs. - Contaminant patterns is linked to phylogeny and species-specific differences in

  11. Drivers of time-activity budget variability during breeding in a pelagic seabird.

    Directory of Open Access Journals (Sweden)

    Gavin M Rishworth

    Full Text Available During breeding, animal behaviour is particularly sensitive to environmental and food resource availability. Additionally, factors such as sex, body condition, and offspring developmental stage can influence behaviour. Amongst seabirds, behaviour is generally predictably affected by local foraging conditions and has therefore been suggested as a potentially useful proxy to indicate prey state. However, besides prey availability and distribution, a range of other variables also influence seabird behavior, and these need to be accounted for to increase the signal-to-noise ratio when assessing specific characteristics of the environment based on behavioural attributes. The aim of this study was to use continuous, fine-scale time-activity budget data from a pelagic seabird (Cape gannet, Morus capensis to determine the influence of intrinsic (sex and body condition and extrinsic (offspring and time variables on parent behaviour during breeding. Foraging trip duration and chick provisioning rates were clearly sex-specific and associated with chick developmental stage. Females made fewer, longer foraging trips and spent less time at the nest during chick provisioning. These sex-specific differences became increasingly apparent with chick development. Additionally, parents in better body condition spent longer periods at their nests and those which returned later in the day had longer overall nest attendance bouts. Using recent technological advances, this study provides new insights into the foraging behaviour of breeding seabirds, particularly during the post-guarding phase. The biparental strategy of chick provisioning revealed in this study appears to be an example where the costs of egg development to the female are balanced by paternal-dominated chick provisioning particularly as the chick nears fledging.

  12. INTRAVENOUS REGIONAL ANTIBIOTIC PERFUSION THERAPY AS AN ADJUNCTIVE TREATMENT FOR DIGITAL LESIONS IN SEABIRDS.

    Science.gov (United States)

    Fiorello, Christine V

    2017-03-01

    Foot infections are a common problem among seabirds in wildlife rehabilitation. Pododermatitis and digital infections are often challenging to treat because of the presence of suboptimal substrates, abnormal weight-bearing due to injuries, and suboptimal nutritional or health status. Seabirds represent the majority of animals requiring rehabilitation after oil spills, and foot problems are a common reason for euthanasia among these birds. Antibiotic intravenous regional perfusion therapy is frequently used in humans and other species to treat infections of the distal extremities, but it has not been evaluated in seabirds. During the 2015 Refugio oil spill response, four birds with foot lesions (pododermatitis, osteomyelitis, or both) were treated with ampicillin/sulbactam administered intravenously to the affected limb(s) in addition to systemic antibiotics and anti-inflammatories. Three of the birds, all brown pelicans ( Pelecanus occidentalis ) recovered rapidly and were released. Two of these birds had acute pododermatitis and were treated once with intravenous regional perfusion. They were released approximately 3 wk after the perfusion therapy. The third pelican had osteomyelitis of a digit. It was treated twice with intravenous regional perfusion and was released about 1 mo after the initial perfusion therapy. The fourth bird, a Pacific loon ( Gavia pacifica ), was treated once with perfusion therapy but did not respond to treatment and was euthanatized. No serious adverse effects were observed. This technique should be explored further in avian species.

  13. Study on elements concentrations on seabird feathers by instrumental neutron activation analysis

    Energy Technology Data Exchange (ETDEWEB)

    Theophilo, Carolina Y.S.; Moreira, Edson G. [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), São Paulo, SP (Brazil); Figueira, Rubens C.L.; Colabuono, Fernanda I., E-mail: carolina.theophilo@gmail.com, E-mail: emoreira@ipen.br, E-mail: rfigueira@usp.br, E-mail: ficolabuono@gmail.com [Universidade de São Paulo (USP), São Paulo, SP (Brazil). Instituto Oceanográfico

    2017-07-01

    Seabirds are very sensitive to environmental changes and because of their large longevity they are also sensitive to cumulative impacts. These birds usually occupy the higher trophic levels. White-chinned petrel (Procellaria aequinoctialis) and black-browed albatross (Thalassarche melanophris) are Procellariiformes, which is a seabird order, composed of 4 families. In the last years, researches are being done and actions are being taken to reduce the mortality of albatrosses and petrels caused by human activities. Due to the great ecological importance of these birds and the developed work with Procellariiformes, this study purpose is to quantify the Br, Cl, Cu, K, Mg, Mn, Na and V elements in white-chinned petrel and black-browed albatross feathers. Bird specimens were killed accidentally by pelagic longline fisheries operating off southern Brazil. Feathers were cleaned with acetone and then milled in a cryogenic mill. Instrumental Neutron Activation Analysis (INAA) was used for quantification of the element concentrations and measurements of induced activities were performed in a HPGe detector for gamma ray spectrometry. The obtained results on feathers showed that concentrations in these birds are not higher than others studies with the same species and, with exception of Br, there are no significant differences between elements mean concentrations in the two seabirds. (author)

  14. Abundance and breeding distribution of seabirds in the northern part of the Danco Coast, Antarctic Peninsula

    Directory of Open Access Journals (Sweden)

    Mariana A. Juáres

    2013-02-01

    Full Text Available Seabird abundances and breeding distribution have the potential to serve as ecological indicators. The western Antarctic Peninsula is one of the three sites in the world with the greatest increases in local temperature during the last 50 years. The aim of this study was to monitor the distribution and abundance of breeding populations of seabirds in the northern sector of the Danco Coast, north-west of the Antarctic Peninsula, during the breeding season 2010/11. The birds were the Wilson′s storm petrel (Oceanites oceanicus, South Polar skua (Stercorarius maccormicki, kelp gull (Larus dominicanus, Antarctic tern (Sterna vittata, snowy sheathbill (Chionis alba, chinstrap penguin (Pygoscelis antarctica, southern giant petrel (Macronectes giganteus, gentoo penguin (Pygoscelis papua, Cape petrel (Daption capense and Antarctic shag (Phalacrocorax bransfieldensis. Annual breeding population growth increased in pygoscelids, southern giant petrel and sheathbill, and for the remaining species, breeding population trends were stable. Given that seabird populations can provide valuable information on the conditions of their feeding and nesting environments, this study highlights the need to maintain basics monitoring studies.

  15. Acetylcholinesterase activity in seabirds affected by the Prestige oil spill on the Galician coast (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Oropesa, Ana-Lourdes; Perez-Lopez, Marcos; Hernandez, David; Soler, Francisco [Toxicology Area, Faculty of Veterinary Science (UEX), Avda. de la Universidad s/n. 10071 Caceres (Spain); Garcia, Jesus-Pablo [Toxicology Area, National Centre of Environmental Health, Instituto de Salud Carlos III, Majadahonda, Madrid (Spain); Fidalgo, Luis-Eusebio; Lopez-Beceiro, Ana [Rof Codina Clinical Hospital, Faculty of Veterinary Science (USC), Estrada de Granxa s/n. 27003 Lugo (Spain)

    2007-01-01

    In November 2002, the tanker Prestige broke in two and sank at the bottom of the ocean spilling about 70,000 t of fuel oil, which reached the coast of Galicia. It was considered the largest spill in maritime history, greatly affecting marine and related avian species. The spilled fuel oil contained high concentrations of polycyclic aromatic hydrocarbons (PAHs). Many species were affected and were found dead, although ongoing research is still being carried out on the sublethal effects. In this sense, little is known about the action of PAHs on Cholinesterase activity in seabirds. Consequently, the purpose of this study was to provide more information on the neurotoxicity of fuel oil on the seabirds most affected by the Prestige accident: common guillemot, Atlantic puffin and razorbill. On the other hand, data on normal values of acetylcholinesterase (AChE) activity were obtained to supply non-exposed values in seabirds. The oil spill produced a clear inhibitory effect on brain AChE activity in common guillemot (16%, p {<=} 0.01) and razorbill (22%, p {<=} 0.01), but not in Atlantic puffin (4%). Physiological levels of brain AChE, expressed in nmol acetylcholine hydrolysed min{sup -} {sup 1} mg{sup -} {sup 1} protein were similar in non-exposed common guillemot (388.6 {+-} 95.0) and Atlantic puffin (474.0 {+-} 60.7), however, razorbill values were higher (644.6 {+-} 66.9). (author)

  16. Oceanographic drivers and mistiming processes shape breeding success in a seabird.

    Science.gov (United States)

    Ramírez, Francisco; Afán, Isabel; Tavecchia, Giacomo; Catalán, Ignacio A; Oro, Daniel; Sanz-Aguilar, Ana

    2016-03-16

    Understanding the processes driving seabirds' reproductive performance through trophic interactions requires the identification of seasonal pulses in marine productivity. We investigated the sequence of environmental and biological processes driving the reproductive phenology and performance of the storm petrel (Hydrobates pelagicus) in the Western Mediterranean. The enhanced light and nutrient availability at the onset of water stratification (late winter/early spring) resulted in annual consecutive peaks in relative abundance of phytoplankton, zooplankton and ichthyoplankton. The high energy-demanding period of egg production and chick rearing coincided with these successive pulses in food availability, pointing to a phenological adjustment to such seasonal patterns with important fitness consequences. Indeed, delayed reproduction with respect to the onset of water stratification resulted in both hatching and breeding failure. This pattern was observed at the population level, but also when confounding factors such as individuals' age or experience were also accounted for. We provide the first evidence of oceanographic drivers leading to the optimal time-window for reproduction in an inshore seabird at southern European latitudes, along with a suitable framework for assessing the impact of environmentally driven changes in marine productivity patterns in seabird performance. © 2016 The Author(s).

  17. Remotely sensed wind speed predicts soaring behaviour in a wide-ranging pelagic seabird.

    Science.gov (United States)

    Gibb, Rory; Shoji, Akiko; Fayet, Annette L; Perrins, Chris M; Guilford, Tim; Freeman, Robin

    2017-07-01

    Global wind patterns affect flight strategies in many birds, including pelagic seabirds, many of which use wind-powered soaring to reduce energy costs during at-sea foraging trips and migration. Such long-distance movement patterns are underpinned by local interactions between wind conditions and flight behaviour, but these fine-scale relationships are far less well understood. Here we show that remotely sensed ocean wind speed and direction are highly significant predictors of soaring behaviour in a migratory pelagic seabird, the Manx shearwater ( Puffinus puffinus ). We used high-frequency GPS tracking data (10 Hz) and statistical behaviour state classification to identify two energetic modes in at-sea flight, corresponding to flap-like and soar-like flight. We show that soaring is significantly more likely to occur in tailwinds and crosswinds above a wind speed threshold of around 8 m s -1 , suggesting that these conditions enable birds to reduce metabolic costs by preferentially soaring over flapping. Our results suggest a behavioural mechanism by which wind conditions may shape foraging and migration ecology in pelagic seabirds, and thus indicate that shifts in wind patterns driven by climate change could impact this and other species. They also emphasize the emerging potential of high-frequency GPS biologgers to provide detailed quantitative insights into fine-scale flight behaviour in free-living animals. © 2017 The Author(s).

  18. Study on elements concentrations on seabird feathers by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Theophilo, Carolina Y.S.; Moreira, Edson G.; Figueira, Rubens C.L.; Colabuono, Fernanda I.

    2017-01-01

    Seabirds are very sensitive to environmental changes and because of their large longevity they are also sensitive to cumulative impacts. These birds usually occupy the higher trophic levels. White-chinned petrel (Procellaria aequinoctialis) and black-browed albatross (Thalassarche melanophris) are Procellariiformes, which is a seabird order, composed of 4 families. In the last years, researches are being done and actions are being taken to reduce the mortality of albatrosses and petrels caused by human activities. Due to the great ecological importance of these birds and the developed work with Procellariiformes, this study purpose is to quantify the Br, Cl, Cu, K, Mg, Mn, Na and V elements in white-chinned petrel and black-browed albatross feathers. Bird specimens were killed accidentally by pelagic longline fisheries operating off southern Brazil. Feathers were cleaned with acetone and then milled in a cryogenic mill. Instrumental Neutron Activation Analysis (INAA) was used for quantification of the element concentrations and measurements of induced activities were performed in a HPGe detector for gamma ray spectrometry. The obtained results on feathers showed that concentrations in these birds are not higher than others studies with the same species and, with exception of Br, there are no significant differences between elements mean concentrations in the two seabirds. (author)

  19. Colonial army recruitment patterns and post-colonial Military Coups ...

    African Journals Online (AJOL)

    Since time immemorial, societies, states and state builders have been challenged and transformed by the need and quest for military manpower. European states relied on conscript armies to 'pacify' and retain colonies in parts of the non-European world. These facts underscore the meticulous attention paid by the British to ...

  20. Colonial Bilingual Heritage and Post-Colonial Myths in Cameroon's ...

    African Journals Online (AJOL)

    Thus, the study traces and shows that an uncritical support of the existing school bilingualism, a aspect of the general political objective of national unity and integration, hinges on a fictitious collective post-colonial dream about using the bilingual heritage of French and English, and the cultures that lie behind them, ...

  1. Colony social organization and population genetic structure of an introduced population of formosan subterranean termite from New Orleans, Louisiana.

    Science.gov (United States)

    Husseneder, Claudia; Messenger, Matthew T; Su, Nan-Yao; Grace, J Kenneth; Vargo, Edward L

    2005-10-01

    The Formosan subterranean termite, Coptotermes formosanus Shiraki, is an invasive species in many parts of the world, including the U.S. mainland. The reasons for its invasive success may have to do with the flexible social and spatial organization of colonies. We investigated the population and breeding structure of 14 C. formosanus colonies in Louis Armstrong Park, New Orleans, LA. This population has been the focus of extensive study for many years, providing the opportunity to relate aspects of colony breeding structure to previous findings on colony characteristics such as body weight and number of workers, wood consumption, and intercolony aggression. Eight colonies were headed by a single pair of outbred reproductives (simple families), whereas six colonies were headed by low numbers of multiple kings and/or queens that were likely the neotenic descendants of the original colony (extended families). Within the foraging area of one large extended family colony, we found genetic differentiation among different collection sites, suggesting the presence of separate reproductive centers. No significant difference between simple family colonies and extended family colonies was found in worker body weight, soldier body weight, foraging area, population size, or wood consumption. However, level of inbreeding within colonies was negatively correlated with worker body weight and positively correlated with wood consumption. Also, genetic distance between colonies was positively correlated with aggression levels, suggesting a genetic basis to nestmate discrimination cues in this termite population. No obvious trait associated with colony reproductive structure was found that could account for the invasion success of this species.

  2. Age and breeding success related to nest position in a White stork Ciconia ciconia colony

    Science.gov (United States)

    Vergara, Pablo; Aguirre, José I.

    2006-11-01

    Coloniality is a breeding system that may produce benefits in terms of breeding success, although these advantages could vary according to factors such as colony size or nest position. We studied breeder's age in relation to nest position (peripheral or central) within the colony. In addition, we studied the relationship between breeding success and nest position, controlling for breeder's age, a highly correlated factor, in a White Stork Ciconia ciconia colony over a 7-year period. Our results show that central nests are mainly occupied by adult birds and had lower failure rates. However, controlling for breeder's age, nest position per se did not explain breeding success. The scarce predation and the lack of human disturbance in the study colony could explain the absence of differences in breeding success between different nest positions within the colony.

  3. Egg production in a coastal seabird, the glaucous-winged gull (Larus glaucescens, declines during the last century.

    Directory of Open Access Journals (Sweden)

    Louise K Blight

    Full Text Available Seabirds integrate information about oceanic ecosystems across time and space, and are considered sensitive indicators of marine conditions. To assess whether hypothesized long-term foodweb changes such as forage fish declines may be reflected in a consumer's life history traits over time, I used meta-regression to evaluate multi-decadal changes in aspects of egg production in the glaucous-winged gull (Larus glaucescens, a common coastal bird. Study data were derived from literature searches of published papers and unpublished historical accounts, museum egg collections, and modern field studies, with inclusion criteria based on data quality and geographic area of the original study. Combined historical and modern data showed that gull egg size declined at an average of 0.04 cc y(-1 from 1902 (108 y, equivalent to a decline of 5% of mean egg volume, while clutch size decreased over 48 y from a mean of 2.82 eggs per clutch in 1962 to 2.25 in 2009. There was a negative relationship between lay date and mean clutch size in a given year, with smaller clutches occurring in years where egg laying commenced later. Lay date itself advanced over time, with commencement of laying presently (2008-2010 7 d later than in previous studies (1959-1986. This study demonstrates that glaucous-winged gull investment in egg production has declined significantly over the past ∼50-100 y, with such changes potentially contributing to recent population declines. Though gulls are generalist feeders that should readily be able to buffer themselves against food web changes, they are likely nutritionally constrained during the early breeding period, when egg production requirements are ideally met by consumption of high-quality prey such as forage fish. This study's results suggest a possible decline in the availability of such prey, and the incremental long-term impoverishment of a coastal marine ecosystem bordering one of North America's rapidly growing urban areas.

  4. Egg Production in a Coastal Seabird, the Glaucous-Winged Gull (Larus glaucescens), Declines during the Last Century

    Science.gov (United States)

    Blight, Louise K.

    2011-01-01

    Seabirds integrate information about oceanic ecosystems across time and space, and are considered sensitive indicators of marine conditions. To assess whether hypothesized long-term foodweb changes such as forage fish declines may be reflected in a consumer's life history traits over time, I used meta-regression to evaluate multi-decadal changes in aspects of egg production in the glaucous-winged gull (Larus glaucescens), a common coastal bird. Study data were derived from literature searches of published papers and unpublished historical accounts, museum egg collections, and modern field studies, with inclusion criteria based on data quality and geographic area of the original study. Combined historical and modern data showed that gull egg size declined at an average of 0.04 cc y−1 from 1902 (108 y), equivalent to a decline of 5% of mean egg volume, while clutch size decreased over 48 y from a mean of 2.82 eggs per clutch in 1962 to 2.25 in 2009. There was a negative relationship between lay date and mean clutch size in a given year, with smaller clutches occurring in years where egg laying commenced later. Lay date itself advanced over time, with commencement of laying presently (2008–2010) 7 d later than in previous studies (1959–1986). This study demonstrates that glaucous-winged gull investment in egg production has declined significantly over the past ∼50–100 y, with such changes potentially contributing to recent population declines. Though gulls are generalist feeders that should readily be able to buffer themselves against food web changes, they are likely nutritionally constrained during the early breeding period, when egg production requirements are ideally met by consumption of high-quality prey such as forage fish. This study's results suggest a possible decline in the availability of such prey, and the incremental long-term impoverishment of a coastal marine ecosystem bordering one of North America's rapidly growing urban areas. PMID

  5. Forty years of change: a northern Alaskan seabird's response to a warming Arctic

    Science.gov (United States)

    Divoky, G.; Suydam, R.

    2012-12-01

    While recent decadal-scale decreases in the snow and ice habitats of the Arctic are well documented, there are few concurrent long-term biological data sets, especially for species dependent on the cryopelagic ecosystem associated with arctic sea ice. The Black Guillemot (Cepphus grylle mandti), a marine apex predator specializing on prey associated with arctic pack ice has been studied annually since 1975 at a colony on Cooper Island, 35 km east of Point Barrow, Alaska. Over the last four decades critical components of the species' life history have been found to be sensitive to a number of physical and biological effects associated with the region's increasing atmospheric temperatures. Black Guillemots first colonized northern Alaska in the late 1960s and early 1970s as the annual snow-free period increased sufficiently to allow access to nesting cavities for the 80 days required to successfully raise young. At the Cooper Island colony abundance increased during the 1970s and 1980s as summer length continued to increase and wooden nest cavities were provided to increase sample size for monitoring. During this time breeding success was high as summer sea ice remained in the 30-km foraging range of guillemot parents, providing Arctic Cod (Boreogadus saida), the principal forage fish associated with sea ice and the preferred prey of Black Guillemots. Decreasing summer sea ice extent in the 1990s that accelerated in the last decade reduced the guillemots' access to cryopelagic prey during the critical period when parents are provisioning nestlings. Distance from the colony to the pack ice on 15 August averaged 100 km from 2003-2011. This ice retreat had a major affect on Arctic Cod availability, causing parent guillemots to shift to lower quality benthic fish resulting in decreases in nestling quality and breeding success when sea ice had retreated and SST was > 4o C. Increasing loss of summer ice in the last decade also facilitated changes in the distribution of a

  6. Dutch Colonial Nostalgia Across Decolonisation

    NARCIS (Netherlands)

    Bijl, P.

    2013-01-01

    This article argues that nostalgia for colonialism in the Netherlands, the so called tempo doeloe culture, is not a specifically postcolonial phenomenon caused by the collapse of the Dutch empire in Asia. In fact, nostalgia for the Dutch East Indies can be traced back to the nineteenth century, when

  7. Colonial adventures in tropical agriculture

    NARCIS (Netherlands)

    Buelens, Frans; Frankema, Ewout

    2016-01-01

    How profitable were foreign investments in plantation agriculture in the Netherlands Indies during the late colonial era? We use a new dataset of monthly quoted stock prices and dividends of international companies at the Brussels stock exchange to estimate the returns to investment in tropical

  8. Affective Politics and Colonial Heritage

    DEFF Research Database (Denmark)

    Knudsen, Britta Timm; Andersen, Casper

    2017-01-01

    The article analyses the spatial entanglement of colonial heritage struggles through a study of the Rhodes Must Fall student movement at the University of Cape Town and the University of Oxford. We explore affective politics and the role heritage can play in the landscape of body politics. We aim...

  9. Ant Colony Optimization for Control

    NARCIS (Netherlands)

    Van Ast, J.M.

    2010-01-01

    The very basis of this thesis is the collective behavior of ants in colonies. Ants are an excellent example of how rather simple behavior on a local level can lead to complex behavior on a global level that is beneficial for the individuals. The key in the self-organization of ants is communication

  10. Low temperature and Daphnia-associated infochemicals promote colony formation of Scenedesmus obliquus and its harvesting.

    Science.gov (United States)

    Zhu, Xuexia; Yang, Jingwen; Zhang, Xingxing; Zhang, Lu; Wang, Xiaojun; Huang, Yuan; Yang, Zhou

    2017-01-01

    To explore the combined effects of temperature and Daphnia-associated infochemicals on colony formation of Scenedesmus obliquus to faciliate harvesting the algal biomass. A three-parameter modified Gaussian model fitted the changes of the number of cells per particle in S. obliquus induced by Daphnia culture filtrate well under any temperature. Decreases in temperature enhanced the induced-colony formation of Scenedesmus. The maximum colony size at 15-25 °C was significantly larger than those at 30-35 °C. An additional 1 or 2 days at low temperature was needed to reach the maximum colony size, which indicates the best harvest time for algal biomass. Induced-colony formation of Scenedesmus by Daphnia culture filtrate at 15-25 °C is recommended to settle algal cells. This condition facilitates harvesting the biomass.

  11. Data for automated, high-throughput microscopy analysis of intracellular bacterial colonies using spot detection

    DEFF Research Database (Denmark)

    Ernstsen, Christina Lundgaard; Login, Frédéric H.; Jensen, Helene Halkjær

    2017-01-01

    Quantification of intracellular bacterial colonies is useful in strategies directed against bacterial attachment, subsequent cellular invasion and intracellular proliferation. An automated, high-throughput microscopy-method was established to quantify the number and size of intracellular bacteria...

  12. Seabirds maintain offspring provisioning rate despite fluctuations in prey abundance: A multi-species functional response for guillemots in the North Sea

    DEFF Research Database (Denmark)

    Smout, Sophie; Rindorf, Anna; Wanless, Sarah

    2013-01-01

    1. Seabirds that consume more than one prey type may adjust their foraging to maintain provisioning rates for their chicks. How energetically effective are these strategies, and what are the implications for the management of seabirds and their marine habitat? 2. A multi-species functional respon...

  13. Queen promiscuity lowers disease within honeybee colonies

    Science.gov (United States)

    Seeley, Thomas D; Tarpy, David R

    2006-01-01

    Most species of social insects have singly mated queens, but in some species each queen mates with numerous males to create a colony with a genetically diverse worker force. The adaptive significance of polyandry by social insect queens remains an evolutionary puzzle. Using the honeybee (Apis mellifera), we tested the hypothesis that polyandry improves a colony's resistance to disease. We established colonies headed by queens that had been artificially inseminated by either one or 10 drones. Later, we inoculated these colonies with spores of Paenibacillus larvae, the bacterium that causes a highly virulent disease of honeybee larvae (American foulbrood). We found that, on average, colonies headed by multiple-drone inseminated queens had markedly lower disease intensity and higher colony strength at the end of the summer relative to colonies headed by single-drone inseminated queens. These findings support the hypothesis that polyandry by social insect queens is an adaptation to counter disease within their colonies. PMID:17015336

  14. Health assessments of brown pelican (Pelecanus occidentalis) nestlings from colonies in South Carolina and Georgia, U.S.A.

    Science.gov (United States)

    Ferguson, L.M.; Norton, Terry M.; Cray, Carolyn; Oliva, M.; Jodice, Patrick G.R.

    2014-01-01

    Health evaluations of brown pelican (Pelecanus occidentalis) nestlings from three colonies along the Atlantic coast of the southeastern United States were performed in 2005, 2007, and 2008. The primary objective of this study was to establish baseline data for hematologic, biochemical, and serologic values from a relatively healthy population of free-living pelicans during early chick development. Relationships among health variables and colony site, ectoparasite infestation, sex, and body condition index were also evaluated. Reference intervals are presented for health variables, including novel analytes for the species, as well as a comparison of these results with previously published values for wild pelicans. No significant relationships were found between health variables and nestling sex or body condition; however, differences between colony sites and the presence of ectoparasites were detected. The inclusion of health assessments as a regular component of management programs for seabirds can provide data to better understand the effect to species of concern when drastic changes occur to the population and its environment.

  15. Monitoring of colonies and provisioning of rooks with nest material as a potential tool for stabilizing colonies and increasing nesting opportunities in the countryside. Project report

    Directory of Open Access Journals (Sweden)

    Slobodník Roman

    2017-12-01

    Full Text Available The rook is a species inhabiting open agricultural landscape whose non-active nests are also used by other bird species for nesting. It is the decline in rook colonies that has been posited as one of the reasons for decrease in the red-footed falcon (Falco vespertinus population in Slovakia since the 1970s. During the period from 2012 till 2016, four monitorings of rook colonies were carried out in south-western Slovakia (Diakovce, Nitrianska Osada, Sokolce and Tvrdošovce. In the colony at Tvrdošovce, supporting activity involving provisioning of rooks with nest material was under way from 2014 until 2016. While the colonies at Diakovce and Nitrianska Osada have been showing a slight decrease in the number of nesting rooks, despite larger interannual differences the colony at Sokolce has been showing an upward trend. The size of the colony at Tvrdošovce has been stable since the beginning of the supporting activity. This activity had a statistically significant positive effect on the width of rook nests. In 74 cases in the studied rook colonies we have recorded nesting by three other bird species – Eurasian kestrel (Falco tinnunculus 43.8%, western jackdaw (Corvus monedula 39.7% and long-eared owl (Asio otus 16.4%. In 2015 two female redfooted falcons were observed in the colony at Tvrdošovce.

  16. Age, sex, and telomere dynamics in a long-lived seabird with male-biased parental care.

    Directory of Open Access Journals (Sweden)

    Rebecca C Young

    Full Text Available The examination of telomere dynamics is a recent technique in ecology for assessing physiological state and age-related traits from individuals of unknown age. Telomeres shorten with age in most species and are expected to reflect physiological state, reproductive investment, and chronological age. Loss of telomere length is used as an indicator of biological aging, as this detrimental deterioration is associated with lowered survival. Lifespan dimorphism and more rapid senescence in the larger, shorter-lived sex are predicted in species with sexual size dimorphism, however, little is known about the effects of behavioral dimorphism on senescence and life history traits in species with sexual monomorphism. Here we compare telomere dynamics of thick-billed murres (Urialomvia, a species with male-biased parental care, in two ways: 1 cross-sectionally in birds of known-age (0-28 years from one colony and 2 longitudinally in birds from four colonies. Telomere dynamics are compared using three measures: the telomere restriction fragment (TRF, a lower window of TRF (TOE, and qPCR. All showed age-related shortening of telomeres, but the TRF measure also indicated that adult female murres have shorter telomere length than adult males, consistent with sex-specific patterns of ageing. Adult males had longer telomeres than adult females on all colonies examined, but chick telomere length did not differ by sex. Additionally, inter-annual telomere changes may be related to environmental conditions; birds from a potentially low quality colony lost telomeres, while those at more hospitable colonies maintained telomere length. We conclude that sex-specific patterns of telomere loss exist in the sexually monomorphic thick-billed murre but are likely to occur between fledging and recruitment. Longer telomeres in males may be related to their homogamous sex chromosomes (ZZ or to selection for longer life in the care-giving sex. Environmental conditions appeared to

  17. Highest PBDE levels (max 63 ppm) yet found in biota measured in seabird eggs from San Francisco Bay

    Energy Technology Data Exchange (ETDEWEB)

    She, J.; Holden, A.; Tanner, M.; Sharp, M.; Hooper, K. [Department of Toxic Substances Control, Berkeley, CA (United States). Hazardous Materials Lab.; Adelsbach, T. [Environmental Contaminants Division, Sacramento Fish and Wildlife Office, US Fish and Wildlife Service, Sacramento, CA (United States)

    2004-09-15

    High levels of polybrominated diphenylethers (PBDEs) have been found in humans and wildlife from the San Francisco Bay Area, with levels in women among the highest in the world, and levels in piscivorous seabird eggs at the ppm level. Seabirds are useful for monitoring and assessing ecosystem health at various times and places because they occupy a high trophic level in the marine food web, are long-lived, and are generally localized near their breeding and non-breeding sites. In collaboration with the US Fish and Wildlife Services (USFWS), we are carrying out a three-year investigation of dioxin, PCB and PBDE levels in eggs from fish-eating seabirds. Year 1 (2002) PBDE measurements from 73 bird eggs were reported at Dioxin2003. Year 2 (2003) PBDE measurements from 45 samples are presented in this report. The highest PBDE level measured in eggs was 63 ppm, lipid, which is the highest PBDE level, yet reported in biota.

  18. Recent Honey Bee Colony Declines

    Science.gov (United States)

    2007-06-20

    podcasts.psu.edu/taxonomy/term/62]. Staple crops such as wheat , corn, and rice do not rely on insect pollination and are mostly wind pollinated...are interacting to weaken bee colonies and are allowing stress-related pathogens, such as fungi , thus causing a final collapse.27 Others note the...possible role of miticide resistance in bees. High levels of bacteria, viruses, and fungi have been found in the guts of the recoverable dead bees

  19. Honeybee immunity and colony losses

    Directory of Open Access Journals (Sweden)

    F. Nazzi

    2014-10-01

    Full Text Available The decline of honeybee colonies and their eventual collapse is a widespread phenomenon in the Northern hemisphere of the globe, which severely limits the beekeeping industry. This dramatic event is associated with an enhanced impact of parasites and pathogens on honeybees, which is indicative of reduced immunocompetence. The parasitic mite Varroa destructor and the vectored viral pathogens appear to play a key-role in the induction of this complex syndrome. In particular, the Deformed Wing Virus (DWV is widespread and is now considered, along with Varroa, one of the major causes of bee colony losses. Several lines of evidence indicate that this mite/DWV association severely affects the immune system of honeybees and makes them more sensitive to the action of other stress factors. The molecular mechanisms underpinning these complex interactions are currently being investigated and the emerging information has allowed the development of a new functional model, describing how different stress factors may synergistically concur in the induction of bee immune alteration and health decline. This provides a new logical framework in which to interpret the proposed multifactorial origin of bee colony losses and sets the stage for a more comprehensive and integrated analysis of the effect that multiple stress agents may have on honeybees.

  20. Morphology and dynamics of tumor cell colonies propagating in epidermal growth factor supplemented media

    Science.gov (United States)

    Muzzio, N. E.; Carballido, M.; Pasquale, M. A.; González, P. H.; Azzaroni, O.; Arvia, A. J.

    2018-07-01

    The epidermal growth factor (EGF) plays a key role in physiological and pathological processes. This work reports on the influence of EGF concentration (c EGF) on the modulation of individual cell phenotype and cell colony kinetics with the aim of perturbing the colony front roughness fluctuations. For this purpose, HeLa cell colonies that remain confluent along the whole expansion process with initial quasi-radial geometry and different initial cell populations, as well as colonies with initial quasi-linear geometry and large cell population, are employed. Cell size and morphology as well as its adhesive characteristics depend on c EGF. Quasi-radial colonies (QRC) expansion kinetics in EGF-containing medium exhibits a complex behavior. Namely, at the first stages of growth, the average QRC radius evolution can be described by a t 1/2 diffusion term coupled with exponential growth kinetics up to a critical time, and afterwards a growth regime approaching constant velocity. The extension of each regime depends on c EGF and colony history. In the presence of EGF, the initial expansion of quasi-linear colonies (QLCs) also exhibits morphological changes at both the cell and the colony levels. In these cases, the cell density at the colony border region becomes smaller than in the absence of EGF and consequently, the extension of the effective rim where cell duplication and motility contribute to the colony expansion increases. QLC front displacement velocity increases with c EGF up to a maximum value in the 2–10 ng ml‑1 range. Individual cell velocity is increased by EGF, and an enhancement in both the persistence and the ballistic characteristics of cell trajectories can be distinguished. For an intermediate c EGF, collective cell displacements contribute to the roughening of the colony contours. This global dynamics becomes compatible with the standard Kardar–Parisi–Zhang growth model, although a faster colony roughness saturation in EGF-containing medium

  1. Queen Size Variation in the Ponerine Ant Ponera coarctata (Hymenoptera: Formicidae

    Directory of Open Access Journals (Sweden)

    J. Liebig

    1995-01-01

    Full Text Available Queens of Ponera coarctata show a pronounced variation in size as measured by ommatidia number and Weber's alitrunk length. Isometric size variation and the normal distribution of size categories indicate that, despite these differences, only one queen morph exists. Queen size varies less within colonies than between colonies, and thus appears to be colony specific. Ovary length apparently varies with queen size. Similar size variations as in queens also occured in males, but not in workers.

  2. Polychlorinated biphenyl exposure and corticosterone levels in seven polar seabird species

    International Nuclear Information System (INIS)

    Tartu, S.; Angelier, F.; Bustnes, J.O.; Moe, B.; Hanssen, S.A.; Herzke, D.; Gabrielsen, G.W.; Verboven, N.; Verreault, J.; Labadie, P.; Budzinski, H.; Wingfield, J.C.

    2015-01-01

    The role of polychlorinated biphenyls (PCBs) on exposure-related endocrine effects has been poorly investigated in wild birds. This is the case for stress hormones including corticosterone (CORT). Some studies have suggested that environmental exposure to PCBs and altered CORT secretion might be associated. Here we investigated the relationships between blood PCB concentrations and circulating CORT levels in seven free-ranging polar seabird species occupying different trophic positions, and hence covering a wide range of PCB exposure. Blood ∑ 7 PCB concentrations (range: 61–115,632 ng/g lw) were positively associated to baseline or stress-induced CORT levels in three species and negatively associated to stress-induced CORT levels in one species. Global analysis suggests that in males, baseline CORT levels generally increase with increasing blood ∑ 7 PCB concentrations, whereas stress-induced CORT levels decrease when reaching high blood ∑ 7 PCB concentrations. This study suggests that the nature of the PCB-CORT relationships may depend on the level of PCB exposure. - Highlights: • Relationships between PCBs and stress hormones (CORT) are not well known in birds. • We measured blood PCBs, baseline and stress-induced CORT in seven seabird species. • ∑PCB was positively associated to baseline or stress-induced CORT in three species. • ∑PCBs was negatively linked to stress-induced CORT in the most contaminated species. • The nature of the PCB-CORT relationships may depend on the level of PCB exposure. - In polar seabird species, the relationship between PCB and CORT concentrations may be related to the levels of contamination

  3. Where the wild things are: Predicting hotspots of seabird aggregations in the California Current System

    Science.gov (United States)

    Nur, N.; Jahncke, J.; Herzog, M.P.; Howar, J.; Hyrenbach, K.D.; Zamon, J.E.; Ainley, D.G.; Wiens, J.A.; Morgan, K.; Balance, L.T.; Stralberg, D.

    2011-01-01

    Marine Protected Areas (MPAs) provide an important tool for conservation of marine ecosystems. To be most effective, these areas should be strategically located in a manner that supports ecosystem function. To inform marine spatial planning and support strategic establishment of MPAs within the California Current System, we identified areas predicted to support multispecies aggregations of seabirds ("hotspot????). We developed habitat-association models for 16 species using information from at-sea observations collected over an 11-year period (1997-2008), bathymetric data, and remotely sensed oceanographic data for an area from north of Vancouver Island, Canada, to the USA/Mexico border and seaward 600 km from the coast. This approach enabled us to predict distribution and abundance of seabirds even in areas of few or no surveys. We developed single-species predictive models using a machine-learning algorithm: bagged decision trees. Single-species predictions were then combined to identify potential hotspots of seabird aggregation, using three criteria: (1) overall abundance among species, (2) importance of specific areas ("core area????) to individual species, and (3) predicted persistence of hotspots across years. Model predictions were applied to the entire California Current for four seasons (represented by February, May, July, and October) in each of 11 years. Overall, bathymetric variables were often important predictive variables, whereas oceanographic variables derived from remotely sensed data were generally less important. Predicted hotspots often aligned with currently protected areas (e.g., National Marine Sanctuaries), but we also identified potential hotspots in Northern California/Southern Oregon (from Cape Mendocino to Heceta Bank), Southern California (adjacent to the Channel Islands), and adjacent to Vancouver Island, British Columbia, that are not currently included in protected areas. Prioritization and identification of multispecies hotspots

  4. A long-term retrospective study on rehabilitation of seabirds in Gran Canaria Island, Spain (2003-2013)

    Science.gov (United States)

    Montesdeoca, Natalia; Calabuig, Pascual; Corbera, Juan A.

    2017-01-01

    Aims The aims of this study were to analyze the causes of morbidity and mortality in a large population of seabirds admitted to the Tafira Wildlife Rehabilitation Center (TWRC) in Gran Canaria Island, Spain, from 2003 to 2013, and to analyze the outcomes of the rehabilitation process. Methods We included 1,956 seabirds (133 dead on admission and 1,823 admitted alive) in this study. Causes of morbidity were classified into nine categories: light pollution (fallout), fishing gear interaction, crude oil, poisoning/intoxication, other traumas, metabolic/nutritional disorder, orphaned young birds, other causes, and unknown/undetermined. The crude and stratified (by causes of admission) rates of the three final disposition categories (euthanasia Er, unassisted mortality Mr, and release Rr), the time until death, and the length of stay were also studied for the seabirds admitted alive. Results Yellow-legged Gull (Larus michahellis) was the species most frequently admitted (46.52%), followed by Cory’s Shearwater (Calonectris diomedea borealis) (20.09%). The most frequent causes of morbidity were light pollution (fallout) (25.81%), poisoning/intoxication (24.69%), and other traumas (18.14%). The final disposition rates were: Er = 15.35%, Mr = 16.29%, and Rr = 68.34%. The highest Er was observed in the ‘other traumas’ category (58.08%). Seabirds admitted due to metabolic/nutritional disorder had the highest Mr (50%). The highest Rr was observed in the light pollution (fallout) category (99.20%). Conclusions This survey provides useful information for the conservation of several seabird species. We suggest that at least the stratified analysis by causes of admission of the three final disposition rates, and the parameters time until death and length of stay at the center should be included in the outcome research of the rehabilitation of seabirds. The high release rate for seabirds (68.34%) achieved at the TWRC emphasizes the importance of wildlife rehabilitation

  5. All you can eat: is food supply unlimited in a colonially breeding bird?

    Science.gov (United States)

    Hoi, Herbert; Krištofík, Ján; Darolová, Alžbeta

    2015-01-01

    Food availability is generally considered to determine breeding site selection and therefore plays an important role in hypotheses explaining the evolution of colony formation. Hypotheses trying to explain why birds join a colony usually assume that food is not limited, whereas those explaining variation in colony size suggest that food is under constraint. In this study, we investigate the composition and amount of food items not eaten by the nestlings and found in nest burrows of colonially nesting European bee-eaters (Merops apiaster). We aimed to determine whether this unconsumed food is an indicator of unlimited food supply, the result of mistakes during food transfer between parents and chicks or foraging selectivity of chicks. Therefore, we investigated the amount of dropped food for each nest in relation to reproductive performance and parameters reflecting parental quality. Our data suggest that parents carry more food to the nest than chicks can eat and, hence, food is not limited. This assumption is supported by the facts that there is a positive relationship between dropped food found in a nest and the number of fledglings, nestling age, and chick health condition and that the amount of dropped food is independent of colony size. There is variation in the amount of dropped food within colonies, suggesting that parent foraging efficiency may also be an important determinant. Pairs nesting in the center of a colony performed better than those nesting on the edge, which supports the assumption that quality differences between parents are important as well. However, dropped food cannot be used as an indicator of local food availability as (1) within-colony variation in dropped food is larger than between colony variation and, (2) the average amount of dropped food is not related to colony size.

  6. Accumulation of plastic-derived chemicals in tissues of seabirds ingesting marine plastics.

    Science.gov (United States)

    Tanaka, Kosuke; Takada, Hideshige; Yamashita, Rei; Mizukawa, Kaoruko; Fukuwaka, Masa-aki; Watanuki, Yutaka

    2013-04-15

    We analyzed polybrominated diphenyl ethers (PBDEs) in abdominal adipose of oceanic seabirds (short-tailed shearwaters, Puffinus tenuirostris) collected in northern North Pacific Ocean. In 3 of 12 birds, we detected higher-brominated congeners (viz., BDE209 and BDE183), which are not present in the natural prey (pelagic fish) of the birds. The same compounds were present in plastic found in the stomachs of the 3 birds. These data suggested the transfer of plastic-derived chemicals from ingested plastics to the tissues of marine-based organisms. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Impedimetric quantification of the formation process and the chemosensitivity of cancer cell colonies suspended in 3D environment.

    Science.gov (United States)

    Lei, Kin Fong; Wu, Zong-Ming; Huang, Chia-Hao

    2015-12-15

    In cancer research, colony formation assay is a gold standard for the investigation of the development of early tumors and the effects of cytotoxic agents on tumors in vitro. Quantification of cancer cell colonies suspended in hydrogel is currently achieved by manual counting under microscope. It is challenging to microscopically quantify the colony number and size without subjective bias. In this work, impedimetric quantification of cancer cell colonies suspended in hydrogel was successfully developed and provides a quantitative and objective method to describe the colony formation process and the development of colony size during the culture course. A biosensor embedded with a pair of parallel plate electrodes was fabricated for the impedimetric quantification. Cancer cell (cell line: Huh-7) were encapsulated in methyl cellulose hydrogel and cultured to gradually form cancer cell colonies suspended in 3D environment. At pre-set schedule during the culture course, small volume (50 μL) of colonies/MC hydrogel was collected, mixed with measurement hydrogel, and loaded to the biosensor for measurement. Hence, the colony formation process could be quantitatively represented by a colony index and a colony size index calculated from electrical impedance. Based on these developments, chemosensitivity of cancer cell colonies under different concentrations of anti-cancer drug, i.e., doxorubicin, was quantitatively investigated to study the efficacy of anti-cancer drug. Also, dose-response curve was constructed to calculate the IC50 value, which is an important indicator for chemosensitivity assay. These results showed the impedimetric quantification is a promising technique for the colony formation assay. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Honey bee (Apis mellifera) colony health and pathogen composition in migratory beekeeping operations involved in California almond pollination.

    Science.gov (United States)

    Glenny, William; Cavigli, Ian; Daughenbaugh, Katie F; Radford, Rosemarie; Kegley, Susan E; Flenniken, Michelle L

    2017-01-01

    Honey bees are important pollinators of agricultural crops. Pathogens and other factors have been implicated in high annual losses of honey bee colonies in North America and some European countries. To further investigate the relationship between multiple factors, including pathogen prevalence and abundance and colony health, we monitored commercially managed migratory honey bee colonies involved in California almond pollination in 2014. At each sampling event, honey bee colony health was assessed, using colony population size as a proxy for health, and the prevalence and abundance of seven honey bee pathogens was evaluated using PCR and quantitative PCR, respectively. In this sample cohort, pathogen prevalence and abundance did not correlate with colony health, but did correlate with the date of sampling. In general, pathogen prevalence (i.e., the number of specific pathogens harbored within a colony) was lower early in the year (January-March) and was greater in the summer, with peak prevalence occurring in June. Pathogen abundance in individual honey bee colonies varied throughout the year and was strongly associated with the sampling date, and was influenced by beekeeping operation, colony health, and mite infestation level. Together, data from this and other observational cohort studies that monitor individual honey bee colonies and precisely account for sampling date (i.e., day of year) will lead to a better understanding of the influence of pathogens on colony mortality and the effects of other factors on these associations.

  9. Honey bee (Apis mellifera colony health and pathogen composition in migratory beekeeping operations involved in California almond pollination.

    Directory of Open Access Journals (Sweden)

    William Glenny

    Full Text Available Honey bees are important pollinators of agricultural crops. Pathogens and other factors have been implicated in high annual losses of honey bee colonies in North America and some European countries. To further investigate the relationship between multiple factors, including pathogen prevalence and abundance and colony health, we monitored commercially managed migratory honey bee colonies involved in California almond pollination in 2014. At each sampling event, honey bee colony health was assessed, using colony population size as a proxy for health, and the prevalence and abundance of seven honey bee pathogens was evaluated using PCR and quantitative PCR, respectively. In this sample cohort, pathogen prevalence and abundance did not correlate with colony health, but did correlate with the date of sampling. In general, pathogen prevalence (i.e., the number of specific pathogens harbored within a colony was lower early in the year (January-March and was greater in the summer, with peak prevalence occurring in June. Pathogen abundance in individual honey bee colonies varied throughout the year and was strongly associated with the sampling date, and was influenced by beekeeping operation, colony health, and mite infestation level. Together, data from this and other observational cohort studies that monitor individual honey bee colonies and precisely account for sampling date (i.e., day of year will lead to a better understanding of the influence of pathogens on colony mortality and the effects of other factors on these associations.

  10. Commercial bacterial colony counter for semiautomatic track counting

    International Nuclear Information System (INIS)

    Griffith, R.V.; McMahon, T.A.; Espinosa, G.

    1983-01-01

    Bacterial colony counters have not been widely used for track counting. However, they do provide an economical alternative to sophisticated optical analyzers for applications that require reproducible track density measurements for large numbers of samples. Simple measurements of size characteristics can be made when there is little need for high resolutions. Such systems are particularly well suited for neutron and alpha dosimetry work, particularly if electrochemical etching or some other track enhancement method has been used. 5 refs., 3 figs

  11. Levels and pattern of polybrominated diphenyl ethers in eggs of Antarctic seabirds: Endemic versus migratory species

    Energy Technology Data Exchange (ETDEWEB)

    Yogui, G.T. [Geochemical and Environmental Research Group, College of Geosciences, Texas A and M University, 833 Graham Road, College Station, TX 77845 (United States)], E-mail: gtyogui@ocean.tamu.edu; Sericano, J.L. [Geochemical and Environmental Research Group, College of Geosciences, Texas A and M University, 833 Graham Road, College Station, TX 77845 (United States)], E-mail: jsericano@gerg.tamu.edu

    2009-03-15

    Chinstrap and gentoo penguins are endemic species that live year round south of the Antarctic Convergence. South polar skua is a migratory seabird that can be observed in Antarctica during the breeding season (i.e., austral summer). This study compares concentration and pattern of polybrominated diphenyl ethers (PBDEs) in eggs of seabirds breeding at King George Island, Antarctic Peninsula. PBDEs in south polar skua eggs are approximately 20 times higher than in penguin eggs suggesting that skuas are more exposed to contaminants during the non-breeding season when they migrate to waters of the northern hemisphere. The pattern of PBDE congeners also differs between south polar skua and penguin eggs. The latter exhibited a pattern similar to that found in the local biota. In contrast, the congener pattern in south polar skua eggs suggests that birds breeding at King George Island may winter in the northwestern Pacific Ocean. - Skua and penguin eggs collected at King George Island have different concentration and pattern of PBDEs.

  12. Low Density of Top Predators (Seabirds and Marine Mammals in the High Arctic Pack Ice

    Directory of Open Access Journals (Sweden)

    Claude R. Joiris

    2016-01-01

    Full Text Available The at-sea distribution of top predators, seabirds and marine mammals, was determined in the high Arctic pack ice on board the icebreaker RV Polarstern in July to September 2014. In total, 1,620 transect counts were realised, lasting 30 min each. The five most numerous seabird species represented 74% of the total of 15,150 individuals registered: kittiwake Rissa tridactyla, fulmar Fulmarus glacialis, puffin Fratercula arctica, Ross’s gull Rhodostethia rosea, and little auk Alle alle. Eight cetacean species were tallied for a total of 330 individuals, mainly white-beaked dolphin Lagenorhynchus albirostris and fin whale Balaenoptera physalus. Five pinniped species were represented by a total of 55 individuals and the polar bear Ursus maritimus was represented by 12 individuals. Four main geographical zones were identified: from Tromsø to the outer marginal ice zone (OMIZ, the Arctic pack ice (close pack ice, CPI, the end of Lomonosov Ridge off Siberia, and the route off Siberia and northern Norway. Important differences were detected between zones, both in species composition and in individual abundance. Low numbers of species and high proportion of individuals for some of them can be considered to reflect very low biodiversity. Numbers encountered in zones 2 to 4 were very low in comparison with other European Arctic seas. The observed differences showed strong patterns.

  13. Mercury accumulation in sediments and seabird feathers from the Antarctic Peninsula

    International Nuclear Information System (INIS)

    Calle, Paola; Alvarado, Omar; Monserrate, Lorena; Cevallos, Juan Manuel; Calle, Nastenka; Alava, Juan José

    2015-01-01

    Highlights: • We assessed mercury bioaccumulation in seabirds in the Antarctic Peninsula. • Levels of Hg were higher in gentoo penguins & brown skuas than chinstrap penguins. • Mercury BMF in the brown skua/penguins relationship was higher than 1. • Long-range environmental transport is the likely mercury route in Antarctic. - Abstract: In an effort to assess the impact of mercury in the Antarctic Peninsula, we conducted ecotoxicological research in this region during the summer of 2012 and 2013. The objectives were to assess: (a) mercury levels in sediment samples; (b) mercury accumulation in Antarctic seabird feathers: Catharacta lonnbergi (brown skua), Pygoscelis papua (gentoo penguin) and Pygoscelis antarctica (chinstrap penguin); and (c) biomagnification (BMF predator/prey) and biota sediment accumulation (BSAF skuas/sediment) factors. Mercury concentrations in sediment were relatively low. Mercury concentrations were significantly higher in brown skuas and gentoo penguins than in chinstrap penguins (2012), and significantly higher in brown skuas than in both penguins (2013). BMF indicated 2–7.5 times greater mercury levels in brown skuas than in penguins. BSAF values suggested an apparent temporal decrease of 18.2% of this ratio from 2012 to 2013. Long-range environmental transport is the likely route of entry of mercury into the Antarctic Peninsula

  14. Levels and pattern of polybrominated diphenyl ethers in eggs of Antarctic seabirds: Endemic versus migratory species

    International Nuclear Information System (INIS)

    Yogui, G.T.; Sericano, J.L.

    2009-01-01

    Chinstrap and gentoo penguins are endemic species that live year round south of the Antarctic Convergence. South polar skua is a migratory seabird that can be observed in Antarctica during the breeding season (i.e., austral summer). This study compares concentration and pattern of polybrominated diphenyl ethers (PBDEs) in eggs of seabirds breeding at King George Island, Antarctic Peninsula. PBDEs in south polar skua eggs are approximately 20 times higher than in penguin eggs suggesting that skuas are more exposed to contaminants during the non-breeding season when they migrate to waters of the northern hemisphere. The pattern of PBDE congeners also differs between south polar skua and penguin eggs. The latter exhibited a pattern similar to that found in the local biota. In contrast, the congener pattern in south polar skua eggs suggests that birds breeding at King George Island may winter in the northwestern Pacific Ocean. - Skua and penguin eggs collected at King George Island have different concentration and pattern of PBDEs

  15. Approaching population thresholds in presence of uncertainty: Assessing displacement of seabirds from offshore wind farms

    International Nuclear Information System (INIS)

    Busch, Malte; Garthe, Stefan

    2016-01-01

    Assessment of the displacement impacts of offshore wind farms on seabirds is impeded by a lack of evidence regarding species-specific reactions to developed sites and the potential ecological consequences faced by displaced individuals. In this study, we present a method that makes best use of the currently limited understanding of displacement impacts. The combination of a matrix table displaying the full range of potential displacement and mortality levels together with seasonal potential biological removal (PBR) assessments provides a tool that increases confidence in the conclusions of impact assessments. If unrealistic displacement levels and/or mortality rates are required to equal or approach seasonal PBRs, this gives an indication of the likeliness of adverse impacts on the assessed population. This approach is demonstrated by assessing the displacement impacts of an offshore wind farm cluster in the German North Sea on the local common guillemot (Uria aalge) population. - Highlights: • A novel approach for assessing displacement impacts of offshore wind farms on seabirds is presented making best use of limited data • A displacement matrix approach is linked with PBR analysis to increased confidence in assessment conclusions drawn • A case example demonstrates the applicability of the methods described in practice

  16. Approaching population thresholds in presence of uncertainty: Assessing displacement of seabirds from offshore wind farms

    Energy Technology Data Exchange (ETDEWEB)

    Busch, Malte, E-mail: der.malte.busch@gmail.com; Garthe, Stefan

    2016-01-15

    Assessment of the displacement impacts of offshore wind farms on seabirds is impeded by a lack of evidence regarding species-specific reactions to developed sites and the potential ecological consequences faced by displaced individuals. In this study, we present a method that makes best use of the currently limited understanding of displacement impacts. The combination of a matrix table displaying the full range of potential displacement and mortality levels together with seasonal potential biological removal (PBR) assessments provides a tool that increases confidence in the conclusions of impact assessments. If unrealistic displacement levels and/or mortality rates are required to equal or approach seasonal PBRs, this gives an indication of the likeliness of adverse impacts on the assessed population. This approach is demonstrated by assessing the displacement impacts of an offshore wind farm cluster in the German North Sea on the local common guillemot (Uria aalge) population. - Highlights: • A novel approach for assessing displacement impacts of offshore wind farms on seabirds is presented making best use of limited data • A displacement matrix approach is linked with PBR analysis to increased confidence in assessment conclusions drawn • A case example demonstrates the applicability of the methods described in practice.

  17. Evaluation of the effectiveness of light streamer tori-lines and characteristics of bait attacks by seabirds in the western North Pacific.

    Directory of Open Access Journals (Sweden)

    Noriyosi Sato

    Full Text Available To improve the effectiveness of tori-lines it is necessary to evaluate the ability of tori-lines to mitigate seabird bycatch and determine what kind of seabird species gather during line settings, attack the bait and are incidentally caught. We conducted two experiments in the western North Pacific and examined the effectiveness for seabird mitigation of light streamer tori-lines which have no long streamers but many light (short streamers and are mainly used in the North Pacific area. Firstly, the effectiveness of two different types of tori-line (light streamer (1 m and long streamer (up to 7 m tori-line and of two different colors (yellow and red of light streamers for seabird bycatch avoidance was evaluated using 567 sets based on data from 20 offshore surface commercial longliners. No significant difference in the bycatch number between the different tori-line types and streamer colors was found. Secondly, we investigated the characteristics of the seabird bycatch in the North Pacific and the effectiveness of three different types of streamers (light, hybrid and modified light types by detailed observations of seabird attacks using a chartered longline vessel. Although the appearance rate of albatrosses and shearwaters were 40.9% and 27.7%, Laysan albatross was the main seabird species that followed the vessel but shearwaters seldom followed the vessel and did not aggregate during line setting. In all attacks on bait observed during line settings, 81% and 7% were by albatrosses and shearwaters, respectively. In the number of primary attacks by Laysan albatrosses which attacked most aggressively of all seabirds, there were no significant differences among the tori-line types. No individuals of shearwater were caught. The results of both experiments indicated that light streamer tori-lines were as effective as tori-lines with long streamers for mitigating seabird bycatch in the North Pacific.

  18. Alternative Modernities for Colonial Korea

    Directory of Open Access Journals (Sweden)

    Steven Lee

    2016-06-01

    Full Text Available Sunyoung Park. The Proletarian Wave: Literature and Leftist Culture in Colonial Korea, 1910–1945. Cambridge, MA: Harvard University Asia Center, 2015. 348 pp. $50 (cloth. Vladimir Tikhonov. Modern Korea and Its Others: Perceptions of the Neighbouring Countries and Korean Modernity. London: Routledge, 2016. 218 pp. $160 (cloth. It has become a global scholarly undertaking: how to rethink modernity so as to decouple it from Westernization (Chakrabarty 2000. Strategies have included foregrounding the plurality of history to disrupt linear progress; positing non-Western centers of modernity in, say, Moscow or Shanghai; and tracing anticolonial circuits connecting Asia to Africa to Latin America. The two recent books under review here add colonial-era Korea to such far-reaching discussions by situating the country across national boundaries. Interestingly, one connecting thread here is the alternative world system provided by the interwar, Soviet-oriented Left. The result is an unsettling of binaries that subsequently became entrenched during the Cold War: for example, north-south, socialist-nationalist, and, for literature, realist-modernist. But more broadly, pervading both books is the sense that history could have turned out differently—that revisiting northeast Asia’s porous borders in the early twentieth century reveals the Korean peninsula’s lost, internationalist potential...

  19. Escalated convergent artificial bee colony

    Science.gov (United States)

    Jadon, Shimpi Singh; Bansal, Jagdish Chand; Tiwari, Ritu

    2016-03-01

    Artificial bee colony (ABC) optimisation algorithm is a recent, fast and easy-to-implement population-based meta heuristic for optimisation. ABC has been proved a rival algorithm with some popular swarm intelligence-based algorithms such as particle swarm optimisation, firefly algorithm and ant colony optimisation. The solution search equation of ABC is influenced by a random quantity which helps its search process in exploration at the cost of exploitation. In order to find a fast convergent behaviour of ABC while exploitation capability is maintained, in this paper basic ABC is modified in two ways. First, to improve exploitation capability, two local search strategies, namely classical unidimensional local search and levy flight random walk-based local search are incorporated with ABC. Furthermore, a new solution search strategy, namely stochastic diffusion scout search is proposed and incorporated into the scout bee phase to provide more chance to abandon solution to improve itself. Efficiency of the proposed algorithm is tested on 20 benchmark test functions of different complexities and characteristics. Results are very promising and they prove it to be a competitive algorithm in the field of swarm intelligence-based algorithms.

  20. Meeting reproductive demands in a dynamic upwelling system: foraging strategies of a pursuit-diving seabird, the marbled murrelet

    Science.gov (United States)

    M. Zachariah Peery; Scott H. Newman; Curt D. Storlazzi; Steven R. Beissinger

    2009-01-01

    Seabirds maintain plasticity in their foraging behavior to cope with energy demands and foraging constraints that vary over the reproductive cycle, but behavioral studies comparing breeding and nonbreeding individuals are rare. Here we characterize how Marbled Murrelets (Brachyramphus marmoratus) adjust their foraging effort in response to changes...

  1. Comment on "Marine plastic debris emits a keystone infochemical for olfactory foraging seabirds" by Savoca et al.

    NARCIS (Netherlands)

    dell'Ariccia, Gaia; Phillips, Richard A.; Franeker, van J.A.; Gaidet, Nicolas; Catrey, Paulo; Granadeiro, Jose P.; Ryan, Peter G.; Bonadonna, Franceso

    2017-01-01

    In their recent paper, Savoca and collaborators (2016) showed that plastic debris in the ocean may acquire a dimethyl sulfide (DMS) signature from biofouling developing on their surface. According to them, DMS emission may represent an olfactory trap for foraging seabirds, which explains patterns of

  2. Co-distribution of seabirds and their polar cod prey near the ice edge in southern Baffin Bay

    DEFF Research Database (Denmark)

    LeBlanc, Mathieu; Gauthier, S; Mosbech, Anders

    species, and age-1 polar cod found in bird stomachs were likely individuals associated to ice. At a large scale of hundreds of kilometers, seabirds and age-0 polar cod were more abundant in ice-covered habitats (30 to 100% ice concentration). At medium and small scale of 12.5 and 1 km respectively...

  3. Responses of seabirds, in particular prions (Pachyptila sp.), to small-scale processes in the Antarctic Polar Front

    NARCIS (Netherlands)

    Franeker, van J.A.; Brink, van den N.W.; Bathmann, U.V.; Pollard, R.T.; Baar, de H.J.W.; Wolff, W.J.

    2002-01-01

    Small-scale distribution patterns of seabirds in the Antarctic Polar Front (APF) were investigated in relation to other biological, physical, and chemical features during the ANT-XIII/2 research cruise of R.V. Polarstern from December 1995 to January 1996. The APF is characterized by steep gradients

  4. Conspecific and not performance-based attraction on immigrants drives colony growth in a waterbird.

    Science.gov (United States)

    Tenan, Simone; Fasola, Mauro; Volponi, Stefano; Tavecchia, Giacomo

    2017-09-01

    Local recruitment and immigration play an important part in the dynamics and growth of animal populations. However, their estimation and incorporation into open population models is, in most cases, problematic. We studied factors affecting the growth of a recently established colony of Eurasian spoonbill (Platalea leucorodia) and assessed the contribution of local recruits, i.e. birds born in the colony, and immigrants, i.e. birds of unknown origin, to colony growth. We applied an integrated population model that accounts for uncertainty in breeding state assignment and merges population surveys, local fecundity and individual longitudinal data of breeding and non-breeding birds, to estimate demographic rates and the relative role of recruitment and immigration in driving the local dynamics. We also used this analytical framework to assess the degree of support for the 'performance-based' and 'conspecific attraction' hypotheses as possible mechanisms of colony growth. Among the demographic rates, only immigration was positively and significantly correlated with population growth rate. In addition, the number of immigrants settling in the colony was positively correlated with colony size in the previous and current year, but was not correlated with fecundity of the previous year. Our results suggest that the variation in immigration affected colony dynamics and that conspecific attraction likely triggered the relevant role of immigration in the growth of a recently formed waterbird colony, supporting the need of including immigration in population analysis. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  5. Queen promiscuity lowers disease within honeybee colonies

    OpenAIRE

    Seeley, Thomas D; Tarpy, David R

    2006-01-01

    Most species of social insects have singly mated queens, but in some species each queen mates with numerous males to create a colony with a genetically diverse worker force. The adaptive significance of polyandry by social insect queens remains an evolutionary puzzle. Using the honeybee (Apis mellifera), we tested the hypothesis that polyandry improves a colony's resistance to disease. We established colonies headed by queens that had been artificially inseminated by either one or 10 drones. ...

  6. Data for automated, high-throughput microscopy analysis of intracellular bacterial colonies using spot detection.

    Science.gov (United States)

    Ernstsen, Christina L; Login, Frédéric H; Jensen, Helene H; Nørregaard, Rikke; Møller-Jensen, Jakob; Nejsum, Lene N

    2017-10-01

    Quantification of intracellular bacterial colonies is useful in strategies directed against bacterial attachment, subsequent cellular invasion and intracellular proliferation. An automated, high-throughput microscopy-method was established to quantify the number and size of intracellular bacterial colonies in infected host cells (Detection and quantification of intracellular bacterial colonies by automated, high-throughput microscopy, Ernstsen et al., 2017 [1]). The infected cells were imaged with a 10× objective and number of intracellular bacterial colonies, their size distribution and the number of cell nuclei were automatically quantified using a spot detection-tool. The spot detection-output was exported to Excel, where data analysis was performed. In this article, micrographs and spot detection data are made available to facilitate implementation of the method.

  7. Triclosan-Induced Aminoglycoside-Tolerant Listeria monocytogenes Isolates Can Appear as Small-Colony Variants

    DEFF Research Database (Denmark)

    Kastbjerg, Vicky Gaedt; Hein-Kristensen, Line; Gram, Lone

    2014-01-01

    Exposure of the human food-borne pathogen Listeria monocytogenes to sublethal concentrations of triclosan can cause resistance to several aminoglycosides. Aminoglycoside-resistant isolates exhibit two colony morphologies: normal-size and pinpoint colonies. The purposes of the present study were...... to characterize the small colonies of L. monocytogenes and to determine if specific genetic changes could explain the triclosan-induced aminoglycoside resistance in both pinpoint and normal-size isolates. Isolates from the pinpoint colonies grew poorly under aerated conditions, but growth was restored by addition......I and that exposure to triclosan can cause resistance to antibiotics that enters the cell via active transport. Further studies are needed to elucidate if L. monocytogenes pinpoint isolates could have any clinical impact, e.g., in persistent infections....

  8. Understanding Long-Run African Growth : Colonial Institutions or Colonial Education?

    NARCIS (Netherlands)

    Bolt, J.; Bezemer, D.J.

    2009-01-01

    Long-term growth in developing countries has been explained in four frameworks: 'extractive colonial institutions' (Acemoglu et al., 2001), 'colonial legal origin' (La Porta et al., 2004), 'geography' (Gallup et al., 1998) and 'colonial human capital' (Glaeser et al., 2004). In this paper we test

  9. Shortlist masterplan wind. Ship-based monitoring of seabirds and cetaceans

    Energy Technology Data Exchange (ETDEWEB)

    Van Bemmelen, R.; Geelhoed, S.; Leopold, M. [Institute for Marine Resources and Ecosystem Studies IMARES, Wageningen UR, IJmuiden (Netherlands)

    2011-02-15

    During April 2010 - February 2011, monthly surveys of seabirds and marine mammals were conducted aboard ships engaged in plankton surveys. After many years of little or no effort in far offshore areas of the DCS (Dutch Continental Shelf), this series of surveys provided the first recent ship-based data on seabirds, covering a large area (the entire DCS, including some Belgian and British waters) almost year round. Due to changes in the design of the survey grid, the use of several ships, spells of bad weather conditions and seasonal differences in the number of daylight hours, the resulting coverage is not evenly spread in space and time. Still, both in terms of areas covered and detailed data gathered, this series of surveys complement the aerial surveys carried out under the same programme Shortlist Masterplan Wind. By surveying beyond the designated areas for round II offshore wind farms on the DCS, areas that might be targeted for round III, such as the shallow Dogger Bank area, got a first boost in T-zero survey effort. From April 2010 till February 2011 11 surveys, totalling to 48 at-sea days, 4610 5-minute counts were conducted over a distance of 9021 km. At a counting strip width of mostly 300 m (200 m over a very small percentage of the counts), this amounts to a total surveyed area of 2706 km{sup 2}. The surveys have provided rough data on seabird distribution in far offshore areas. In total, 54,593 individuals of 90 bird species were recorded, from which 15,003 individuals of 36 species were recorded within the counting strip. Marine mammals were represented by 616 individuals of seven species, of which 389 individuals of six species were seen within the counting strip. Flying heights were noted for 5044 clusters of individuals, covering 75 species. Behaviour was noted for 1790 (clusters of) individuals. Apart from birds and marine mammals, 352 balloons were counted (of which 164 were within the counting strip) and proved omnipresent in periods of

  10. Modeled prevalance of seabirds and relative abundance of cetaceans in NW Atlantic (limit-40 W) from 1980-04-01 to 1988-10-01 (NCEI Accession 0130025)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data set is a compilation of modeled seabird prevalence predictions for a selection of species including Razorbill (Alca torda), Greater Shearwater (Puffinus...

  11. Trace elements (Cu, Zn, and Hg) and δ13C/δ15N in seabird subfossils from three islands of the South China Sea and its implications.

    Science.gov (United States)

    Xu, Liqiang; Liu, Xiaodong; Nie, Yaguang

    2016-05-01

    Seabird subfossils were collected on three islands of the Xisha Archipelago, South China Sea. Via elemental analysis, we identified that bird guano was a significant source for heavy metals Cu, Zn, and Hg. Cu and Zn levels in these guano samples are comparable to their levels in wildbird feces, but guano Hg was lower than previously reported. Trophic positions significantly impacted transfer efficiency of heavy metals by seabirds. Despite of a common source, trace elements, as well as stable isotopes (i.e., guano δ(13)C and collagen δ(15)N), showed island-specific characteristics. Bird subfossils on larger island had relatively greater metal concentrations and revealed higher trophic positions. Partition of element and isotope levels among the islands suggested that transfer efficacy of seabirds on different islands was different, and bird species were probably unevenly distributed among the islets. Island area is possibly a driving factor for distributions of seabird species.

  12. NCCOS Assessment: Predictive Mapping of Seabirds, Pinnipeds and Cetaceans off the Pacific Coast of Washington from 1995-07-21 to 2015-12-08 (NCEI Accession 0148762)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This data collection comprises seasonal distribution maps and model outputs of selected seabird, pinniped and cetacean species off the Pacific coast of Washington....

  13. NOAA ESRI Grid - predictions of relative uncertainty for seabird diversity metrics in the New York offshore planning area by NOAA Biogeography Branch

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset represents relative seabird abundance predictions from spatial models developed for the New York offshore spatial planning area. This raster was derived...

  14. Atlantic Offshore Seabird Dataset Catalog, Atlantic Coast and Outer Continental Shelf, from 1938-01-01 to 2013-12-31 (NODC Accession 0115356)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Several bureaus within the Department of Interior compiled available information from seabird observation datasets from the Atlantic Outer Continental Shelf into a...

  15. NOAA ESRI Grid - predictions of seabird species richness in the New York offshore planning area made by the NOAA Biogeography Branch

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset represents seabird species richness, or number of species, predictions from spatial models developed for the New York offshore spatial planning area....

  16. NOAA ESRI Grid - predictions of relative seabird abundance in the New York offshore planning area made by the NOAA Biogeography Branch

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset represents relative seabird abundance predictions from spatial models developed for the New York offshore spatial planning area. This raster was derived...

  17. Colony Collapse Disorder (CCD) and bee age impact honey bee pathophysiology.

    Science.gov (United States)

    vanEngelsdorp, Dennis; Traynor, Kirsten S; Andree, Michael; Lichtenberg, Elinor M; Chen, Yanping; Saegerman, Claude; Cox-Foster, Diana L

    2017-01-01

    Honey bee (Apis mellifera) colonies continue to experience high annual losses that remain poorly explained. Numerous interacting factors have been linked to colony declines. Understanding the pathways linking pathophysiology with symptoms is an important step in understanding the mechanisms of disease. In this study we examined the specific pathologies associated with honey bees collected from colonies suffering from Colony Collapse Disorder (CCD) and compared these with bees collected from apparently healthy colonies. We identified a set of pathological physical characteristics that occurred at different rates in CCD diagnosed colonies prior to their collapse: rectum distension, Malpighian tubule iridescence, fecal matter consistency, rectal enteroliths (hard concretions), and venom sac color. The multiple differences in rectum symptomology in bees from CCD apiaries and colonies suggest effected bees had trouble regulating water. To ensure that pathologies we found associated with CCD were indeed pathologies and not due to normal changes in physical appearances that occur as an adult bee ages (CCD colonies are assumed to be composed mostly of young bees), we documented the changes in bees of different ages taken from healthy colonies. We found that young bees had much greater incidences of white nodules than older cohorts. Prevalent in newly-emerged bees, these white nodules or cellular encapsulations indicate an active immune response. Comparing the two sets of characteristics, we determined a subset of pathologies that reliably predict CCD status rather than bee age (fecal matter consistency, rectal distension size, rectal enteroliths and Malpighian tubule iridescence) and that may serve as biomarkers for colony health. In addition, these pathologies suggest that CCD bees are experiencing disrupted excretory physiology. Our identification of these symptoms is an important first step in understanding the physiological pathways that underlie CCD and factors

  18. Colony Collapse Disorder (CCD and bee age impact honey bee pathophysiology.

    Directory of Open Access Journals (Sweden)

    Dennis vanEngelsdorp

    Full Text Available Honey bee (Apis mellifera colonies continue to experience high annual losses that remain poorly explained. Numerous interacting factors have been linked to colony declines. Understanding the pathways linking pathophysiology with symptoms is an important step in understanding the mechanisms of disease. In this study we examined the specific pathologies associated with honey bees collected from colonies suffering from Colony Collapse Disorder (CCD and compared these with bees collected from apparently healthy colonies. We identified a set of pathological physical characteristics that occurred at different rates in CCD diagnosed colonies prior to their collapse: rectum distension, Malpighian tubule iridescence, fecal matter consistency, rectal enteroliths (hard concretions, and venom sac color. The multiple differences in rectum symptomology in bees from CCD apiaries and colonies suggest effected bees had trouble regulating water. To ensure that pathologies we found associated with CCD were indeed pathologies and not due to normal changes in physical appearances that occur as an adult bee ages (CCD colonies are assumed to be composed mostly of young bees, we documented the changes in bees of different ages taken from healthy colonies. We found that young bees had much greater incidences of white nodules than older cohorts. Prevalent in newly-emerged bees, these white nodules or cellular encapsulations indicate an active immune response. Comparing the two sets of characteristics, we determined a subset of pathologies that reliably predict CCD status rather than bee age (fecal matter consistency, rectal distension size, rectal enteroliths and Malpighian tubule iridescence and that may serve as biomarkers for colony health. In addition, these pathologies suggest that CCD bees are experiencing disrupted excretory physiology. Our identification of these symptoms is an important first step in understanding the physiological pathways that underlie CCD and

  19. Post-Colonialism Perspectives on Educational Competition

    Science.gov (United States)

    Yeh, Chuan-Rong

    2016-01-01

    Educational competition has always been the puzzle issue of educational researches. In this article, I analyze several aspects of educational competition within the perspective of post-colonialism discourse. In the political aspect, Taiwanese education is linked with political power, to present the post-colonial spirit by continuing dynastic…

  20. [Notes about other epidemics in Colonial Chile].

    Science.gov (United States)

    Laval, Enrique

    2015-10-01

    In chronicles or in the historiography of the Colony in Chile there are few references about epidemics different to smallpox; like typhus, typhoid fever, dysentery, etc. Almost all, fast spreading in the country and some with high lethality, which led to overflowing the capacity of hospitals in the Chilean colonial period.

  1. Effects of Wintering Environment and Parasite-Pathogen Interactions on Honey Bee Colony Loss in North Temperate Regions.

    Directory of Open Access Journals (Sweden)

    Suresh D Desai

    Full Text Available Extreme winter losses of honey bee colonies are a major threat to beekeeping but the combinations of factors underlying colony loss remain debatable. We monitored colonies in two environments (colonies wintered indoors or outdoors and characterized the effects of two parasitic mites, seven viruses, and Nosema on honey bee colony mortality and population loss over winter. Samples were collected from two locations within hives in fall, mid-winter and spring of 2009/2010. Although fall parasite and pathogen loads were similar in outdoor and indoor-wintered colonies, the outdoor-wintered colonies had greater relative reductions in bee population score over winter. Seasonal patterns in deformed wing virus (DWV, black queen cell virus (BQCV, and Nosema level also differed with the wintering environment. DWV and Nosema levels decreased over winter for indoor-wintered colonies but BQCV did not. Both BQCV and Nosema concentration increased over winter in outdoor-wintered colonies. The mean abundance of Varroa decreased and concentration of Sacbrood virus (SBV, Kashmir bee virus (KBV, and Chronic bee paralysis virus (CBPV increased over winter but seasonal patterns were not affected by wintering method. For most viruses, either entrance or brood area samples were reasonable predictors of colony virus load but there were significant season*sample location interactions for Nosema and BQCV, indicating that care must be taken when selecting samples from a single location. For Nosema spp., the fall entrance samples were better predictors of future infestation levels than were fall brood area samples. For indoor-wintered colonies, Israeli acute paralysis virus IAPV concentration was negatively correlated with spring population size. For outdoor-wintered hives, spring Varroa abundance and DWV concentration were positively correlated with bee loss and negatively correlated with spring population size. Multivariate analyses for fall collected samples indicated

  2. Hegemony and Accommodation in the History Curriculum in Colonial Botswana

    Science.gov (United States)

    Mafela, Lily

    2014-01-01

    A reanalysis of colonial education is necessary in order to highlight its multifaceted and hybrid nature in specific colonial contexts. Although in general, colonial education served the socio-political needs of the colonial machinery, the colonial government's hegemonic authority over the school curriculum did not operate as a totalising project.…

  3. Incidence of marine debris in seabirds feeding at different water depths.

    Science.gov (United States)

    Tavares, D C; de Moura, J F; Merico, A; Siciliano, S

    2017-06-30

    Marine debris such as plastic fragments and fishing gears are accumulating in the ocean at alarming rates. This study assesses the incidence of debris in the gastrointestinal tracts of seabirds feeding at different depths and found stranded along the Brazilian coast in the period 2010-2013. More than half (55%) of the species analysed, corresponding to 16% of the total number of individuals, presented plastic particles in their gastrointestinal tracts. The incidence of debris was higher in birds feeding predominantly at intermediate (3-6m) and deep (20-100m) waters than those feeding at surface (pollution has on marine life and highlight the ubiquitous and three-dimensional distribution of plastic in the oceans. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Weights, hematology and serum chemistry of seven species of free-ranging tropical pelagic seabirds

    Science.gov (United States)

    Work, Thierry M.

    1996-01-01

    I established reference values for weight, hematology, and serum chemistry for seven species of free-ranging Hawaiian tropical pelagic seabirds comprising three orders (Procellariiformes, Pelecaniformes, Charadriiformes) and six families (Procellariidae, Phaethontidae, Diomedeidae, Sulidae, Fregatidae, and Laridae). Species examined included 84 Hawaiian dark-rumped petrels (Pterodoma phaeopygia), 90 wedge-tailed shearwaters (Puffinus pacificus), 151 Laysan albatrosses (Diomedea immutabilis), 69 red-footed boobies (Sula sula), 154 red-tailed tropicbirds (Phaeton rubricauda), 90 great frigatebirds (Fregata minor), and 72 sooty terns (Sterna fuscata). Hematocrit, total plasma solids, total and differential white cell counts, serum glucose, calcium, phosphorus, uric acid, total protein, albumin, globulin, aspartate aminotransferase and creatinine phosphokinase were analyzed. Among and within species, hematology and chemistry values varied with age, sex, season, and island of collection. Despite this variation, order-wide trends were observed.

  5. Predictive ethoinformatics reveals the complex migratory behaviour of a pelagic seabird, the Manx Shearwater

    Science.gov (United States)

    Freeman, Robin; Dean, Ben; Kirk, Holly; Leonard, Kerry; Phillips, Richard A.; Perrins, Chris M.; Guilford, Tim

    2013-01-01

    Understanding the behaviour of animals in the wild is fundamental to conservation efforts. Advances in bio-logging technologies have offered insights into the behaviour of animals during foraging, migration and social interaction. However, broader application of these systems has been limited by device mass, cost and longevity. Here, we use information from multiple logger types to predict individual behaviour in a highly pelagic, migratory seabird, the Manx Shearwater (Puffinus puffinus). Using behavioural states resolved from GPS tracking of foraging during the breeding season, we demonstrate that individual behaviours can be accurately predicted during multi-year migrations from low cost, lightweight, salt-water immersion devices. This reveals a complex pattern of migratory stopovers: some involving high proportions of foraging, and others of rest behaviour. We use this technique to examine three consecutive years of global migrations, revealing the prominence of foraging behaviour during migration and the importance of highly productive waters during migratory stopover. PMID:23635496

  6. Diving physiology of seabirds and marine mammals: Relevance, challenges and some solutions for field studies.

    Science.gov (United States)

    Andrews, Russel D; Enstipp, Manfred R

    2016-12-01

    To fully understand how diving seabirds and marine mammals balance the potentially conflicting demands of holding their breath while living their lives underwater (and maintaining physiological homeostasis during exercise, feeding, growth, and reproduction), physiological studies must be conducted with animals in their natural environments. The purpose of this article is to review the importance of making physiological measurements on diving animals in field settings, while acknowledging the challenges and highlighting some solutions. The most extreme divers are great candidates for study, especially in a comparative and mechanistic context. However, physiological data are also required of a wide range of species for problems relating to other disciplines, in particular ecology and conservation biology. Physiological data help with understanding and predicting the outcomes of environmental change, and the direct impacts of anthropogenic activities. Methodological approaches that have facilitated the development of field-based diving physiology include the isolated diving hole protocol and the translocation paradigm, and while there are many techniques for remote observation, animal-borne biotelemetry, or "biologging", has been critical. We discuss issues related to the attachment of instruments, the retrieval of data and sensing of physiological variables, while also considering negative impacts of tagging. This is illustrated with examples from a variety of species, and an in-depth look at one of the best studied and most extreme divers, the emperor penguin (Aptenodytes forsteri). With a variety of approaches and high demand for data on the physiology of diving seabirds and marine mammals, the future of field studies is bright. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Keeping it regular: Development of thermoregulation in four tropical seabird species.

    Science.gov (United States)

    Hart, Lorinda A; Downs, Colleen T; Brown, Mark

    2017-02-01

    The thermoregulatory capacity of a species can determine which climatic niche it occupies. Its development in avian chicks is influenced by numerous factors. Furthermore, it is suggested that altricial chicks develop their thermoregulatory capacity post-hatching, while precocial chicks develop aspects of this in the egg. We investigated the development of thermoregulation of four co-occurring seabird species in the Seychelles; namely white, ground-nesting white-tailed tropicbirds (Phaethon lepturus) and tree-nesting fairy terns (Gygis alba); and dark plumaged, tree-nesting lesser noddies (Anous tenuirostris) and ground- and tree-nesting brown noddies (A. stolidus). White-tailed tropicbirds have semi-altricial chicks, while the remaining species have semi-precocial chicks. Cloacal temperatures (T b ) were measured at five day intervals from newly hatched chicks and compared over time, and with adult T b s. Initial T b s of all chicks, except fairy terns, were lower than those taken when chicks were older. Brooding cessation generally coincided with feather development, as did an increase in T b. Mean chick T b was significantly lower than mean adult T b for all species, but only white-tailed tropicbird and brown noddy chicks in tree nests differed significantly from mean adult T b when chick T b at five day intervals were considered. There was a significant interactive effect of nest site and age on brown noddy chick T b, but chick colour did not have a significant effect on T b . However, brown noddy chicks on dune crests maintained a constant T b sooner than chicks in tree nests. Our results demonstrate that tropical seabird species have a more delayed onset of thermoregulatory capabilities when compared with those in temperate environments, perhaps as nest sites are less thermally challenging. Nest microhabitats and behavioural thermoregulation, are likely more important during early chick development for these species. Copyright © 2016 Elsevier Ltd. All rights

  8. Mercury concentrations in seabird tissues from Machias Seal Island, New Brunswick, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Bond, Alexander L., E-mail: abond@mun.ca [Atlantic Cooperative Wildlife Ecology Research Network, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, E3B 5A3 (Canada); Department of Biology, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, E3B 5A3 (Canada); Diamond, Antony W. [Atlantic Cooperative Wildlife Ecology Research Network, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, E3B 5A3 (Canada); Department of Biology, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick, E3B 5A3 (Canada)

    2009-07-01

    Mercury is a pervasive environmental contaminant, the anthropogenic portion of which is increasing globally, and in northeastern North America in particular. Seabirds frequently are used as indicators of the marine environment, including mercury contamination. We analysed paired samples for total mercury (Hg) concentrations in feathers and blood from adult and chick, albumen, and lipid-free yolk of seven seabirds breeding on Machias Seal Island, New Brunswick, Canada - Arctic Tern (Sterna paradisaea), Atlantic Puffin (Fratercula arctica), Common Eider (Somateria mollissima), Common Murre (Uria aalge), Common Tern (Sterna hirundo), Leach's Storm-petrel (Oceanodroma leucorhoa), and Razorbill (Alca torda). We also used stable-isotope ratios of carbon ({delta}{sup 13}C), and nitrogen ({delta}{sup 15}N) to evaluate the relationship between carbon source and trophic position and mercury. We found high Hg concentrations across tissue types in Leach's Storm-petrels, and Razorbills, with lower concentrations in other species, the lowest being in Common Eiders. Storm-petrels prey on mesopelagic fish that accumulate mercury, and Razorbills feed on larger, older fish that bioaccumulate heavy metals. Biomagnification of Hg, or the increase in Hg concentration with trophic position as measured by {delta}{sup 15}N, was significant and greater in albumen than other tissues, whereas in other tissues, {delta}{sup 15}N explained little of the overall variation in Hg concentration. Hg concentrations in egg components are higher on Machias Seal Island than other sites globally and in the Gulf of Maine region, but only for some species. Further detailed investigations are required to determine the cause of this trend.

  9. Coloniality of birds in the Kalahari – spatial distribution of trees and nests of the Sociable Weaver (Philetairus socius)

    CSIR Research Space (South Africa)

    Rösner, S

    2010-01-01

    Full Text Available The spatial distribution of suitable nest sites is a limiting resource for many colonial breeding animals. Therefore, we investigated and mapped the spatial distribution of nests of Sociable Weaver (Philetairus socius) to evaluate whether the size...

  10. Continental-Scale Mapping of Adelie Penguin Colonies from Landsat Imagery

    Science.gov (United States)

    Schwaller, Mathew R.; Southwell, Colin; Emmerson, Louise

    2013-01-01

    Breeding distribution of the Adlie penguin, Pygoscelis adeliae, was surveyed with Landsat-7 Enhanced Thematic Mapper Plus (ETM+) data in an area covering approximately 330 of longitude along the coastline of Antarctica.An algorithm was designed to minimize radiometric noise and to retrieve Adlie penguin colony location and spatial extent from the ETM+data. In all, 9143 individual pixels were classified as belonging to an Adlie penguin colony class out of the entire dataset of 195 ETM+ scenes, where the dimension of each pixel is 30 m by 30 m,and each scene is approximately 180 km by 180 km. Pixel clustering identified a total of 187 individual Adlie penguin colonies, ranging in size from a single pixel (900 sq m) to a maximum of 875 pixels (0.788 sq km). Colony retrievals have a very low error of commission, on the order of 1% or less, and the error of omission was estimated to be 3% to 4% by population based on comparisons with direct observations from surveys across east Antarctica. Thus, the Landsat retrievals successfully located Adlie penguin colonies that accounted for 96 to 97% of the regional population used as ground truth. Geographic coordinates and the spatial extent of each colony retrieved from the Landsat data are available publically. Regional analysis found several areas where the Landsat retrievals suggest populations that are significantly larger than published estimates. Six Adlie penguin colonies were found that are believed to be previously unreported in the literature.

  11. Fluctuating survival selection explains variation in avian group size.

    Science.gov (United States)

    Brown, Charles R; Brown, Mary Bomberger; Roche, Erin A; O'Brien, Valerie A; Page, Catherine E

    2016-05-03

    Most animal groups vary extensively in size. Because individuals in certain sizes of groups often have higher apparent fitness than those in other groups, why wide group size variation persists in most populations remains unexplained. We used a 30-y mark-recapture study of colonially breeding cliff swallows (Petrochelidon pyrrhonota) to show that the survival advantages of different colony sizes fluctuated among years. Colony size was under both stabilizing and directional selection in different years, and reversals in the sign of directional selection regularly occurred. Directional selection was predicted in part by drought conditions: birds in larger colonies tended to be favored in cooler and wetter years, and birds in smaller colonies in hotter and drier years. Oscillating selection on colony size likely reflected annual differences in food availability and the consequent importance of information transfer, and/or the level of ectoparasitism, with the net benefit of sociality varying under these different conditions. Averaged across years, there was no net directional change in selection on colony size. The wide range in cliff swallow group size is probably maintained by fluctuating survival selection and represents the first case, to our knowledge, in which fitness advantages of different group sizes regularly oscillate over time in a natural vertebrate population.

  12. The occurrence of the cold-water coral Lophelia pertusa (Scleractinia) on oil and gas platforms in the North Sea: Colony growth recruitment and environmental controls on distribution

    Energy Technology Data Exchange (ETDEWEB)

    Gass, S.E.; Roberts, J.M. [Scottish Association for Marine Science, Dunstaffnage Marine Laboratory, Oban, Argyll (United Kingdom)

    2006-05-15

    This study reports a newly established sub-population of Lophelia pertusa, the dominant reef-framework forming coral species in the north-east Atlantic, on oil and gas platforms in the northern North Sea. L. pertusa was positively identified on 13 of 14 platforms examined using existing oil and gas industry visual inspections. Two platforms were inspected in more detail to examine depth and colony size distributions. We recorded 947 colonies occurring between 59 and 132 m depth that coincides with cold Atlantic water at depths below the summer thermocline in the northern North Sea. We suggest that these colonies provide evidence for a planktonic larval stage of L. pertusa with recruits initially originating from populations in the north-east Atlantic and now self recruiting to the platforms. Size class distribution showed a continuous range of size classes, but with few outlying large colonies. The break between the largest colonies and the rest of the population is considered as the point when colonies began self recruiting to the platforms, resulting in greater colonization success. We present the first documented in situ colony growth rate estimate (26 {+-} 5 mm yr{sup -1}) for L. pertusa based on 15 colonies from the Tern Alpha platform with evidence for yearly recruitment events starting the year the platform was installed. Evidence of contamination from drill muds and cuttings was observed on the Heather platform but appeared limited to regions close to drilling discharge points, where colonies experience partial as well as whole colony mortality. (author)

  13. A modified scout bee for artificial bee colony algorithm and its performance on optimization problems

    Directory of Open Access Journals (Sweden)

    Syahid Anuar

    2016-10-01

    Full Text Available The artificial bee colony (ABC is one of the swarm intelligence algorithms used to solve optimization problems which is inspired by the foraging behaviour of the honey bees. In this paper, artificial bee colony with the rate of change technique which models the behaviour of scout bee to improve the performance of the standard ABC in terms of exploration is introduced. The technique is called artificial bee colony rate of change (ABC-ROC because the scout bee process depends on the rate of change on the performance graph, replace the parameter limit. The performance of ABC-ROC is analysed on a set of benchmark problems and also on the effect of the parameter colony size. Furthermore, the performance of ABC-ROC is compared with the state of the art algorithms.

  14. At-sea behavior varies with lunar phase in a nocturnal pelagic seabird, the swallow-tailed gull.

    Directory of Open Access Journals (Sweden)

    Sebastian M Cruz

    Full Text Available Strong and predictable environmental variability can reward flexible behaviors among animals. We used long-term records of activity data that cover several lunar cycles to investigate whether behavior at-sea of swallow-tailed gulls Creagrus furcatus, a nocturnal pelagic seabird, varied with lunar phase in the Galápagos Islands. A Bayesian hierarchical model showed that nighttime at-sea activity of 37 breeding swallow-tailed gulls was clearly associated with changes in moon phase. Proportion of nighttime spent on water was highest during darker periods of the lunar cycle, coinciding with the cycle of the diel vertical migration (DVM that brings prey to the sea surface at night. Our data show that at-sea behavior of a tropical seabird can vary with environmental changes, including lunar phase.

  15. At-sea behavior varies with lunar phase in a nocturnal pelagic seabird, the swallow-tailed gull

    Science.gov (United States)

    Cruz, Sebastian M.; Hooten, Mevin; Huyvaert, Kathryn P.; Proaño, Carolina B.; Anderson, David J.; Afanasyev, Vsevolod; Wikelski, Martin

    2013-01-01

    Strong and predictable environmental variability can reward flexible behaviors among animals. We used long-term records of activity data that cover several lunar cycles to investigate whether behavior at-sea of swallow-tailed gulls Creagrus furcatus, a nocturnal pelagic seabird, varied with lunar phase in the Galápagos Islands. A Bayesian hierarchical model showed that nighttime at-sea activity of 37 breeding swallow-tailed gulls was clearly associated with changes in moon phase. Proportion of nighttime spent on water was highest during darker periods of the lunar cycle, coinciding with the cycle of the diel vertical migration (DVM) that brings prey to the sea surface at night. Our data show that at-sea behavior of a tropical seabird can vary with environmental changes, including lunar phase.

  16. Environmental conditions and prey-switching by a seabird predator impact juvenile salmon survival

    Science.gov (United States)

    Wells, Brian K.; Santora, Jarrod A.; Henderson, Mark J.; Warzybok, Pete; Jahncke, Jaime; Bradley, Russell W.; Huff, David D.; Schroeder, Isaac D.; Nelson, Peter; Field, John C.; Ainley, David G.

    2017-01-01

    Due to spatio-temporal variability of lower trophic-level productivity along the California Current Ecosystem (CCE), predators must be capable of switching prey or foraging areas in response to changes in environmental conditions and available forage. The Gulf of the Farallones in central California represents a biodiversity hotspot and contains the largest common murre (Uria aalge) colonies along the CCE. During spring, one of the West Coast's most important Chinook salmon (Oncorhynchus tshawytscha) populations out-migrates into the Gulf of the Farallones. We quantify the effect of predation on juvenile Chinook salmon associated with ecosystem-level variability by integrating long-term time series of environmental conditions (upwelling, river discharge), forage species abundance within central CCE, and population size, at-sea distribution, and diet of the common murre. Our results demonstrate common murres typically forage in the vicinity of their offshore breeding sites, but in years in which their primary prey, pelagic young-of-year rockfish (Sebastesspp.), are less available they forage for adult northern anchovies (Engraulis mordax) nearshore. Incidentally, while foraging inshore, common murre consumption of out-migrating juvenile Chinook salmon, which are collocated with northern anchovy, increases and population survival of the salmon is significantly reduced. Results support earlier findings that show timing and strength of upwelling, and the resultant forage fish assemblage, is related to Chinook salmon recruitment variability in the CCE, but we extend those results by demonstrating the significance of top-down impacts associated with these bottom-up dynamics. Our results demonstrate the complexity of ecosystem interactions and impacts between higher trophic-level predators and their prey, complexities necessary to quantify in order to parameterize ecosystem models and evaluate likely outcomes of ecosystem management options.

  17. Environmental conditions and prey-switching by a seabird predator impact juvenile salmon survival

    Science.gov (United States)

    Wells, Brian K.; Santora, Jarrod A.; Henderson, Mark J.; Warzybok, Pete; Jahncke, Jaime; Bradley, Russell W.; Huff, David D.; Schroeder, Isaac D.; Nelson, Peter; Field, John C.; Ainley, David G.

    2017-10-01

    Due to spatio-temporal variability of lower trophic-level productivity along the California Current Ecosystem (CCE), predators must be capable of switching prey or foraging areas in response to changes in environmental conditions and available forage. The Gulf of the Farallones in central California represents a biodiversity hotspot and contains the largest common murre (Uria aalge) colonies along the CCE. During spring, one of the West Coast's most important Chinook salmon (Oncorhynchus tshawytscha) populations out-migrates into the Gulf of the Farallones. We quantify the effect of predation on juvenile Chinook salmon associated with ecosystem-level variability by integrating long-term time series of environmental conditions (upwelling, river discharge), forage species abundance within central CCE, and population size, at-sea distribution, and diet of the common murre. Our results demonstrate common murres typically forage in the vicinity of their offshore breeding sites, but in years in which their primary prey, pelagic young-of-year rockfish (Sebastes spp.), are less available they forage for adult northern anchovies (Engraulis mordax) nearshore. Incidentally, while foraging inshore, common murre consumption of out-migrating juvenile Chinook salmon, which are collocated with northern anchovy, increases and population survival of the salmon is significantly reduced. Results support earlier findings that show timing and strength of upwelling, and the resultant forage fish assemblage, is related to Chinook salmon recruitment variability in the CCE, but we extend those results by demonstrating the significance of top-down impacts associated with these bottom-up dynamics. Our results demonstrate the complexity of ecosystem interactions and impacts between higher trophic-level predators and their prey, complexities necessary to quantify in order to parameterize ecosystem models and evaluate likely outcomes of ecosystem management options.

  18. 21 CFR 866.2170 - Automated colony counter.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2170 Automated colony counter. (a) Identification. An automated colony counter is a mechanical device intended for medical...

  19. Influence of Seasonal Food Availability on the Dynamics of Seabird Feeding Flocks at a Coastal Upwelling Area.

    Science.gov (United States)

    Anguita, Cristóbal; Simeone, Alejandro

    2015-01-01

    The formation of multi-species feeding flocks (MSFFs) through visual recruitment is considered an important strategy for obtaining food in seabirds and its functionality has been ascribed to enhanced foraging efficiency. Its use has been demonstrated in much of the world's oceans and includes numerous species. However, there is scant information on the temporal stability of the composition and abundance of MSFFs as well as the effect of seasonal food availability on their dynamics. Between July 2006 and September 2014, we conducted monthly at-sea seabird counts at Valparaiso Bay (32°56' to 33°01'S, 71°36' to 71°46'W) within the area of influence of the Humboldt Current in central Chile. This area is characterized by a marked seasonality in primary and secondary production associated with upwelling, mainly during austral spring-summer. Based on studies that provide evidence that flocking is most frequent when food is both scarce and patchy, we hypothesized that seabird MSFF attributes (i.e. frequency of occurrence, abundance and composition) will be modified according to the seasonal availability of food. Using generalized linear models (GLMs), our results show that the contrasting seasonality in food availability of the study area (using chlorophyll-a concentration as a proxy) had no significant influence on MSFF attributes, sparsely explaining their variations (P>0.05). Rather than seasonal food availability, the observed pattern for MSFF attributes at Valparaiso Bay suggests a substantial influence of reproductive and migratory (boreal and austral migrants) habits of birds that modulates MSFF dynamics consistently throughout the whole year in this highly variable and patchy environment. We highlight the importance of visual recruitment as a mechanism by which migratory and resident birds interact. This would allow them to reduce resource unpredictability, which in turn has a major impact on structuring seabird's MSFF dynamics.

  20. Influence of Seasonal Food Availability on the Dynamics of Seabird Feeding Flocks at a Coastal Upwelling Area.

    Directory of Open Access Journals (Sweden)

    Cristóbal Anguita

    Full Text Available The formation of multi-species feeding flocks (MSFFs through visual recruitment is considered an important strategy for obtaining food in seabirds and its functionality has been ascribed to enhanced foraging efficiency. Its use has been demonstrated in much of the world's oceans and includes numerous species. However, there is scant information on the temporal stability of the composition and abundance of MSFFs as well as the effect of seasonal food availability on their dynamics. Between July 2006 and September 2014, we conducted monthly at-sea seabird counts at Valparaiso Bay (32°56' to 33°01'S, 71°36' to 71°46'W within the area of influence of the Humboldt Current in central Chile. This area is characterized by a marked seasonality in primary and secondary production associated with upwelling, mainly during austral spring-summer. Based on studies that provide evidence that flocking is most frequent when food is both scarce and patchy, we hypothesized that seabird MSFF attributes (i.e. frequency of occurrence, abundance and composition will be modified according to the seasonal availability of food. Using generalized linear models (GLMs, our results show that the contrasting seasonality in food availability of the study area (using chlorophyll-a concentration as a proxy had no significant influence on MSFF attributes, sparsely explaining their variations (P>0.05. Rather than seasonal food availability, the observed pattern for MSFF attributes at Valparaiso Bay suggests a substantial influence of reproductive and migratory (boreal and austral migrants habits of birds that modulates MSFF dynamics consistently throughout the whole year in this highly variable and patchy environment. We highlight the importance of visual recruitment as a mechanism by which migratory and resident birds interact. This would allow them to reduce resource unpredictability, which in turn has a major impact on structuring seabird's MSFF dynamics.

  1. Black Petrels (Procellaria parkinsoni patrol the ocean shelf-break: GPS tracking of a vulnerable procellariiform seabird.

    Directory of Open Access Journals (Sweden)

    Robin Freeman

    Full Text Available BACKGROUND: Determining the foraging movements of pelagic seabirds is fundamental for their conservation. However, the vulnerability and elusive lifestyles of these animals have made them notoriously difficult to study. Recent developments in satellite telemetry have enabled tracking of smaller seabirds during foraging excursions. METHODOLOGY/PRINCIPAL FINDINGS: Here, we report the first successful precision tracking of a c. 700 g seabird, the vulnerable Black Petrel, Procellaria parkinsoni, foraging at sea during the breeding season, using miniature GPS-logging technology. Employing a combination of high-resolution fixes and low-power duty-cycles, we present data from nine individual foraging excursions tracked during the chick-rearing period in February 2006. CONCLUSIONS/SIGNIFICANCE: We provide a snapshot of the species' foraging range and behaviour in relation to detailed underlying bathymetry off the coast of New Zealand, finding a significant relationship between foraging movements and regions of the shelf-break. We also highlight the potential of more sophisticated analyses to identify behavioural phenomena from position data alone.

  2. Active accumulation of internal DIC pools reduces transport limitation in large colonies of Nostoc pruniforme

    DEFF Research Database (Denmark)

    Raun, Ane-Marie Løvendahl; Borum, Jens; Jensen, Kaj Sand

    2009-01-01

    Nostoc pruniforme is a freshwater cyanobacterium forming large spherical colonies of up to several centimeters in diameter. The size and shape result in low surface area to volume (SA/V) ratios that potentially put severe constraints on resource acquisition. In the present study we have specifica......Nostoc pruniforme is a freshwater cyanobacterium forming large spherical colonies of up to several centimeters in diameter. The size and shape result in low surface area to volume (SA/V) ratios that potentially put severe constraints on resource acquisition. In the present study we have...

  3. Colonial Taxation, Corruption and Resistance in Igbominaland ...

    African Journals Online (AJOL)

    Colonial Taxation, Corruption and Resistance in Igbominaland. ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search · USING AJOL · RESOURCES ... While taxation definitely stimulated economic activities in Igbominaland at ...

  4. Post-colonial identity in Greenland?

    DEFF Research Database (Denmark)

    Gad, Ulrik Pram

    2009-01-01

    could be furthered by bringing politics back in. Based on a discourse analysis of the Greenlandic debate on language, this paper makes three claims: First, the identity projects promoted in Greenland are based on an essentialist conception of identity. Secondly, Greenlandic identity discourse combines......In the gradual unravelling of Greenland’s colonial relationship to Denmark, an essentialist conceptualization of Greenlandic identity has played a significant role. However, both our scholarly understanding of post-colonial Greenlandic identity and the process towards independence for Greenland...... elements of traditional Inuit culture and elements of colonial modernity. Thirdly, monolingual Greenlanders are those with the most to gain from abandoning the dichotomy of essentialist identities. Strategically, the paper suggests a post-post-colonial Greenlandic identity as a means of avoiding...

  5. Does temporal variation of mercury levels in Arctic seabirds reflect changes in global environmental contamination, or a modification of Arctic marine food web functioning?

    International Nuclear Information System (INIS)

    Fort, Jérôme; Grémillet, David; Traisnel, Gwendoline; Amélineau, Françoise; Bustamante, Paco

    2016-01-01

    Studying long-term trends of contaminants in Arctic biota is essential to better understand impacts of anthropogenic activities and climate change on the exposure of sensitive species and marine ecosystems. We concurrently measured temporal changes (2006–2014) in mercury (Hg) contamination of little auks (Alle alle; the most abundant Arctic seabird) and in their major zooplankton prey species (Calanoid copepods, Themisto libellula, Gammarus spp.). We found an increasing contamination of the food-chain in East Greenland during summer over the last decade. More specifically, bird contamination (determined by body feather analyses) has increased at a rate of 3.4% per year. Conversely, bird exposure to Hg during winter in the northwest Atlantic (determined by head feather analyses) decreased over the study period (at a rate of 1.5% per year), although winter concentrations remained consistently higher than during summer. By combining mercury levels measured in birds and zooplankton to isotopic analyses, our results demonstrate that inter-annual variations of Hg levels in little auks reflect changes in food-chain contamination, rather than a reorganization of the food web and a modification of seabird trophic ecology. They therefore underline the value of little auks, and Arctic seabirds in general, as bio-indicators of long-term changes in environmental contamination. - Highlights: • We examined temporal trends of Hg in Arctic seabirds and major zooplankton species. • We investigated the role of underlying ecological drivers in seabird contamination. • Hg contamination of the East Greenland marine food web increased over the last decade. • Hg levels in Arctic seabirds reflect changes in the food-chain contamination. • Little auks are bio-indicators of long-term changes in environmental contamination. - Temporal increase of seabird exposure to Hg reflects changes in Arctic environmental contamination.

  6. Post-Colonial Theory and Action Research

    Directory of Open Access Journals (Sweden)

    Jim Parsons

    2011-02-01

    Full Text Available This essay explores connections between post-colonial theory and action research. Post-colonial theory is committed to addressing the plague of colonialism. Action research, at its core, promises to problematize uncontested ‘colonial’ hegemonies of any form. Both post-colonial theory and action research engage dialogic, critically reflective and collaborative values to offer a fuller range of human wisdom. The authors contend that post-colonialism theory calls for justice and seeks to speak to social and psychological suffering, exploitation, violence and enslavement done to the powerless victims of colonization around the world by challenging the superiority of dominant perspectives and seeking to re-position and empower the marginalized and subordinated. In similar ways, action research works to eradicate oppression, powerlessness and worthlessness by affirming solidarity with the oppressed, helping humans move from passive to active and by fundamentally reshaping power. Because both post-colonial theory and action research position the insider or oppressed in an ethic of efficacy, it values community, relationships, communication and equality, and is committed to reciprocity, reflexivity and reflection. Thus, both hold the potential to help reconstruct conditions for a more democratic and just society

  7. Post-Colonial Theory and Action Research

    Directory of Open Access Journals (Sweden)

    Jim B. Parsons

    2011-04-01

    Full Text Available This essay explores connections between post-colonial theory and action research. Post-colonial theory is committed to addressing the plague of colonialism. Action research, at its core, promises to problematize uncontested ‘colonial’ hegemonies of any form. Both post-colonial theory and action research engage dialogic, critically reflective and collaborative values to offer a fuller range of human wisdom. The authors contend that post-colonialism theory calls for justice and seeks to speak to social and psychological suffering, exploitation, violence and enslavement done to the powerless victims of colonization around the world by challenging the superiority of dominant perspectives and seeking to re-position and empower the marginalized and subordinated. In similar ways, action research works to eradicate oppression, powerlessness and worthlessness by affirming solidarity with the oppressed, helping humans move from passive to active and by fundamentally reshaping power. Because both post-colonial theory and action research position the insider or oppressed in an ethic of efficacy, it values community, relationships, communication and equality, and is committed to reciprocity, reflexivity and reflection. Thus, both hold the potential to help reconstruct conditions for a more democratic and just society.

  8. Investigation of multimodal forward scatter phenotyping from bacterial colonies

    Science.gov (United States)

    Kim, Huisung

    the 2-D spatial density map from the ICMA. The MS-BARDOT can measure multispectral elastic-light-scatter patterns of the bacterial colony and its spectral OD to overcome the inherent limits of the single-wavelength BARDOT. A theoretical model for spectral forward scatter patterns from a bacterial colony based on elastic light scatter is presented. The spectral forward scatter patterns are computed by scalar diffraction theory, and compared with experimental results of three discrete wavelengths (405 nm, 635 nm, and 904 nm). Both model and experiment results show an excellent agreement; a longer wavelength induces a wider ring width, a wider ring gap, a smaller pattern size, and smaller numbers of rings. Further analysis using spatial fast Fourier transform (SFFT) shows a good agreement; the spatial frequencies are increasing towards the inward direction, and the slope is inversely proportional to the incoming wavelength. Four major pathogenic bacterial genera (Escherichia coli O157:H7 EDL933, Listeria monocytogenes F4244, Salmonella enterica serovar Enteritidis PT21, and Staphylococcus aureus ATCC 25923) and the seven major Escherichia coli serovar (O26, O45, O103, O111, O121, O145, and O157) with 3-4 strains each are measured and analyzed with the proposed instrument and algorithm. The MM-BARDOT can measure six different modalities: 1) light microscopy, 2) 3D morphology map from confocal microscopy, 3) 3D optical density map, 4) spectral forward scattering pattern, 5) spectral OD, 6) surface backward reflection pattern, and 7) fluorescence of a bacterial colony without moving the specimen. A custom-built confocal microscope with a controller which can be easily attached to an infinity-corrected commercial microscope is designed and built. Since the current BARDOT needs additional information from a bacterial colony to enhance the identification/classification ratio for a lower hierarchy of bacterial taxonomy such as serovar or strain level, the approach can offer a

  9. Chlorinated biphenyls and pesticides in migrating and resident seabirds from East and West Antarctica.

    Science.gov (United States)

    Corsolini, Simonetta; Borghesi, Nicoletta; Ademollo, Nicoletta; Focardi, Silvano

    2011-11-01

    The unhatched eggs of the following seabirds were analyzed to quantify PCBs, hexachlorobenzene (HCB), α-, β-, γ-, δ-hexachlorocyclohexanes (HCHs), o,p' and p,p' isomers of DDT, DDD and DDE: resident Adèlie (Pygoscelis adèliae, ADPE) and Emperor (Aptenodytes forsteri, EMPE) penguins, migrating snow petrel (Pagodroma nivea, SNPT) and South Polar skua (Catharacta maccormicki, SPSK) from the Ross Sea (East Antarctica); and migrating Brown skua (Catharacta antartica, BRSK) and resident ADPE from the Brainsfield Strait (West Antarctica). The general aims were to evaluate the contaminant accumulation in eggs of migrating and resident species in the two study areas, and to compare levels in penguins and skuas nesting in East and West Antarctica. PCB congener and HCH and DDT isomer profiles were also assessed. Comparisons were evaluated using seven PCB congeners (IUPAC nos. 28, 52, 101, 118+149, 138, 153, and 180), p,p'-DDE, ΣDDTs, and ΣHCHs. Higher contaminant concentrations were detected in migrating seabirds (South polar skua and brown skua)>sub-Antarctic species (snow petrel)>Antarctic species (penguins) from both the sampling sites, suggesting contamination events at lower latitudes for those birds migrating northward. HCHs showed the lowest concentrations in all species (from 0.03±0.03 ng/g wet wt in SPSK to 1.81±1.23 ng/g wet wt in ADPE from West Antarctica), and PCBs were the most abundant contaminants (from 4.34±2.15 ng/g wet wt. in EMPE to 53.41±19.61 ng/g wet wt. in brown skua). Among pesticides, it is relevant the detection of p,p'-DDT in Adèlie penguin from West Antarctica and in both species of skua; the detection of this pesticide can confirm its actual use in certain malaria-endemic countries from where it is transferred through the long range transport to the polar regions. Contaminants did not show any significant temporal trend during a ten year time span, from 1994/95 to 2004/05, in organisms collected in East Antarctica and they did not

  10. [Effect of habitat and interspecific competition on Apis cerana cerana colony distribution].

    Science.gov (United States)

    Yu, Linsheng; Han, Shengming

    2003-04-01

    Habitat change and interspecific competition were the main factors affecting, Apis cerana cerana colony distribution among Wannan and Wanxi Dabie mountainous areas, Jianghuai area and Huaibei plain. Wannan and Wanxi Dabie mountainous areas were the ideal places for Apis cerana cerana' habitation and propogation, in which, there were integrated natural vegetation, fine ecological condition, abundant nectariferous plants, and Apis cerana cerana had large colony size, wide distribution, high density, no disturbances of natural mating, and was dominant interspecific competition. In Jianghuai area and Huaibei plain, there were small covering of natural vegetation, different degree of degradation of ecological balance, few kinds of nectariferous plants with almost the same blooming periods, natural mating perturbed by Apis mellifera ligustica for Apis cerana cerana, and which was inferior in interspecific competition, colony size sharply decreased, distribution area reduced, and density cut down to a great extent. In Huaibei plain, the negative factors were more conspicuous.

  11. Sublethal Effects of Imidacloprid on Honey Bee Colony Growth and Activity at Three Sites in the U.S.

    Science.gov (United States)

    Meikle, William G; Adamczyk, John J; Weiss, Milagra; Gregorc, Ales; Johnson, Don R; Stewart, Scott D; Zawislak, Jon; Carroll, Mark J; Lorenz, Gus M

    2016-01-01

    Imidacloprid is a neonicotinoid pesticide heavily used by the agricultural industry and shown to have negative impacts on honey bees above certain concentrations. We evaluated the effects of different imidacloprid concentrations in sugar syrup using cage and field studies, and across different environments. Honey bee colonies fed sublethal concentrations of imidicloprid (0, 5, 20 and 100 ppb) over 6 weeks in field trials at a desert site (Arizona), a site near intensive agriculture (Arkansas) and a site with little nearby agriculture but abundant natural forage (Mississippi) were monitored with respect to colony metrics, such as adult bee and brood population sizes, as well as pesticide residues. Hive weight and internal hive temperature were monitored continuously over two trials in Arizona. Colonies fed 100 ppb imidacloprid in Arizona had significantly lower adult bee populations, brood surface areas and average frame weights, and reduced temperature control, compared to colonies in one or more of the other treatment groups, and consumption rates of those colonies were lower compared to other colonies in Arizona and Arkansas, although no differences in capped brood or average frame weight were observed among treatments in Arkansas. At the Mississippi site, also rich in alternative forage, colonies fed 5 ppb imidacloprid had less capped brood than control colonies, but contamination of control colonies was detected. In contrast, significantly higher daily hive weight variability among colonies fed 5 ppb imidacloprid in Arizona suggested greater foraging activity during a nectar flow post treatment, than any other treatment group. Imidacloprid concentrations in stored honey corresponded well with the respective syrup concentrations fed to the colonies and remained stable within the hive for at least 7 months after the end of treatment.

  12. Nest fidelity is driven by multi-scale information in a long-lived seabird.

    Science.gov (United States)

    Robert, Alexandre; Paiva, Vítor H; Bolton, Mark; Jiguet, Frédéric; Bried, Joël

    2014-10-22

    Although the reproductive success of most organisms depends on factors acting at several spatial scales, little is known about how organisms are able to synthesize multi-scale information to optimize reproduction. Using longitudinal data from a long-lived seabird, Monteiro's storm-petrel, we show that average breeding success is strongly related to oceanic conditions at the population level, and we postulate that (i) individuals use proximal information (their own reproduction outcome in year t) to assess the qualities of their mate and nest and to decide to retain them or not in year t + 1; (ii) the intensity of these responses depends on the quality of the oceanic environment in year t, which affects the predictability of reproduction outcome in year t + 1. Our results confirm that mate and nest fidelities are higher following successful reproduction and that the relationship between the success of a given pair and subsequent nest fidelity is stronger in years with unfavourable oceanic conditions, suggesting that individuals rely on distant information to modulate their use of proximal information and adjust their breeding strategy. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

  13. Patterns of seabird and marine mammal carcass deposition along the central California coast, 1980-1986

    Science.gov (United States)

    Bodkin, James L.; Jameson, Ronald J.

    1991-01-01

    At monthly intervals from February 1980 through December 1986, a 14.5-km section of central California coastline was systematically surveyed for beach-cast carcasses of marine birds and mammals. Five hundred and fifty-four bird carcasses and 194 marine mammal carcasses were found. Common murres, western grebes, and Brandt's cormorants composed 45% of the bird total. California sea lions, sea otters, and harbor seals composed 90% of the mammal total. Several factors appeared to affect patterns of carcass deposition. The El Niño – Southern Oscillation (ENSO) of 1982–1983 was the dominant influence in terms of interannual variation in carcass deposition. During this ENSO, 56% of the seabirds and 48% of the marine mammals washed ashore. Patterns of intra-annual variation were species specific and were related to animal migration patterns, reproduction, and seasonal changes in weather. Nearshore currents and winds influenced the general area of carcass deposition, while beach substrate type and local patterns of sand deposition influenced the location of carcass deposition on a smaller spatial scale. Weekly surveys along a 1.1-km section of coastline indicated that 62% of bird carcasses and 41% of mammal carcasses remained on the beach less than 9 days. Cause of death was determined for only 8% of the carcasses. Oiling was the most common indication of cause of death in birds (6%). Neonates composed 8% of all mammal carcasses.

  14. Breeding phenology and winter activity predict subsequent breeding success in a trans-global migratory seabird.

    Science.gov (United States)

    Shoji, A; Aris-Brosou, S; Culina, A; Fayet, A; Kirk, H; Padget, O; Juarez-Martinez, I; Boyle, D; Nakata, T; Perrins, C M; Guilford, T

    2015-10-01

    Inter-seasonal events are believed to connect and affect reproductive performance (RP) in animals. However, much remains unknown about such carry-over effects (COEs), in particular how behaviour patterns during highly mobile life-history stages, such as migration, affect RP. To address this question, we measured at-sea behaviour in a long-lived migratory seabird, the Manx shearwater (Puffinus puffinus) and obtained data for individual migration cycles over 5 years, by tracking with geolocator/immersion loggers, along with 6 years of RP data. We found that individual breeding and non-breeding phenology correlated with subsequent RP, with birds hyperactive during winter more likely to fail to reproduce. Furthermore, parental investment during one year influenced breeding success during the next, a COE reflecting the trade-off between current and future RP. Our results suggest that different life-history stages interact to influence RP in the next breeding season, so that behaviour patterns during winter may be important determinants of variation in subsequent fitness among individuals. © 2015 The Authors.

  15. Thyroid hormones correlate with resting metabolic rate, not daily energy expenditure, in two charadriiform seabirds

    Directory of Open Access Journals (Sweden)

    Kyle H. Elliott

    2013-04-01

    Thyroid hormones affect in vitro metabolic intensity, increase basal metabolic rate (BMR in the lab, and are sometimes correlated with basal and/or resting metabolic rate (RMR in a field environment. Given the difficulty of measuring metabolic rate in the field—and the likelihood that capture and long-term restraint necessary to measure metabolic rate in the field jeopardizes other measurements—we examined the possibility that circulating thyroid hormone levels were correlated with RMR in two free-ranging bird species with high levels of energy expenditure (the black-legged kittiwake, Rissa tridactyla, and thick-billed murre, Uria lomvia. Because BMR and daily energy expenditure (DEE are purported to be linked, we also tested for a correlation between thyroid hormones and DEE. We examined the relationships between free and bound levels of the thyroid hormones thyroxine (T4 and triiodothyronine (T3 with DEE and with 4-hour long measurements of post-absorptive and thermoneutral resting metabolism (resting metabolic rate; RMR. RMR but not DEE increased with T3 in both species; both metabolic rates were independent of T4. T3 and T4 were not correlated with one another. DEE correlated with body mass in kittiwakes but not in murres, presumably owing to the larger coefficient of variation in body mass during chick rearing for the more sexually dimorphic kittiwakes. We suggest T3 provides a good proxy for resting metabolism but not DEE in these seabird species.

  16. Mercury accumulation in sediments and seabird feathers from the Antarctic Peninsula.

    Science.gov (United States)

    Calle, Paola; Alvarado, Omar; Monserrate, Lorena; Cevallos, Juan Manuel; Calle, Nastenka; Alava, Juan José

    2015-02-28

    In an effort to assess the impact of mercury in the Antarctic Peninsula, we conducted ecotoxicological research in this region during the summer of 2012 and 2013. The objectives were to assess: (a) mercury levels in sediment samples; (b) mercury accumulation in Antarctic seabird feathers: Catharacta lonnbergi (brown skua), Pygoscelis papua (gentoo penguin) and Pygoscelis antarctica (chinstrap penguin); and (c) biomagnification (BMF predator/prey) and biota sediment accumulation (BSAF skuas/sediment) factors. Mercury concentrations in sediment were relatively low. Mercury concentrations were significantly higher in brown skuas and gentoo penguins than in chinstrap penguins (2012), and significantly higher in brown skuas than in both penguins (2013). BMF indicated 2-7.5 times greater mercury levels in brown skuas than in penguins. BSAF values suggested an apparent temporal decrease of 18.2% of this ratio from 2012 to 2013. Long-range environmental transport is the likely route of entry of mercury into the Antarctic Peninsula. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Colonialism, customary law and the post-colonial state in Africa: the ...

    African Journals Online (AJOL)

    Colonialism became a fact of life in many African countries. An effect of colonialism especially in the former British colonized countries was the transplantation of the British legal system, which led to recognition of both systems and the gradual relegation of the indigenous system otherwise called customary law. The use and ...

  18. Colonial Legal Reasoning in the Post-Colonial African State: A ...

    African Journals Online (AJOL)

    Colonial Legal Reasoning in the Post-Colonial African State: A Critique and a Defense of the Argument from African Metaphysical Epistemology. ... Africa, as it has the advantageous result of helping in the search for truth concerning such offences, thereby promoting the delivery of effective legal justice, and thus contributing ...

  19. Review Essay A history of colonialism through post-colonial lenses ...

    African Journals Online (AJOL)

    Review Essay A history of colonialism through post-colonial lenses: reading Mahmood Mamdani's citizen and subject. Sanya Osha. Abstract. No Abstract. The Nigerian Journal of Economic History Vol. 2, 1999: 155-161. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  20. Colony collapse disorder: a descriptive study.

    Directory of Open Access Journals (Sweden)

    Dennis Vanengelsdorp

    Full Text Available BACKGROUND: Over the last two winters, there have been large-scale, unexplained losses of managed honey bee (Apis mellifera L. colonies in the United States. In the absence of a known cause, this syndrome was named Colony Collapse Disorder (CCD because the main trait was a rapid loss of adult worker bees. We initiated a descriptive epizootiological study in order to better characterize CCD and compare risk factor exposure between populations afflicted by and not afflicted by CCD. METHODS AND PRINCIPAL FINDINGS: Of 61 quantified variables (including adult bee physiology, pathogen loads, and pesticide levels, no single measure emerged as a most-likely cause of CCD. Bees in CCD colonies had higher pathogen loads and were co-infected with a greater number of pathogens than control populations, suggesting either an increased exposure to pathogens or a reduced resistance of bees toward pathogens. Levels of the synthetic acaricide coumaphos (used by beekeepers to control the parasitic mite Varroa destructor were higher in control colonies than CCD-affected colonies. CONCLUSIONS/SIGNIFICANCE: This is the first comprehensive survey of CCD-affected bee populations that suggests CCD involves an interaction between pathogens and other stress factors. We present evidence that this condition is contagious or the result of exposure to a common risk factor. Potentially important areas for future hypothesis-driven research, including the possible legacy effect of mite parasitism and the role of honey bee resistance to pesticides, are highlighted.

  1. Spatial Distribution of Lactococcus lactis Colonies Modulates the Production of Major Metabolites during the Ripening of a Model Cheese.

    Science.gov (United States)

    Le Boucher, Clémentine; Gagnaire, Valérie; Briard-Bion, Valérie; Jardin, Julien; Maillard, Marie-Bernadette; Dervilly-Pinel, Gaud; Le Bizec, Bruno; Lortal, Sylvie; Jeanson, Sophie; Thierry, Anne

    2016-01-01

    In cheese, lactic acid bacteria are immobilized at the coagulation step and grow as colonies. The spatial distribution of bacterial colonies is characterized by the size and number of colonies for a given bacterial population within cheese. Our objective was to demonstrate that different spatial distributions, which lead to differences in the exchange surface between the colonies and the cheese matrix, can influence the ripening process. The strategy was to generate cheeses with the same growth and acidification of a Lactococcus lactis strain with two different spatial distributions, big and small colonies, to monitor the production of the major ripening metabolites, including sugars, organic acids, peptides, free amino acids, and volatile metabolites, over 1 month of ripening. The monitored metabolites were qualitatively the same for both cheeses, but many of them were more abundant in the small-colony cheeses than in the big-colony cheeses over 1 month of ripening. Therefore, the results obtained showed that two different spatial distributions of L. lactis modulated the ripening time course by generating moderate but significant differences in the rates of production or consumption for many of the metabolites commonly monitored throughout ripening. The present work further explores the immobilization of bacteria as colonies within cheese and highlights the consequences of this immobilization on cheese ripening. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  2. The evolution of coloniality in birds in relation to food, habitat, predation, and life-history traits: a comparative analysis.

    Science.gov (United States)

    Rolland, C; Danchin, E; de Fraipont, M

    1998-06-01

    Coloniality in birds has been intensively studied under the cost and benefit approach, but no general conclusion can be given concerning its evolutionary function. Here, we report on a comparative analysis carried out on 320 species of birds using the general method of comparative analysis for discrete variables and the contrast method to analyze the evolution of coloniality. Showing a mean of 23 convergences and 10 reversals, coloniality appears to be a rather labile trait. Colonial breeding appears strongly correlated with the absence of feeding territory, the aquatic habitat, and nest exposure to predators but was not correlated with changes in life-history traits (body mass and clutch size). The correlation of coloniality with the aquatic habitat is in fact explained by a strong correlation with the marine habitat. Unexpectedly, we found that the evolution toward a marine habitat in birds was contingent on coloniality and that coloniality evolved before the passage to a marine life. These results-along with the lack of transitions from the nonmarine to marine habitat in solitary species and the precedence of the loss of feeding territoriality on the passage to a marine life-contradict most of the hypotheses classically accepted to explain coloniality and suggest that we use a different framework to study this evolutionary enigma.

  3. Is colonialism history? The declining impact of colonial legacies on African institutional and economic development : The declining impact of colonial legacies on African institutional and economic development

    NARCIS (Netherlands)

    Maseland, Robbert

    2018-01-01

    This paper investigates the claim that colonial history has left an enduring imprint on Africa's institutional and economic development. The literature following Acemoglu, Johnson and Robinson (2001) and Sokoloff and Engerman (2000) maintains that different types of colonialism affected the

  4. The Concept of British Education Policy in the Colonies 1850-1960

    Science.gov (United States)

    Whitehead, Clive

    2007-01-01

    It is common in the literature to refer to British colonial education policy as if it were "a settled course adopted and purposefully carried into action", but in reality it was never like that. Contrary to popular belief, the size and diversity of the empire meant that no one really ruled it in any direct sense. Clearly some kind of…

  5. An assessment of oceanic seabird abundance and distribution off the southern Brazilian coast using observations obtained during deep-water fishing operations.

    Science.gov (United States)

    Branco, J O; Fracasso, H A A; Pérez, J A A; Rodrigues-Filho, J L

    2014-08-01

    The use of discarded fish over baited hooks used in longline fishery, and fish caught in gillnets, as a food source for gulls, albatrosses and petrels has been intensively studied in northern and southern oceans. This study describes the occurrence and abundance of seabirds observed from 20 foreign vessels which operated during the period between July 2001 and May 2005, off the southeastern and southern Brazilian coast. A total of 353,557 seabirds were observed; comprising eight families and 28 species. The most abundant species was Procellaria conspicillata followed by Daption capense, Puffinus gravis, Thalassarche melanophrys and Oceanites oceanicus. Ten species of seabirds (392 individual birds) were incidentally captured in gillnets; and 122 birds (9 species) by longline hooks, with P. gravis, D. capense and Procellaria aequinoctialis having the largest capture rates.

  6. Surveys of the distribution of seabirds found in the vicinity of proposed geothermal project subzones in the District of Puna, Hawaii. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, M.; Ritchotte, G.; Viggiano, A.; Dwyer, J.; Nielsen, B.; Jacobi, J.D. [Fish and Wildlife Service, Hawaii National Park, HI (United States). Hawaii Research Station

    1994-08-01

    In 1993, the US Fish and Wildlife Service (USFWS) entered into an interagency agreement with the Department of Energy (DOE) to conduct specific biological surveys to identify potential impacts of the proposed geothermal development on the natural resources of the East Rift Zone. This report presents information from published literature information and new field data on seabird populations on the island of Hawaii. These data are analyzed with regard to potential impacts of geothermal development on seabird populations in this area. Fifteen species of seabirds, waterbirds, and shorebirds are documented or suspected of being found using habitats within or immediately adjacent to the three geothermal subzones located in the Puna district on the island of Hawai`i. Of these species, two are on the federal Endangered Species List, three are on the State of Hawaii Endangered Species List, and all 15 are protected by the federal Migratory Bird Act.

  7. Abyssal fiction: common shares, colonial cleavages

    Directory of Open Access Journals (Sweden)

    Alexandre Montaury

    2016-12-01

    Full Text Available The paper aims to develop a reflection on the interaction between the legacies of colonialism and traditional symbolic and cultural practices in African Portuguese-speaking spaces. From a preliminary analysis of fictional texts of wide circulation in Brazil, aims to examine the cleavages, or “abyssal lines” that constitute experiences printed in the daily life of the former Portuguese colony of Cape Verde, Mozambique and Angola.---DOI: http://dx.doi.org/10.21881/abriluff.2016n17a378

  8. Behavioral Modulation of Infestation by Varroa destructor in Bee Colonies. Implications for Colony Stability.

    Science.gov (United States)

    de Figueiró Santos, Joyce; Coelho, Flávio Codeço; Bliman, Pierre-Alexandre

    2016-01-01

    Colony Collapse Disorder (CCD) has become a global problem for beekeepers and for the crops that depend on bee pollination. While many factors are known to increase the risk of colony collapse, the ectoparasitic mite Varroa destructor is considered to be the most serious one. Although this mite is unlikely to cause the collapse of hives itself, it is the vector for many viral diseases which are among the likely causes for Colony Collapse Disorder. The effects of V. destructor infestation differ from one part of the world to another, with greater morbidity and higher colony losses in European honey bees (EHB) in Europe, Asia and North America. Although this mite has been present in Brazil for many years, there have been no reports of colony losses amongst Africanized Honey Bees (AHB). Studies carried out in Mexico have highlighted different behavioral responses by the AHB to the presence of the mite, notably as far as grooming and hygienic behavior are concerned. Could these explain why the AHB are less susceptible to Colony Collapse Disorder? In order to answer this question, we have developed a mathematical model of the infestation dynamics to analyze the role of resistance behavior by bees in the overall health of the colony, and as a consequence, its ability to face epidemiological challenges.

  9. Behavioral Modulation of Infestation by Varroa destructor in Bee Colonies. Implications for Colony Stability.

    Directory of Open Access Journals (Sweden)

    Joyce de Figueiró Santos

    Full Text Available Colony Collapse Disorder (CCD has become a global problem for beekeepers and for the crops that depend on bee pollination. While many factors are known to increase the risk of colony collapse, the ectoparasitic mite Varroa destructor is considered to be the most serious one. Although this mite is unlikely to cause the collapse of hives itself, it is the vector for many viral diseases which are among the likely causes for Colony Collapse Disorder. The effects of V. destructor infestation differ from one part of the world to another, with greater morbidity and higher colony losses in European honey bees (EHB in Europe, Asia and North America. Although this mite has been present in Brazil for many years, there have been no reports of colony losses amongst Africanized Honey Bees (AHB. Studies carried out in Mexico have highlighted different behavioral responses by the AHB to the presence of the mite, notably as far as grooming and hygienic behavior are concerned. Could these explain why the AHB are less susceptible to Colony Collapse Disorder? In order to answer this question, we have developed a mathematical model of the infestation dynamics to analyze the role of resistance behavior by bees in the overall health of the colony, and as a consequence, its ability to face epidemiological challenges.

  10. Massive Mortality of a Planktivorous Seabird in Response to a Marine Heatwave: A Citizen Science Case-study

    Science.gov (United States)

    Jones, T.; Parrish, J.; MacCready, P.; Peterson, W. T.; Bjorkstedt, E.; Bond, N. A.; Ballance, L. T.; Bowes, V.; Hipfner, J. M.; Lindquist, K.; Lindsey, J.; Nevins, H. M.; Burgess, H. K.; Robertson, R.; Roletto, J.; Wilson, L.; Joyce, T. W.; Harvey, J.

    2017-12-01

    Citizen science data collection is a powerful tool for documenting mass mortality events, as they often occur without warning and can be extensive in space, precluding standard methods of data collection. The Coastal Observation and Seabird Survey Team (COASST) is one such citizen science program that specializes in the collection of information on beachcast seabird abundance and identity. Using the COASST dataset, in combination with federal monitoring data and novel modeling techniques, we investigated the 2014/15 mass mortality event of Cassin's Auklets (Ptychoramphus aleuticus), a small zooplanktivorous seabird, that occurred during the largest marine heatwave (MHW) ever recorded - the NE Pacific MHW of 2014-2016. Estimated at 275,000-530,000 birds, or 11% of the global adult population, and spanning 2,000 km of the North American Pacific coastline, this marine bird die-off is among the largest ever recorded. Carcass deposition followed an effective reduction in the energy content of zooplankton, coincident with the loss of cold-water foraging habitat caused by the intrusion of the NE Pacific MHW. Models examining interannual variability in effort-controlled carcass abundance (2001-2014) identified the biomass of lipid-poor zooplankton as the primary predictor of increased carcass abundance, suggesting that the relative abundance of smaller, lipid-poor zooplankton is a strong predictor of Cassin's Auklets overwinter survival. Furthermore, dispersing Cassin's Auklets were likely compressed into a nearshore band of upwelled water, and ultimately died from starvation following the shift in zooplankton composition associated with the onshore transport of the NE Pacific MHW. The information regarding the magnitude of this event, as well as its causal mechanism, comes as a direct result of rigorous data collection by citizen science volunteers, demonstrating that citizen science can, and does, contribute to our understanding of how climate change is altering marine

  11. Regional, temporal, and species patterns of mercury in Alaskan seabird eggs: Mercury sources and cycling or food web effects?

    International Nuclear Information System (INIS)

    Day, Rusty D.; Roseneau, David G.; Vander Pol, Stacy S.; Hobson, Keith A.; Donard, Olivier F.X.; Pugh, Rebecca S.; Moors, Amanda J.; Becker, Paul R.

    2012-01-01

    Mercury concentration ([Hg]), δ 15 N, and δ 13 C values were measured in eggs from common murres (Uria aalge), thick-billed murres (U. lomvia), glaucous gulls (Larus hyperboreus), and glaucous-winged gulls (L. glaucescens) collected in Alaska from 1999 to 2005. [Hg] was normalized to a common trophic level using egg δ 15 N values and published Hg trophic magnification factors. Egg [Hg] was higher in murres from Gulf of Alaska, Cook Inlet, and Norton Sound regions compared to Bering Sea and Bering Strait regions, independent of trophic level. We believe the Yukon River outflow and terrestrial Hg sources on the southern Seward Peninsula are responsible for the elevated [Hg] in Norton Sound eggs. Normalizing for trophic level generally diminished or eliminated differences in [Hg] among taxa, but temporal variability was unrelated to trophic level. Normalizing murre egg [Hg] by trophic level improves the confidence in regional comparisons of Hg sources and biogeochemical cycling in Alaska. - Highlights: ► Seabird eggs used for monitoring Hg in Alaskan marine environment. ► Egg Hg concentrations normalized to common trophic level using δ 15 N. ► Geographic Hg patterns persist independent of trophic normalization. ► Trophic normalization reduces difference among taxa, but not temporal variability. ► Measuring δ 15 N and δ 13 C improve interpretation of seabird mercury monitoring data. - Normalizing mercury concentrations in seabird eggs to a common trophic level reveals that geographic patterns of mercury contamination exist in the Alaskan marine environment that are independent of food web effects.

  12. An assessment of the effects on seabirds of a possible oil exploration at the shelf outside Central Norway out to 1o East

    International Nuclear Information System (INIS)

    Strand, K.-B.; Bustnes, J.O.; Kroglund, R.T.; Oestnes, J.E.

    1993-05-01

    This report gives the results of an assessment of the effects on seabirds of possible petroleum exploration at the shelf outside Central-Norway out to 1 o East. By combining oil spill simulations with the valued ecosystem components, i.e. seabirds, their distribution, and their vulnerability indexes, the relative index values for the direct effects of oil spills were calculated. For the purpose, the analysis system SIMPACT was used. On the basis of these results and other relevant considerations, recommendations for limiting a possible drilling activity are given. 85 refs., 49 figs., 9 tabs

  13. Evaluation of drone brood removal for management of Varroa destructor (Acari: Varroidae) in colonies of Apis mellifera (Hymenoptera: Apidae) in the northeastern United States.

    Science.gov (United States)

    Calderone, N W

    2005-06-01

    The efficacy of drone brood removal for the management of Varroa destructor Anderson & Trueman in colonies of the honey bee, A. mellifera L., was evaluated. Colonies were treated with CheckMite+ in the fall of 2002. The following spring, quantities of bees and brood were equalized, but colonies were not retreated. The brood nest of each colony consisted of 18 full-depth worker combs and two full-depth drone combs. Each worker comb had drone cells. Standard management practices were used throughout the season. Colonies were randomly assigned to one of two groups. In the control group, drone combs remained in place throughout the season. In the treatment group, drone combs were removed on 16 June, 16 July, 16 August, and 16 September and replaced with empty drone combs (16 June) or with drone combs removed on the previous replacement date. In the early fall, the average mite-to-bee ratio in the control group was significantly greater than the corresponding ratio in the treatment group. Drone brood removal did not adversely affect colony health as measured by the size of the worker population or by honey production. Fall worker populations were similar in the two groups. Honey production in treatment colonies was greater than or similar to production in control colonies. These data demonstrate that drone brood removal can serve as a valuable component in an integrated pest management program for V. destructor and may reduce the need for other treatments on a colony-by-colony basis.

  14. Risk indicators affecting honeybee colony survival in Europe: one year of surveillance

    DEFF Research Database (Denmark)

    Jacques, Antoine; Laurent, Marion; Bougeard, Stéphanie

    2016-01-01

    The first pan-European harmonized active epidemiological surveillance program on honeybee colony mortality (EPILOBEE) was set up across 17 European Member States to estimate honeybee colony mortality over winter and during the beekeeping season. In nine Member States, overwinter losses were higher...... and statistically different from the empirical level of 10 % under which the level of overwinter mortality was considered as acceptable with usual beekeeping conditions. In four other countries, these losses were lower. Using multivariable Poisson regression models, it was showed that the size of the operation...

  15. Small-cell comb does not control Varroa mites in colonies of honeybees of European origin

    OpenAIRE

    Seeley , Thomas; Griffin , Sean

    2011-01-01

    International audience; We tested the idea that Varroa destructor can be controlled in colonies of the European subspecies of Apis mellifera by providing them with combs built of small cells, in which immature mites might have difficulty developing for lack of space. We established seven pairs of equal-size colonies that started out equally infested with mites. In each pair, one hive contained only standard-cell (5.4 mm) comb, and the other contained only small-cell (4.8 mm) comb. We measured...

  16. An assessment of the effects on seabirds of oil exploration in the Norwegian part of the Skagerrak

    International Nuclear Information System (INIS)

    Lorentsen, S.-H.; Anker-Nilssen, T.; Kroglund, R.T.; Oestnes, J.E.

    1993-03-01

    This report presents the results of an assessment of the effects on seabirds of possible petroleum exploration in the North Sea east of 7 o East (Skagerrak). Relative index values for the direct effects of oil spills were calculated by combining oil spill simulations with the distribution of the valued ecosystem components, Common Eider and auks, and their vulnerability indexes, using the analysis system SIMPACT. Based on these results and other considerations, recommendations for limiting possible drilling activity are given. 105 refs., 30 figs., 9 tabs

  17. Project Final Report: HPC-Colony II

    Energy Technology Data Exchange (ETDEWEB)

    Jones, Terry R [ORNL; Kale, Laxmikant V [University of Illinois, Urbana-Champaign; Moreira, Jose [IBM T. J. Watson Research Center

    2013-11-01

    This report recounts the HPC Colony II Project which was a computer science effort funded by DOE's Advanced Scientific Computing Research office. The project included researchers from ORNL, IBM, and the University of Illinois at Urbana-Champaign. The topic of the effort was adaptive system software for extreme scale parallel machines. A description of findings is included.

  18. English Literatures in Post-Colonial Singapore

    Science.gov (United States)

    Dass, Rozita

    2015-01-01

    The emergence of a vibrant literary, culture and arts scene promotes Singapore's claims as a hub for arts and culture in the Asian region, and as a global arts city by the 21st century. The richness and variety of Singapore literature from the early post-colonial years are evident in the evolution of a Singapore literary culture. The diaspora of…

  19. Latin America: Essays Interpretating Colonial Legacy

    Directory of Open Access Journals (Sweden)

    María Pia López

    2013-12-01

    Full Text Available A large part of the Latin–American literature of the 19th and 20th century tried to deal with the national question intertwining different dimensions: the weight of colonial legacy, the cultural peculiarity of the nation and the inner relations between social classes and ethnic groups. Thinking the nation implied, in any case, to think the difference and the conflict with others, as well as the inner conflict and the logic of local colonialism. Analyzing some of these essays that played a central role in such process of recasting the origin of the nation, the author moves around three main axes: the formulation of dualist writings (colonial/national; white /indigenous; civilization/wilderness, the issue of language (the language inherited from the colonial experience versus the multilingual nature of indigenous Latin American societies, and the hypothesis about the birth of the nation – appointed to different groups – and its normal functioning as legitimization of the order sprung from independences.

  20. Teaching the History of Colonial Peru.

    Science.gov (United States)

    Campbell, Leon G.

    1981-01-01

    Presents a bibliographic review essay on the topic of colonial Peru organized according to the following topics: Pre-Columbian Peru, 5500 B.C.- 1532; the conquest of Peru, 1532-1572; Peru under the Hapsburgs, 1516-1700; Bourbon Peru, 1700-1808; and the coming of independence, 1808-1821. The essay is based on a bibliography composed largely of…

  1. PRE-COLONIAL TRANSPORT SYSTEMS: A VERITABLE ...

    African Journals Online (AJOL)

    FBL

    ideas between places and over-time and mediate relationship and interactions between individuals and ... International Journal of Development and Management Review (INJODEMAR) Vol. 9, No 1 ..... Colonial Times, “Ahiajoku Lecture Series, Owerri: Ministry of Information, Youth and Sports Government Press. Afigbo A.E ...

  2. Policing native pleasures: a colonial history.

    Science.gov (United States)

    Jabbar, Naheem

    2012-12-01

    The moral modality of colonial power is still with us when it comes to the recreation of sexual norms of traditional or feudal society. We can examine the emergent properties of colonial knowledge anew by exploring how the colonial regime's strategic attention of regulating brothels in India differed from the analytic of power Foucault described for sexuality in European society. It turns out that amongst other things, public anxieties about the failure of adaptation by South Asians are incapable of leaving sexuality aside as a key interpretive device for their culture. The British preoccupation with reproducing the dynamics of the bourgeois matrimonial market on foreign soil in the mid-nineteenth century similarly necessitated a sociological pretext for racial purity. However, the kind of knowledge a typical traveller and employee of the East India Company brought to the Victorian public from his own researches in the brothels and streets of colonial India, which revealed how popular prostitution was as a vice amongst the officer class, was also more than a welcome imaginary relief from Christian morality; it was an alternative vision of modernity. © London School of Economics and Political Science 2012.

  3. Hyphal growth and colony expansion (Forum Commentary)

    NARCIS (Netherlands)

    Bruggen, van A.H.C.; Termorshuizen, A.J.; Semenov, A.M.

    2000-01-01

    Bailey et al. have used a quite simple but elegant experimental method and developed innovative concepts about phase transitions in colony behavior based on non-linearity of invasion probability with distance between substrate particles. This proves again the old adage that significant scientific

  4. 128 COLONIALISM: NEXUS FOR MYRIAD RELIGIOUS ...

    African Journals Online (AJOL)

    In recent times, the version of Christians we have, who also practice ATR is ... Colonialism is not a new concept in the history of Africa. .... of their kits and kin still living. ..... believe that God could be reached through different media. ..... Hornby, A.S., (2006), Oxford Advanced Learner's Dictionary of Current English, New York,.

  5. Buckling instability in ordered bacterial colonies

    Science.gov (United States)

    Boyer, Denis; Mather, William; Mondragón-Palomino, Octavio; Orozco-Fuentes, Sirio; Danino, Tal; Hasty, Jeff; Tsimring, Lev S.

    2011-04-01

    Bacterial colonies often exhibit complex spatio-temporal organization. This collective behavior is affected by a multitude of factors ranging from the properties of individual cells (shape, motility, membrane structure) to chemotaxis and other means of cell-cell communication. One of the important but often overlooked mechanisms of spatio-temporal organization is direct mechanical contact among cells in dense colonies such as biofilms. While in natural habitats all these different mechanisms and factors act in concert, one can use laboratory cell cultures to study certain mechanisms in isolation. Recent work demonstrated that growth and ensuing expansion flow of rod-like bacteria Escherichia coli in confined environments leads to orientation of cells along the flow direction and thus to ordering of cells. However, the cell orientational ordering remained imperfect. In this paper we study one mechanism responsible for the persistence of disorder in growing cell populations. We demonstrate experimentally that a growing colony of nematically ordered cells is prone to the buckling instability. Our theoretical analysis and discrete-element simulations suggest that the nature of this instability is related to the anisotropy of the stress tensor in the ordered cell colony.

  6. Buckling instability in ordered bacterial colonies

    International Nuclear Information System (INIS)

    Boyer, Denis; Mather, William; Mondragón-Palomino, Octavio; Danino, Tal; Hasty, Jeff; Orozco-Fuentes, Sirio; Tsimring, Lev S

    2011-01-01

    Bacterial colonies often exhibit complex spatio-temporal organization. This collective behavior is affected by a multitude of factors ranging from the properties of individual cells (shape, motility, membrane structure) to chemotaxis and other means of cell–cell communication. One of the important but often overlooked mechanisms of spatio-temporal organization is direct mechanical contact among cells in dense colonies such as biofilms. While in natural habitats all these different mechanisms and factors act in concert, one can use laboratory cell cultures to study certain mechanisms in isolation. Recent work demonstrated that growth and ensuing expansion flow of rod-like bacteria Escherichia coli in confined environments leads to orientation of cells along the flow direction and thus to ordering of cells. However, the cell orientational ordering remained imperfect. In this paper we study one mechanism responsible for the persistence of disorder in growing cell populations. We demonstrate experimentally that a growing colony of nematically ordered cells is prone to the buckling instability. Our theoretical analysis and discrete-element simulations suggest that the nature of this instability is related to the anisotropy of the stress tensor in the ordered cell colony

  7. 178 MULTIPLE COLONIALISM IN WESTERN SAHARA Macharia ...

    African Journals Online (AJOL)

    Administrator

    Civil War, the colony had also been a possible bargaining chip with Adolph Hitler when ... Morocco gave rise to an Army of Liberation that inspired the Sahrawi to fight ..... or defense, matters, and promised the Sahrawi the right to vote for their ...

  8. Isotopic characterization of flight feathers in two pelagic seabirds: Sampling strategies for ecological studies

    Science.gov (United States)

    Wiley, Anne E.; Ostrom, Peggy H.; Stricker, Craig A.; James, Helen F.; Gandhi, Hasand

    2010-01-01

    We wish to use stable-isotope analysis of flight feathers to understand the feeding behavior of pelagic seabirds, such as the Hawaiian Petrel (Pterodroma sandwichensis) and Newell’s Shearwater (Puffinus auricularis newelli). Analysis of remiges is particularly informative because the sequence and timing of remex molt are often known. The initial step, reported here, is to obtain accurate isotope values from whole remiges by means of a minimally invasive protocol appropriate for live birds or museum specimens. The high variability observed in D13C and D15N values within a feather precludes the use of a small section of vane. We found the average range within 42 Hawaiian Petrel remiges to be 1.3‰ for both D13C and D15N and that within 10 Newell’s Shearwater remiges to be 1.3‰ and 0.7‰ for D13C and D15N, respectively. The D13C of all 52 feathers increased from tip to base, and the majority of Hawaiian Petrel feathers showed an analogous trend in D15N. Although the average range of DD in 21 Hawaiian Petrel remiges was 11‰, we found no longitudinal trend. We discuss influences of trophic level, foraging location, metabolism, and pigmentation on isotope values and compare three methods of obtaining isotope averages of whole feathers. Our novel barb-sampling protocol requires only 1.0 mg of feather and minimal preparation time. Because it leaves the feather nearly intact, this protocol will likely facilitate obtaining isotope values from remiges of live birds and museum specimens. As a consequence, it will help expand the understanding of historical trends in foraging behavior

  9. Taking movement data to new depths: Inferring prey availability and patch profitability from seabird foraging behavior.

    Science.gov (United States)

    Chimienti, Marianna; Cornulier, Thomas; Owen, Ellie; Bolton, Mark; Davies, Ian M; Travis, Justin M J; Scott, Beth E

    2017-12-01

    Detailed information acquired using tracking technology has the potential to provide accurate pictures of the types of movements and behaviors performed by animals. To date, such data have not been widely exploited to provide inferred information about the foraging habitat. We collected data using multiple sensors (GPS, time depth recorders, and accelerometers) from two species of diving seabirds, razorbills ( Alca torda , N  = 5, from Fair Isle, UK) and common guillemots ( Uria aalge , N  = 2 from Fair Isle and N  = 2 from Colonsay, UK). We used a clustering algorithm to identify pursuit and catching events and the time spent pursuing and catching underwater, which we then used as indicators for inferring prey encounters throughout the water column and responses to changes in prey availability of the areas visited at two levels: individual dives and groups of dives. For each individual dive ( N  = 661 for guillemots, 6214 for razorbills), we modeled the number of pursuit and catching events, in relation to dive depth, duration, and type of dive performed (benthic vs. pelagic). For groups of dives ( N  = 58 for guillemots, 156 for razorbills), we modeled the total time spent pursuing and catching in relation to time spent underwater. Razorbills performed only pelagic dives, most likely exploiting prey available at shallow depths as indicated by the vertical distribution of pursuit and catching events. In contrast, guillemots were more flexible in their behavior, switching between benthic and pelagic dives. Capture attempt rates indicated that they were exploiting deep prey aggregations. The study highlights how novel analysis of movement data can give new insights into how animals exploit food patches, offering a unique opportunity to comprehend the behavioral ecology behind different movement patterns and understand how animals might respond to changes in prey distributions.

  10. Benefits and costs of increased levels of corticosterone in seabird chicks

    Science.gov (United States)

    Kitaysky, A.S.; Kitaiskaia, E.V.; Piatt, John F.; Wingfield, J.C.

    2003-01-01

    Seabird chicks respond to food shortages by increasing corticosterone (cort) secretion, which is probably associated with fitness benefits and costs. To examine this, we experimentally increased levels of circulating cort in captive black-legged kittiwake chicks fed ad libitum. We found that cort-implanted chicks begged more frequently and were more aggressive compared to controls. These behavioral modifications must be beneficial to chicks as they facilitate acquisition of food from the parents and might trigger brood reduction and reduced competition for food. Cort-implanted chicks also increased food intake; however, their growth rates were similar to controls. To examine the costs of chronically increased circulating levels of cort, we removed cort implants and, after a 10-day recovery period, tested cognitive abilities of young kittiwakes. We found that the ability of kittiwakes to associate a visual cue with the presence of food in a choice situation was compromised by the experimental elevation of cort during development. To examine the long-term costs of increased levels of cort, 8 months later we tested the performance of the same individuals in a spatial task requiring them to make a detour around a barrier in order to escape from an enclosure. Individuals treated with cort during development took significantly more time to solve this task compared to controls. The results of this study suggest that the adrenocortical response of a developing bird to environmental stressors is associated with both benefits (increased food intake, foraging behavior, and aggression) and costs (low growth efficiency and compromised cognitive abilities later in life). This provides an evolutionary framework for relating juvenile physiological traits to fitness of birds in subsequent life-history stages. ?? 2003 Elsevier Science (USA). All rights reserved.

  11. Windscapes shape seabird instantaneous energy costs but adult behavior buffers impact on offspring.

    Science.gov (United States)

    Elliott, Kyle Hamish; Chivers, Lorraine S; Bessey, Lauren; Gaston, Anthony J; Hatch, Scott A; Kato, Akiko; Osborne, Orla; Ropert-Coudert, Yan; Speakman, John R; Hare, James F

    2014-01-01

    Windscapes affect energy costs for flying animals, but animals can adjust their behavior to accommodate wind-induced energy costs. Theory predicts that flying animals should decrease air speed to compensate for increased tailwind speed and increase air speed to compensate for increased crosswind speed. In addition, animals are expected to vary their foraging effort in time and space to maximize energy efficiency across variable windscapes. We examined the influence of wind on seabird (thick-billed murre Uria lomvia and black-legged kittiwake Rissa tridactyla) foraging behavior. Airspeed and mechanical flight costs (dynamic body acceleration and wing beat frequency) increased with headwind speed during commuting flights. As predicted, birds adjusted their airspeed to compensate for crosswinds and to reduce the effect of a headwind, but they could not completely compensate for the latter. As we were able to account for the effect of sampling frequency and wind speed, we accurately estimated commuting flight speed with no wind as 16.6 ms(?1) (murres) and 10.6 ms(?1) (kittiwakes). High winds decreased delivery rates of schooling fish (murres), energy (murres) and food (kittiwakes) but did not impact daily energy expenditure or chick growth rates. During high winds, murres switched from feeding their offspring with schooling fish, which required substantial above-water searching, to amphipods, which required less above-water searching. Adults buffered the adverse effect of high winds on chick growth rates by switching to other food sources during windy days or increasing food delivery rates when weather improved.

  12. Stress hormones in relation to breeding status and territory location in colonial king penguin: a role for social density?

    Science.gov (United States)

    Viblanc, Vincent A; Gineste, Benoit; Stier, Antoine; Robin, Jean-Patrice; Groscolas, René

    2014-07-01

    Because glucocorticoid (stress) hormones fundamentally affect various aspects of the behaviour, life history and fitness of free-living vertebrates, there is a need to understand the environmental factors shaping their variation in natural populations. Here, we examined whether spatial heterogeneity in breeding territory quality affected the stress of colonial king penguin (Aptenodytes patagonicus). We assessed the effects of local climate (wind, sun and ambient temperature) and social conditions (number of neighbours, distance to neighbours) on the baseline levels of plasma total corticosterone (CORT) in 77 incubating and 42 chick-brooding birds, breeding on territories of central or peripheral colony location. We also assessed the oxidative stress status of a sub-sample of central vs. peripheral chick-brooders to determine whether chronic stress arose from breeding on specific territories. On average, we found that brooders had 55% higher CORT levels than incubators. Regardless of breeding status, central birds experienced greater social density (higher number of neighbours, shorter distance between territories) and had higher CORT levels than peripheral birds. Increasing social density positively explained 40% of the variation in CORT levels of both incubators and brooders, but the effect was more pronounced in brooders. In contrast, climate was similar among breeding territories and did not significantly affect the CORT levels of breeding birds. In brooders, oxidative stress status was not affected by local density or weather conditions. These results highlight that local heterogeneity in breeding (including social) conditions may strongly affect the stress levels of breeding seabirds. The fitness consequences of such variation remain to be investigated.

  13. Cellulolytic Protist Numbers Rise and Fall Dramatically in Termite Queens and Kings during Colony Foundation

    Science.gov (United States)

    Shimada, Keisuke; Lo, Nathan; Kitade, Osamu; Wakui, Akane

    2013-01-01

    Among the best-known examples of mutualistic symbioses is that between lower termites and the cellulolytic flagellate protists in their hindguts. Although the symbiosis in worker termites has attracted much attention, there have been only a few studies of protists in other castes. We have performed the first examination of protist population dynamics in queens and kings during termite colony foundation. Protist numbers, as well as measurements of hindgut and reproductive tissue sizes, were undertaken at five time points over 400 days in incipient colonies of Reticulitermes speratus, as well as in other castes of mature colonies of this species. We found that protist numbers increased dramatically in both queens and kings during the first 50 days of colony foundation but began to decrease by day 100, eventually disappearing by day 400. Hindgut width followed a pattern similar to that of protist numbers, while ovary and testis widths increased significantly only at day 400. Kings were found to contain higher numbers of protists than queens in incipient colonies, which may be linked to higher levels of nutrient transfer from kings to queens than vice versa, as is known in some other termite species. Protists were found to be abundant in soldiers from mature colonies but absent in neotenics. This probably reflects feeding of soldiers by workers via proctodeal trophallaxis and of reproductives via stomodeal trophallaxis. The results reveal the dynamic nature of protist numbers during colony foundation and highlight the trade-offs that exist between reproduction and parental care during this critical phase of the termite life cycle. PMID:23376945

  14. Design and economic optimization of shell and tube heat exchangers using Artificial Bee Colony (ABC) algorithm

    International Nuclear Information System (INIS)

    Sencan Sahin, Arzu; Kilic, Bayram; Kilic, Ulas

    2011-01-01

    Highlights: → Artificial Bee Colony for shell and tube heat exchanger optimization is used. → The total cost is minimized by varying design variables. → This new approach can be applied for optimization of heat exchangers. - Abstract: In this study, a new shell and tube heat exchanger optimization design approach is developed. Artificial Bee Colony (ABC) has been applied to minimize the total cost of the equipment including capital investment and the sum of discounted annual energy expenditures related to pumping of shell and tube heat exchanger by varying various design variables such as tube length, tube outer diameter, pitch size, baffle spacing, etc. Finally, the results are compared to those obtained by literature approaches. The obtained results indicate that Artificial Bee Colony (ABC) algorithm can be successfully applied for optimal design of shell and tube heat exchangers.

  15. Design and economic optimization of shell and tube heat exchangers using Artificial Bee Colony (ABC) algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Sencan Sahin, Arzu, E-mail: sencan@tef.sdu.edu.tr [Department of Mechanical Education, Technical Education Faculty, Sueleyman Demirel University, 32260 Isparta (Turkey); Kilic, Bayram, E-mail: bayramkilic@hotmail.com [Bucak Emin Guelmez Vocational School, Mehmet Akif Ersoy University, Bucak (Turkey); Kilic, Ulas, E-mail: ulaskilic@mehmetakif.edu.tr [Bucak Emin Guelmez Vocational School, Mehmet Akif Ersoy University, Bucak (Turkey)

    2011-10-15

    Highlights: {yields} Artificial Bee Colony for shell and tube heat exchanger optimization is used. {yields} The total cost is minimized by varying design variables. {yields} This new approach can be applied for optimization of heat exchangers. - Abstract: In this study, a new shell and tube heat exchanger optimization design approach is developed. Artificial Bee Colony (ABC) has been applied to minimize the total cost of the equipment including capital investment and the sum of discounted annual energy expenditures related to pumping of shell and tube heat exchanger by varying various design variables such as tube length, tube outer diameter, pitch size, baffle spacing, etc. Finally, the results are compared to those obtained by literature approaches. The obtained results indicate that Artificial Bee Colony (ABC) algorithm can be successfully applied for optimal design of shell and tube heat exchangers.

  16. An American termite in Paris: temporal colony dynamics.

    Science.gov (United States)

    Baudouin, Guillaume; Dedeine, Franck; Bech, Nicolas; Bankhead-Dronnet, Stéphanie; Dupont, Simon; Bagnères, Anne-Geneviève

    2017-12-01

    Termites of the genus Reticulitermes are widespread invaders, particularly in urban habitats. Their cryptic and subterranean lifestyle makes them difficult to detect, and we know little about their colony dynamics over time. In this study we examined the persistence of Reticulitermes flavipes (Kollar) colonies in the city of Paris over a period of 15 years. The aim was (1) to define the boundaries of colonies sampled within the same four areas over two sampling periods, (2) to determine whether the colonies identified during the first sampling period persisted to the second sampling period, and (3) to compare the results obtained when colonies were delineated using a standard population genetic approach versus a Bayesian clustering method that combined both spatial and genetic information. Herein, colony delineations were inferred from genetic differences at nine microsatellite loci and one mitochondrial locus. Four of the 18 identified colonies did not show significant differences in their genotype distributions between the two sampling periods. While allelic richness was low, making it hard to reliably distinguish colony family type, most colonies appeared to retain the same breeding structure over time. These large and expansive colonies showed an important ability to fuse (39% were mixed-family colonies), contained hundreds of reproductives and displayed evidence of isolation-by-distance, suggesting budding dispersal. These traits, which favor colony persistence over time, present a challenge for pest control efforts, which apply treatment locally. The other colonies showed significant differences, but we cannot exclude the possibility that their genotype distributions simply changed over time.

  17. Colonial Army Formats in Africa and Post-Colonial Military Coups:

    African Journals Online (AJOL)

    BSOS USER

    The centralised and autocratic features of Caliphate rule were .... latter's participation in the affairs of their respective societies, and leadership ..... deployment of the army by the NPC for internal colonial-style repression duties in the Middle Belt ...

  18. Ireland – a test case of Post-colonialism / Post colonialism

    Directory of Open Access Journals (Sweden)

    Brenda Murray

    2006-05-01

    Full Text Available Contextualisation This review attempts to set the stage for post-colonial theorising, in the light of alternative representations of ‘whiteness’, on issues of gender, race and language within the discourse of equality. In this paper Ireland and the Irish provide a backdrop against which the nature and impact of colonialism on the colonised and the coloniser are explored. Many challenging questions emerge about the ideological basis of post colonial theory, not least when traditional paradigms of racism, as conveyed by the black / white dichotomy, are examined: Ireland presents a context, it is argued, where subjugation is of white on white. Linked to this is the language of the coloniser, a powerful hegemonic force which, in some situations, has been nurtured by the colonised and later developed into a text which is unique, producing a new literature which, it is asserted, truly invokes the ‘post colonial’. Abstract: Post-colonialism – essentially a critique of colonialism, is characterised by a process of disengagement from the colonial epoch and has taken many forms. In this article a set of phenomena are examined that have become inscribed in the cultures of the colonised with a view to identifying alternative cultural origins and dispositions recovered in this post-colonial era. Ireland and the Irish provide the background context of this exploration into perspectives generated by the peripheral or post-colonial nations. Globalisation, too, has had a role to play in the increasing de-territorialisation of communities as a result of cross-frontier mobility, increased intra-community mobility and new communication technologies. A critical reflection on the process of disengagement leads the author to conclude that we must come to recognise new cultural forms which are accepting of a heterogeneous and inclusive society: one which is not characterised by difference.

  19. Growth and asymmetry of soil microfungal colonies from "Evolution Canyon," Lower Nahal Oren, Mount Carmel, Israel.

    Directory of Open Access Journals (Sweden)

    Shmuel Raz

    Full Text Available Fluctuating asymmetry is a contentious indicator of stress in populations of animals and plants. Nevertheless, it is a measure of developmental noise, typically obtained by measuring asymmetry across an individual organism's left-right axis of symmetry. These individual, signed asymmetries are symmetrically distributed around a mean of zero. Fluctuating asymmetry, however, has rarely been studied in microorganisms, and never in fungi.We examined colony growth and random phenotypic variation of five soil microfungal species isolated from the opposing slopes of "Evolution Canyon," Mount Carmel, Israel. This canyon provides an opportunity to study diverse taxa inhabiting a single microsite, under different kinds and intensities of abiotic and biotic stress. The south-facing "African" slope of "Evolution Canyon" is xeric, warm, and tropical. It is only 200 m, on average, from the north-facing "European" slope, which is mesic, cool, and temperate. Five fungal species inhabiting both the south-facing "African" slope, and the north-facing "European" slope of the canyon were grown under controlled laboratory conditions, where we measured the fluctuating radial asymmetry and sizes of their colonies.Different species displayed different amounts of radial asymmetry (and colony size. Moreover, there were highly significant slope by species interactions for size, and marginally significant ones for fluctuating asymmetry. There were no universal differences (i.e., across all species in radial asymmetry and colony size between strains from "African" and "European" slopes, but colonies of Clonostachys rosea from the "African" slope were more asymmetric than those from the "European" slope.Our study suggests that fluctuating radial asymmetry has potential as an indicator of random phenotypic variation and stress in soil microfungi. Interaction of slope and species for both growth rate and asymmetry of microfungi in a common environment is evidence of genetic

  20. Stable genetic diversity despite parasite and pathogen spread in honey bee colonies

    Science.gov (United States)

    Jara, Laura; Muñoz, Irene; Cepero, Almudena; Martín-Hernández, Raquel; Serrano, José; Higes, Mariano; De la Rúa, Pilar

    2015-10-01

    In the last decades, the rapid spread of diseases, such as varroosis and nosemosis, associated with massive honey bee colonies mortality around the world has significantly decreased the number and size of honey bee populations and possibly their genetic diversity. Here, we compare the genetic diversity of Iberian honey bee colonies in two samplings performed in 2006 and 2010 in relation to the presence of the pathogenic agents Nosema apis, Nosema ceranae, and Varroa destructor in order to determine whether parasite and pathogen spread in honey bee colonies reflects changes in genetic diversity. We found that the genetic diversity remained similar, while the incidence of N. ceranae increased and the incidence of N. apis and V. destructor decreased slightly. These results indicate that the genetic diversity was not affected by the presence of these pathogenic agents in the analyzed period. However, the two groups of colonies with and without Nosema/Varroa detected showed significant genetic differentiation (G test). A detailed analysis of the allelic segregation of microsatellite loci in Nosema/Varroa-negative colonies and parasitized ones revealed two outlier loci related to genes involved in immune response.

  1. Stable genetic diversity despite parasite and pathogen spread in honey bee colonies.

    Science.gov (United States)

    Jara, Laura; Muñoz, Irene; Cepero, Almudena; Martín-Hernández, Raquel; Serrano, José; Higes, Mariano; De la Rúa, Pilar

    2015-10-01

    In the last decades, the rapid spread of diseases, such as varroosis and nosemosis, associated with massive honey bee colonies mortality around the world has significantly decreased the number and size of honey bee populations and possibly their genetic diversity. Here, we compare the genetic diversity of Iberian honey bee colonies in two samplings performed in 2006 and 2010 in relation to the presence of the pathogenic agents Nosema apis, Nosema ceranae, and Varroa destructor in order to determine whether parasite and pathogen spread in honey bee colonies reflects changes in genetic diversity. We found that the genetic diversity remained similar, while the incidence of N. ceranae increased and the incidence of N. apis and V. destructor decreased slightly. These results indicate that the genetic diversity was not affected by the presence of these pathogenic agents in the analyzed period. However, the two groups of colonies with and without Nosema/Varroa detected showed significant genetic differentiation (G test). A detailed analysis of the allelic segregation of microsatellite loci in Nosema/Varroa-negative colonies and parasitized ones revealed two outlier loci related to genes involved in immune response.

  2. Diversity and abundance of invertebrate epifaunal assemblages associated with gorgonians are driven by colony attributes

    KAUST Repository

    Curdia, Joao

    2015-03-20

    The present study aimed to explicitly quantify the link between the attributes of shallow-water gorgonian colonies (Octocorallia: Alcyonacea) and the ecological patterns of associated non-colonial epifaunal invertebrates. Based on multiple regression analysis, we tested the contribution of several attributes (colony height, width, and area, fractal dimension as a measure of colony complexity, lacunarity as a measure of the heterogeneity, and “colonial” epibiont cover) to abundance and taxonomic richness of associated assemblages. The results highlight the variation in the response of epifaunal assemblages to the gorgonian colony characteristics. The nature and intensity of the relationships were gorgonian species-dependent and varied from one taxonomic group to another. For both gorgonian species analyzed, the strongest predictor of species richness and abundance of the epifaunal assemblages was “colonial” epibiont cover, possibly due to a trophic effect (direct or indirect enhancement of food availability) combined with the surface available for colonization (species–area effect). Although structural complexity is usually indicated as the main driver for rich and abundant coral-associated assemblages, no significant relationship was observed between fractal dimension and the community descriptors; lacunarity, which reflects the sizes of the inter-branch spaces, was only linked to taxonomic richness in the assemblages associated with Leptogorgia lusitanica. The validity of the paradigm that structural complexity enhances biodiversity may be scale-dependent. In the case of gorgonians, the effect of complexity at the “garden” level may be more relevant than at the individual colony level. This reinforces the need for the conservation of gorgonian aggregation areas as a whole in order to preserve host diversity and size structure. © 2015 Springer-Verlag Berlin Heidelberg

  3. 21 CFR 866.2180 - Manual colony counter.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2180 Manual colony counter. (a) Identification. A manual colony counter is a device intended for medical purposes that consists...

  4. Hybrid Bee Ant Colony Algorithm for Effective Load Balancing And ...

    African Journals Online (AJOL)

    PROF. OLIVER OSUAGWA

    Ant Colony algorithm is used in this hybrid Bee Ant Colony algorithm to solve load balancing issues ... Genetic Algorithm (MO-GA) for dynamic job scheduling that .... Information Networking and Applications Workshops. [7]. M. Dorigo & T.

  5. Conflict and conflict resolution in Africa: Engaging the colonial factor

    African Journals Online (AJOL)

    maintaining colonial-style approaches to African conflicts at the expense of a ... Educational Leadership at the College of Education and Human Services, University of .... Colonial rule was the antithesis of democracy, because it was premised.

  6. Honeybee colony marketing and its implications for queen rearing ...

    African Journals Online (AJOL)

    Honeybee colony marketing and its implications for queen rearing and beekeeping development in Werieleke ... Thus, colony marketing is an important venture in Werieleke district of Tigray region. ... EMAIL FULL TEXT EMAIL FULL TEXT

  7. Growth pattern of the surface of fungus Aspergillus colony

    Science.gov (United States)

    Matsuura, Shu; Miyazima, Sasuke

    1992-05-01

    Aspergillus oryzae colonies were grown under various glucose concentrations, temperatures, and agar concentrations, and the effects on the pattern were investigated. Patterns of colony were found to vary from uniform to diffusion-limited aggregation type.

  8. High summertime aerosol organic functional group concentrations from marine and seabird sources at Ross Island, Antarctica, during AWARE

    Directory of Open Access Journals (Sweden)

    J. Liu

    2018-06-01

    Full Text Available Observations of the organic components of the natural aerosol are scarce in Antarctica, which limits our understanding of natural aerosols and their connection to seasonal and spatial patterns of cloud albedo in the region. From November 2015 to December 2016, the ARM West Antarctic Radiation Experiment (AWARE measured submicron aerosol properties near McMurdo Station at the southern tip of Ross Island. Submicron organic mass (OM, particle number, and cloud condensation nuclei concentrations were higher in summer than other seasons. The measurements included a range of compositions and concentrations that likely reflected both local anthropogenic emissions and natural background sources. We isolated the natural organic components by separating a natural factor and a local combustion factor. The natural OM was 150 times higher in summer than in winter. The local anthropogenic emissions were not hygroscopic and had little contribution to the CCN concentrations. Natural sources that included marine sea spray and seabird emissions contributed 56 % OM in summer but only 3 % in winter. The natural OM had high hydroxyl group fraction (55 %, 6 % alkane, and 6 % amine group mass, consistent with marine organic composition. In addition, the Fourier transform infrared (FTIR spectra showed the natural sources of organic aerosol were characterized by amide group absorption, which may be from seabird populations. Carboxylic acid group contributions were high in summer and associated with natural sources, likely forming by secondary reactions.

  9. Population Structure and Dispersal Patterns within and between Atlantic and Mediterranean Populations of a Large-Range Pelagic Seabird

    Science.gov (United States)

    Genovart, Meritxell; Thibault, Jean-Claude; Igual, José Manuel; Bauzà-Ribot, Maria del Mar; Rabouam, Corinne; Bretagnolle, Vincent

    2013-01-01

    Dispersal is critically linked to the demographic and evolutionary trajectories of populations, but in most seabird species it may be difficult to estimate. Using molecular tools, we explored population structure and the spatial dispersal pattern of a highly pelagic but philopatric seabird, the Cory's shearwater Calonectris diomedea. Microsatellite fragments were analysed from samples collected across almost the entire breeding range of the species. To help disentangle the taxonomic status of the two subspecies described, the Atlantic form C. d. borealis and the Mediterranean form C. d. diomedea, we analysed genetic divergence between subspecies and quantified both historical and recent migration rates between the Mediterranean and Atlantic basins. We also searched for evidence of isolation by distance (IBD) and addressed spatial patterns of gene flow. We found a low genetic structure in the Mediterranean basin. Conversely, strong genetic differentiation appeared in the Atlantic basin. Even if the species was mostly philopatric (97%), results suggest recent dispersal between basins, especially from the Atlantic to the Mediterranean (aprox. 10% of migrants/generation across the last two generations). Long-term gene flow analyses also suggested an historical exchange between basins (about 70 breeders/generation). Spatial analysis of genetic variation indicates that distance is not the main factor in shaping genetic structure in this species. Given our results we recommend gathering more data before concluded whether these taxa should be treated as two species or subspecies. PMID:23950986

  10. Seabirds indicate changes in the composition of plastic litter in the Atlantic and south-western Indian Oceans.

    Science.gov (United States)

    Ryan, Peter G

    2008-08-01

    I compare plastic ingested by five species of seabirds sampled in the 1980s and again in 1999-2006. The numbers of ingested plastic particles have not changed significantly, but the proportion of virgin pellets has decreased 44-79% in all five species: great shearwater Puffinus gravis, white-chinned petrel Procellaria aequinoctialis, broad-billed prion Pachyptila vittata, white-faced storm petrel Pelagodroma marina and white-bellied storm petrel Fregetta grallaria. The populations sampled range widely in the South Atlantic and western Indian Oceans. The most marked reduction occurred in great shearwaters, where the average number of pellets per bird decreased from 10.5 to 1.6. This species migrates between the South and North Atlantic each year. Similar decreases in virgin pellets have been recorded in short-tailed shearwaters Puffinus tenuirostris in the Pacific Ocean and northern fulmars Fulmarus glacialis in the North Sea. More data are needed on the relationship between plastic loads in seabirds and the density of plastic at sea in their foraging areas, but the consistent decrease in pellets in birds suggests there has been a global change in the composition of small plastic debris at sea over the last two decades.

  11. Comparative investigations of oiled seabirds and beaches in the Netherlands, Denmark, and the Federal Republic of Germany

    International Nuclear Information System (INIS)

    Dahlmann, G.; Timm, D.

    1993-01-01

    The Oiled Seabirds project (January 3, 1990, to March 31, 1993) consisted of two parts: regular surveillance of the beaches in the Netherlands, Denmark, and the Federal Republic of Germany, and sampling and analysis. The aims of the project were: To identify and compare the main sources of oil pollution in the countries involved; To trace definite sources (i.e., particular ships), in more severe cases, to promote prosecution of the offenders; and To gauge the efficiency of countermeasures, e.g., the joint material surveillance in the countries involved. Although the term open-quotes oiledclose quotes was used in the project title, the investigations were not restricted to petroleum. An attempt was made to identify all the products that could have caused the deaths of seabirds. The major sources of oil pollution in the Netherlands and Germany appear to be from normal shipping operations, e.g. engine room residues, while in Denmark the major component of chronic oil pollution is crude oil from tank washings of tanker ships

  12. Optimizing Drone Fertility With Spring Nutritional Supplements to Honey Bee (Hymenoptera: Apidae) Colonies.

    Science.gov (United States)

    Rousseau, Andrée; Giovenazzo, Pierre

    2016-03-27

    Supplemental feeding of honey bee (Apis melliferaL., Hymenoptera: Apidae) colonies in spring is essential for colony buildup in northern apicultural regions. The impact of pollen and syrup feeding on drone production and sperm quality is not well-documented, but may improve fecundation of early-bred queens. We measured the impact of feeding sucrose syrup, and protein supplements to colonies in early spring in eastern Canada. Drones were reared under different nutritional regimes, and mature individuals were then assessed in regard to size, weight, and semen quality (semen volume, sperm count, and viability). Results showed significant increases in drone weight and abdomen size when colonies were fed sucrose and a protein supplement. Colonies receiving no additional nourishment had significantly less semen volume per drone and lower sperm viability. Our study demonstrates that feeding honey bee colonies in spring with sucrose syrup and a protein supplement is important to enhance drone reproductive quality. RÉSUMÉ: L'administration de suppléments alimentaires aux colonies de l'abeille domestique (Apis melliferaL., Hymenoptera: Apidae) au printemps est essentielle pour le bon développement des colonies dans les régions apicoles nordiques. L'impact de la supplémentation des colonies en pollen et en sirop sur la production des faux-bourdons et la qualité du sperme demeure peu documenté mais pourrait résulter en une meilleure fécondation des reines produites tôt en saison. Nous avons mesuré l'impact de la supplémentation en sirop et/ou en supplément de pollen sur les colonies d'abeilles tôt au printemps dans l'est du Canada. Les faux-bourdons ont été élevé sous différents régimes alimentaires et les individus matures ont ensuite été évalués pour leur taille, leur poids ainsi que la qualité de leur sperme (volume de sperme, nombre et viabilité des spermatozoïdes. Les résultats montrent une augmentation significative du poids et de la taille

  13. Methods and measurement variance for field estimations of coral colony planar area using underwater photographs and semi-automated image segmentation.

    Science.gov (United States)

    Neal, Benjamin P; Lin, Tsung-Han; Winter, Rivah N; Treibitz, Tali; Beijbom, Oscar; Kriegman, David; Kline, David I; Greg Mitchell, B

    2015-08-01

    Size and growth rates for individual colonies are some of the most essential descriptive parameters for understanding coral communities, which are currently experiencing worldwide declines in health and extent. Accurately measuring coral colony size and changes over multiple years can reveal demographic, growth, or mortality patterns often not apparent from short-term observations and can expose environmental stress responses that may take years to manifest. Describing community size structure can reveal population dynamics patterns, such as periods of failed recruitment or patterns of colony fission, which have implications for the future sustainability of these ecosystems. However, rapidly and non-invasively measuring coral colony sizes in situ remains a difficult task, as three-dimensional underwater digital reconstruction methods are currently not practical for large numbers of colonies. Two-dimensional (2D) planar area measurements from projection of underwater photographs are a practical size proxy, although this method presents operational difficulties in obtaining well-controlled photographs in the highly rugose environment of the coral reef, and requires extensive time for image processing. Here, we present and test the measurement variance for a method of making rapid planar area estimates of small to medium-sized coral colonies using a lightweight monopod image-framing system and a custom semi-automated image segmentation analysis program. This method demonstrated a coefficient of variation of 2.26% for repeated measurements in realistic ocean conditions, a level of error appropriate for rapid, inexpensive field studies of coral size structure, inferring change in colony size over time, or measuring bleaching or disease extent of large numbers of individual colonies.

  14. Does by-catch pose a threat for the conservation of seabird populations in the southern Ionian Sea (eastern Mediterranean? A questionnaire based survey of local fisheries

    Directory of Open Access Journals (Sweden)

    G. KARRIS

    2013-09-01

    Full Text Available A significant number of studies worldwide have shown that incidental catches (by-catch of seabirds in fishing gear might pose a considerable risk for the conservation of their populations. Nevertheless reliable data on by-catch rates of seabirds in European marine ecosystems are patchy and need to be improved. This study constitutes a first attempt at the evaluation of by-catch rates in the southern Ionian Sea. Data were obtained by distributing a specific questionnaire to the fishers of Zakynthos Island. 150 professional fishers (representing 90% of the local fishing fleet participated in the research, and were interviewed during July-December 2010. The information collected showed that commercial longline and (to a lesser extent gillnet fishery gears caused incidental catches mostly of Scopoli’s Shearwater and Mediterranean Shag. The temporal analysis of the incidental bird mortality showed that seabirds were more susceptible to be trapped in fishery gears set around sunrise during spring and summer whereas spatial analysis of by-catch data indicated variations in the number of seabirds caught in different fishery areas.

  15. An assessment of the number of seabirds at risk during the November 2004 Terra Nova FPSO oil spill on the Grand Banks

    International Nuclear Information System (INIS)

    Wilhelm, S.I.; Robertson, G.J.; Ryan, P.C.; Schneider, D.C.

    2006-01-01

    This paper reported on the number of seabirds impacted by the Terra Nova floating production, storage and offloading (FPSO) vessel, which released 160,000 litres of crude oil after it struck the Grand Banks, an area located approximately 340 km east of St. John's, Newfoundland. An area of approximately 340 km 2 was impacted by the spill, which occurred at a time when large numbers of dovekies and murres inhabit the region. After the spill, both vessel-based and helicopter-based surveys were conducted in order to estimate seabird densities in the immediate region. Densities were then compared to other data from similar time periods. The number of birds at risk was estimated base on seabird densities noted from on-vessel surveys. A mean density of 3.46 murres per km 2 and 1.07 dovekies per km 2 were recorded. Mean density increased when birds in flight were also considered. Density estimates were similar to data previously reported. The scenarios yielded a mean of 9858 murres and dovekies. The estimate was then compared to mortality estimates based on published empirical relationship between the volume of oil released, and the number of seabirds killed. It was concluded that between 10,000 and 16,000 alcids were put at risk by the spill. 30 refs., 5 tabs., 4 figs.

  16. Feeding associations between Guiana dolphins, Sotalia guianensis (Van Bénèden, 1864) and seabirds in the Lagamar estuary, Brazil.

    Science.gov (United States)

    Santos, M C O; Oshima, J E F; Pacífico, E S; Silva, E

    2010-02-01

    The main objective of the present study was to describe the characteristics regarding interactions between Guiana dolphins, Sotalia guianensis and seabirds in feeding associations in two distinct areas of the Lagamar estuary, Brazil. Boat-based surveys directed towards photo-identification studies of S. guianensis were conducted in the Cananéia Estuary (CE) (25 degrees 01' S and 47 degrees 55' W) from July 2004 to March 2008, as well as in the Paranaguá Estuarine Complex (PEC) (25 degrees 24' S and 48 degrees 24' W) from April 2006 to February 2008. On all occasions when seabirds were observed engaging in multi-species feeding associations with S. guianensis, data on species involved and their numbers were gathered. From 435 observed groups of S. guianensis in the CE, 38 (8.7%) involved interactions with seabirds. In the PEC, from the 286 observed groups, 32 (11.2%) involved the mentioned interactions. The following seabirds were observed in feeding associations with S. guianensis: Fregata magnificens, Sula leucogaster, Phalacrocorax brasilianus, and Sterna sp. In the CE, S. leucogaster was more commonly observed in feeding associations with Guiana dolphins (chi2 = 22.84; d.f. = 3, p Lagamar estuary.

  17. A survey of honey bee colony losses in the U.S., fall 2007 to spring 2008.

    Directory of Open Access Journals (Sweden)

    Dennis van Engelsdorp

    Full Text Available BACKGROUND: Honey bees are an essential component of modern agriculture. A recently recognized ailment, Colony Collapse Disorder (CCD, devastates colonies, leaving hives with a complete lack of bees, dead or alive. Up to now, estimates of honey bee population decline have not included losses occurring during the wintering period, thus underestimating actual colony mortality. Our survey quantifies the extent of colony losses in the United States over the winter of 2007-2008. METHODOLOGY/PRINCIPAL FINDINGS: Surveys were conducted to quantify and identify management factors (e.g. operation size, hive migration that contribute to high colony losses in general and CCD symptoms in particular. Over 19% of the country's estimated 2.44 million colonies were surveyed. A total loss of 35.8% of colonies was recorded; an increase of 11.4% compared to last year. Operations that pollinated almonds lost, on average, the same number of colonies as those that did not. The 37.9% of operations that reported having at least some of their colonies die with a complete lack of bees had a total loss of 40.8% of colonies compared to the 17.1% loss reported by beekeepers without this symptom. Large operations were more likely to have this symptom suggesting that a contagious condition may be a causal factor. Sixty percent of all colonies that were reported dead in this survey died without dead bees, and thus possibly suffered from CCD. In PA, losses varied with region, indicating that ambient temperature over winter may be an important factor. CONCLUSIONS/SIGNIFICANCE: Of utmost importance to understanding the recent losses and CCD is keeping track of losses over time and on a large geographic scale. Given that our surveys are representative of the losses across all beekeeping operations, between 0.75 and 1.00 million honey bee colonies are estimated to have died in the United States over the winter of 2007-2008. This article is an extensive survey of U.S. beekeepers

  18. The importance of confronting a colonial, patriarchal and racist past ...

    African Journals Online (AJOL)

    The importance of confronting a colonial, patriarchal and racist past in addressing post-apartheid sexual violence. ... It also needs to redress problems of social and economic inequality that exist in South Africa as hangovers from this country's colonial and apartheid-era past. Keywords: Zuma, rape, Kipling, colonialism, ...

  19. Military labour mobilisation in colonial Lesotho during World War II ...

    African Journals Online (AJOL)

    In 1940, Great Britain's wartime exploitation of the human and material resources of its colonial empire was extended to colonial Lesotho (then known as Basutoland). The aim of this article, therefore, is to trace the four-year military labour mobilisation process in that colony, with special attention to the timing, number and ...

  20. Deconstructive Pedagogy and Ideological Demystification in Post-Colonial Pakistan

    Science.gov (United States)

    Mansoor, Asma; Malik, Samina

    2016-01-01

    With post-colonial Pakistan inheriting the British colonial ideological and governmental apparatus, the English literature curriculum implemented at the university level in Pakistan carried the interpellatory baggage of its colonial past. Our interdisciplinary exploration focuses on using deconstructive pedagogy to demystify and subvert the…

  1. The Genesis of Public Relations in British Colonial Practice.

    Science.gov (United States)

    Smyth, Rosaleen

    2001-01-01

    Demonstrates how the British Colonial Office employed public relations strategies as they administered the British colony of Northern Rhodesia before, during, and after World War II. Demonstrates how civil servants in London and colonial officials implemented public relations policies, strategies, and tactics on an ad hoc basis, covering political…

  2. Metabolism and resources of spherical colonies of Nostoc zetterstedtii

    DEFF Research Database (Denmark)

    Jensen, Kaj Sand; Raun, Ane-Marie Løvendahl; Borum, Jens

    2009-01-01

    Constraints imposed by the spherical form and gelatinous matrix of centimeter-thick colonies of the cyanobacterium Nostoc zetterstedtii on its functional properties were tested by examining the scaling of its composition, light absorption, photosynthesis, and respiration to individual size....... Nostoc absorbed 96% of incident light from the surface to the center because of high areal pigment density, but absorbed photons were used with low quantum efficiency (11- 38 mmol O2 mol21 photon) and photosynthesis was low relative to dark respiration (2.0-5.4). Therefore, N. zetterstedtii is threatened...... by reduced light availability and only extended to lake depths receiving about 12% of surface irradiance, whereas mosses, characeans, and angiosperms with thin photosynthetic tissues grew deeper (3.1-7.5% of surface irradiance). Nostoc ameliorated the restrictions of low lake DIC and long diffusion paths...

  3. Artificial bee colony algorithm with dynamic multi-population

    Science.gov (United States)

    Zhang, Ming; Ji, Zhicheng; Wang, Yan

    2017-07-01

    To improve the convergence rate and make a balance between the global search and local turning abilities, this paper proposes a decentralized form of artificial bee colony (ABC) algorithm with dynamic multi-populations by means of fuzzy C-means (FCM) clustering. Each subpopulation periodically enlarges with the same size during the search process, and the overlapping individuals among different subareas work for delivering information acting as exploring the search space with diffusion of solutions. Moreover, a Gaussian-based search equation with redefined local attractor is proposed to further accelerate the diffusion of the best solution and guide the search towards potential areas. Experimental results on a set of benchmarks demonstrate the competitive performance of our proposed approach.

  4. African Economic Development and Colonial Legacies

    Directory of Open Access Journals (Sweden)

    Gareth Austin

    2010-03-01

    Full Text Available This article reviews how colonial rule and African actions during the colonial period affected the resources and institutional settings for subsequent economic development south of the Sahara. The issue is seen from the perspective of the dynamics of development in what was in 1900 an overwhelmingly land-abundant region characterised by shortages of labour and capital, by perhaps surprisingly extensive indigenous market activities and by varying but often low levels of political centralisation. The differential impact of French and British rule is explored, but it is argued that a bigger determinant of the differential evolution of poverty, welfare and structural change was the contrast between “settler” and “peasant” economies.

  5. Teaching South Asia beyond Colonial Boundaries

    Directory of Open Access Journals (Sweden)

    Brian Caton

    2014-06-01

    Full Text Available Because of the methodological innovations of Subaltern Studies in the 1980s and 1990s, most historians’ familiarity with South Asian history is limited to the colonial or modern period. While the subalternist view is undoubtedly useful, it does not provide much help in thinking about what came before or after the colonial period. This limited context may prove to be a problem for a non-specialist constructing a full course in South Asian history or adding South Asia content to a course that seeks to break down area studies or nation-state boundaries. This article provides a starting point for such an enterprise. It reviews the South Asian history textbooks available in the market and identifies some of the scholarship that would suit courses or units organized by theme or by a larger Asian geography. It also reviews some of the collections of primary sources that could be used in such coursework.

  6. Ant colony optimization and constraint programming

    CERN Document Server

    Solnon, Christine

    2013-01-01

    Ant colony optimization is a metaheuristic which has been successfully applied to a wide range of combinatorial optimization problems. The author describes this metaheuristic and studies its efficiency for solving some hard combinatorial problems, with a specific focus on constraint programming. The text is organized into three parts. The first part introduces constraint programming, which provides high level features to declaratively model problems by means of constraints. It describes the main existing approaches for solving constraint satisfaction problems, including complete tree search

  7. Influence of feeding bee colonies on colony strenght and honey authenticity

    Directory of Open Access Journals (Sweden)

    Andreja KANDOLF BOROVŠAK

    2015-12-01

    Full Text Available For the natural development of bee colonies, there is the need for appropriate nutrition. Lack of natural honey flow must be supplemented by feeding bee colonies with sugar syrups or candy paste. This supplementary feeding encourages brood breeding and forage activity, whereby stronger colonies collect more honey. Sugar syrups can cause honey adulteration, which is more frequent with the reversing of the brood combs with the bee food, with the combs moved from the brood chamber to the upper chamber. Authentication of honey from the standpoint of the presence of sugar syrup is very complex, because there is no single method by which honey adulteration can be reliably confirmed. Feeding the colonies in spring should result in stronger colonies and hence the collection of more honey in the brood chambers. The objective of the present study was to determine whether this has effects also on honey authenticity, and to discover a simple method for detection of honey adulteration. The colonies were fed with candy paste that had added yeast and blue dye, to provide markers for detection of honey adulteration. The strength of the colonies and quantity of honey in the brood chambers were monitored. The results of the analysis of stable isotope and activity of foreign enzymes were compared with the results of yeast quantity and colour of the honey (absorbance, L*, a*, b* parameters. Detection of yeast in the honey samples and presence of colour as a consequence of added dye appear to be appropriate methods to follow honey adulteration, and further studies are ongoing.

  8. Review Essay: Governmentality in Late Colonial Korea?

    Directory of Open Access Journals (Sweden)

    Henry Em

    2012-12-01

    Full Text Available Takashi Fujitani, Race for Empire: Koreans as Japanese and Japanese as Americans during World War II. Berkeley: University of California Press, 2011. 520 pp. $65 (cloth.Jun Uchida, Brokers of Empire: Japanese Settler Colonialism in Korea, 1876-1945. Cambridge, MA: Harvard University Press, 2011. 500 pp. $50 (cloth.In South Korea, more so than in most other postcolonial countries, the issue of sovereignty and the colonial past remains a central feature of politics. Most recently, during a televised presidential debate on December 4, 2012, Lee Jung-hee of the Unified Progressive Party said something that likely had never been said on South Korean television: “Takaki Masao signed an oath of loyalty [to the Emperor of Japan], in his own blood, to become an officer in the Japanese [Imperial] Army. You know who he is. His Korean name is Park Chung Hee.” Lee Jung-hee then made the connection between that colonial past and the willingness to sell out the nation’s sovereignty in the present. The conservative candidate Park Geun-hye, the daughter of the late President Park Chung Hee who ruled South Korea from 1961 through 1979, and members of Park’s Saenuri Party, remain true to their “roots”: these “descendants of pro-Japanese collaborators and dictators” (again sold out South Korea’s sovereignty (on November 22, 2011 when they rammed the US-ROK Free Trade Agreement through the National Assembly.

  9. Colony stimulating factors and their clinical implication

    International Nuclear Information System (INIS)

    Asano, Shigetaka

    1989-01-01

    Granulocytes and macrophage are dependent for their production and/or functional activation in vitro on the presence of a family of glycoproteins. They are generally called colony-stimulating factors (CSFs) because of their capacity to stimulate colony formation in semi-solid cultures, and are currently classified into four distinct subtypes, that is, Multi-CSF, GM-CSF, G-CSF and M-CSF, according to the cell type of colonies formed under their stimulation or their target cell specificity. All of the murine and human CSF subtypes and the genes for them have become available in a purified form and in a large scale, and now allow us to investigate their interactions, the mechanisms for their actions, the cell-cell interactions leading to their production and secretion, and their actions in vivo. Furthermore, the preclinical and/or clinical studies which were carried out using the purified CSFs strongly indicate that human CSFs will be effective strategies for preventing and treating opportunistic bacterial and fungal infection as a major cause of death in granulocytopenic patients. (author)

  10. Contrasted demographic responses facing future climate change in Southern Ocean seabirds.

    Science.gov (United States)

    Barbraud, Christophe; Rivalan, Philippe; Inchausti, Pablo; Nevoux, Marie; Rolland, Virginie; Weimerskirch, Henri

    2011-01-01

    1. Recent climate change has affected a wide range of species, but predicting population responses to projected climate change using population dynamics theory and models remains challenging, and very few attempts have been made. The Southern Ocean sea surface temperature and sea ice extent are projected to warm and shrink as concentrations of atmospheric greenhouse gases increase, and several top predator species are affected by fluctuations in these oceanographic variables. 2. We compared and projected the population responses of three seabird species living in sub-tropical, sub-Antarctic and Antarctic biomes to predicted climate change over the next 50 years. Using stochastic population models we combined long-term demographic datasets and projections of sea surface temperature and sea ice extent for three different IPCC emission scenarios (from most to least severe: A1B, A2, B1) from general circulation models of Earth's climate. 3. We found that climate mostly affected the probability to breed successfully, and in one case adult survival. Interestingly, frequent nonlinear relationships in demographic responses to climate were detected. Models forced by future predicted climatic change provided contrasted population responses depending on the species considered. The northernmost distributed species was predicted to be little affected by a future warming of the Southern Ocean, whereas steep declines were projected for the more southerly distributed species due to sea surface temperature warming and decrease in sea ice extent. For the most southerly distributed species, the A1B and B1 emission scenarios were respectively the most and less damaging. For the two other species, population responses were similar for all emission scenarios. 4. This is among the first attempts to study the demographic responses for several populations with contrasted environmental conditions, which illustrates that investigating the effects of climate change on core population dynamics

  11. Climate change and functional traits affect population dynamics of a long-lived seabird.

    Science.gov (United States)

    Jenouvrier, Stéphanie; Desprez, Marine; Fay, Remi; Barbraud, Christophe; Weimerskirch, Henri; Delord, Karine; Caswell, Hal

    2018-07-01

    Recent studies unravelled the effect of climate changes on populations through their impact on functional traits and demographic rates in terrestrial and freshwater ecosystems, but such understanding in marine ecosystems remains incomplete. Here, we evaluate the impact of the combined effects of climate and functional traits on population dynamics of a long-lived migratory seabird breeding in the southern ocean: the black-browed albatross (Thalassarche melanophris, BBA). We address the following prospective question: "Of all the changes in the climate and functional traits, which would produce the biggest impact on the BBA population growth rate?" We develop a structured matrix population model that includes the effect of climate and functional traits on the complete BBA life cycle. A detailed sensitivity analysis is conducted to understand the main pathway by which climate and functional trait changes affect the population growth rate. The population growth rate of BBA is driven by the combined effects of climate over various seasons and multiple functional traits with carry-over effects across seasons on demographic processes. Changes in sea surface temperature (SST) during late winter cause the biggest changes in the population growth rate, through their effect on juvenile survival. Adults appeared to respond to changes in winter climate conditions by adapting their migratory schedule rather than by modifying their at-sea foraging activity. However, the sensitivity of the population growth rate to SST affecting BBA migratory schedule is small. BBA foraging activity during the pre-breeding period has the biggest impact on population growth rate among functional traits. Finally, changes in SST during the breeding season have little effect on the population growth rate. These results highlight the importance of early life histories and carry-over effects of climate and functional traits on demographic rates across multiple seasons in population response to climate

  12. Carry-over effects on the annual cycle of a migratory seabird: an experimental study.

    Science.gov (United States)

    Fayet, Annette L; Freeman, Robin; Shoji, Akiko; Kirk, Holly L; Padget, Oliver; Perrins, Chris M; Guilford, Tim

    2016-11-01

    Long-lived migratory animals must balance the cost of current reproduction with their own condition ahead of a challenging migration and future reproduction. In these species, carry-over effects, which occur when events in one season affect the outcome of the subsequent season, may be particularly exacerbated. However, how carry-over effects influence future breeding outcomes and whether (and how) they also affect behaviour during migration and wintering is unclear. Here we investigate carry-over effects induced by a controlled, bidirectional manipulation of the duration of reproductive effort on the migratory, wintering and subsequent breeding behaviour of a long-lived migratory seabird, the Manx shearwater Puffinus puffinus. By cross-fostering chicks of different age between nests, we successfully prolonged or shortened by ∼25% the chick-rearing period of 42 breeding pairs. We tracked the adults with geolocators over the subsequent year and combined migration route data with at-sea activity budgets obtained from high-resolution saltwater-immersion data. Migratory behaviour was also recorded during non-experimental years (the year before and/or two years after manipulation) for a subset of birds, allowing comparison between experimental and non-experimental years within treatment groups. All birds cared for chicks until normal fledging age, resulting in birds with a longer breeding period delaying their departure on migration; however, birds that finished breeding earlier did not start migrating earlier. Increased reproductive effort resulted in less time spent at the wintering grounds, a reduction in time spent resting daily and a delayed start of breeding with lighter eggs and chicks and lower breeding success the following breeding season. Conversely, reduced reproductive effort resulted in more time resting and less time foraging during the winter, but a similar breeding phenology and success compared with control birds the following year, suggesting that

  13. Disentangling effects of growth and nutritional status on seabird stable isotope ratios

    Science.gov (United States)

    Sears, J.; Hatch, Shyla A.; O'Brien, D. M.

    2009-01-01

    A growing number of studies suggest that an individual's physiology affects its carbon and nitrogen stable isotope signatures, obscuring a signal often assumed to be only a reflection of diet and foraging location. We examined effects of growth and moderate food restriction on red blood cell (RBC) and feather ??15N and ??13C in rhinoceros auklet chicks (Cerorhinca monocerata), a piscivorous seabird. Chicks were reared in captivity and fed either control (75 g/day; n = 7) or ~40% restricted (40 g/day; n = 6) amounts of high quality forage fish. We quantified effects of growth on isotopic fractionation by comparing ??15N and ??13C in control chicks to those of captive, non-growing subadult auklets (n = 11) fed the same diet. To estimate natural levels of isotopic variation, we also collected blood from a random sample of free-living rhinoceros auklet adults and chicks in the Gulf of Alaska (n = 15 for each), as well as adult feather samples (n = 13). In the captive experiment, moderate food restriction caused significant depletion in ??15N of both RBCs and feathers in treatment chicks compared to control chicks. Growth also induced depletion in RBC ??15N, with chicks exhibiting lower ??15N when they were growing the fastest. As growth slowed, ??15N increased, resulting in an overall pattern of enrichment over the course of the nestling period. Combined effects of growth and restriction depleted ??15N in chick RBCs by 0.92???. We propose that increased nitrogen-use efficiency is responsible for 15N depletion in both growing and food-restricted chicks. ??15N values in RBCs of free-ranging auklets fell within a range of only 1.03???, while feather ??15N varied widely. Together, our captive and field results suggest that both growth and moderate food restriction can affect stable isotope ratios in an ecologically meaningful way in RBCs although not feathers due to greater natural variability in this tissue. ?? 2008 Springer-Verlag.

  14. Worms at war: interspecific parasite competition and host resources alter trematode colony structure and fitness.

    Science.gov (United States)

    Mouritsen, Kim N; Andersen, Cecillie

    2017-09-01

    Parasites competing over limited host resources are faced with a tradeoff between reproductive success and host overexploitation jeopardizing survival. Surprisingly little is known about the outcome of such competitive scenarios, and we therefore aimed at elucidating interactions between the trematodes Himasthla elongata and Renicola roscovita coinfecting the periwinkle first intermediate host. The results show that the success of Himasthla colonies (rediae) in terms of cercarial emission is unaffected by Renicola competition (sporocysts), whereas deteriating host condition decreases fitness. Furthermore, double infection has no bearing on Himasthla's colony size but elevated the proportion of non-reproductive rediae that play a decisive role in colony defence. Opposite, the development of the Renicola colony (size/maturity), and in turn fitness, is markedly reduced in presence of Himasthla, whereas the nutritional state of the host appears less important. Hence, the intramolluscan competition between Himasthla and Renicola is asymmetrical, Himasthla being the superior competitor. Himasthla not only adjusts its virulence according to the hosts immediate nutritional state, it also nullifies the negative impact of a heterospecific competitor on own fitness. The latter is argued to follow in part from direct predation on the competitor, for which purpose more defensive non-reproductive rediae are strategically produced.

  15. Detection and quantification of intracellular bacterial colonies by automated, high-throughput microscopy.

    Science.gov (United States)

    Ernstsen, Christina L; Login, Frédéric H; Jensen, Helene H; Nørregaard, Rikke; Møller-Jensen, Jakob; Nejsum, Lene N

    2017-08-01

    To target bacterial pathogens that invade and proliferate inside host cells, it is necessary to design intervention strategies directed against bacterial attachment, cellular invasion and intracellular proliferation. We present an automated microscopy-based, fast, high-throughput method for analyzing size and number of intracellular bacterial colonies in infected tissue culture cells. Cells are seeded in 48-well plates and infected with a GFP-expressing bacterial pathogen. Following gentamicin treatment to remove extracellular pathogens, cells are fixed and cell nuclei stained. This is followed by automated microscopy and subsequent semi-automated spot detection to determine the number of intracellular bacterial colonies, their size distribution, and the average number per host cell. Multiple 48-well plates can be processed sequentially and the procedure can be completed in one working day. As a model we quantified intracellular bacterial colonies formed by uropathogenic Escherichia coli (UPEC) during infection of human kidney cells (HKC-8). Urinary tract infections caused by UPEC are among the most common bacterial infectious diseases in humans. UPEC can colonize tissues of the urinary tract and is responsible for acute, chronic, and recurrent infections. In the bladder, UPEC can form intracellular quiescent reservoirs, thought to be responsible for recurrent infections. In the kidney, UPEC can colonize renal epithelial cells and pass to the blood stream, either via epithelial cell disruption or transcellular passage, to cause sepsis. Intracellular colonies are known to be clonal, originating from single invading UPEC. In our experimental setup, we found UPEC CFT073 intracellular bacterial colonies to be heterogeneous in size and present in nearly one third of the HKC-8 cells. This high-throughput experimental format substantially reduces experimental time and enables fast screening of the intracellular bacterial load and cellular distribution of multiple

  16. Foraging plasticity in seabirds: A non-invasive study of the diet of greater crested terns breeding in the Benguela region

    Science.gov (United States)

    2018-01-01

    Marine predators, such as seabirds, are useful indicators of marine ecosystem functioning. In particular, seabird diet may reflect variability in food-web composition due to natural or human-induced environmental change. Diet monitoring programmes, which sample diet non-invasively, are valuable aids to conservation and management decision-making. We investigated the diet of an increasing population of greater crested terns Thalasseus bergii in the Western Cape, South Africa, during three successive breeding seasons (2013 to 2015), when populations of other seabirds feeding on small pelagic schooling fish in the region were decreasing. Breeding greater crested terns carry prey in their bills, so we used an intensive photo-sampling method to record their diet with little disturbance. We identified 24,607 prey items from at least 47 different families, with 34 new prey species recorded. Fish dominated the diet, constituting 94% of prey by number, followed by cephalopods (3%), crustaceans (2%) and insects (1%). The terns mainly targeted surface-schooling Clupeiformes, with anchovy Engraulis encrasicolus the most abundant prey in all three breeding seasons (65% overall). Prey composition differed significantly between breeding stages and years, with anchovy most abundant at the start of the breeding season, becoming less frequent as the season progressed. The proportion of anchovy in the diet also was influenced by environmental factors; anchovy occurred more frequently with increasing wind speeds and was scarce on foggy days, presumably because terns rely in part on social facilitation to locate anchovy schools. The application of this intensive and non-invasive photo-sampling method revealed an important degree of foraging plasticity for this seabird within a context of locally reduced food availability, suggesting that, unlike species that specialise on a few high-quality prey, opportunistic seabirds may be better able to cope with reductions in the abundance of

  17. Area-based cell colony surviving fraction evaluation: A novel fully automatic approach using general-purpose acquisition hardware.

    Science.gov (United States)

    Militello, Carmelo; Rundo, Leonardo; Conti, Vincenzo; Minafra, Luigi; Cammarata, Francesco Paolo; Mauri, Giancarlo; Gilardi, Maria Carla; Porcino, Nunziatina

    2017-10-01

    The current methodology for the Surviving Fraction (SF) measurement in clonogenic assay, which is a technique to study the anti-proliferative effect of treatments on cell cultures, involves manual counting of cell colony forming units. This procedure is operator-dependent and error-prone. Moreover, the identification of the exact colony number is often not feasible due to the high growth rate leading to the adjacent colony merging. As a matter of fact, conventional assessment does not deal with the colony size, which is generally correlated with the delivered radiation dose or the administered cytotoxic agent. Considering that the Area Covered by Colony (ACC) is proportional to the colony number and size as well as to the growth rate, we propose a novel fully automatic approach exploiting Circle Hough Transform, to automatically detect the wells in the plate, and local adaptive thresholding, which calculates the percentage of ACC for the SF quantification. This measurement relies just on this covering percentage and does not consider the colony number, preventing inconsistencies due to intra- and inter-operator variability. To evaluate the accuracy of the proposed approach, we compared the SFs obtained by our automatic ACC-based method against the conventional counting procedure. The achieved results (r = 0.9791 and r = 0.9682 on MCF7 and MCF10A cells, respectively) showed values highly correlated with the measurements using the traditional approach based on colony number alone. The proposed computer-assisted methodology could be integrated in laboratory practice as an expert system for the SF evaluation in clonogenic assays. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Comparison and assessment of aerial and ground estimates of waterbird colonies

    Science.gov (United States)

    Green, M.C.; Luent, M.C.; Michot, T.C.; Jeske, C.W.; Leberg, P.L.

    2008-01-01

    Aerial surveys are often used to quantify sizes of waterbird colonies; however, these surveys would benefit from a better understanding of associated biases. We compared estimates of breeding pairs of waterbirds, in colonies across southern Louisiana, USA, made from the ground, fixed-wing aircraft, and a helicopter. We used a marked-subsample method for ground-counting colonies to obtain estimates of error and visibility bias. We made comparisons over 2 sampling periods: 1) surveys conducted on the same colonies using all 3 methods during 3-11 May 2005 and 2) an expanded fixed-wing and ground-survey comparison conducted over 4 periods (May and Jun, 2004-2005). Estimates from fixed-wing aircraft were approximately 65% higher than those from ground counts for overall estimated number of breeding pairs and for both dark and white-plumaged species. The coefficient of determination between estimates based on ground and fixed-wing aircraft was ???0.40 for most species, and based on the assumption that estimates from the ground were closer to the true count, fixed-wing aerial surveys appeared to overestimate numbers of nesting birds of some species; this bias often increased with the size of the colony. Unlike estimates from fixed-wing aircraft, numbers of nesting pairs made from ground and helicopter surveys were very similar for all species we observed. Ground counts by one observer resulted in underestimated number of breeding pairs by 20% on average. The marked-subsample method provided an estimate of the number of missed nests as well as an estimate of precision. These estimates represent a major advantage of marked-subsample ground counts over aerial methods; however, ground counts are difficult in large or remote colonies. Helicopter surveys and ground counts provide less biased, more precise estimates of breeding pairs than do surveys made from fixed-wing aircraft. We recommend managers employ ground counts using double observers for surveying waterbird colonies

  19. Morphological Diversity of the Colony Produced by Bacteria Proteus mirabilis

    Science.gov (United States)

    Nakahara, Akio; Shimada, Yuji; Wakita, Jun-ichi; Matsushita, Mitsugu; Matsuyama, Tohey

    1996-08-01

    Morphological changes of colonies have been investigatedfor a bacterial strain of Proteus mirabilis, which is a famous speciesfor producing concentric-ring-like colonies. It was found that colony patterns can be classified into three types,i.e., cyclic spreading, diffusion-limited growth (DLA-like)and three-dimensional growth (inside the agar medium) patterns. Cyclic spreading patterns can further be classifiedinto three subgroups, i.e., concentric-ring, homogeneous and spatiotemporal patterns. These subgroups were classified by examining the development of colony structure after colonies spread all over petri-dishes. Comparison of the results with thoseof another bacterial species Bacillus subtilis is also discussed.

  20. Assessing the living and dead proportions of cold-water coral colonies: implications for deep-water Marine Protected Area monitoring in a changing ocean

    Directory of Open Access Journals (Sweden)

    Johanne Vad

    2017-10-01

    Full Text Available Coral growth patterns result from an interplay of coral biology and environmental conditions. In this study colony size and proportion of live and dead skeletons in the cold-water coral (CWC Lophelia pertusa (Linnaeus, 1758 were measured using video footage from Remotely Operated Vehicle (ROV transects conducted at the inshore Mingulay Reef Complex (MRC and at the offshore PISCES site (Rockall Bank in the NE Atlantic. The main goal of this paper was to explore the development of a simple method to quantify coral growth and its potential application as an assessment tool of the health of these remote habitats. Eighteen colonies were selected and whole colony and dead/living layer size were measured. Live to dead layer ratios for each colony were then determined and analysed. The age of each colony was estimated using previously published data. Our paper shows that: (1 two distinct morphotypes can be described: at the MRC, colonies displayed a ‘cauliflower-shaped’ morphotype whereas at the PISCES site, colonies presented a more flattened ‘bush-shaped’ morphotype; (2 living layer size was positively correlated with whole colony size; (3 live to dead layer ratio was negatively correlated to whole colony size; (4 live to dead layer ratio never exceeded 0.27. These results suggest that as a colony develops and its growth rate slows down, the proportion of living polyps in the colony decreases. Furthermore, at least 73% of L. pertusa colonies are composed of exposed dead coral skeleton, vulnerable to ocean acidification and the associated shallowing of the aragonite saturation horizon, with significant implications for future deep-sea reef framework integrity. The clear visual contrast between white/pale living and grey/dark dead portions of the colonies also gives a new way by which they can be visually monitored over time. The increased use of marine autonomous survey vehicles offers an important new platform from which such a surveying

  1. Life in the colonies: learning the alien ways of colonial organisms.

    Science.gov (United States)

    Winston, Judith E

    2010-12-01

    Who needs to go to outer space to study alien beings when the oceans of our own planet abound with bizarre and unknown creatures? Many of them belong to sessile clonal and colonial groups, including sponges, hydroids, corals, octocorals, ascidians, bryozoans, and some polychaetes. Their life histories, in many ways unlike our own, are a challenge for biologists. Studying their ecology, behavior, and taxonomy means trying to “think like a colony” to understand the factors important in their lives. Until the 1980s, most marine ecologists ignored these difficult modular organisms. Plant ecologists showed them ways to deal with the two levels of asexually produced modules and genetic individuals, leading to a surge in research on the ecology of clonal and colonial marine invertebrates. Bryozoans make excellent model colonial animals. Their life histories range from ephemeral to perennial. Aspects of their lives such as growth, reproduction, partial mortality due to predation or fouling, and the behavior of both autozooids and polymorphs can be studied at the level of the colony, as well as that of the individual module, in living colonies and over time.

  2. Ecology of selected marine communities in Glacier Bay: Zooplankton, forage fish, seabirds and marine mammals

    Science.gov (United States)

    Robards, Martin D.; Drew, Gary S.; Piatt, John F.; Anson, Jennifer Marie; Abookire, Alisa A.; Bodkin, James L.; Hooge, Philip N.; Speckman, Suzann G.

    2003-01-01

    -Bay.We identified 55 species of fish during this study (1999 and 2000) from beach seines, mid-water trawls, and rod and line catches. The diversity of physical, oceanographic, and glacial chronological conditions within Glacier Bay contribute a suite of factors that influence the distribution and abundance of fish. Accordingly, we observed significant differences in the abundance and distribution of fish within the Bay. Most significantly, abundance and diversity (primarily juvenile fish including walleye Pollock, eelblennies, and capelin) were greatest at the head of both the east and west arms where zooplankton abundance was greatest – in close proximity to tidewater glaciers and freshwater runoff. All of Glacier Bay and Icy Strait were surveyed hydroacoustically for plankton and fish during June 1999 surveys. Acoustically determined forage biomass was concentrated in relatively few important areas such as Pt. Adolphus, Berg Bay, on the Geikie-Scidmore shelf, around the Beardslee/Marble islands, and the upper arms of Glacier Bay. Forage biomass (primarily small schooling fish and euphausiids) was concentrated in shallow, nearshore waters; 50 % of acoustic biomass was found at depths 0.01 fish/m3) for seabirds foraging on zooplankton and small schooling fish. Less than 1 % of the area contained patches suitable (e.g., >0.1 fish/m3) for whales foraging on zooplankton and small schooling fish. High-density aggregations of 0.1-10 fish/m3 were comprised mostly of schools containing capelin, pollock, herring or euphausiids (0.1-1 kg/m3).During predator surveys (1999-2000), we observed 63 species of birds and 7 species of marine mammals. Seasonal distribution and abundance of these “apex” predators was highly variable by species. Glacier Bay supports high numbers of seabirds and marine mammals that consume zooplankton and small schooling fish. Nearshore areas had higher densities of both birds and marine mammals. Several areas, such as Pt. Adolphus, Berg Bay, on the Geikie

  3. Engaging With Colonial Archives: Reflections Of An End-User

    Directory of Open Access Journals (Sweden)

    Ayodeji Olukoju

    2016-06-01

    Full Text Available Official and/or public archives were a byproduct of colonial rule in Africa. (Archives are a byproduct of administrative governance everywhere. Given the density and diversity of colonial archival records, historians have tended to rely on them for the study of the colonial period. Publications on the use of archives have not captured the perspective of end-users, who often face peculiar challenges in the use of colonial and metropolitan archives. This paper provides an end-user perspective on colonial archives in Nigeria and the United Kingdom. It highlights the challenges of data collection and prospects of optimal use of archival source material. The discussion is of general application to users of colonial archives especially in the former British colonies in Africa.

  4. Varroa-Virus Interaction in Collapsing Honey Bee Colonies

    DEFF Research Database (Denmark)

    Francis, Roy Mathew; Nielsen, Steen L.; Kryger, Per

    2013-01-01

    Varroa mites and viruses are the currently the high-profile suspects in collapsing bee colonies. Therefore, seasonal variation in varroa load and viruses (Acute-Kashmir-Israeli complex (AKI) and Deformed Wing Virus (DWV)) were monitored in a year-long study. We investigated the viral titres...... in honey bees and varroa mites from 23 colonies (15 apiaries) under three treatment conditions: Organic acids (11 colonies), pyrethroid (9 colonies) and untreated (3 colonies). Approximately 200 bees were sampled every month from April 2011 to October 2011, and April 2012. The 200 bees were split to 10...... subsamples of 20 bees and analysed separately, which allows us to determine the prevalence of virus-infected bees. The treatment efficacy was often low for both treatments. In colonies where varroa treatment reduced the mite load, colonies overwintered successfully, allowing the mites and viruses...

  5. Analysis of multidrug resistant group B streptococci with reduced penicillin susceptibility forming small, less hemolytic colonies.

    Directory of Open Access Journals (Sweden)

    Hirotsugu Banno

    Full Text Available Group B streptococci (GBS; Streptococcus agalactiae are the leading cause of neonatal invasive diseases and are also important pathogens for elderly adults. Until now, nearly all GBS with reduced penicillin susceptibility (PRGBS have shown β-hemolytic activity and grow on sheep blood agar. However, we have previously reported three PRGBS clinical isolates harboring a CylK deletion that form small less hemolytic colonies. In this study, we examined the causes of small, less hemolytic colony formation in these clinical isolates. Isogenic strains were sequenced to identify the mutation related to a small colony size. We identified a 276_277insG nucleic acid insertion in the thiamin pyrophosphokinase (tpk gene, resulting in premature termination at amino acid 103 in TPK, as a candidate mutation responsible for small colony formation. The recombinant strain Δtpk, which harbored the 276_277insG insertion in the tpk gene, showed small colony formation. The recombinant strain ΔcylK, which harbored the G379T substitution in cylK, showed a reduction in hemolytic activity. The phenotypes of both recombinant strains were complemented by the expression of intact TPK or CylK, respectively. Moreover, the use of Rapid ID 32 API and VITEK MS to identify strains as GBS was evaluated clinical isolates and recombinant strains. VITEK MS, but not Rapid ID 32 API, was able to accurately identify the strains as GBS. In conclusion, we determined that mutations in tpk and cylK caused small colonies and reduced hemolytic activity, respectively, and characterized the clinical isolates in detail.

  6. Intraspecific Variation among Social Insect Colonies: Persistent Regional and Colony-Level Differences in Fire Ant Foraging Behavior.

    Directory of Open Access Journals (Sweden)

    Alison A Bockoven

    Full Text Available Individuals vary within a species in many ecologically important ways, but the causes and consequences of such variation are often poorly understood. Foraging behavior is among the most profitable and risky activities in which organisms engage and is expected to be under strong selection. Among social insects there is evidence that within-colony variation in traits such as foraging behavior can increase colony fitness, but variation between colonies and the potential consequences of such variation are poorly documented. In this study, we tested natural populations of the red imported fire ant, Solenopsis invicta, for the existence of colony and regional variation in foraging behavior and tested the persistence of this variation over time and across foraging habitats. We also reared single-lineage colonies in standardized environments to explore the contribution of colony lineage. Fire ants from natural populations exhibited significant and persistent colony and regional-level variation in foraging behaviors such as extra-nest activity, exploration, and discovery of and recruitment to resources. Moreover, colony-level variation in extra-nest activity was significantly correlated with colony growth, suggesting that this variation has fitness consequences. Lineage of the colony had a significant effect on extra-nest activity and exploratory activity and explained approximately half of the variation observed in foraging behaviors, suggesting a heritable component to colony-level variation in behavior.

  7. Globalization in the post - colonial world

    Directory of Open Access Journals (Sweden)

    Korobeynikova Larisa A.

    2016-01-01

    Full Text Available The paper presents a new interpretation of globalization within the boundaries of the author’s concept of soft globalization, which exploits a normatively attractive alternative to the concept of the Empire. It is argued here that the conditions of development of contemporary post - colonial world communities do not require any unification in the form of the Empire, but instead the creation of a non repressive mechanism of social regulation - the implementation of a form of soft globalization, a globalization with a mental form are expedient here. Historically, globalization occurred in a strict material(i.e. economical and military form that prompted the conditions for the evolution of civilization as the Empire: a case in which the development of the world occurs under the power of a single dominating state. Imperialistic politics leads to colonial politics formation. The history of the phenomena of civilization shows many instances of Empire globalization. Globalization in the Empire form was already observed at the time of the Roman Empire. At this time processes of development inside the Empire were manifestations of globalization in its highest cultural shape. But ancient Rome was also a social and political experiment that acquired the attributes of a purely material globalization in the end, and historically brought about the irreversible crash of the Roman Empire itself. Contemporary fluctuations referring to the process of globalization can be registered in the US’s attempts of material domination inside this or that existing case of civilization, which causes colonialism appearance. The main idea stressed in the paper is that only a mental globalization could succeed in the end.

  8. Detecting change in seabird distributions at sea in arctic and sub-arctic waters over six decades

    DEFF Research Database (Denmark)

    Gjerdrum, Carina; Wong, Sarah; Johansen, Kasper Lambert

    predictive models to investigate how ice cover and ocean processes influence the distribution thick-billed murre (Uria lomvia), northern fulmar (Fulmarus glacialis), dovekie (Alle alle), and black-legged kittiwake (Rissa tridactyla) in summer and autumn between Canada and Greenland. We used the PIROP data......In the western North Atlantic and eastern Arctic, data on the distribution and abundance of seabirds at sea have been collected by the Canadian Wildlife Service from two main survey programs using ships of opportunity. The first, PIROP (Programme intégré de recherches sur les oiseaux pélagiques...... to examine how the distribution of these four species has changed over the last six decades. We discuss the results in relation to ocean climate variability, but also the challenges that exist when comparisons span such long time periods, including monitoring programs with changing priorities, differences...

  9. The highest global concentrations and increased abundance of oceanic plastic debris in the North Pacific: Evidence from seabirds

    Science.gov (United States)

    Robards, Martin D.; Gould, Patrick J.; Coe, James M.; Rogers, Donald B.

    1997-01-01

    Plastic pollution has risen dramatically with an increase in production of plastic resin during the past few decades. Plastic production in the United States increased from 2.9 million tons in I960 to 47.9 million tons in 1985 (Society of the Plastics Industry 1986). This has been paralleled by a significant increase in the concentration of plastic particles in oceanic surface waters of the North Pacific from the 1970s to the late 1980s (Day and Shaw 1987; Day et al. 1990a). Research during the past few decades has indicated two major interactions between marine life and oceanic plastic: entanglement and ingestion (Laist 1987). Studies in the last decade have documented the prevalence of plastic in the diets of many seabird species in the North Pacific and the need for further monitoring of those species and groups that ingest the most plastic (Day et al. 1985).

  10. Plastic pollution in the Labrador Sea: An assessment using the seabird northern fulmar Fulmarus glacialis as a biological monitoring species.

    Science.gov (United States)

    Avery-Gomm, Stephanie; Provencher, Jennifer F; Liboiron, Max; Poon, Florence E; Smith, Paul A

    2018-02-01

    Plastic is now one among one of the most pervasive pollutants on the planet, and ocean circulation models predict that the Arctic will become another accumulation zone. As solutions to address marine plastic emerge, is essential that baselines are available to monitor progress towards targets. The northern fulmar (Fulmarus glacialis), a widely-distributed seabird species, has been used as a biological monitor for plastic pollution in the North Sea, and could be a useful monitoring species elsewhere. We quantified plastic ingested by northern fulmars from the southeastern Canadian waters of the Labrador Sea with the objective of establishing a standardized baseline for future comparisons. Over two years we sampled 70 fulmars and found that 79% had ingested plastic, with an average of 11.6 pieces or 0.151g per bird. Overall, 34% of all fulmars exceeded the Ecological Quality Objective for marine litter, having ingested >0.1g of plastic. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Combined Final Report for Colony II Project

    Energy Technology Data Exchange (ETDEWEB)

    Kale, Laxmikant [University of Illinois; Jones, Terry [Oak Ridge National Laboratory; Moreira, Jose [IBM Corp.

    2013-10-23

    (This report was originally submmited by the lead PI (Terry Jones, ORNL) on October 22, 2013 to the program manager, Lucy Nowell. It is being submitted from University of Illinois in accordance with instructions). HPC Colony II seeks to provide portable performance for leadership class machines. Our strategy is based on adaptive system software that aims to make the intelligent decisions necessary to allow domain scientists to safely focus on their task at hand and allow the system software stack to adapt their application to the underlying architecture. This report describes the research undertaken towards these objectives and the results obtained over the performance period of the project.

  12. Mamary neoplasia in a closed beagle colony

    International Nuclear Information System (INIS)

    Taylor, G.N.; Shabestari, L.; Williams, J.; Mays, C.W.; Angus, W.; McFarland, S.

    1975-01-01

    The incidence rate of mammary neoplasia in a large colony of beagles and its relationship to internal skeletal and/or liver radiation, age, relatively late ovariectomy (4 years and older), endometritis, parity status, and adrenal weight was examined. Of these various factors, age was the only condition that was clearly correlated with changes in the mammary tumor incidence. The rate became significant at approximately eight years of age and increased progressively throughout the successively older age classes. Within the female dogs, the incidence of mammary cancer was higher that that of any other form of spontaneous malignancy

  13. Colonial Subjectification: Foucault, Christianity and Governmentality

    Directory of Open Access Journals (Sweden)

    Christina Petterson

    2012-09-01

    Full Text Available Foucault’s concept of pastoral power is envisioned as a technique of power developed from the medieval period and carried through into modern political rationalities. As such, it is an old power technique – which originated in Christian institutions – in a new political shape, which he coined governmentality. This article uses Foucault’s genealogy of pastoral power and governmentality to discuss the intersection of domination and technology of self in the Greenlandic colonial context and to bring out the central role of religion in Foucault’s conceptualisation of governmentality.

  14. Image Edge Tracking via Ant Colony Optimization

    Science.gov (United States)

    Li, Ruowei; Wu, Hongkun; Liu, Shilong; Rahman, M. A.; Liu, Sanchi; Kwok, Ngai Ming

    2018-04-01

    A good edge plot should use continuous thin lines to describe the complete contour of the captured object. However, the detection of weak edges is a challenging task because of the associated low pixel intensities. Ant Colony Optimization (ACO) has been employed by many researchers to address this problem. The algorithm is a meta-heuristic method developed by mimicking the natural behaviour of ants. It uses iterative searches to find the optimal solution that cannot be found via traditional optimization approaches. In this work, ACO is employed to track and repair broken edges obtained via conventional Sobel edge detector to produced a result with more connected edges.

  15. In the Post-Colonial Waiting Room

    DEFF Research Database (Denmark)

    Adler-Nissen, Rebecca; Gad, Ulrik Pram

    2017-01-01

    ready for sovereignty. It explores a number of European overseas countries and territories. More specifically, it focuses on French dependencies in the Pacific and Indian Oceans, and North Atlantic Greenland constitutionally connected to Denmark. The immediate aim of anti-colonial struggles was to make...... acknowledge. A number of overseas territories take alternative routes to agency; not by resisting the norm of sovereignty - but by creatively articulating it beyond its claim to represent an 'either/or' distinction. The chapter demonstrates that territories not formally decolonized may very well perform...

  16. CHRISTIANITY AND COLONIALISM IN SOME ENGLISH SHORT STORIES

    Directory of Open Access Journals (Sweden)

    Tatang Iskarna

    2017-04-01

    Full Text Available Colonial and postcolonial studies are often linked to the power domination of the West upon the East in the way that the East economically, politically, and socially oppressed. Colonialism is often associated with three elements, the explorers dealing with geographical information, missionaries approaching the local people culturally, and the colonial administrators ruling the colony. Gold, glory, and gospel are the European’s concern. However, in representing the relation between Christianity and colonialism there is critical dialectic amongst historians, anthropologists, Christian missions, or cultural critics. Some propose that Christianity is considered to be the religious arm of colonialism. Others state that Christianity is spread without any secular interest as it is a great commandment of Jesus Christ. A few believe that Christianity give critical resistance against colonialism. The relation between Christianity and colonialism cannot be simplified as being neutral, in complicity, or in opposition. So, it is worth-discussing to understand how European writers construct the relation between Christianity and colonialism in their literary work. How Christianity is constructed and how Christianity is related to colonialism will be discussed in this paper. Using postcolonial paradigm, two English short stories will be analyzed in that way. They are Rudyard Kipling’s “Lispeth” and Doris Lessing’s “No Witchcraft for Sale”.

  17. Inbred or Outbred? Genetic Diversity in Laboratory Rodent Colonies

    Science.gov (United States)

    Brekke, Thomas D.; Steele, Katherine A.; Mulley, John F.

    2017-01-01

    Nonmodel rodents are widely used as subjects for both basic and applied biological research, but the genetic diversity of the study individuals is rarely quantified. University-housed colonies tend to be small and subject to founder effects and genetic drift; so they may be highly inbred or show substantial genetic divergence from other colonies, even those derived from the same source. Disregard for the levels of genetic diversity in an animal colony may result in a failure to replicate results if a different colony is used to repeat an experiment, as different colonies may have fixed alternative variants. Here we use high throughput sequencing to demonstrate genetic divergence in three isolated colonies of Mongolian gerbil (Meriones unguiculatus) even though they were all established recently from the same source. We also show that genetic diversity in allegedly “outbred” colonies of nonmodel rodents (gerbils, hamsters, house mice, deer mice, and rats) varies considerably from nearly no segregating diversity to very high levels of polymorphism. We conclude that genetic divergence in isolated colonies may play an important role in the “replication crisis.” In a more positive light, divergent rodent colonies represent an opportunity to leverage genetically distinct individuals in genetic crossing experiments. In sum, awareness of the genetic diversity of an animal colony is paramount as it allows researchers to properly replicate experiments and also to capitalize on other genetically distinct individuals to explore the genetic basis of a trait. PMID:29242387

  18. Weathering a Dynamic Seascape: Influences of Wind and Rain on a Seabird's Year-Round Activity Budgets.

    Directory of Open Access Journals (Sweden)

    Pierre A Pistorius

    Full Text Available How animals respond to varying environmental conditions is fundamental to ecology and is a question that has gained impetus due to mounting evidence indicating negative effects of global change on biodiversity. Behavioural plasticity is one mechanism that enables individuals and species to deal with environmental changes, yet for many taxa information on behavioural parameters and their capacity to change are lacking or restricted to certain periods within the annual cycle. This is particularly true for seabirds where year-round behavioural information is intrinsically challenging to acquire due to their reliance on the marine environment where they are difficult to study. Using data from over 13,000 foraging trips throughout the annual cycle, acquired using new-generation automated VHF technology, we described sex-specific, year-round activity budgets in Cape gannets. Using these data we investigated the role of weather (wind and rain on foraging activity and time allocated to nest attendance. Foraging activity was clearly influenced by wind speed, wind direction and rainfall during and outside the breeding season. Generally, strong wind conditions throughout the year resulted in relatively short foraging trips. Birds spent longer periods foraging when rainfall was moderate. Nest attendance, which was sex-specific outside of the breeding season, was also influenced by meteorological conditions. Large amounts of rainfall (> 2.5 mm per hour and strong winds (> 13 m s-1 resulted in gannets spending shorter amounts of time at their nests. We discuss these findings in terms of life history strategies and implications for the use of seabirds as bio-indicators.

  19. Effects of individual quality, reproductive success and environmental variability on survival of a long-lived seabird.

    Science.gov (United States)

    Lescroël, Amélie; Dugger, Katie M; Ballard, Grant; Ainley, David G

    2009-07-01

    1. Heterogeneity in individual quality (i.e. individuals having different performance levels that are consistent throughout life) can drive the demography of iteroparous species, but quality in the context of environmental variability has rarely been evaluated. 2. We investigated the demographic responses of a long-lived seabird, the Adélie penguin (Pygoscelis adeliae), to contrasting environmental conditions as a function of reproductive success, breeding quality (BQ) and experience. A continuous index of BQ (BQI) was developed to reflect an individual's ability, relative to others, to produce viable offspring. 3. First, we assessed the relative importance of costs of reproduction vs. heterogeneity in quality by comparing survival and reproductive probabilities among deferred, successful and unsuccessful breeders under 'demanding' conditions using multistate capture-mark-recapture modelling. Then, we quantified the influence of BQI on adult survival among experienced breeders vs. the whole study population under both 'normal' and 'demanding' conditions. 4. Higher survival rates were exhibited by successful (74-76%) compared to unsuccessful breeders (64%); the former also more frequently reproduced successfully at year t + 1. 5. From 1997 to 2006, adult survival ranged from 64-79%, with BQI accounting for 91% of variability in the entire study population, but only 17% in experienced breeders. The weakened relationship between BQI and survival in experienced breeders supports the theory that selection during the first reproductive event accounts for a more homogeneous pool of experienced breeders. 6. No significant effect of environmental covariates on survival was evident, suggesting that what appeared to be demanding conditions were within the range that could be buffered by this species. 7. For the first time in seabirds, a quadratic relationship between adult survival and BQI showed that adult survival is shaped by both heterogeneity in quality and reproductive

  20. Summer distribution and ecological role of seabirds and marine mammals in the Norwegian and Greenland seas (June 1988)

    Science.gov (United States)

    Joiris, Claude R.

    1992-03-01

    During the ARK V /2 expedition of RV Polarstern in the Norwegian and Greenland seas in June 1988, 380 half hour counts for marine vertebrates (seabirds, pinnipeds and cetaceans) were carried out. Results are presented as total numbers encountered and then converted into density and food intake. Mean food intake was 2.2 kg fresh weight per km 2 per day for seabirds, with a higher value in Atlantic water (2.5) lower values in polar water and the pack ice (1.7 and 1.9), and an intermediate value at the ice edge. The main species were the alcids (1.5, primarily Little Auk, Alle alle and Brünnich's Guillemot, Urea Iomvia) ,the Fulmar, Fulmarus glacialis (0.5), and the Kittiwake, Rissa tridactyla (0.2). The ecological role of cetaceans was clearly lower, with a mean value of 0.2 and a maximum of 0.7 in Atlantic water (rough evaluation, due to the low number of contacts). The food intake by pinnipeds was 0.55 kg/km 2 day at the ice edge and 0.4 in the pack ice; they were mainly harp, Phoca groenlandica and hooded seals, Cystophora cristata, in one main concentration each and ringed seals, Phoca hispida, scattered on the pack. Data for July 1988 show a great similarity with these results, except for a lower density of alcids, which probably reflects that Little Auk, Brünnich's Guillemot and Common Guillemot, Uria aalge already had started to leave the region.

  1. Buoyancy under control: underwater locomotor performance in a deep diving seabird suggests respiratory strategies for reducing foraging effort.

    Directory of Open Access Journals (Sweden)

    Timothée R Cook

    Full Text Available BACKGROUND: Because they have air stored in many body compartments, diving seabirds are expected to exhibit efficient behavioural strategies for reducing costs related to buoyancy control. We study the underwater locomotor activity of a deep-diving species from the Cormorant family (Kerguelen shag and report locomotor adjustments to the change of buoyancy with depth. METHODOLOGY/PRINCIPAL FINDINGS: Using accelerometers, we show that during both the descent and ascent phases of dives, shags modelled their acceleration and stroking activity on the natural variation of buoyancy with depth. For example, during the descent phase, birds increased swim speed with depth. But in parallel, and with a decay constant similar to the one in the equation explaining the decrease of buoyancy with depth, they decreased foot-stroke frequency exponentially, a behaviour that enables birds to reduce oxygen consumption. During ascent, birds also reduced locomotor cost by ascending passively. We considered the depth at which they started gliding as a proxy to their depth of neutral buoyancy. This depth increased with maximum dive depth. As an explanation for this, we propose that shags adjust their buoyancy to depth by varying the amount of respiratory air they dive with. CONCLUSIONS/SIGNIFICANCE: Calculations based on known values of stored body oxygen volumes and on deep-diving metabolic rates in avian divers suggest that the variations of volume of respiratory oxygen associated with a respiration mediated buoyancy control only influence aerobic dive duration moderately. Therefore, we propose that an advantage in cormorants--as in other families of diving seabirds--of respiratory air volume adjustment upon diving could be related less to increasing time of submergence, through an increased volume of body oxygen stores, than to reducing the locomotor costs of buoyancy control.

  2. Political instability and discontinuity in Nigeria: The pre-colonial past and public goods provision under colonial and post-colonial political orders

    NARCIS (Netherlands)

    Papaioannou, K.I.; Dalrymple-Smith, A.E.

    2015-01-01

    This article explores the relative importance of pre-colonial institutional capacity and the effects of periods of peace and stability on long-term development outcomes in Nigeria. We use data on education, health, and public works at a provincial level from a variety of colonial and Nigerian state

  3. Effect of fluid motion on colony formation in Microcystis aeruginosa

    Directory of Open Access Journals (Sweden)

    Lin Li

    2013-01-01

    Full Text Available Microcystis aeruginosa, generally occurring in large colonies under natural conditions, mainly exists as single cells in laboratory cultures. The mechanisms involved in colony formation in Microcystis aeruginosa and their roles in algal blooms remain unknown. In this study, based on previous research findings that fluid motion may stimulate the colony formation in green algae, culture experiments were conducted under axenic conditions in a circular water chamber where the flow rate, temperature, light, and nutrients were controlled. The number of cells of Microcystis aeruginosa, the number of cells per colony, and the colonial characteristics in various growth phases were observed and measured. The results indicated that the colony formation in Microcystis aeruginosa, which was not observed under stagnant conditions, was evident when there was fluid motion, with the number of cells per largest colony reaching 120 and the proportion of the number of cells in colonial form to the total number of cells and the mean number of cells per colony reaching their peak values at a flow rate of 35 cm/s. Based on the analysis of colony formation process, fluid motion stimulates the colony formation in Microcystis aeruginosa in the lag growth phase, while flushes and disaggregates the colonies in the exponential growth phase. The stimulation effect in the lag growth phase may be attributable to the involvement of fluid motion in a series of physiological processes, including the uptake of trace elements and the synthesis and secretion of polysaccharides. In addition, the experimental groups exhibiting typical colonial characteristics in the lag growth phase were found to have higher cell biomass in the later phase.

  4. Leukemic blast cell colony formation in semisolid culture with erythropoietin: a case report of acute poorly differentiated erythroid leukemia.

    Science.gov (United States)

    Tomonaga, M; Jinnai, I; Tagawa, M; Amenomori, T; Nishino, K; Yao, E; Nonaka, H; Kuriyama, K; Yoshida, Y; Matsuo, T

    1987-02-01

    The bone marrow of a patient with acute undifferentiated leukemia developed unique colonies after a 14-day culture in erythropoietin (EPO)-containing methylcellulose. The colonies consisted of 20 to 200 nonhemoglobinized large blast cells. Cytogenetic analysis of single colonies revealed hypotetraploid karyotypes with several marker chromosomes that were identical to those found in directly sampled bone marrow. The concurrently formed erythroid bursts showed only normal karyotypes. No leukemic colony formation was observed in other culture systems with either colony-stimulating activity (CSA) or phytohemagglutinin-stimulated leukocyte-conditioned medium (PHA-LCM). The leukemic colonies exhibited a complete EPO-dose dependency similar to that of the patient's normal BFU-E. Although cytochemical and immunologic marker studies of the bone marrow cells failed to clarify the cell lineage of the leukemic cells with extraordinarily large cell size, ultrastructural study revealed erythroid differentiation such as siderosome formation in the cytoplasm and ferritin particles in the rhophecytosis invaginations. These findings indicate that the patient had poorly differentiated erythroid leukemia and that some of the clonogenic cells might respond to EPO in vitro. Corresponding to this biological feature, the leukemic cells were markedly decreased in number in response to repeated RBC transfusions, and partial remission was obtained. These observations suggest that erythroid leukemia distinct from erythroleukemia (M6) with a myeloblastic component, can develop as a minor entity of human acute leukemia.

  5. Abuse of Modernity: The Korean Medical Journal and Colonial Identity

    Directory of Open Access Journals (Sweden)

    Mark Caprio

    2014-03-01

    Full Text Available Medical researcher Kubo Takeshi’s contributions to professional publications, such as Chōsen igakkai zasshi (The Korean medical journal, and more popular magazines, such as Chōsen oyobi Manshū (Korea and Manchuria, reflected many of the prejudicial attitudes that Japanese held toward Koreans during the first decade of colonial rule. His scholarship was based on biological determinist thinking, an approach developed by eighteenth-century European medical researchers to establish race, class, and gender hierarchies. For Kubo this approach provided a means for exploiting scientific inquiry to establish and manage Japanese superiority over Korean subjects in a more stable manner than one based on more malleable cultural differences. A people could adjust its customs or mannerisms to amalgamate with a suzerain culture but could not do so with hereditarily determined features, such as blood type or cranium size, shape, or weight. Practitioners, however, often linked the physical with the cultural by arguing that a people’s physical structure was a product of its cultural heritage. The subjectivity injected into this seemingly objective research methodology abused the lay community’s blind trust in modern science in two ways. First, it employed this inquiry to verify biased observations, rather than to uncover new truths; second, it altered the approach, rather than the conclusions, when this inquiry demonstrated the desired truths to be inaccurate. Biological determinism proved useful in substantiating a Japanese-Korean colonial relationship that acknowledged historically similar origins while arguing for the historically different evolutions of the two peoples.

  6. Accumulation of neutral mutations in growing cell colonies with competition.

    Science.gov (United States)

    Sorace, Ron; Komarova, Natalia L

    2012-12-07

    Neutral mutations play an important role in many biological processes including cancer initiation and progression, the generation of drug resistance in bacterial and viral diseases as well as cancers, and the development of organs in multicellular organisms. In this paper we study how neutral mutants are accumulated in nonlinearly growing colonies of cells subject to growth constraints such as crowding or lack of resources. We investigate different types of growth control which range from "division-controlled" to "death-controlled" growth (and various mixtures of both). In division-controlled growth, the burden of handling overcrowding lies with the process of cell-divisions, the divisions slow down as the carrying capacity is approached. In death-controlled growth, it is death rate that increases to slow down expansion. We show that division-controlled growth minimizes the number of accumulated mutations, and death-controlled growth corresponds to the maximum number of mutants. We check that these results hold in both deterministic and stochastic settings. We further develop a general (deterministic) theory of neutral mutations and achieve an analytical understanding of the mutant accumulation in colonies of a given size in the absence of back-mutations. The long-term dynamics of mutants in the presence of back-mutations is also addressed. In particular, with equal forward- and back-mutation rates, if division-controlled and a death-controlled types are competing for space and nutrients, cells obeying division-controlled growth will dominate the population. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Fenbendazole treatment and litter size in rats.

    Science.gov (United States)

    Johnston, Nancy A; Bieszczak, Jeremiah R; Verhulst, Steven; Disney, Kimberly E; Montgomery, Kyle E; Toth, Linda A

    2006-11-01

    Fenbendazole is commonly used in laboratory animal medicine as an anthelmintic for elimination of pinworms. It is generally regarded as a safe drug with minimal side effects. In our facility, 2 breeding colonies of rats were treated with fenbendazole to eliminate pinworms. Analysis of the breeding records revealed that feeding Sprague-Dawley rats a diet containing fenbendazole on a continuous basis for 7 consecutive weeks was associated with a significant reduction in litter size. Although the mechanism underlying this effect is unknown, the finding prompts caution when using fenbendazole to treat valuable breeding colonies or strains that are poor breeders.

  8. Genetic favouring of pheomelanin-based pigmentation limits physiological benefits of coloniality in lesser kestrels Falco naumanni.

    Science.gov (United States)

    Galván, Ismael; Moraleda, Virginia; Otero, Ignacio; Álvarez, Ernesto; Inácio, Ângela

    2017-10-01

    Pheomelanin contributes to the pigmentation phenotype of animals by producing orange and light brown colours in the integument. However, pheomelanin synthesis in melanocytes requires consumption of glutathione (GSH), the most important intracellular antioxidant. Therefore, a genetic control favouring the production of large amounts of pheomelanin for pigmentation may lead to physiological costs under environmental conditions that promote oxidative stress. We investigated this possibility in the context of breeding coloniality, a reproductive strategy that may affect oxidative stress. We found in lesser kestrel Falco naumanni nestlings that the GSH:GSSG ratio, which decreases with systemic oxidative stress, increased with the size of the colony where they were reared, but the expression in feather melanocytes of five genes involved in pheomelanin synthesis (Slc7a11, Slc45a2, CTNS, MC1R and AGRP) did not vary with colony size. The antioxidant capacity (TEAC) of lesser kestrel nestlings also increased with colony size, but in a manner that depended on Slc7a11 expression and not on the expression of the other genes. Thus, antioxidant capacity increased with colony size only in nestlings least expressing Slc7a11, a gene with a known role in mediating cysteine (a constituent amino acid of GSH) consumption for pheomelanin production. The main predictor of the intensity of pheomelanin-based feather colour was Slc45a2 expression followed in importance by Slc7a11 expression, hence suggesting that the genetic regulation of the pigmentation phenotype mediated by Slc7a11 and a lack of epigenetic lability in this gene limits birds from benefiting from the physiological benefits of coloniality. © 2017 John Wiley & Sons Ltd.

  9. Disrupting the Coloniality of Being: Toward De-Colonial Ontologies in Philosophy of Education

    Science.gov (United States)

    Richardson, Troy A.

    2012-01-01

    This essay works to bridge conversations in philosophy of education with decolonial theory. The author considers Margonis' (1999, 2011a, b) use of Rousseau (1979) and Heidegger (1962) in developing an ontological attitude that counters social hierarchies and promotes anti-colonial relations. While affirming this effort, the essay outlines a…

  10. The regulation of British colonial lunatic asylums and the origins of colonial psychiatry, 1860-1864.

    Science.gov (United States)

    Swartz, Sally

    2010-05-01

    In this paper I outline a brief period in the history of the British Empire, during which colonial lunatic asylum policy began to be formulated. I begin with a scandal that erupted in Jamaica and suggest that this set in motion processes that led to critical changes in asylum administration. The first of these processes was an audit of hospitals and asylums in the colonies. The results of the audit and the policy that emerged from it marked the beginning of systematic regulation of lunatic asylum practice across the British Empire. It revealed a formulation of policy that was intended to cut across the self-governing regimes that had up to this point been allowed to evolve. Drawing on the work of Michel Foucault and Nikolas Rose, I argue that the policy and the practices associated with it contribute to an understanding of the emergence of the psy-sciences in colonial settings. They illustrate the establishment of a panoptic gaze on previously neglected insane spaces. Systematic surveillance constituted government at a distance and made colonial lunacy administration a governable discursive space. The regulation of the medical officers, lunatic attendants, and hospital boards began the process of creating a professional psychiatric workforce. I conclude with a discussion of the implications and the mixed impact of this policy change for the mentally ill across the empire, over the ensuing decades.

  11. Economic mobility in a colonial and post-colonial economy: the case of Indonesia.

    NARCIS (Netherlands)

    van Leeuwen, Bas; Földvári, Peter

    2016-01-01

    Despite a consensus about the main factors influencing economic mobility in Indonesia, such as labor-market opportunities and childhood circumstances, virtually nothing is known about how these factors increased economic standing in the colonial and postcolonial periods. The use of height data as a

  12. Stable isotope enrichment in laboratory ant colonies: effects of colony age, metamorphosis, diet, and fat storage

    Science.gov (United States)

    Ecologists use stable isotopes to infer diets and trophic levels of animals in food webs, yet some assumptions underlying these inferences have not been thoroughly tested. We used laboratory-reared colonies of Solenopsis invicta Buren (Formicidae: Solenopsidini) to test the effects of metamorphosis,...

  13. Fish skin bacteria: Colonial and cellular hydrophobicity.

    Science.gov (United States)

    Sar, N; Rosenberg, E

    1987-05-01

    Bacteria were desorbed from the skin of healthy, fast-swimming fish by several procedures, including brief exposure to sonic oscillation and treatment with nontoxic surface active agents. The surface properties of these bacteria were studied by measuring their adhesion to hexadecane, as well as by a newly developed, simple method for studying the hydrophobicity of bacterial lawns. This method, referred to as the "Direction of Spreading" (DOS) method, consists of recording the direction to which a water drop spreads when introduced at the border between bacterial lawns and other surfaces. Of the 13 fish skin isolates examined, two strains were as hydrophobic as polystyrene by the DOS method. Suspended cells of one of these strains adhered strongly to hexadecane (84%), whereas cells of the other strain adhered poorly (13%). Another strain which was almost as hydrophobic as polystyrene by the DOS method did not adhere to hexadecane at all. Similarly, lawns of three other strains were more hydrophobic than glass by the DOS method, but cell suspensions prepared from these colonies showed little or no adhesion to hexadecane. The high colonial but relatively low cellular hydrophobicity could be due to a hydrophobic slime that is removed during the suspension and washing procedures. The possibility that specific bacteria assist in fish locomotion by changing the surface properties of the fish skin and by producing drag-reducing polymers is discussed.

  14. Risk factors associated with honey bee colony loss in apiaries in Galicia, NW Spain

    Directory of Open Access Journals (Sweden)

    Aranzazu Meana

    2017-04-01

    Full Text Available A cross-sectional study was carried out in Galicia, NW Spain, in order to estimate the magnitude of honey bee colony losses and to identify potential risk factors involved. A total of 99 samples from 99 apiaries were collected in spring using simple random sampling. According to international guidelines, the apiaries were classified as affected by colony loss or asymptomatic. Each sample consisted of worker bees, brood and comb-stored pollen. All worker bees and brood samples were analysed individually in order to detect the main honey bee pathogens. Moreover,