Breeding bird density does not drive vocal individuality

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Daniel T. BLUMSTEIN, Douglas R. MCCLAIN, Carrie DE JESUS, Gustavo ALARCÓN-NIETO

2012-10-01

Full Text Available Many species produce individually specific vocalizations and sociality is a hypothesized driver of such individuality. Previous studies of how social variation influenced individuality focused on colonial or non-colonial avian species, and how social group size influenced individuality in sciurid rodents. Since sociality is an important driver of individuality, we expected that bird species that defend nesting territories in higher density neighborhoods should have more individually-distinctive calls than those that defend nesting territories in lower-density neighborhoods. We used Beecher’s information statistic to quantify individuality, and we examined the relationship between bird density (calculated with point-counts and vocal individuality on seven species of passerines. We found non-significant relationships between breeding bird density and vocal individuality whether regressions were fitted on species values, or on phylogenetically-independent contrast values. From these results, we infer that while individuality may be explained by social factors, breeding bird density is unlikely to be generally important in driving the evolution of individually-specific vocalizations [Current Zoology 58 (5: 765–772, 2012].

Review of the breeding status of birds in Rio Grande do Sul, Brazil

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Giovanni N. Maurício

2013-06-01

Full Text Available Information on the breeding biology of birds is essential for improving avian life-history theory and implementing sound management and conservation actions for these organisms. Comprehensive reviews of this kind of information are lacking for most Neotropical regions, including Rio Grande do Sul, the southernmost Brazilian state. Aiming to update the knowledge on the reproductive status of birds in Rio Grande do Sul, we reviewed breeding records of all potential breeding species recorded in the state using a set of predefined, restrictive criteria for accepting breeding evidences as effective. Data satisfying our criteria were available for 165 species in the literature. We also collected novel breeding information obtained in the state for an additional 126 species, including observations for several species whose reproductive biology is poorly known. Among these are birds previously unknown to breed in Brazil. This new data and the critical review of the previous information resulted in a total of 291 species for which breeding evidences are accepted as effective. This corresponds to 54.7% of the 532 species considered either confirmed or potential breeders in the state. In addition to providing information on nesting dates, clutch size, nest architecture and breeding behavior of south Brazilian birds, our review serves as a benchmark for the adequate assessment of avian breeding records elsewhere. We hope to stimulate observers to rigorously document breeding events, especially for taxa for which basic information is lacking.

Reproduction of coastal birds breeding in the Wadden Sea: variation, influencing factors and monitoring

OpenAIRE

Thyen, Stefan

2005-01-01

The study was aimed to determine breeding success including its variability of coastal birds breeding in the Wadden Sea. A further aim was to assess the contribution of current breeding success to population trends of single species. The studies were conducted during the mid 1990s and at the beginning of the 2000s investigating six frequent breeding bird species at 17 breeding sites throughout the German part of the Wadden Sea area. In general, hatching and breeding success was higher on isla...

Iowa Breed Bird Atlas 2, 2008-2012

Data.gov (United States)

Iowa State University GIS Support and Research Facility — These are the locations of Iowa's Second Breeding Bird Atlas. Blocks are 3 by 3 miles in size. Some of the blocks are the same as those surveyed in the first BBA,...

[Book review] Massachusetts breeding bird atlas

Science.gov (United States)

Robbins, Chandler S.

2005-01-01

A glance at the dust jacket of this handsome volume drives home the conservation message that breeding bird atlases are designed to promote—that bird populations are changing over vast areas and, unless we become aware of changes in status and take remedial action, some species will disappear from our neighborhoods and even our county or state. A case in point involves the closely related Golden-winged Warbler (Vermivora chrysoptera) and Blue- winged Warbler (Vermivora pinus). The males are shown in the atlas with their breeding distribution maps. When I was an active birder in the Boston suburbs in the 1930s, the Golden-winged Warbler was a common breeder and it was a treat to find a Blue-winged Warbler. The atlas map 40 years later (1974–1979) shows only five confirmed records statewide for the Golden-winged Warbler, compared with 73 for the Blue-winged Warbler, and the Golden-winged Warbler is now listed as endangered by the Massachusetts Division of Fisheries and Wildlife. Nationally, it is a species of management concern.

Low effect of young afforestations on bird communities inhabiting heterogeneous Mediterranean cropland

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Juan S. Sánchez-Oliver

2015-12-01

Full Text Available Afforestation programs such as the one promoted by the EU Common Agricultural Policy have spread tree plantations on former cropland. These afforestations attract generalist forest and ubiquitous species but may cause severe damage to open habitat species, especially birds of high conservation value. We investigated the effects of young (<20 yr tree plantations dominated by pine P. halepensis on bird communities inhabiting the adjacent open farmland habitat in central Spain. We hypothesize that pine plantations located at shorter distances from open fields and with larger surface would affect species richness and conservation value of bird communities. Regression models controlling for the influence of land use types around plantations revealed positive effects of higher distance to pine plantation edge on community species richness in winter, and negative effects on an index of conservation concern (SPEC during the breeding season. However, plantation area did not have any effect on species richness or community conservation value. Our results indicate that the effects of pine afforestation on bird communities inhabiting Mediterranean cropland are diluted by heterogeneous agricultural landscapes.

Forest fragmentation and bird community dynamics: inference at regional scales

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Boulinier, T.; Nichols, J.D.; Hines, J.E.; Sauer, J.R.; Flather, C.H.; Pollock, K.H.

2001-01-01

With increasing fragmentation of natural areas and a dramatic reduction of forest cover in several parts of the world, quantifying the impact of such changes on species richness and community dynamics has been a subject of much concern. Here, we tested whether in more fragmented landscapes there was a lower number of area-sensitive species and higher local extinction and turnover rates, which could explain higher temporal variability in species richness. To investigate such potential landscape effects at a regional scale, we merged two independent, large-scale monitoring efforts: the North American Breeding Bird Survey (BBS) and the Land Use and Land Cover Classification data from the U.S. Geological Survey. We used methods that accounted for heterogeneity in the probability of detecting species to estimate species richness and temporal changes in the bird communities for BBS routes in three mid-Atlantic U.S. states. Forest breeding bird species were grouped prior to the analyses into area-sensitive and non-area-sensitive species according to previous studies. We tested predictions relating measures of forest structure at one point in time (1974) to species richness at that time and to parameters of forest bird community change over the following 22-yr-period (1975-1996). We used the mean size of forest patches to characterize landscape structure, as high correlations among landscape variables did not allow us to disentangle the relative roles of habitat fragmentation per se and habitat loss. As predicted, together with lower species richness for area-sensitive species on routes surrounded by landscapes with lower mean forest-patch size, we found higher mean year-to-year rates of local extinction. Moreover, the mean year-to-year rates of local turnover (proportion of locally new species) for area-sensitive species were also higher in landscapes with lower mean forest-patch size. These associations were not observed for the non-area-sensitive species group. These

Bird communities and biomass yields in potential bioenergy grasslands.

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Peter J Blank

Full Text Available Demand for bioenergy is increasing, but the ecological consequences of bioenergy crop production on working lands remain unresolved. Corn is currently a dominant bioenergy crop, but perennial grasslands could produce renewable bioenergy resources and enhance biodiversity. Grassland bird populations have declined in recent decades and may particularly benefit from perennial grasslands grown for bioenergy. We asked how breeding bird community assemblages, vegetation characteristics, and biomass yields varied among three types of potential bioenergy grassland fields (grass monocultures, grass-dominated fields, and forb-dominated fields, and assessed tradeoffs between grassland biomass production and bird habitat. We also compared the bird communities in grassland fields to nearby cornfields. Cornfields had few birds compared to perennial grassland fields. Ten bird Species of Greatest Conservation Need (SGCN were observed in perennial grassland fields. Bird species richness and total bird density increased with forb cover and were greater in forb-dominated fields than grass monocultures. SGCN density declined with increasing vertical vegetation density, indicating that tall, dense grassland fields managed for maximum biomass yield would be of lesser value to imperiled grassland bird species. The proportion of grassland habitat within 1 km of study sites was positively associated with bird species richness and the density of total birds and SGCNs, suggesting that grassland bioenergy fields may be more beneficial for grassland birds if they are established near other grassland parcels. Predicted total bird density peaked below maximum biomass yields and predicted SGCN density was negatively related to biomass yields. Our results indicate that perennial grassland fields could produce bioenergy feedstocks while providing bird habitat. Bioenergy grasslands promote agricultural multifunctionality and conservation of biodiversity in working landscapes.

Adult sex ratios and their implications for cooperative breeding in birds.

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Komdeur, Jan; Székely, Tamás; Long, Xiaoyan; Kingma, Sjouke A

2017-09-19

Cooperative breeding is a form of breeding system where in addition to a core breeding pair, one or more usually non-breeding individuals provide offspring care. Cooperative breeding is widespread in birds, but its origin and maintenance in contemporary populations are debated. Although deviations in adult sex ratio (ASR, the proportion of males in the adult population) have been hypothesized to influence the occurrence of cooperative breeding because of the resulting surplus of one sex and limited availability of breeding partners, this hypothesis has not been tested across a wide range of taxa. By using data from 188 bird species and phylogenetically controlled analyses, we show that cooperatively breeding species have more male-biased ASRs than non-cooperative species. Importantly, ASR predicts helper sex ratio: in species with more male-biased ASR, helper sex ratio is also more male biased. We also show that offspring sex ratios do not predict ASRs, so that the skewed ASRs emerge during the period when individuals aim to obtain a breeding position or later during adulthood. In line with this result, we found that ASR (among both cooperatively and non-cooperatively breeding species) is inversely related to sex bias in dispersal distance, suggesting that the cost of dispersal is more severe for the further-dispersing sex. As females usually disperse further in birds, this explains the generally male-biased ASR, and in combination with benefits of philopatry for males, this probably explains why ASR is more biased in cooperatively breeding species. Taken together, our results suggest that a sex bias in helping in cooperatively breeding species relates to biased ASRs. We propose that this relationship is driven by sex-specific costs and benefits of dispersal and helping, as well as other demographic factors. Future phylogenetic comparative and experimental work is needed to establish how this relationship emerges.This article is part of the themed issue 'Adult sex

Recreation-induced changes in boreal bird communities in protected areas.

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Kangas, K; Luoto, M; Ihantola, A; Tomppo, E; Siikamäki, P

2010-09-01

The impacts of human-induced disturbance on birds have been studied in growing extent, but there are relatively few studies about the effects of recreation on forest bird communities in protected areas. In this paper, the relative importance of recreation as well as environmental variables on bird communities in Oulanka National Park, in northeastern Finland, was investigated using general additive models (GAM). Bird data collected using the line transect method along hiking trails and in undisturbed control areas were related to number of visits, area of tourism infrastructure, and habitat variables. We further examined the impact of spatial autocorrelation by calculating an autocovariate term for GAMs. Our results indicate that number of visits affects the occurrence and composition of bird communities, but it had no impact on total species richness. Open-cup nesters breeding on the ground showed strongest negative response to visitor pressure, whereas the open-cup nesters nesting in trees and shrubs were more tolerant. For cavity-nesting species, recreation had no significant impact. The contribution of the number of visits was generally low also in models in which it was selected, and the occurrence of birds was mainly determined by habitat characteristics of the area. However, our results show that the recreation-induced disturbance with relatively low visitor pressure can have negative impacts on some bird species and groups of species and should be considered in management of protected areas with recreational activities.

Bird community responses to the edge between suburbs and reserves.

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Ikin, Karen; Barton, Philip S; Knight, Emma; Lindenmayer, David B; Fischer, Joern; Manning, Adrian D

2014-02-01

New insights into community-level responses at the urban fringe, and the mechanisms underlying them, are needed. In our study, we investigated the compositional distinctiveness and variability of a breeding bird community at both sides of established edges between suburban residential areas and woodland reserves in Canberra, Australia. Our goals were to determine if: (1) community-level responses were direct (differed with distance from the edge, independent of vegetation) or indirect (differed in response to edge-related changes in vegetation), and (2) if guild-level responses provided the mechanism underpinning community-level responses. We found that suburbs and reserves supported significantly distinct bird communities. The suburban bird community, characterised by urban-adapted native and exotic species, had a weak direct edge response, with decreasing compositional variability with distance from the edge. In comparison, the reserve bird community, characterised by woodland-dependent species, was related to local tree and shrub cover. This was not an indirect response, however, as tree and shrub cover was not related to edge distance. We found that the relative richness of nesting, foraging and body size guilds also displayed similar edge responses, indicating that they underpinned the observed community-level responses. Our study illustrates how community-level responses provide valuable insights into how communities respond to differences in resources between two contrasting habitats. Further, the effects of the suburban matrix penetrate into reserves for greater distances than previously thought. Suburbs and adjacent reserves, however, provided important habitat resources for many native species and the conservation of these areas should not be discounted from continued management strategies.

Lack of evidence for short-term structural changes in bird assemblages breeding in Mediterranean mosaics moderately perforated by a wind farm

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C. Battisti

2016-04-01

Full Text Available We studied a set of common breeding birds living in a heterogeneous oak wood mosaic of Apennines (central Italy where a wind farm occurred. Aim to assess differences in composition and structure between a treatment area (with wind farm turbines and a control area (without wind farm turbines. We did not observe differences at assemblage (uni-and bi-variate metrics of diversity: mean species richness, Shannon–Wiener diversity index, evenness, Whittaker βw index and diversity/dominance diagrams, guild and species level (relative frequencies. The limited habitat perforation and dissection induced by wind farm turbines and service roads (10% in area and the consequent changes in spatial heterogeneity and level of anthropogenic disturbance (induced by a higher motor-car and people frequentation did not seem to affect the breeding bird communities in oak mosaics, as supported also by the diversity/dominance analysis. However, our preliminary conclusions are limited only to the indirect impact on common breeding bird species and are not related on to possible direct impacts deriving from wind farm facilities and related infrastructures (e.g., direct impact for collision. Moreover, further research is necessary to detect possible higher thresholds in habitat perforation that may induce changes in breeding bird assemblages.

Using the North American Breeding Bird Survey to assess broad-scale response of the continent's most imperiled avian community, grassland birds, to weather variability

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Gorzo, Jessica; Pidgeon, Anna M.; Thogmartin, Wayne E.; Allstadt, Andrew J.; Radeloff, Volker C.; Heglund, Patricia J.; Vavrus, Stephen J.

2016-01-01

Avian populations can respond dramatically to extreme weather such as droughts and heat waves, yet patterns of response to weather at broad scales remain largely unknown. Our goal was to evaluate annual variation in abundance of 14 grassland bird species breeding in the northern mixed-grass prairie in relation to annual variation in precipitation and temperature. We modeled avian abundance during the breeding season using North American Breeding Bird Survey (BBS) data for the U.S. Badlands and Prairies Bird Conservation Region (BCR 17) from 1980 to 2012. We used hierarchical Bayesian methods to fit models and estimate the candidate weather parameters standardized precipitation index (SPI) and standardized temperature index (STI) for the same year and the previous year. Upland Sandpiper (Bartramia longicauda) responded positively to within-year STI (β = 0.101), and Baird's Sparrow (Ammodramus bairdii) responded negatively to within-year STI (β = −0.161) and positively to within-year SPI (β = 0.195). The parameter estimates were superficially similar (STI β = −0.075, SPI β = 0.11) for Grasshopper Sparrow (Ammodramus savannarum), but the best-selected model included an interaction between SPI and STI. The best model for both Eastern Kingbird (Tyrannus tyrannus) and Vesper Sparrow (Pooecetes gramineus) included the additive effects of within-year SPI (β = −0.032 and β = −0.054, respectively) and the previous-year's SPI (β = −0.057 and −0.02, respectively), although for Vesper Sparrow the lag effect was insignificant. With projected warmer, drier weather during summer in the Badlands and Prairies BCR, Baird's and Grasshopper sparrows may be especially threatened by future climate change.

Breeding bird use of and nesting success in exotic Russian olive in New Mexico

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Scott H. Stoleson; Deborah M. Finch

2001-01-01

The exotic tree, Russian olive (Elaeagnus angustifolia), has invaded riparian zones throughout much of the western Unites States. Although promoted as a useful species for wildlife because of its abundant edible fruit, evidence for its value to breeding birds remains sparse. We compared relative rates of usage, nest success, and cowbird parasitism of birds breeding in...

Differences in breeding bird assemblages related to reed canary grass cover cover and forest structure on the Upper Mississippi River

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Kirsch, Eileen M.; Gray, Brian R.

2017-01-01

Floodplain forest of the Upper Mississippi River provides habitat for an abundant and diverse breeding bird community. However, reed canary grass Phalaris arundinacea invasion is a serious threat to the future condition of this forest. Reed canary grass is a well-known aggressive invader of wetland systems in the northern tier states of the conterminous United States. Aided by altered flow regimes and nutrient inputs from agriculture, reed canary grass has formed dense stands in canopy gaps and forest edges, retarding tree regeneration. We sampled vegetation and breeding birds in Upper Mississippi River floodplain forest edge and interior areas to 1) measure reed canary grass cover and 2) evaluate whether the breeding bird assemblage responded to differences in reed canary grass cover. Reed canary grass was found far into forest interiors, and its cover was similar between interior and edge sites. Bird assemblages differed between areas with more or less reed canary grass cover (.53% cover breakpoint). Common yellowthroat Geothlypis trichas, black-capped chickadee Parus atricapillus, and rose-breasted grosbeak Pheucticus ludovicianus were more common and American redstart Setophaga ruticilla, great crested flycatcher Myiarchus crinitus, and Baltimore oriole Icterus galbula were less common in sites with more reed canary grass cover. Bird diversity and abundance were similar between sites with different reed canary grass cover. A stronger divergence in bird assemblages was associated with ground cover ,15%, resulting from prolonged spring flooding. These sites hosted more prothonotary warbler Protonotaria citrea, but they had reduced bird abundance and diversity compared to other sites. Our results indicate that frequently flooded sites may be important for prothonotary warblers and that bird assemblages shift in response to reed canary grass invasion.

Strategic Plan for the North American Breeding Bird Survey: 2006-2010

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,

2007-01-01

program to continue to meet the evolving needs of the conservation community for information on bird population change. By setting clear goals, strategies, and measures of success, this plan provides a cohesive framework and vision for maintenance and development of the BBS. The plan identifies two major goals for the BBS, with a number of strategies and objectives to achieve these goals. Over the next 5 years, progress made in addressing each long-term goal and its associated 5-year strategies and objectives will gage the plan's success. Specific actions, projected outcomes, and measures of success related to accomplishing these are outlined in Table 1, with a timeline in Table 2. The two main goals for the program, with a summary of the strategies to achieve them, are: Goal 1: Collect scientifically credible measures of the status and trends of North American bird populations at continental and regional scales. The North American Breeding Bird Survey will continue to support North American natural resource conservation through the collection of scientifically credible measures of the status and trends of continental bird populations. While doing this, the BBS will work to improve the science behind the program to better meet its mission and the changing needs of the avian conservation community. In partnership with collaborators, the BBS will address detection probability bias and habitat bias, improve analytical methods, and more fully assess and account for observer quality. Moreover, the BBS will improve the quality and breadth of avian population data through strategic increases in route density and the establishment of a Mexican BBS program. Goal 2: Ensure BBS data and analytical results are widely available and easily accessible for use by the avian conservation and management communities. At the heart of the BBS lies a four-million-record database containing more than 40 years of data on more than 600 bird species. These data are of no valu

Family living sets the stage for cooperative breeding and ecological resilience in birds.

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Michael Griesser

2017-06-01

Full Text Available Cooperative breeding is an extreme form of cooperation that evolved in a range of lineages, including arthropods, fish, birds, and mammals. Although cooperative breeding in birds is widespread and well-studied, the conditions that favored its evolution are still unclear. Based on phylogenetic comparative analyses on 3,005 bird species, we demonstrate here that family living acted as an essential stepping stone in the evolution of cooperative breeding in the vast majority of species. First, families formed by prolonging parent-offspring associations beyond nutritional independency, and second, retained offspring began helping at the nest. These findings suggest that assessment of the conditions that favor the evolution of cooperative breeding can be confounded if this process is not considered to include 2 steps. Specifically, phylogenetic linear mixed models show that the formation of families was associated with more productive and seasonal environments, where prolonged parent-offspring associations are likely to be less costly. However, our data show that the subsequent evolution of cooperative breeding was instead linked to environments with variable productivity, where helpers at the nest can buffer reproductive failure in harsh years. The proposed 2-step framework helps resolve current disagreements about the role of environmental forces in the evolution of cooperative breeding and better explains the geographic distribution of this trait. Many geographic hotspots of cooperative breeding have experienced a historical decline in productivity, suggesting that a higher proportion of family-living species could have been able to avoid extinction under harshening conditions through the evolution of cooperative breeding. These findings underscore the importance of considering the potentially different factors that drive different steps in the evolution of complex adaptations.

Family living sets the stage for cooperative breeding and ecological resilience in birds.

Science.gov (United States)

Griesser, Michael; Drobniak, Szymon M; Nakagawa, Shinichi; Botero, Carlos A

2017-06-01

Cooperative breeding is an extreme form of cooperation that evolved in a range of lineages, including arthropods, fish, birds, and mammals. Although cooperative breeding in birds is widespread and well-studied, the conditions that favored its evolution are still unclear. Based on phylogenetic comparative analyses on 3,005 bird species, we demonstrate here that family living acted as an essential stepping stone in the evolution of cooperative breeding in the vast majority of species. First, families formed by prolonging parent-offspring associations beyond nutritional independency, and second, retained offspring began helping at the nest. These findings suggest that assessment of the conditions that favor the evolution of cooperative breeding can be confounded if this process is not considered to include 2 steps. Specifically, phylogenetic linear mixed models show that the formation of families was associated with more productive and seasonal environments, where prolonged parent-offspring associations are likely to be less costly. However, our data show that the subsequent evolution of cooperative breeding was instead linked to environments with variable productivity, where helpers at the nest can buffer reproductive failure in harsh years. The proposed 2-step framework helps resolve current disagreements about the role of environmental forces in the evolution of cooperative breeding and better explains the geographic distribution of this trait. Many geographic hotspots of cooperative breeding have experienced a historical decline in productivity, suggesting that a higher proportion of family-living species could have been able to avoid extinction under harshening conditions through the evolution of cooperative breeding. These findings underscore the importance of considering the potentially different factors that drive different steps in the evolution of complex adaptations.

Conservation of forest birds: evidence of a shifting baseline in community structure.

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Rittenhouse, Chadwick D; Pidgeon, Anna M; Albright, Thomas P; Culbert, Patrick D; Clayton, Murray K; Flather, Curtis H; Huang, Chengquan; Masek, Jeffrey G; Stewart, Susan I; Radeloff, Volker C

2010-08-02

Quantifying changes in forest bird diversity is an essential task for developing effective conservation actions. When subtle changes in diversity accumulate over time, annual comparisons may offer an incomplete perspective of changes in diversity. In this case, progressive change, the comparison of changes in diversity from a baseline condition, may offer greater insight because changes in diversity are assessed over longer periods of times. Our objectives were to determine how forest bird diversity has changed over time and whether those changes were associated with forest disturbance. We used North American Breeding Bird Survey data, a time series of Landsat images classified with respect to land cover change, and mixed-effects models to associate changes in forest bird community structure with forest disturbance, latitude, and longitude in the conterminous United States for the years 1985 to 2006. We document a significant divergence from the baseline structure for all birds of similar migratory habit and nest location, and all forest birds as a group from 1985 to 2006. Unexpectedly, decreases in progressive similarity resulted from small changes in richness (<1 species per route for the 22-year study period) and modest losses in abundance (-28.7 - -10.2 individuals per route) that varied by migratory habit and nest location. Forest disturbance increased progressive similarity for Neotropical migrants, permanent residents, ground nesting, and cavity nesting species. We also documented highest progressive similarity in the eastern United States. Contemporary forest bird community structure is changing rapidly over a relatively short period of time (e.g., approximately 22 years). Forest disturbance and forest regeneration are primary factors associated with contemporary forest bird community structure, longitude and latitude are secondary factors, and forest loss is a tertiary factor. Importantly, these findings suggest some regions of the United States may

Presence of Breeding Birds Improves Body Condition for a Crocodilian Nest Protector.

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Nell, Lucas A; Frederick, Peter C; Mazzotti, Frank J; Vliet, Kent A; Brandt, Laura A

2016-01-01

Ecological associations where one species enhances habitat for another nearby species (facilitations) shape fundamental community dynamics and can promote niche expansion, thereby influencing how and where species persist and coexist. For the many breeding birds facing high nest-predation pressure, enemy-free space can be gained by nesting near more formidable animals for physical protection. While the benefits to protected species seem well documented, very few studies have explored whether and how protector species are affected by nest protection associations. Long-legged wading birds (Pelecaniformes and Ciconiiformes) actively choose nesting sites above resident American alligators (Alligator mississippiensis), apparently to take advantage of the protection from mammalian nest predators that alligator presence offers. Previous research has shown that wading bird nesting colonies could provide substantial food for alligators in the form of dropped chicks. We compared alligator body condition in similar habitat with and without wading bird nesting colonies present. Alligator morphometric body condition indices were significantly higher in colony than in non-colony locations, an effect that was statistically independent of a range of environmental variables. Since colonially nesting birds and crocodilians co-occur in many tropical and subtropical wetlands, our results highlight a potentially widespread keystone process between two ecologically important species-groups. These findings suggest the interaction is highly beneficial for both groups of actors, and illustrate how selective pressures may have acted to form and reinforce a strongly positive ecological interaction.

Presence of Breeding Birds Improves Body Condition for a Crocodilian Nest Protector

Science.gov (United States)

Nell, Lucas A.; Frederick, Peter C.; Mazzotti, Frank J.; Vliet, Kent A.; Brandt, Laura A.

2016-01-01

Ecological associations where one species enhances habitat for another nearby species (facilitations) shape fundamental community dynamics and can promote niche expansion, thereby influencing how and where species persist and coexist. For the many breeding birds facing high nest-predation pressure, enemy-free space can be gained by nesting near more formidable animals for physical protection. While the benefits to protected species seem well documented, very few studies have explored whether and how protector species are affected by nest protection associations. Long-legged wading birds (Pelecaniformes and Ciconiiformes) actively choose nesting sites above resident American alligators (Alligator mississippiensis), apparently to take advantage of the protection from mammalian nest predators that alligator presence offers. Previous research has shown that wading bird nesting colonies could provide substantial food for alligators in the form of dropped chicks. We compared alligator body condition in similar habitat with and without wading bird nesting colonies present. Alligator morphometric body condition indices were significantly higher in colony than in non-colony locations, an effect that was statistically independent of a range of environmental variables. Since colonially nesting birds and crocodilians co-occur in many tropical and subtropical wetlands, our results highlight a potentially widespread keystone process between two ecologically important species-groups. These findings suggest the interaction is highly beneficial for both groups of actors, and illustrate how selective pressures may have acted to form and reinforce a strongly positive ecological interaction. PMID:26934602

Potential Sensitivity of Québec's Breeding Birds to Climate Change

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Jean-Luc DesGranges

2010-12-01

Full Text Available We examined the relationship between climatic factors and the distribution of breeding birds in southern Québec, Canada to identify the species whose distribution renders them potentially sensitive to climate change in the study area. We determined the degree of association between the distribution of 65 breeding bird species (601 presence-absence squares of the Atlas of the Breeding Birds of Québec and climate variables (212 climatological stations in operation for at least 20 years over the period 1953-1984 by statistically correcting for the effects of several factors that are correlated with bird distribution. Factors considered were the nature and scale of land cover patterns that included vegetation types and landscape characterization, geographical coordinates, and elevation. Canonical Correspondence Analysis (CCA was used to investigate the effect of climatic variables on breeding bird distribution. Independent variables accounted for a total of 29.1% of the variation in the species matrix. A very large portion of the variance explained by climate variables was shared with spatial variables, reflecting the relationships among latitude, longitude, elevation, and climate. After correcting for the effect of land cover variables, climatic variables still explained 11.4% of the variation in the species matrix, with temperature, i.e., warmer summers and milder winters, having a greater influence than precipitation, i.e., wetter summers. Of the 65 species, 14 appeared to be particularly climate-sensitive. Eight are insectivorous neotropical migrants and six species are at the northern limit of their range in the study area. The opposite is largely true for the eight others; they are practically absent from the southern part of the study area, except for the Dark-eyed Junco (Junco hyemalis, which is widespread there. The White-breasted Nuthatch (Sitta carolinensis is the only resident species that seemed responsive to climatic variables, i

Interspecific reciprocity explains mobbing behaviour of the breeding chaffinches, Fringilla coelebs.

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Krams, Indrikis; Krama, Tatjana

2002-01-01

When prey animals discover a predator close by, they mob it while uttering characteristic sounds that attract other prey individuals to the vicinity. Mobbing causes a predator to vacate its immediate foraging area, which gives an opportunity for prey individuals to continue their interrupted daily activity. Besides the increased benefits, mobbing behaviour also has its costs owing to injuries or death. The initiator of mobbing may be at increased risk of predation by attracting the predator's attention, especially if not joined by other neighbouring prey individuals. Communities of breeding birds have always been considered as temporal aggregations. Since an altruist could not prevent cheaters from exploiting its altruism in an anonymous community, this excluded any possibility of explaining mobbing behaviour in terms of reciprocal altruism. However, sedentary birds may have become acquainted since the previous non-breeding season. Migrant birds, forming anonymous communities at the beginning of the breeding season, may also develop closer social ties during the course of the breeding season. We tested whether a male chaffinch, a migrant bird, would initiate active harassment of a predator both at the beginning of the breeding season and a week later when it has become a member of a non-anonymous multi-species aggregation of sedentary birds. We expected that male chaffinches would be less likely to initiate a mob at the beginning of the breeding season when part of an anonymous multi-species aggregation of migratory birds. However, their mobbing activity should increase as the breeding season advances. Our results support these predictions. Cooperation among individuals belonging to different species in driving the predator away may be explained as interspecific reciprocity based on interspecific recognition and temporal stability of the breeding communities. PMID:12495502

Breeding of marine birds on Farwa Island, western Libya | Etayeb ...

African Journals Online (AJOL)

Breeding of marine birds on Farwa Island, western Libya. ... They provide food, shelter and nesting grounds for many avifauna during their migration ... northern part of the island and at Ras-Attalgha, beside the plant cover of the island itself.

Passerine birds breeding under chronic noise experience reduced fitness.

Directory of Open Access Journals (Sweden)

Julia Schroeder

Full Text Available BACKGROUND: Fitness in birds has been shown to be negatively associated with anthropogenic noise, but the underlying mechanisms remain obscure. It is however crucial to understand the mechanisms of how urban noise impinges on fitness to obtain a better understanding of the role of chronic noise in urban ecology. Here, we examine three hypotheses on how noise might reduce reproductive output in passerine birds: (H1 by impairing mate choice, (H2 by reducing territory quality and (H3 by impeding chick development. METHODOLOGY/PRINCIPAL FINDINGS: We used long-term data from an island population of house sparrows, Passer domesticus, in which we can precisely estimate fitness. We found that nests in an area affected by the noise from large generators produced fewer young, of lower body mass, and fewer recruits, even when we corrected statistically for parental genetic quality using a cross-fostering set-up, supporting H3. Also, individual females provided their young with food less often when they bred in the noisy area compared to breeding attempts by the same females elsewhere. Furthermore, we show that females reacted flexibly to increased noise levels by adjusting their provisioning rate in the short term, which suggests that noise may be a causal factor that reduces reproductive output. We rejected H1 and H2 because nestbox occupancy, parental body mass, age and reproductive investment did not differ significantly between noisy and quiet areas. CONCLUSIONS/SIGNIFICANCE: OUR RESULTS SUGGEST A PREVIOUSLY UNDESCRIBED MECHANISM TO EXPLAIN HOW ENVIRONMENTAL NOISE CAN REDUCE FITNESS IN PASSERINE BIRDS: by acoustically masking parent-offspring communication. More importantly, using a cross-fostering set-up, our results demonstrate that birds breeding in a noisy environment experience significant fitness costs. Chronic noise is omnipresent around human habitation and may produces similar fitness consequences in a wide range of urban bird species.

Mourning dove population trend estimates from Call-Count and North American Breeding Bird Surveys

Science.gov (United States)

Sauer, J.R.; Dolton, D.D.; Droege, S.

1994-01-01

The mourning dove (Zenaida macroura) Callcount Survey and the North American Breeding Bird Survey provide information on population trends of mourning doves throughout the continental United States. Because surveys are an integral part of the development of hunting regulations, a need exists to determine which survey provides precise information. We estimated population trends from 1966 to 1988 by state and dove management unit, and assessed the relative efficiency of each survey. Estimates of population trend differ (P lt 0.05) between surveys in 11 of 48 states; 9 of 11 states with divergent results occur in the Eastern Management Unit. Differences were probably a consequence of smaller sample sizes in the Callcount Survey. The Breeding Bird Survey generally provided trend estimates with smaller variances than did the Callcount Survey. Although the Callcount Survey probably provides more withinroute accuracy because of survey methods and timing, the Breeding Bird Survey has a larger sample size of survey routes and greater consistency of coverage in the Eastern Unit.

Effects of haying on breeding birds in CRP grasslands

Science.gov (United States)

Igl, Lawrence D.; Johnson, Douglas H.

2016-01-01

The Conservation Reserve Program (CRP) is a voluntary program that is available to agricultural producers to help protect environmentally sensitive or highly erodible land. Management disturbances of CRP grasslands generally are not allowed unless authorized to provide relief to livestock producers during severe drought or a similar natural disaster (i.e., emergency haying and grazing) or to improve the quality and performance of the CRP cover (i.e., managed haying and grazing). Although CRP grasslands may not be hayed or grazed during the primary bird-nesting season, these disturbances may have short-term (1 yr after disturbance) and long-term (≥2 yr after disturbance) effects on grassland bird populations. We assessed the effects of haying on 20 grassland bird species in 483 CRP grasslands in 9 counties of 4 states in the northern Great Plains, USA between 1993 and 2008. We compared breeding bird densities (as determined by total-area counts) in idle and hayed fields to evaluate changes 1, 2, 3, and 4 years after haying. Haying of CRP grasslands had either positive or negative effects on grassland birds, depending on the species, the county, and the number of years after the initial disturbance. Some species (e.g., horned lark [Eremophila alpestris], bobolink [Dolichonyx oryzivorus]) responded positively after haying, and others (e.g., song sparrow [Melospiza melodia]) responded negatively. The responses of some species changed direction as the fields recovered from haying. For example, densities for common yellowthroat (Geothlypis trichas), sedge wren (Cistothorus platensis), and clay-colored sparrow (Spizella pallida) declined the first year after haying but increased in the subsequent 3 years. Ten species showed treatment × county interactions, indicating that the effects of haying varied geographically. This long-term evaluation on the effects of haying on breeding birds provides important information on the strength and direction of changes in

Conservation of forest birds: evidence of a shifting baseline in community structure.

Directory of Open Access Journals (Sweden)

Chadwick D Rittenhouse

2010-08-01

Full Text Available Quantifying changes in forest bird diversity is an essential task for developing effective conservation actions. When subtle changes in diversity accumulate over time, annual comparisons may offer an incomplete perspective of changes in diversity. In this case, progressive change, the comparison of changes in diversity from a baseline condition, may offer greater insight because changes in diversity are assessed over longer periods of times. Our objectives were to determine how forest bird diversity has changed over time and whether those changes were associated with forest disturbance.We used North American Breeding Bird Survey data, a time series of Landsat images classified with respect to land cover change, and mixed-effects models to associate changes in forest bird community structure with forest disturbance, latitude, and longitude in the conterminous United States for the years 1985 to 2006. We document a significant divergence from the baseline structure for all birds of similar migratory habit and nest location, and all forest birds as a group from 1985 to 2006. Unexpectedly, decreases in progressive similarity resulted from small changes in richness (<1 species per route for the 22-year study period and modest losses in abundance (-28.7 - -10.2 individuals per route that varied by migratory habit and nest location. Forest disturbance increased progressive similarity for Neotropical migrants, permanent residents, ground nesting, and cavity nesting species. We also documented highest progressive similarity in the eastern United States.Contemporary forest bird community structure is changing rapidly over a relatively short period of time (e.g., approximately 22 years. Forest disturbance and forest regeneration are primary factors associated with contemporary forest bird community structure, longitude and latitude are secondary factors, and forest loss is a tertiary factor. Importantly, these findings suggest some regions of the United

Breeding ornithical communities in the Natural Reserve “Monte Soratte” (Central Italy: composition and structure.

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Corrado Battisti

2012-12-01

Full Text Available In this study we obtained further data on the breeding bird communities of “Monte Soratte” nature reserve (Latium, central Italy. We sampled 55 breeding species (49 during the standard sampling with point counts in four habitat types (Quercus ilex oak woods, landscape mosaics, urban habitats and wet habitat mosaics along the Tiber river. Landscape mosaics and wet mosaics along the Tiber river showed higher values both of richness (also normalizing with the Margalef index and Shannon diversity when compared to the other habitat types. Bird community in urban habitats showed a high mean species richness but a low β-diversity index, probably due to low spatial heterogeneity. The values of mean species richness are not significantly different among habitat types. Further research should be promoted to confirm the nesting of some species, yet observed in this area (e.g., Falco peregrinus, Phylloscopus bonelli. “Monte Soratte” nature reserve may represent a stop-over site and a foraging area for migrant raptors of conservation concern (e.g., for Circaetus gallicus.

Reasons for the decline in bird numbers breeding near the Ravenglass Estuary

International Nuclear Information System (INIS)

Anderson, N.; Evans, P.R.

1987-07-01

Black-headed Gulls breeding at Ravenglass (and at other coastal sites in Cumbria) fed exclusively inland during the breeding season and so could not have acquired any radionuclide contaminants present in the estuarine muds and invertebrates. They, and two other ground-nesting bird species have suffered severe disturbance and predation by foxes at Ravenglass in recent years. In contrast, the Shelduck, which nests in holes (and so does not suffer fox predation) but feeds at Ravenglass on estuarine invertebrates, has bred successfully. Levels of heavy metal contaminants in gull tissues and eggs were too low to have caused the observed breeding failures at Ravenglass. Gulls feeding on the estuary before the breeding season, but which then moved to other (inland) breeding sites, nested successfully. (author)

Short Note Some additional breeding records for birds in Angola ...

African Journals Online (AJOL)

Short Note Some additional breeding records for birds in Angola. W Richard J Dean, Suzanne J Milton. Abstract. No abstract. Ostrich 2007, 78(3): 645–647. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.2989/OSTRICH.2007.78.3.13.324.

Patterns of forest use and endemism in resident bird communities of north-central Michoacan, Mexico

Science.gov (United States)

Santiago Garcia; Deborah M. Finch; Gilberto Chavez. Leon

1998-01-01

We compared breeding avian communities among 11 habitat types in north-central Michoacan, Mexico, to determine patterns of forest use by endemic and nonendemic resident species. Point counts of birds and vegetation measurements were conducted at 124 sampling localities from May through July, in 1994 and 1995. Six native forest types sampled were pine, pine-oak, oak-...

Breeding Bird Assemblage in a Mosaic of Urbanized Habitats in a Central European City

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Kopij Grzegorz

2016-04-01

Full Text Available There is a lack of data on the population densities of birds breeding in a mosaic of typical urbanized habitats. This study was undertaken to partly fulfil this gap in our knowledge. Counts were conducted in 2008 by means of simplified territory mapping method in a fragment (1197 ha of a large Central European city (Wrocław, SW Poland. In total, 50 bird species were breeding in the study area in 2008. The House Sparrow Passer domesticus, Common Swift Apus apus and Rock Dove comprised about 3/5 of all breeding pairs. The other group of species, each one with a density between 6 and 13 pairs per 100 ha, included seven species, namely the Starling, Sturnus vulgaris, Greenfinch, Carduelis chloris, House Martin, Delichon urbica, Tree Sparrow, Passer montanus, Great Tit, Parus major, Blue Tit, Parus caeruleus, and Jackdaw, Corvus monedula. They comprised together about 1/5. The remaining 40 species nested in a density between 0.1 and 3.5 pairs per 100 ha. The most numerous feeding guild were granivores (53.8% and insectivores (37.9 %. Birds nesting on buildings comprised together 74 % of all breeding pairs. For a few species (Luscinia megarhynchos, Saxicola torquata, Corvus cornix and Turdus pilaris an increase in their numbers in the last three decades has been evidenced.

How extensive is the effect of modern farming on bird communities in a sand dune desert?

Directory of Open Access Journals (Sweden)

Faris Khoury

2009-12-01

Full Text Available Bird community structure and diversity measures in sand dune habitats far from and close to modern farms in Wadi Araba, south-west Jordan, were compared using 52 line transects for breeding birds and habitat variables. A change in the bird community of sand dunes surrounding farming projects was measured to a distance of 1 km, but could neither be related to changes in habitat structure nor to the activity of op- portunistic predators (Red Fox as these did not vary significantly between the two samples. The farms included lines of trees and offered a constant source of water, which attracted a variety of opportunistic species, thus increasing bird diversity and total bird abundances. The absence of characteristic ground-dwelling species of open sand dune habitats in the structurally intact sand dunes surrounding farms was likely to be the result of localized, but effectively far-reaching habitat modification (farms acting as barriers and/or competition with some of the opportunistic species, which were common around farms.

Counteracting wetland overgrowth increases breeding and staging bird abundances

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Lehikoinen, Petteri; Lehikoinen, Aleksi; Mikkola-Roos, Markku; Jaatinen, Kim

2017-01-01

Human actions have led to loss and degradation of wetlands, impairing their suitability as habitat especially for waterbirds. Such negative effects may be mitigated through habitat management. To date scientific evidence regarding the impacts of these actions remains scarce. We studied guild specific abundances of breeding and staging birds in response to habitat management on 15 Finnish wetlands. In this study management actions comprised several means of vegetation removal to thwart overgrowth. Management cost efficiency was assessed by examining the association between site-specific costs and bird abundances. Several bird guilds exhibited positive connections with both habitat management as well as with invested funds. Most importantly, however, red-listed species and species with special conservation concern as outlined by the EU showed positive correlations with management actions, underlining the conservation value of wetland management. The results suggest that grazing was especially efficient in restoring overgrown wetlands. As a whole this study makes it clear that wetland habitat management constitutes a feasible conservation tool. The marked association between invested funds and bird abundance may prove to be a valuable tool for decision makers when balancing costs and impact of conservation measures against one another.

Impact of Eucalyptus plantations on the avian breeding community ...

African Journals Online (AJOL)

The nesting bird species in natural forests and Eucalyptus plantations on the Amani Plateau, East Usambara, were studied during the breeding season of September 2003 to March 2004. Some forest birds — like barbets, batis, broadbills, doves, flycatchers, greenbuls, hornbills, and tinkerbirds — utilised similar nest sites ...

Interspecific competition and the structure of bird guilds in boreal Europe: the importance of doing fieldwork in the right season.

Science.gov (United States)

Oksanen, L

1987-12-01

Bird studies have gained a central role in the debate on the importance of interspecific competition in nature. Thus, the negative results reported from a breeding bird community in a North American shrubsteppe area have created ripples throughout community ecology. However, the set of coexisting breeding birds might be an inappropriate operational definition of a bird community, because the intensity of interspecific competition can be expected to peak in autumn-winter. A review of North European data on wintering birds suggests that the case for the competition theory remains strong when bird communities are defined on the basis of winter coexistence. Copyright © 1987. Published by Elsevier Ltd.

Gnezdilke Parka Škocjanske jame (Kras, JZ Slovenija/ The breeding birds of Škocjan Caves Park (Kras, SW Slovenia

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Figelj Jernej

2014-12-01

Full Text Available The aim of the study done in 2011 and 2012 was to identify the number of breeding bird species, to provide population estimates as well as to evaluate the conservational importance of Škocjan Caves Park for birds. Common bird species were surveyed using the territory mapping method. Rare species and nocturnally active species were surveyed using species-specific methods: observation, the playback method and the line transect method. 81 species were registered, 49 of which bred within the boundaries of the Park. The most abundant breeding species were Blackcap Sylvia atricapilla (260-320 breeding pairs, Robin Erithacus rubecula (250-310 breeding pairs, Blackbird Turdus merula (230-280 breeding pairs, Chaffinch Fringilla coelebs (230-280 breeding pairs and Marsh Tit Poecile palustris (200-240 breeding pairs. Qualifying species for the Special Protected Area (SPA Kras (SI5000023 also bred within the Park: Peregrine Falcon Falco peregrinus, Nightjar Caprimulgus europaeus, Scops Owl Otus scops and Woodlark Lululla arborea. Eagle Owl Bubo bubo was also registered, but breeding attempts during the study period were unsuccessful due to the negative influence of several factors. One of the largest colonies of Alpine Swifts Apus melba, a rare and localized species in Slovenia, is also of conservation concern.

Response of breeding birds to aerial sprays of trichlorfon (Dylox) and carbaryl (Sevin-4-Oil) in Montana forests

Science.gov (United States)

DeWeese, L.R.; Henny, C.J.; Floyd, R.L.; Bobal, K.A.; Schultz, A.W.

1979-01-01

Breeding density, food, nesting success, and mortality of 20 bird species were monitored at Beaverhead National Forest, Montana, in 1975 in conjunction with experimental applications of trichlorfon (Dylox) and carbaryl (Sevin-4-oil) to western budworms (Choristoneura occidentalis). Bird species on nine 350- to 550-ha forested plots (three controls and three treated with each pesticide) were studied before and for 14 days after the spraying of trichlorfon at 1.1 kg in?9.4 L of Panasol AN3 per ha (1 pound active ingredient in 1.0 gallon/acre) and of carbaryl at 1.1 kg in 4.7 L of diesel oil per ha (l pound active ingredient in 0.5 gallon/acre). No significant decrease in bird numbers was detected from breeding-pair estimates or live bird counts after the spraying. Of the breeding pairs present before spraying, 92% remained on control plots, 89% on trichlorfon plots, and 92% on carbaryl plots. Counts of live birds made before and after spraying in three types of habitat supported the. results of the breeding-pair estimates. Nests with eggs or with young at the time of spraying were 74 and 97% successful, respectively, in control plots, 83 and 100% in plots sprayed with trichlorfon, and 86 and 100% in plots sprayed with carbaryl. No sick or dead birds were found after the spraying, although budworms were found in bird stomachs, and tracer-dye from the pesticide occurred on the feathers or feet of 74% of the 202 birds collected. Species dwelling in the tree canopy encountered the dye (and thus the pesticide) at a slightly higher rate (80%) than did species below the treetops (71 %) or near the ground and in open areas (70%).

Assessment of the Impacts of Green Mountain Power Corporation's Wind Power Facility on Breeding and Migrating Birds in Searsburg, Vermont: July 1996--July 1998

Energy Technology Data Exchange (ETDEWEB)

Kerlinger, P.

2002-03-01

A 6-megawatt, 11 turbine wind power development was constructed by Green Mountain Power Corporation in Searsburg, southern Vermont, in 1996. To determine whether birds were impacted, a series of modified BA (Before, After) studies was conducted before construction (1993-1996), during (1996), and after (1997) construction on the project site. The studies were designed to monitor changes in breeding bird community (species composition and abundance) on the site, examine the behavior and numbers of songbirds migrating at night over the site and hawks migrating over the site in daylight, and search for carcasses of birds that might have collided with the turbines.

Effects of seismic lines on the abundance of breeding birds in the Kendall Island Bird Sanctuary, Northwest Territories, Canada

Energy Technology Data Exchange (ETDEWEB)

Ashenhurst, A.R.; Hannon, S.J. [Alberta Univ., Edmonton, AB (Canada). Dept. of Biological Sciences

2008-06-15

The effects of oil and gas exploration activities on bird abundance in the Arctic were investigated. The study examined the impacts of new and oil visible seismic lines within the Kendall Island Bird Sanctuary on the abundance of breeding passerines, Lapland longspur, common redpoll, American tree sparrow, and red-necked phalarope in upland tundra region and sedge-willow habitats. Results of the study showed that the effects on abundance with newer seismic lines were not statistically significant for most groups of birds. However, more birds were seen on reference transects than on seismic lines. The seismic lines had a significant impact on passerines grouped in upland tundra, as well as for sparrows in sedge and willows. Along older seismic lines, passerine abundance was lower than on reference transects in upland tundra. The study demonstrated that seismic lines created between 10 and 30 years ago had persistent vegetative changes that have reduced bird abundance. It was concluded that although the birds were not avoiding lines, some birds appeared to have increased the size of their territories in order to compensate for vegetative changes. 34 refs., 4 tabs.

Cross-seasonal patterns of avian influenza virus in breeding and wintering migratory birds: a flyway perspective

Science.gov (United States)

Hill, Nichola J.; Takekawa, John Y.; Cardona, Carol J.; Meixell, Brandt W.; Ackerman, Joshua T.; Runstadler, Jonathan A.; Boyce, Walter M.

2012-01-01

The spread of avian influenza viruses (AIV) in nature is intrinsically linked with the movements of wild birds. Wild birds are the reservoirs for the virus and their migration may facilitate the circulation of AIV between breeding and wintering areas. This cycle of dispersal has become widely accepted; however, there are few AIV studies that present cross-seasonal information. A flyway perspective is critical for understanding how wild birds contribute to the persistence of AIV over large spatial and temporal scales, with implications for how to focus surveillance efforts and identify risks to public health. This study characterized spatio-temporal infection patterns in 10,389 waterfowl at two important locations within the Pacific Flyway--breeding sites in Interior Alaska and wintering sites in California's Central Valley during 2007-2009. Among the dabbling ducks sampled, the northern shoveler (Anas clypeata) had the highest prevalence of AIV at both breeding (32.2%) and wintering (5.2%) locations. This is in contrast to surveillance studies conducted in other flyways that have identified the mallard (Anas platyrhynchos) and northern pintail (Anas acuta) as hosts with the highest prevalence. A higher diversity of AIV subtypes was apparent at wintering (n=42) compared with breeding sites (n=17), with evidence of mixed infections at both locations. Our study suggests that wintering sites may act as an important mixing bowl for transmission among waterfowl in a flyway, creating opportunities for the reassortment of the virus. Our findings shed light on how the dynamics of AIV infection of wild bird populations can vary between the two ends of a migratory flyway.

Influence of land use and climate on wetland breeding birds in the Prairie Pothole region of Canada

Science.gov (United States)

Forcey, G.M.; Linz, G.M.; Thogmartin, W.E.; Bleier, W.J.

2007-01-01

Bird populations are influenced by a variety of factors at both small and large scales that range from the presence of suitable nesting habitat, predators, and food supplies to climate conditions and land-use patterns. We evaluated the influences of regional climate and land-use variables on wetland breeding birds in the Canada section of Bird Conservation Region 11 (CA-BCR11), the Prairie Potholes. We used bird abundance data from the North American Breeding Bird Survey, land-use data from the Prairie Farm Rehabilitation Administration, and weather data from the National Climatic Data and Information Archive to model effects of regional environmental variables on bird abundance. Models were constructed a priori using information from published habitat associations in the literature, and fitting was performed with WinBUGS using Markov chain Monte Carlo techniques. Both land-use and climate variables contributed to predicting bird abundance in CA-BCR11, although climate predictors contributed the most to improving model fit. Examination of regional effects of climate and land use on wetland birds in CA-BCR11 revealed relationships with environmental covariates that are often overlooked by small-scale habitat studies. Results from these studies can be used to improve conservation and management planning for regional populations of avifauna. ?? 2007 NRC.

An avifaunal survey of the Istranca mountains, turkish thrace: novel breeding bird records including the first breeding record of Wood Warbler Phylloscopus sibilatrix in Turkey

DEFF Research Database (Denmark)

Özkan, Korhan

2011-01-01

A breeding bird survey in the Istranca (Yıldız) mountains of Turkish Thrace seawards to the Black sea was conducted May–August 2009. Eighty-eight days of field work in 697 locations generated novel breeding evidence for several species. The survey provided the first certain evidence of Wood Warbl...

Nest ectoparasites increase physiological stress in breeding birds: an experiment.

Science.gov (United States)

Martínez-de la Puente, Josué; Merino, Santiago; Tomás, Gustavo; Moreno, Juan; Morales, Judith; Lobato, Elisa; Martínez, Javier

2011-02-01

Parasites are undoubtedly a biotic factor that produces stress. Heat shock proteins (HSPs) are important molecules buffering cellular damage under adverse conditions. During the breeding season, blue tit Cyanistes caeruleus (L.) adults are affected by blood parasites, nest-dwelling parasites and biting flies, potentially affecting their HSP-mediated responses. Here, we treated females with primaquine to reduce blood parasites and fumigated nests with permethrin to reduce nest-dwelling parasites to test whether these treatments affect HSP60 level during the breeding season. Medicated females, but not controls, had a significant reduction of the intensity of infection by Haemoproteus spp. blood parasites. However, final intensity of infection did not differ significantly between groups, and we did not find an effect of medication on change in HSP60 level. Fumigation reduced the abundance of nest-dwelling parasites (mites, fleas and blowfly larvae) and engorged biting midges in nests. Females breeding in non-fumigated nests increased HSP60 levels during the season more than those breeding in fumigated nests. Furthermore, the change in HSP60 level was positively correlated with the abundance of biting midges. These results show how infections by nest ectoparasites during the breeding period can increase the level of HSPs and suggest that biting midges impose physiological costs on breeding female blue tits. Although plausible, the alternative that biting midges prefer to feed on more stressed birds is poorly supported by previous studies.

Evaluation of a reproductive index for estimating productivity of grassland breeding birds

Science.gov (United States)

Morgan, M.R.; Norment, C.; Runge, M.C.

2010-01-01

Declining populations of grassland breeding birds have led to increased efforts to assess habitat quality, typically by estimating density or relative abundance. Because some grassland habitats may function as ecological traps, a more appropriate metric for determining quality is breeding success, which is challenging to determine for many cryptic-nesting grassland birds. This difficulty led Vickery et al. (1992) to propose a reproductive index based on behavioral observations rather than nest fate. We rigorously evaluated the index for 2 years using a Savannah Sparrow (Passerculus sandwichensis) population in western New York and found a weak correlation in classification of the breeding stages of monitored territories among multiple observers (r = 0.398). We also discovered a large difference between overall territory and nest success rates independently estimated with the index (9.8% over the entire breeding cycle) and with nest searching and monitoring (41.7% of nests successfully fledged young). Most importantly, we made territory-level comparisons of index estimates with actual nest fate and found that the index correctly predicted fates for only 43% of the monitored nests. A Mayfield logistic regression analysis demonstrated that only index rank 4 (eggs hatched, but young failed to fledge) showed a strong positive correlation with nest success. Although the reproductive index may function as a coarse indicator of habitat suitability (e.g., documenting production in potential ecological traps), in our study the index exhibited neither internal consistency nor the ability to predict nest fate at the plot or territory level and functioned poorly as a substitute for nest searching and monitoring. ?? 2010 The American Ornithologists' Union.

Breeding birds in riparian and upland dry forests of the Cascade Range

Science.gov (United States)

John F. Lehmkuhl; E. Dorsey Burger; Emily K. Drew; John P. Lindsey; Maryellen Haggard; Kent Z. Woodruff

2007-01-01

We quantified breeding bird abundance, diversity, and indicator species in riparian and upland dry forests along six third- to fourth-order streams on the east slope of the Cascade Range, Washington, USA. Upland mesic forest on southerly aspects was dominated by open ponderosa pine (Pinus ponderosa) and dry Douglas-fir (Pseudotsuga menziesii...

The relative importance of climate and vegetation properties on patterns of North American breeding bird species richness

International Nuclear Information System (INIS)

Goetz, Scott J; Sun, Mindy; Zolkos, Scott; Hansen, Andy; Dubayah, Ralph

2014-01-01

Recent advances in remote sensing and ecological modeling warrant a timely and robust investigation of the ecological variables that underlie large-scale patterns of breeding bird species richness, particularly in the context of intensifying land use and climate change. Our objective was to address this need using an array of bioclimatic and remotely sensed data sets representing vegetation properties and structure, and other aspects of the physical environment. We first build models of bird species richness across breeding bird survey (BBS) routes, and then spatially predict richness across the coterminous US at moderately high spatial resolution (1 km). Predictor variables were derived from various sources and maps of species richness were generated for four groups (guilds) of birds with different breeding habitat affiliation (forest, grassland, open woodland, scrub/shrub), as well as all guilds combined. Predictions of forest bird distributions were strong (R 2 = 0.85), followed by grassland (0.76), scrub/shrub (0.63) and open woodland (0.60) species. Vegetation properties were generally the strongest determinants of species richness, whereas bioclimatic and lidar-derived vertical structure metrics were of variable importance and dependent upon the guild type. Environmental variables (climate and the physical environment) were also frequently selected predictors, but canopy structure variables were not as important as expected based on more local to regional scale studies. Relatively sparse sampling of canopy structure metrics from the satellite lidar sensor may have reduced their importance relative to other predictor variables across the study domain. We discuss these results in the context of the ecological drivers of species richness patterns, the spatial scale of bird diversity analyses, and the potential of next generation space-borne lidar systems relevant to vegetation and ecosystem studies. This study strengthens current understanding of bird species�

Effects of reintroduced beaver (Castor canadensis) on riparian bird community structure along the upper San Pedro River, southeastern Arizona and northern Sonora, Mexico

Science.gov (United States)

Johnson, Glenn E.; van Riper, Charles

2014-01-01

Chapter 1.—We measured bird abundance and richness along the upper San Pedro River in 2005 and 2006, in order to document how beavers (Castor canadensis) may act as ecosystem engineers after their reintroduction to a desert riparian area in the Southwestern United States. In areas where beavers colonized, we found higher bird abundance and richness of bird groups, such as all breeding birds, insectivorous birds, and riparian specialists, and higher relative abundance of many individual species—including several avian species of conservation concern. Chapter 2.—We conducted bird surveys in riparian areas along the upper San Pedro River in southeastern Arizona (United States) and northern Sonora (Mexico) in order to describe factors influencing bird community dynamics and the distribution and abundance of species, particularly those of conservation concern. These surveys were also used to document the effects of the ecosystem-altering activities of a recently reintroduced beavers (Castor canadensis). Chapter 3.—We reviewed Southwestern Willow Flycatcher (Empidonax traillii extimus) nest records and investigated the potential for future breeding along the upper San Pedro River in southeastern Arizona, where in July 2005 we encountered the southernmost verifiable nest attempt for the species. Continued conservation and management of the area’s riparian vegetation and surface water has potential to contribute additional breeding sites for this endangered Willow Flycatcher subspecies. Given the nest record along the upper San Pedro River and the presence of high-density breeding sites to the north, the native cottonwood-willow forests of the upper San Pedro River could become increasingly important to E. t. extimus recovery, especially considering the anticipated effect of the tamarisk leaf beetle (Diorhabda carinulata) on riparian habitat north of the region.

Preferred habitat of breeding birds may be compromised by climate change: unexpected effects of an exceptionally cold, wet spring.

Directory of Open Access Journals (Sweden)

Michael J Whitehouse

Full Text Available Previous studies of the consequences for breeding birds of climate change have explored how their populations may respond to increasing temperatures. However, few have considered the likely outcome of predicted extreme conditions and the relative vulnerability of populations in different habitats. Here, we compare phenology and breeding success in great tits and blue tits over a 10 year period, including the extremely harsh conditions during spring 2012, at three sites in eastern England--mixed deciduous woodland, riparian and urban habitat. Production, measured as brood biomass, was significantly lower in 2012 compared with the previous 9 years, with the decrease in productivity relatively greatest in woodland habitat. Production was related to hatch delay, i.e. birds not initiating incubation immediately after clutch completion, which was more common in 2012 than in previous years. The best predictor of hatch delay was daytime temperature (not nighttime minimum temperature and rainfall, which convincingly reflected low growth and activity of caterpillar prey. We found that birds breeding in riparian and urban habitats were less vulnerable to the extremes of weather than those breeding in mixed deciduous woodland.

The timing of birds' breeding seasons : the Perrins hypothesis revisited especially for migrants

NARCIS (Netherlands)

Drent, Rudolf H.

2006-01-01

Perrins (1970) galvanized thinking on the timing of birds' breeding seasons by pointing out that most individuals laid too late for the offspring to profit fully from the seasonal peak of food abundance, and suggested that the proximate cause was a shortage of food for the female when forming the

Changes in bird community composition in response to growth changes in short-rotation woody crop planting

International Nuclear Information System (INIS)

Tolbert, V.R.; Hanowski, J.; Schiller, A.; Hoffman, W.; Christian, D.; Lindberg, J.

1997-01-01

Hybrid poplar established as intensively managed short-rotation woody crops (SRWC) on former agricultural lands can provide habitat for wildlife. Studies of bird use of SRWC for nesting and during fall migration have shown that the numbers and kinds of breeding birds using mature plantings of hybrid poplar are similar to natural forested lands. In Minnesota, the number of species of breeding birds using habitat provided by clonal-trial plantings and young larger-scale plantings (12-64 ha) of hybrid poplar were initially most similar to those using grasslands and row-crops. As the plantings approached canopy closure, successional species became predominant. In the Pacific Northwest, breeding bird composition and density were very similar for mature plantings and forested areas; however, fall migrants were found primarily in forested areas. In the Southeast, preliminary comparisons of breeding bird use of plantings of sweetgum and sycamore with naturally regenerating forests of different ages and sizes and vegetation structure are showing no size effect on use. As with hybrid poplar, species use of the more mature plantings of sweetgum and sycamore was most similar to that of natural forests. (author)

Effect of Group-Selection Opening Size on Breeding Bird Habitat Use in a Bottomland Forest

Energy Technology Data Exchange (ETDEWEB)

Moorman, C.E.; D.C. Guynn, Jr.

2001-12-01

Research on the effects of creating group-selection openings of various sizes on breeding birds habitat use in a bottomland hardwood forest of the Upper Coastal Plain of South Carolina. Creation of 0.5-ha group selection openings in southern bottomland forests should provide breeding habitat for some field-edge species in gaps and habitat for forest-interior species and canopy-dwelling forest-edge species between gaps provided that enough mature forest is made available.

Explaining individual variation in patterns of mass loss in breeding birds

Directory of Open Access Journals (Sweden)

Cuthill Innes C

2006-05-01

Full Text Available Abstract Background Studies of birds have a disproportionate representation in the literature on life-history evolution, because of the (apparent ease with which the costs and benefits can be quantified and manipulated. During reproduction, birds frequently show a highly conserved pattern of mass change and changes in mass loss during breeding have been widely considered to be a valid short-term measure of the costs of reproduction. Experimental manipulations of the breeding attempts of birds usually argue that the presence of a response shows that a cost of reproduction exists, but there is little consensus as to how the size of these costs can be measured. Results We model this mass loss by considering how a parent can maximise its lifetime reproductive success, using a theoretical framework that is particularly suited to modelling parental care in altricial birds. If lifetime reproductive success is taken to be the sum of a parent's current and future reproductive success, we show that the exact forms of these components will influence the optimal amount of mass a parent should lose. In particular, we demonstrate that the shape of the relationship between parental investment and chick survival will lead to differing degrees of investment between parents of different initial qualities: parents with initially high levels of energy reserves could conceivably invested a lesser, similar or greater amount of resources than parents with initially low reserves, and these initially 'heavy' parents could potentially end up being lighter than the initially 'lighter' individuals. Conclusion We argue that it is difficult to make predictions about the dependence of a parent's final mass on its initial mass, and therefore mass loss should only be used as a short-term measure of the costs of reproduction with caution. The model demonstrates that we require a better understanding of the relationship between mass loss and both current and future reproductive

How disturbances and management practices affect bird communities in a Carpathian river ecosystem?

Science.gov (United States)

Lacko, Jozef; Topercer, Ján; Súľovský, Marek

2018-04-01

We studied how interactions between disturbances, succession, human alterations and other habitat and landscape attributes affect bird community patterns in a lower reach of a large West Carpathian river Váh with complex disturbance and alteration histories. Breeding-bird communities, their habitats (54 variables) and surrounding landscapes (11 metrics) were sampled using standardized point counts with limited distances at 40 riparian sites divided among two transects along a 12.9 km river stretch. The most frequent and abundant birds were generalists typically associated with forest edge habitats, such as Parus major, Sylvia atricapilla, Fringilla coelebs, Oriolus oriolus, Phylloscopus collybita, Sturnus vulgaris, Turdus merula and Luscinia megarhynchos. Abundances show significant increase at the lower transect responding apparently to greater size and heterogeneity of riparian habitats and more abundant food supply linked to more diverse and intense human influences in a suburban zone. Both indirect (NMDS) and direct ordination (CCA) revealed remarkably large number of evenly important factors underlying riparian bird-habitat interactions. It suggests considerable environmental heterogeneity and complexity of these interactions as a likely outcome of long and complex disturbance and alteration histories of the area. Yet structure and relative importance of first two gradients (longitudinal and lateral linkages) remains simple and stable, complying well with predictions of river continuum concept and stream ecosystem theory. Of the nine statistically significant variables most strongly correlated with first two CCA axes, percentages of Helianthus tuberosus, footpaths, fields, Calystegia sepium and steep banks uphold our hypotheses predicting significant effects of invasive species, visitor disturbances, agricultural land use and unaltered river banks/bed on bird community composition and structure. A small but significant contribution of patch size standard

Monitoring the impact of the Gordon C. Leitch oil spill on the breeding bird populations of the Mingan Archipelago National Park Reserve, (QC) Canada

International Nuclear Information System (INIS)

Roberge, B.; Chapdelaine, G.

2000-01-01

Results of a monitoring study of the impact of a 1999 oil spill on the breeding bird population in the Mingan Archipelago National Park Reserve in the Gulf of St. Lawrence, Quebec, are discussed. The common eider, the black guillemot and the bald eagle were the three species studied by observing and comparing the status of these bird populations on islands located inside and outside of the contaminated area. Data from before and after the oil spill were compared. Results show that an estimated 211 to 777 breeding birds have died as a result of the oil spill, however, the overall impact on the reproductive potential of the breeding bird population was insignificant. Various protective measures to mitigate the effects of future oil spills are proposed. 38 refs., 7 tabs., 1 fig

Multi-scale factors influencing the characteristics of avian communities in urban parks across Beijing during the breeding season

Science.gov (United States)

Xie, Shilin; Lu, Fei; Cao, Lei; Zhou, Weiqi; Ouyang, Zhiyun

2016-07-01

Understanding the factors that influence the characteristics of avian communities using urban parks at both the patch and landscape level is important to focus management effort towards enhancing bird diversity. Here, we investigated this issue during the breeding season across urban parks in Beijing, China, using high-resolution satellite imagery. Fifty-two bird species were recorded across 29 parks. Analysis of residence type of birds showed that passengers were the most prevalent (37%), indicating that Beijing is a major node in the East Asian-Australasian Flyway. Park size was crucial for total species abundance, but foliage height diversity was the most important factor influencing avian species diversity. Thus, optimizing the configuration of vertical vegetation structure in certain park areas is critical for supporting avian communities in urban parks. Human visitation also showed negative impact on species diversity. At the landscape level, the percentage of artificial surface and largest patch index of woodland in the buffer region significantly affected total species richness, with insectivores and granivores being more sensitive to the landscape pattern of the buffer region. In conclusion, urban birds in Beijing are influenced by various multi-scale factors; however, these effects vary with different feeding types.

How spatial variation in areal extent and configuration of labile vegetation states affect the riparian bird community in Arctic tundra.

Directory of Open Access Journals (Sweden)

John-André Henden

Full Text Available The Arctic tundra is currently experiencing an unprecedented combination of climate change, change in grazing pressure by large herbivores and growing human activity. Thickets of tall shrubs represent a conspicuous vegetation state in northern and temperate ecosystems, where it serves important ecological functions, including habitat for wildlife. Thickets are however labile, as tall shrubs respond rapidly to both abiotic and biotic environmental drivers. Our aim was to assess how large-scale spatial variation in willow thicket areal extent, configuration and habitat structure affected bird abundance, occupancy rates and species richness so as to provide an empirical basis for predicting the outcome of environmental change for riparian tundra bird communities. Based on a 4-year count data series, obtained through a large-scale study design in low arctic tundra in northern Norway, statistical hierarchical community models were deployed to assess relations between habitat configuration and bird species occupancy and community richness. We found that species abundance, occupancy and richness were greatly affected by willow areal extent and configuration, habitat features likely to be affected by intense ungulate browsing as well as climate warming. In sum, total species richness was maximized in large and tall willow patches of small to intermediate degree of fragmentation. These community effects were mainly driven by responses in the occupancy rates of species depending on tall willows for foraging and breeding, while species favouring other vegetation states were not affected. In light of the predicted climate driven willow shrub encroachment in riparian tundra habitats, our study predicts that many bird species would increase in abundance, and that the bird community as a whole could become enriched. Conversely, in tundra regions where overabundance of large herbivores leads to decreased areal extent, reduced height and increased fragmentation

Breeding Biology of Grassland Birds in Western New York: Conservation and Management Implications

Directory of Open Access Journals (Sweden)

Christopher J. Norment

2010-12-01

Full Text Available Declining grassland breeding bird populations have led to increased efforts to assess habitat quality, typically by estimating density or relative abundance. Because some grassland habitats may function as ecological traps, a more appropriate metric for determining quality may be breeding success. Between 1994 and 2003 we gathered data on the nest fates of Eastern Meadowlarks (Sturnella magna, Bobolinks (Dolichonyx oryzivorous, and Savannah Sparrows (Passerculus sandwichensis in a series of fallow fields and pastures/hayfields in western New York State. We calculated daily survival probabilities using the Mayfield method, and used the logistic-exposure method to model effects of predictor variables on nest success. Nest survival probabilities were 0.464 for Eastern Meadowlarks (n = 26, 0.483 for Bobolinks (n = 91, and 0.585 for Savannah Sparrows (n = 152. Fledge dates for first clutches ranged between 14 June and 23 July. Only one obligate grassland bird nest was parasitized by Brown-headed Cowbirds (Molothrus ater, for an overall brood parasitism rate of 0.004. Logistic-exposure models indicated that daily nest survival probabilities were higher in pastures/hayfields than in fallow fields. Our results, and those from other studies in the Northeast, suggest that properly managed cool season grassland habitats in the region may not act as ecological traps, and that obligate grassland birds in the region may have greater nest survival probabilities, and lower rates of Brown-headed Cowbird parasitism, than in many parts of the Midwest.

Breeding Ecology of Birds -22 ...

Indian Academy of Sciences (India)

or drive the birds away. However, the droppings of the birds provide a rich source of fertilizer and this ... birds of India are under severe threat and require urgent protection. he~ries'(Box 1), can ... there will be no fish and then suddenly a school.

Long-term decline of a winter-resident bird community in Puerto Rico

Science.gov (United States)

J. Faaborg; W. J. Arendt; J. D. Toms; K. M. Dugger; W. A. Cox; M. Canals Mora

2013-01-01

Despite concern expressed two decades ago, there has been little recent discussion about continuing declines of migrant bird populations. Monitoring efforts have been focused almost exclusively on the breeding grounds. We describe the long-term decline of a winter-resident bird population in Guanica Commonwealth Forest, Puerto Rico, one of the last remaining tracts of...

A taxonomic, functional, and phylogenetic perspective on the community assembly of passerine birds along an elevational gradient in southwest China.

Science.gov (United States)

He, Xuelian; Luo, Kang; Brown, Calum; Lin, Luxiang

2018-03-01

Integrating multiple facets of biodiversity to describe spatial and temporal distribution patterns is one way of revealing the mechanisms driving community assembly. We assessed the species, functional, and phylogenetic composition and structure of passerine bird communities along an elevational gradient both in wintering and breeding seasons in the Ailao Mountains, southwest China, in order to identify the dominant ecological processes structuring the communities and how these processes change with elevation and season. Our research confirms that the highest taxonomic diversity, and distinct community composition, was found in the moist evergreen broadleaf forest at high elevation in both seasons. Environmental filtering was the dominant force at high elevations with relatively cold and wet climatic conditions, while the observed value of mean pairwise functional and phylogenetic distances of low elevation was constantly higher than expectation in two seasons, suggested interspecific competition could play the key role at low elevations, perhaps because of relative rich resource result from complex vegetation structure and human-induced disturbance. Across all elevations, there was a trend of decreasing intensity of environmental filtering whereas increasing interspecific competition from wintering season to breeding season. This was likely due to the increased resource availability but reproduction-associated competition in the summer months. In general, there is a clear justification for conservation efforts to protect entire elevational gradients in the Ailao Mountains, given the distinct taxonomic, functional, and phylogenetic compositions and also elevational migration pattern in passerine bird communities.

Densities of breeding birds and changes in vegetation in an alaskan boreal forest following a massive disturbance by spruce beetles

Science.gov (United States)

Matsuoka, S.M.; Handel, C.M.; Ruthrauff, D.R.

2001-01-01

We examined bird and plant communities among forest stands with different levels of spruce mortality following a large outbreak of spruce beetles (Dendroctonus rufipennis (Kirby)) in the Copper River Basin, Alaska. Spruce beetles avoided stands with black spruce (Picea mariana) and selectively killed larger diameter white spruce (Picea glauca), thereby altering forest structure and increasing the dominance of black spruce in the region. Alders (Alnus sp.) and crowberry (Empetrum nigrum) were more abundant in areas with heavy spruce mortality, possibly a response to the death of overstory spruce. Grasses and herbaceous plants did not proliferate as has been recorded following outbreaks in more coastal Alaskan forests. Two species closely tied to coniferous habitats, the tree-nesting Ruby-crowned Kinglet (Regulus calendula) and the red squirrel (Tamiasciurus hudsonicus), a major nest predator, were less abundant in forest stands with high spruce mortality than in low-mortality stands. Understory-nesting birds as a group were more abundant in forest stands with high levels of spruce mortality, although the response of individual bird species to tree mortality was variable. Birds breeding in stands with high spruce mortality likely benefited reproductively from lower squirrel densities and a greater abundance of shrubs to conceal nests from predators.

The role of the North American Breeding Bird Survey in conservation

Science.gov (United States)

Hudson, Marie-Anne R.; Francis, Charles M.; Campbell, Kate J.; Downes, Constance M.; Smith, Adam C.; Pardieck, Keith L.

2017-01-01

The North American Breeding Bird Survey (BBS) was established in 1966 in response to a lack of quantitative data on changes in the populations of many bird species at a continental scale, especially songbirds. The BBS now provides the most reliable regional and continental trends and annual indices of abundance available for >500 bird species. This paper reviews some of the ways in which BBS data have contributed to bird conservation in North America over the past 50 yr, and highlights future program enhancement opportunities. BBS data have contributed to the listing of species under the Canadian Species at Risk Act and, in a few cases, have informed species assessments under the U.S. Endangered Species Act. By raising awareness of population changes, the BBS has helped to motivate bird conservation efforts through the creation of Partners in Flight. BBS data have been used to determine priority species and locations for conservation action at regional and national scales through Bird Conservation Region strategies and Joint Ventures. Data from the BBS have provided the quantitative foundation for North American State of the Birds reports, and have informed the public with regard to environmental health through multiple indicators, such as the Canadian Environmental Sustainability Indicators and the U.S. Environmental Protection Agency's Report on the Environment. BBS data have been analyzed with other data (e.g., environmental, land cover, and demographic) to evaluate potential drivers of population change, which have then informed conservation actions. In a few cases, BBS data have contributed to the evaluation of management actions, including informing the management of Mourning Doves (Zenaida macroura), Wood Ducks (Aix sponsa), and Golden Eagles (Aquila chrysaetos). Improving geographic coverage in northern Canada and in Mexico, improving the analytical approaches required to integrate data from other sources and to address variation in detectability, and

Population Densities of Birds Breeding in Urbanized Habitats in the Grabiszyn District in the City of Wrocław

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Kopij Grzegorz

2014-11-01

Full Text Available Studies were carried out in 2010 by mean of simplified version of the mapping method. The study area (395 ha was located close to the city centre. It comprised a mosaic of urbanized habitats, with a clear dominance of green areas, such as parks (41.1 ha, gardens, cemeteries and tree clumps. A total of 48 breeding bird species were recorded in the whole study area. The most common (<25 pairs/100 ha were Passer domesticus, Passer montanus, Sturnus vulgaris, Parus caeruleus, Parus major, Apus apus and Columba livia. Numerous (7-15 pairs/100 ha were also the following species: Columba palumbus, Turdus pilaris, Sylvia atricapilla, Serinus serinus, Turdus merula and Pica pica. Insectivorous birds were the most common birds constituting 63.3%, and granivorous -32.6% of all pairs recorded. Most birds nested in tree holes (39.3%, in/on buildings (30.2% and in trees/shrubs (25.6%. Distribution of breeding pairs of 23 bird species was presented on maps. Population trends for 17 species were documented. Rapid increase in numbers of Turdus pilaris, Corvus cornix and Phoenicurus phoenicurus and decrease of Pica pica were recorded.

Heart rate responses provide an objective evaluation of human disturbance stimuli in breeding birds.

Science.gov (United States)

Ellenberg, Ursula; Mattern, Thomas; Seddon, Philip J

2013-01-01

Intuition is a poor guide for evaluating the effects of human disturbance on wildlife. Using the endangered Yellow-eyed penguin, Megadyptes antipodes, as an example, we show that heart rate responses provide an objective tool to evaluate human disturbance stimuli and encourage the wider use of this simple and low-impact approach. Yellow-eyed penguins are a flagship species for New Zealand's wildlife tourism; however, unregulated visitor access has recently been associated with reduced breeding success and lower first year survival. We measured heart rate responses of Yellow-eyed penguins via artificial eggs to evaluate a range of human stimuli regularly occurring at their breeding sites. We found the duration of a stimulus to be the most important factor, with elevated heart rate being sustained while a person remained within sight. Human activity was the next important component; a simulated wildlife photographer, crawling slowly around during his stay, elicited a significantly higher heart rate response than an entirely motionless human spending the same time at the same distance. Stimuli we subjectively might perceive as low impact, such as the careful approach of a 'wildlife photographer', resulted in a stronger response than a routine nest-check that involved lifting a bird up to view nest contents. A single, slow-moving human spending 20 min within 2 m from the nest may provoke a response comparable to that of 10 min handling a bird for logger deployment. To reduce cumulative impact of disturbance, any human presence in the proximity of Yellow-eyed penguins needs to be kept at a minimum. Our results highlight the need for objective quantification of the effects of human disturbance in order to provide a sound basis for guidelines to manage human activity around breeding birds.

Nest-site partitioning in a strandveld shrubland bird community ...

African Journals Online (AJOL)

Nest-site selection may vary adaptively among co-existing species as a result of competitive interactions among the species or in response to density-dependent nest predation. We examined nest-site characteristics and degree of partitioning among 14 co-existing bird species breeding in dwarf strandveld shrubland at ...

Habitat fragmentation reduces nest survival in an Afrotropical bird community in a biodiversity hotspot.

Science.gov (United States)

Newmark, William D; Stanley, Thomas R

2011-07-12

Ecologists have long hypothesized that fragmentation of tropical landscapes reduces avian nest success. However, this hypothesis has not been rigorously assessed because of the difficulty of finding large numbers of well-hidden nests in tropical forests. Here we report that in the East Usambara Mountains in Tanzania, which are part of the Eastern Arc Mountains, a global biodiversity hotspot, that daily nest survival rate and nest success for seven of eight common understory bird species that we examined over a single breeding season were significantly lower in fragmented than in continuous forest, with the odds of nest failure for these seven species ranging from 1.9 to 196.8 times higher in fragmented than continuous forest. Cup-shaped nests were particularly vulnerable in fragments. We then examined over six breeding seasons and 14 study sites in a multivariable survival analysis the influence of landscape structure and nest location on daily nest survival for 13 common species representing 1,272 nests and four nest types (plate, cup, dome, and pouch). Across species and nest types, area, distance of nest to edge, and nest height had a dominant influence on daily nest survival, with area being positively related to nest survival and distance of nest to edge and nest height being both positively and negatively associated with daily nest survival. Our results indicate that multiple environmental factors contribute to reduce nest survival within a tropical understory bird community in a fragmented landscape and that maintaining large continuous forest is important for enhancing nest survival for Afrotropical understory birds.

Using occupancy models of forest breeding birds to prioritize conservation planning

Science.gov (United States)

De Wan, A. A.; Sullivan, P.J.; Lembo, A.J.; Smith, C.R.; Maerz, J.C.; Lassoie, J.P.; Richmond, M.E.

2009-01-01

As urban development continues to encroach on the natural and rural landscape, land-use planners struggle to identify high priority conservation areas for protection. Although knowing where urban-sensitive species may be occurring on the landscape would facilitate conservation planning, research efforts are often not sufficiently designed to make quality predictions at unknown locations. Recent advances in occupancy modeling allow for more precise estimates of occupancy by accounting for differences in detectability. We applied these techniques to produce robust estimates of habitat occupancy for a subset of forest breeding birds, a group that has been shown to be sensitive to urbanization, in a rapidly urbanizing yet biological diverse region of New York State. We found that detection probability ranged widely across species, from 0.05 to 0.8. Our models suggest that detection probability declined with increasing forest fragmentation. We also found that the probability of occupancy of forest breeding birds is negatively influenced by increasing perimeter-area ratio of forest fragments and urbanization in the surrounding habitat matrix. We capitalized on our random sampling design to produce spatially explicit models that predict high priority conservation areas across the entire region, where interior-species were most likely to occur. Finally, we use our predictive maps to demonstrate how a strict sampling design coupled with occupancy modeling can be a valuable tool for prioritizing biodiversity conservation in land-use planning. ?? 2009 Elsevier Ltd.

Temporal changes in randomness of bird communities across Central Europe.

Science.gov (United States)

Renner, Swen C; Gossner, Martin M; Kahl, Tiemo; Kalko, Elisabeth K V; Weisser, Wolfgang W; Fischer, Markus; Allan, Eric

2014-01-01

Many studies have examined whether communities are structured by random or deterministic processes, and both are likely to play a role, but relatively few studies have attempted to quantify the degree of randomness in species composition. We quantified, for the first time, the degree of randomness in forest bird communities based on an analysis of spatial autocorrelation in three regions of Germany. The compositional dissimilarity between pairs of forest patches was regressed against the distance between them. We then calculated the y-intercept of the curve, i.e. the 'nugget', which represents the compositional dissimilarity at zero spatial distance. We therefore assume, following similar work on plant communities, that this represents the degree of randomness in species composition. We then analysed how the degree of randomness in community composition varied over time and with forest management intensity, which we expected to reduce the importance of random processes by increasing the strength of environmental drivers. We found that a high portion of the bird community composition could be explained by chance (overall mean of 0.63), implying that most of the variation in local bird community composition is driven by stochastic processes. Forest management intensity did not consistently affect the mean degree of randomness in community composition, perhaps because the bird communities were relatively insensitive to management intensity. We found a high temporal variation in the degree of randomness, which may indicate temporal variation in assembly processes and in the importance of key environmental drivers. We conclude that the degree of randomness in community composition should be considered in bird community studies, and the high values we find may indicate that bird community composition is relatively hard to predict at the regional scale.

Temporal changes in randomness of bird communities across Central Europe.

Directory of Open Access Journals (Sweden)

Swen C Renner

Full Text Available Many studies have examined whether communities are structured by random or deterministic processes, and both are likely to play a role, but relatively few studies have attempted to quantify the degree of randomness in species composition. We quantified, for the first time, the degree of randomness in forest bird communities based on an analysis of spatial autocorrelation in three regions of Germany. The compositional dissimilarity between pairs of forest patches was regressed against the distance between them. We then calculated the y-intercept of the curve, i.e. the 'nugget', which represents the compositional dissimilarity at zero spatial distance. We therefore assume, following similar work on plant communities, that this represents the degree of randomness in species composition. We then analysed how the degree of randomness in community composition varied over time and with forest management intensity, which we expected to reduce the importance of random processes by increasing the strength of environmental drivers. We found that a high portion of the bird community composition could be explained by chance (overall mean of 0.63, implying that most of the variation in local bird community composition is driven by stochastic processes. Forest management intensity did not consistently affect the mean degree of randomness in community composition, perhaps because the bird communities were relatively insensitive to management intensity. We found a high temporal variation in the degree of randomness, which may indicate temporal variation in assembly processes and in the importance of key environmental drivers. We conclude that the degree of randomness in community composition should be considered in bird community studies, and the high values we find may indicate that bird community composition is relatively hard to predict at the regional scale.

Neotropical Migratory Bird Communities in a Developing Pine Plantation

Science.gov (United States)

James G. Dickson; Richard N. Conner; J. Howard Williamson

1993-01-01

Birds were censused annually from 4 250-x80-in transects in a young pine plantation from age to 2 to 17 to assess changes in the bird community.Bird abundance was low and the bird communitry was the least diverse when the pine plantation was sparsely vegetated at age 2. As the plantation developed rapidly into the shrub stage, the bird communitry became more abundant...

Field irradiator gamma: pre-irradiation occurrence of breeding birds in three boreal habitats

International Nuclear Information System (INIS)

Seabloom, R.W.

1975-10-01

A trail census was conducted of the breeding birds found in three major habitats in the Field Irradiator Gamma area at the Whiteshell Nuclear Research Establishment, Pinawa, Manitoba. The area sampled was about 10.50 ha in size, and included 4.25 ha of upland forest, 4.75 ha of lowland conifers, and 1.50 ha of black spruce-tamarack bog. Forty-four species of birds were identified, of which 24 were considered to be resident in the study area. The highest population density was observed in the bog, followed by upland forest and lowland conifer respectively. In contrast, species diversity was greatest in the upland forest, while it decreased markedly in the relatively monotypic lowland conifer and bog habitats. (author)

Scale-dependent homogenization: changes in breeding bird diversity in the Netherlands over a 25-year period

NARCIS (Netherlands)

Turnhout, van C.A.M.; Foppen, R.P.B.; Leuven, R.S.E.W.; Siepel, H.; Esselink, H.

2007-01-01

Changes in breeding bird diversity in the Netherlands between 1973-1977 and 1998-2000 were evaluated by testing three hypotheses related to the loss of biodiversity: (1) species diversity is declining, (2) biotic homogenization is increasing and (3) rare species are declining more severely than

Timing of initial arrival at the breeding site predicts age at first reproduction in a long-lived migratory bird

Science.gov (United States)

Becker, Peter H.; Dittmann, Tobias; Ludwigs, Jan-Dieter; Limmer, Bente; Ludwig, Sonja C.; Bauch, Christina; Braasch, Alexander; Wendeln, Helmut

2008-01-01

In long-lived vertebrates, individuals generally visit potential breeding areas or populations during one or more seasons before reproducing for the first time. During these years of prospecting, they select a future breeding site, colony, or mate and improve various skills and their physical condition to meet the requirements of reproduction. One precondition of successful reproduction is arrival in time on the breeding grounds. Here, we study the intricate links among the date of initial spring arrival, body mass, sex, and the age of first breeding in the common tern Sterna hirundo, a long-lived migratory colonial seabird. The study is based on a unique, individual-based, long-term dataset of sexed birds, marked with transponders, which allow recording their individual arrival, overall attendance, and clutch initiation remotely and automatically year by year over the entire lifetime at the natal colony site. We show that the seasonal date of initial arrival at the breeding grounds predicts the individual age at first reproduction, which mostly occurs years later. Late first-time arrivals remain delayed birds throughout subsequent years. Our findings reveal that timing of arrival at the site of reproduction and timing of reproduction itself are coherent parameters of individual quality, which are linked with the prospects of the breeding career and may have consequences for fitness. PMID:18711134

Bird associations with shrubsteppe plant communities at the proposed reference repository location in southeastern Washington

Energy Technology Data Exchange (ETDEWEB)

Schuler, C.A.; Rickard, W.H.; Sargeant, G.A.

1988-03-01

This report provides information on te seasonal use of shrubsteppe vegetation by bird species at the RRL. Bird abundance and distribution were studied at the RRL to ensure that the DOE monitored migratory bird species pursuant to the Migratory Bird Treaty Act and to assess potential impacts of site characterization activities on bird populations. Birds were counted on two transects that together sampled an areas of 1.39 km/sup 2/. The relative abundance of birds, species richness, seasonal distribution, and the association of breeding shrubsteppe birds with major vegetation types were determined from Janurary through December 1987. Only 38 species were counted during 82 surveys. Total bird density during the nesting season (March-June) was 42.96 birdskm/sup 2/ and the density for the entire year was 26.74 birdskm/sup 2/. The characteristic nesting birds in shrubsteppe habitats were western meadowlark, sage sparrow, burrowing owl, mourning dove, horned lark, long-billed curlew, lark sparrow, and loggerhead shrike. Western meadowlark and sage sparrows were the most abundant breeding birds with an average density of 11.25 and 7.76 birdskm/sup 2/, respectively. Seasonal distribution of birds varied with species, but most species were present from March to September. Distribution and abunandance of nesting birds were correlated with habitat type. About 63% of the habitat surveyed was sagebrush, 26% was cheatgrass, and 11% was spiny hopsage. Sagebrush habitat supproted a greeater total bird density than cheatgrass or hopsage habitats. Sage sparrows were closely associated with sagebrush habitats, while western meadowlarks showed no strong habitat affinities. 22 refs., 9 figs., 6 tabs

Breeding avifauna of mature forest stands in the Borki Forest and its dynamics at the turn of the 21st century

Directory of Open Access Journals (Sweden)

Rąkowski Grzegorz

2016-09-01

Full Text Available The composition and structure of the breeding bird community in the Borki Forest in north-eastern Poland were investigated during two separate periods: 1994–1996 and 2012–2014. Bird censuses were carried out in three plots located in mature oak-hornbeam, ash-alder and mixed coniferous forest stands. A standard combined mapping technique for estimating the number of breeding birds was applied. A total of 74 bird species bred at least once within any plot during 1994–1996 or 2012–2014. The structure of the bird assemblages on particular plots displayed a high degree of similarity, exceeding 75%, which means that they represent essentially the same bird community. However, the investigated assemblages have changed substantially over the 20 years. Both, the number of breeding bird species and the population densities on all plots, were much higher in 2012–2014 than in 1994–1996. The mean number of breeding species on all plots was over 50% higher in 2012–2014 than in 1994–1996, whereas the mean total density of breeding pairs increased by more than 60%. Total population densities on the plots increased as a result of an increase in population densities of individual bird species combined with an increase in the number of breeding species. Due to different rates of population growth for certain species, also the composition of dominating species group have changed. The observed changes in the avifauna of the Borki Forest were most probably due to an enrichment of the forest habitats structure, which was caused by natural factors, such as ageing of forest stands, forest succession and a change in water regime by beaver dams, as well as by forest management, including group felling within or in the vicinity of plots and uncovering of the forest edge.

Importance of Coarse Woody Debris to Avian Communities in Loblolly Pine Forests

Energy Technology Data Exchange (ETDEWEB)

Lohr, S.M.; Gauthreaux, S.A.; Kilgo, J.C.

2001-06-14

Investigates the importance of standing and down coarse woody debris to bird communities in loblolly pine forests, researchers compared breeding and nonbreeding responses of birds among two coarse woody debris removal and control treatments. Quantification of vegetation layers to determine their effects on the experimental outcome coarse woody debris removal had no effect on the nonbreeding bird community. Most breeding and nonbreeding species used habitats with sparse midstory and well-developed understory, where as sparse canopy cover and dense midstory were important to some nonbreeding species. Snag and down coarse woody debris practices that maintain a dense understory, sparse midstory and canopy will create favorable breeding habitat.

Scale-dependent homogenization: Changes in breeding bird diversity in the Netherlands over a 25-year period

NARCIS (Netherlands)

Turnhout, C.A.M. van; Foppen, R.P.B.; Leuven, R.S.E.W.; Siepel, H.; Esselink, J.

2007-01-01

Changes in breeding bird diversity in the Netherlands between 1973–1977 and 1998–2000 were evaluated by testing three hypotheses related to the loss of biodiversity: (1) species diversity is declining, (2) biotic homogenization is increasing and (3) rare species are declining more severely than

LINKING THE COMMUNITY IN THE MIGRATORY RAPTOR BIRDS COUNTS (BIRDS: FALCONIFORM IN EASTERN CUBA

Directory of Open Access Journals (Sweden)

Naylien Barreda-Leyva

2010-09-01

Full Text Available Through interviews, workshops, conferences and sociocultural meeting, is carried out the linking of three communities from the high area of Gran Piedra to the studies and counts of migratory raptors birds developed in the east of Cuba. These small communities are near to one of the two points of count of migratory raptors of the region. During the interviews we could verify that some residents possessed basic knowledge on the raptors birds, but didn't know about the migration of these birds. 100 % of the interviewees coincided in that the main local problematic is the loss of birds of pen due to the attack of raptors, specifically the endemic Cuban threatened Accipitter gundlachi. The workshops were able to create spaces of exchange and reflection about the importance of the raptor’s conservation in the region. This linkage of cooperation and increasing awareness, allow an approaching between the communitarians and the researchers and volunteers that work in the counts of raptor birds in Cuba and the feedback of the scientific knowledge with the popular knowledge.

Cooperative breeding shapes post-fledging survival in an Afrotropical forest bird.

Science.gov (United States)

Van de Loock, Dries; Strubbe, Diederik; De Neve, Liesbeth; Githiru, Mwangi; Matthysen, Erik; Lens, Luc

2017-05-01

For avian group living to be evolutionary stable, multiple fitness benefits are expected. Yet, the difficulty of tracking fledglings, and thus estimating their survival rates, limits our knowledge on how such benefits may manifest postfledging. We radio-tagged breeding females of the Afrotropical cooperatively breeding Placid greenbul ( Phyllastrephus placidus) during nesting. Tracking these females after fledging permitted us to locate juvenile birds, their parents, and any helpers present and to build individual fledgling resighting datasets without incurring mortality costs or causing premature fledging due to handling or transmitter effects. A Bayesian framework was used to infer age-specific mortality rates in relation to group size, fledging date, maternal condition, and nestling condition. Postfledging survival was positively related to group size, with fledglings raised in groups with four helpers showing nearly 30% higher survival until independence compared with pair-only offspring, independent of fledging date, maternal condition or nestling condition. Our results demonstrate the importance of studying the early dependency period just after fledging when assessing presumed benefits of cooperative breeding. While studying small, mobile organisms after they leave the nest remains highly challenging, we argue that the telemetric approach proposed here may be a broadly applicable method to obtain unbiased estimates of postfledging survival.

Breeding in a den of thieves

NARCIS (Netherlands)

Fouw, de Jimmy; Bom, Roeland A.; Klaassen, Raymond H.G.; Müskens, Gerard J.D.M.; Vries, de Peter P.; Popov, Igor Yu; Kokorev, Yakov I.; Ebbinge, Bart; Nolet, Bart A.

2016-01-01

Breeding success of many Arctic-breeding bird populations varies with lemming cycles due to prey switching behavior of generalist predators. Several bird species breed on islands to escape from generalist predators like Arctic fox Vulpes lagopus, but little is known about how these species

Scrub-Successional Bird Community Dynamics in Young and Mature Pine-Wiregrass Savannahs

International Nuclear Information System (INIS)

Krementz, D.G.; Christie, J.S.

2001-01-01

We investigated how management for habitat conditions to support the endangered red-cockaded woodpecker effects the biodiversity of the breeding bird community associated with those habitats. Habitat is created by thinning, burning and mid-story control of hardwoods in mature longleaf stands. In addition, similar habitat structurally can be found in recently harvested areas. We tested the hypothesis that diversity and abundance, as well as survival and reproduction would be greater in mature stands. However, mature stands used for recruitment always had fewer species (36/31) than recently harvested areas (54/55). All species that occurred in recruitment stands also occurred in mature stands. No differences in survival rates were found between mature and recent cuts for Bachman's sparrow and indigo bunting

CEPF Western Ghats Special Series: Birds of lower Palni Hills, Western Ghats, Tamil Nadu

Directory of Open Access Journals (Sweden)

T. Ramesh

2012-11-01

Full Text Available The current altitudinal distribution and breeding observations on birds of lower Palni Hills, Western Ghats were documented by conducting road transects, opportunistic surveys including trail walks and mist netting. A total of 196 species belonging to 63 families were recorded during the study. The Accipitridae family was foremost in species richness, followed by Cuculidae and Muscicapidae, Picidae, Timaliidae and other families. Altitudinal distribution of birds was higher between 600 and 900 m. The general patterns of the decreasing species richness with increasing altitude were observed in mid and upper Palnis. This could be probably because the lower Palnis have more deciduous and scrub forest which can support high food availability. Resident and migrant species made up to 87.76% and 12.24% of the community, respectively. We recorded a species that was threatened, three nearly threatened, and five endemic to the Western Ghats. Most of the endemics were confined to the higher altitudes due to the presence of moist evergreen and high altitude montane forests and grasslands. In total, 51 breeding bird observations were recorded. Interestingly, the variation in the breeding season of some birds was noticed with respect to earlier studies. Overall, our study illustrated useful information on bird community in this region which serves as a baseline for future monitoring programs.

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...

Changes in timing, duration, and symmetry of molt of Hawaiian forest birds.

Science.gov (United States)

Freed, Leonard A; Cann, Rebecca L

2012-01-01

Food limitation greatly affects bird breeding performance, but the effect of nutritive stress on molt has barely been investigated outside of laboratory settings. Here we show changes in molting patterns for an entire native Hawaiian bird community at 1650-1900 m elevation on the Island of Hawaii between 1989-1999 and 2000-2006, associated with severe food limitation throughout the year beginning in 2000. Young birds and adults of all species took longer to complete their molt, including months never or rarely used during the 1989-1999 decade. These included the cold winter months and even the early months of the following breeding season. In addition, more adults of most species initiated their molt one to two months earlier, during the breeding season. Suspended molt, indicated by birds temporarily not molting primary flight feathers during the months of peak primary molt, increased in prevalence. Food limitation reached the point where individuals of all species had asymmetric molt, with different primary flight feathers molted on each wing. These multiple changes in molt, unprecedented in birds, had survival consequences. Adult birds captured during January to March, 2000-2004, had lower survival in four of five species with little effect of extended molt. Extended molt may be adaptive for a nutrient stressed bird to survive warm temperatures but not cool winter temperatures that may obliterate the energy savings. The changing molt of Hawaiian birds has many implications for conservation and for understanding life history aspects of molt of tropical birds.

Pavement and riparian forest shape the bird community along an urban river corridor

Directory of Open Access Journals (Sweden)

Christopher J.W. McClure

2015-07-01

Full Text Available Knowledge of habitat use by animals within urban-riparian corridors during the breeding season is important for conservation, yet remains understudied. We examined the bird community along an urban-riparian corridor through metropolitan Boise, Idaho and predicted that occupancy of individual species and species richness would be greater in forested areas than in urbanized areas. We surveyed birds throughout the summers of 2009 and 2010 and quantified the m2 of each cover-type within 50-m, 100-m, and 200-m buffers surrounding each survey location using satellite imagery. Occupancy modeling revealed that eight of 14 species analyzed were positively associated with riparian forest, and no species avoided forest. Species richness was negatively associated with the amount of paved surface within 100 m of a survey site with richness declining by more than two species for every hectare of paved surface. Most associations with cover-types–especially riparian forest–were at ⩾100 m. Therefore, the riparian forest within 100 m of a given site along an urban-riparian corridor should be the most important for maintaining species richness.

Structure of the community of nesting birds in a ravine oak wood in the valley of the Oskol river

Directory of Open Access Journals (Sweden)

A. A. Atemasov

2016-10-01

Full Text Available This investigation was carried out in a forest on the southern borders of the Central-Russian Upland, on the Prioskolsky plateau, in the Srednedonskoy subprovince of the Pontic steppe province. The aim of this work is to identify the peculiarities of structure and ways of formation of the breeding population of ravine oak forests on the border of two geographic zones. The objectives of the work were to describe quantitative and qualitative characteristics of the population of the nesting birds of ravine oak forests, as well as provide an analysis of the faunogenesic structure of the nesting bird population. To obtain data on the species composition and density of nesting birds we used the line transect method by D. Hayne – Y. Ravkin. The surveys were carried out in 2011–2015 three times per season (April to June. The indicators of the breeding density of each bird species and the totals for each year were calculated. The Polydominant Simpson index was used to characterize species diversity. To evaluate the uniformity we used the calibrated version of G ‘Alatalo index F’. The calculations were performed using the program PAST. In total we observed 34 species of birds over the 5 years of research. The dynamics of the total density of breeding birds in the period researched (2011–2015 showed a maximum in 2013 (1,711 pairs/km2; the average index for the 5 years was 1,288 ± 133 pairs/km2, which is similar to the characteristics of the populations of birds forests of the steppe zone (Donetsk Ridge, Azov Upland. The dominant and subdominant species comprised 32.2–54.7% of the population, indicating a balanced community, in spite of the insular nature of the forest. The absolute dominant in all years was the Chaffinch (an average of 21.2% of the population; subdominant species were the Robin (11.2%, Great Tit (10.5% and the Collared Flycatcher (10.3%. Over a third of the total number of birds are the hollow-nesting birds (37.1%; species

Temporal and Spatial Scales Matter: Circannual Habitat Selection by Bird Communities in Vineyards.

Directory of Open Access Journals (Sweden)

Claire Guyot

Full Text Available Vineyards are likely to be regionally important for wildlife, but we lack biodiversity studies in this agroecosystem which is undergoing a rapid management revolution. As vine cultivation is restricted to arid and warm climatic regions, biodiversity-friendly management would promote species typical of southern biomes. Vineyards are often intensively cultivated, mostly surrounded by few natural features and offering a fairly mineral appearance with little ground vegetation cover. Ground vegetation cover and composition may further strongly vary with respect to season, influencing patterns of habitat selection by ecological communities. We investigated season-specific bird-habitat associations to highlight the importance of semi-natural habitat features and vineyard ground vegetation cover throughout the year. Given that avian habitat selection varies according to taxa, guilds and spatial scale, we modelled bird-habitat associations in all months at two spatial scales using mixed effects regression models. At the landscape scale, birds were recorded along 10 1-km long transects in Southwestern Switzerland (February 2014 -January 2015. At the field scale, we compared the characteristics of visited and unvisited vineyard fields (hereafter called parcels. Bird abundance in vineyards tripled in winter compared to summer. Vineyards surrounded by a greater amount of hedges and small woods harboured higher bird abundance, species richness and diversity, especially during the winter season. Regarding ground vegetation, birds showed a season-specific habitat selection pattern, notably a marked preference for ground-vegetated parcels in winter and for intermediate vegetation cover in spring and summer. These season-specific preferences might be related to species-specific life histories: more insectivorous, ground-foraging species occur during the breeding season whereas granivores predominate in winter. These results highlight the importance of

Mechanistic modeling of insecticide risks to breeding birds in ...

Science.gov (United States)

Insecticide usage in the United States is ubiquitous in urban, suburban, and rural environments. In evaluating data for an insecticide registration application and for registration review, scientists at the United States Environmental Protection Agency (USEPA) assess the fate of the insecticide and the risk the insecticide poses to the environment and non-target wildlife. At the present time, current USEPA risk assessments do not include population-level endpoints. In this paper, we present a new mechanistic model, which allows risk assessors to estimate the effects of insecticide exposure on the survival and seasonal productivity of birds known to use agricultural fields during their breeding season. The new model was created from two existing USEPA avian risk assessment models, the Terrestrial Investigation Model (TIM v.3.0) and the Markov Chain Nest Productivity model (MCnest). The integrated TIM/MCnest model has been applied to assess the relative risk of 12 insecticides used to control corn pests on a suite of 31 avian species known to use cornfields in midwestern agroecosystems. The 12 insecticides that were assessed in this study are all used to treat major pests of corn (corn root worm borer, cutworm, and armyworm). After running the integrated TIM/MCnest model, we found extensive differences in risk to birds among insecticides, with chlorpyrifos and malathion (organophosphates) generally posing the greatest risk, and bifenthrin and ë-cyhalothrin (

A Study of the Effects of Gas Well Compressor Noise on Breeding Bird Populations of the Rattlesnake Canyon Habitat Management Area, San Juan County, New Mexico

Energy Technology Data Exchange (ETDEWEB)

LaGory, K.E.; Chang, Young-Soo; Chun, K.C.; Reeves, T.; Liebich, R.; Smith, K.

2001-06-04

This report, conducted from May through July 2000, addressed the potential effect of compressor noise on breeding birds in gas-production areas administered by the FFO, specifically in the Rattlesnake Canyon Habitat Management Area northeast of Farmington, New Mexico. The study was designed to quantify and characterize noise output from these compressors and to determine if compressor noise affected bird populations in adjacent habitat during the breeding season.

The role of community participation in the control of bird hazards at ...

African Journals Online (AJOL)

... of measures to prevent bird hazards from occurring. One of the most important methods of bird hazard control involves participation of local communities around the airport. This paper illustrates the different ways in which the airport works with the community to control bird collisions with aircraft at Entebbe International ...

The Importance of Corps of Engineers Lands to Migrating and Breeding Birds

National Research Council Canada - National Science Library

Fischer, Richard

2001-01-01

.... Birding is one of the fastest growing recreational activities in the United States. The economic impacts associated with this recreational activity on local communities have only recently been recognized...

Changes in timing, duration, and symmetry of molt of Hawaiian forest birds.

Directory of Open Access Journals (Sweden)

Leonard A Freed

Full Text Available Food limitation greatly affects bird breeding performance, but the effect of nutritive stress on molt has barely been investigated outside of laboratory settings. Here we show changes in molting patterns for an entire native Hawaiian bird community at 1650-1900 m elevation on the Island of Hawaii between 1989-1999 and 2000-2006, associated with severe food limitation throughout the year beginning in 2000. Young birds and adults of all species took longer to complete their molt, including months never or rarely used during the 1989-1999 decade. These included the cold winter months and even the early months of the following breeding season. In addition, more adults of most species initiated their molt one to two months earlier, during the breeding season. Suspended molt, indicated by birds temporarily not molting primary flight feathers during the months of peak primary molt, increased in prevalence. Food limitation reached the point where individuals of all species had asymmetric molt, with different primary flight feathers molted on each wing. These multiple changes in molt, unprecedented in birds, had survival consequences. Adult birds captured during January to March, 2000-2004, had lower survival in four of five species with little effect of extended molt. Extended molt may be adaptive for a nutrient stressed bird to survive warm temperatures but not cool winter temperatures that may obliterate the energy savings. The changing molt of Hawaiian birds has many implications for conservation and for understanding life history aspects of molt of tropical birds.

Changes in Timing, Duration, and Symmetry of Molt of Hawaiian Forest Birds

Science.gov (United States)

Freed, Leonard A.; Cann, Rebecca L.

2012-01-01

Food limitation greatly affects bird breeding performance, but the effect of nutritive stress on molt has barely been investigated outside of laboratory settings. Here we show changes in molting patterns for an entire native Hawaiian bird community at 1650–1900 m elevation on the Island of Hawaii between 1989–1999 and 2000–2006, associated with severe food limitation throughout the year beginning in 2000. Young birds and adults of all species took longer to complete their molt, including months never or rarely used during the 1989–1999 decade. These included the cold winter months and even the early months of the following breeding season. In addition, more adults of most species initiated their molt one to two months earlier, during the breeding season. Suspended molt, indicated by birds temporarily not molting primary flight feathers during the months of peak primary molt, increased in prevalence. Food limitation reached the point where individuals of all species had asymmetric molt, with different primary flight feathers molted on each wing. These multiple changes in molt, unprecedented in birds, had survival consequences. Adult birds captured during January to March, 2000–2004, had lower survival in four of five species with little effect of extended molt. Extended molt may be adaptive for a nutrient stressed bird to survive warm temperatures but not cool winter temperatures that may obliterate the energy savings. The changing molt of Hawaiian birds has many implications for conservation and for understanding life history aspects of molt of tropical birds. PMID:22279547

Breeding Birds Associated with Seasonal Pools in the Northeastern United States

Science.gov (United States)

Seasonal pools in the northeast US are important habitats for amphibians and invertebrates, but little is known of their importance for birds. We examined avian community composition at seasonal pools across an urbanization gradient in Rhode Island to test the hypotheses that se...

Composition and structure of bird communities in vegetational gradients of Bodoquena Mountains, western Brazil

Directory of Open Access Journals (Sweden)

MAURICIO N. GODOI

2016-03-01

Full Text Available ABSTRACT The informations of bird species distribution in different habitats and the structure of their communities are crucial for bird conservation. We tested the differences in composition, richness and abundance of birds in different phytophysiognomies at Bodoquena Mountains, western Brazil, and we demonstrated the variations in richness and abundance of birds between different trophic groups. Sampling was conducted between July 2011 and June 2012 in 200 point counts arranged in the study area. A total of 3350 contacts were obtained belonging to 156 bird species. Woodland savannas, seasonal forests and arboreal savannas had higher bird abundance and richness, while riparian forests, clean pastures and dirty pastures had smaller values of these parameters. The bird community was organized according to local vegetational gradient, with communities of forests, open areas and savannas, although many species occurred in more than one vegetation type. The insectivorous, omnivorous, frugivorous and gramnivorous birds composed most of the community. These data showed how important environmental heterogeneity is to bird communities. Furthermore, the presence of extensive patches of natural habitats, the small distance between these patches and the permeability of pastures, with high arboreal and shrubby cover, are indicated as important factors to maintain the bird diversity.

Breeding bird survey data

Data.gov (United States)

U.S. Environmental Protection Agency — The data are maintained by the USGS (https://www.pwrc.usgs.gov/bbs/RawData/) and provides information on the trends and status of North American bird populations...

Short-Term Effects of Understory and Overstory Management on Breeding Birds in Arkansas Oak-Hickory Forests

Science.gov (United States)

Paul G. Rodewald; Kimberly G. Smith

1998-01-01

Relatively little is known about the effects of uneven-aged forest management practices on eastern forest birds, despite the fact that such methods are now commonly practiced. In 1993-94, we studied the short-term effects of uneven-aged forest management on bird communities in oak-hickory forests of north-western Arkansas. We estimated bird abundance in mature forests...

Assessing regional and interspecific variation in threshold responses of forest breeding birds through broad scale analyses.

Directory of Open Access Journals (Sweden)

Yntze van der Hoek

Full Text Available BACKGROUND: Identifying persistence and extinction thresholds in species-habitat relationships is a major focal point of ecological research and conservation. However, one major concern regarding the incorporation of threshold analyses in conservation is the lack of knowledge on the generality and transferability of results across species and regions. We present a multi-region, multi-species approach of modeling threshold responses, which we use to investigate whether threshold effects are similar across species and regions. METHODOLOGY/PRINCIPAL FINDINGS: We modeled local persistence and extinction dynamics of 25 forest-associated breeding birds based on detection/non-detection data, which were derived from repeated breeding bird atlases for the state of Vermont. We did not find threshold responses to be particularly well-supported, with 9 species supporting extinction thresholds and 5 supporting persistence thresholds. This contrasts with a previous study based on breeding bird atlas data from adjacent New York State, which showed that most species support persistence and extinction threshold models (15 and 22 of 25 study species respectively. In addition, species that supported a threshold model in both states had associated average threshold estimates of 61.41% (SE = 6.11, persistence and 66.45% (SE = 9.15, extinction in New York, compared to 51.08% (SE = 10.60, persistence and 73.67% (SE = 5.70, extinction in Vermont. Across species, thresholds were found at 19.45-87.96% forest cover for persistence and 50.82-91.02% for extinction dynamics. CONCLUSIONS/SIGNIFICANCE: Through an approach that allows for broad-scale comparisons of threshold responses, we show that species vary in their threshold responses with regard to habitat amount, and that differences between even nearby regions can be pronounced. We present both ecological and methodological factors that may contribute to the different model results, but propose that

Assessing regional and interspecific variation in threshold responses of forest breeding birds through broad scale analyses.

Science.gov (United States)

van der Hoek, Yntze; Renfrew, Rosalind; Manne, Lisa L

2013-01-01

Identifying persistence and extinction thresholds in species-habitat relationships is a major focal point of ecological research and conservation. However, one major concern regarding the incorporation of threshold analyses in conservation is the lack of knowledge on the generality and transferability of results across species and regions. We present a multi-region, multi-species approach of modeling threshold responses, which we use to investigate whether threshold effects are similar across species and regions. We modeled local persistence and extinction dynamics of 25 forest-associated breeding birds based on detection/non-detection data, which were derived from repeated breeding bird atlases for the state of Vermont. We did not find threshold responses to be particularly well-supported, with 9 species supporting extinction thresholds and 5 supporting persistence thresholds. This contrasts with a previous study based on breeding bird atlas data from adjacent New York State, which showed that most species support persistence and extinction threshold models (15 and 22 of 25 study species respectively). In addition, species that supported a threshold model in both states had associated average threshold estimates of 61.41% (SE = 6.11, persistence) and 66.45% (SE = 9.15, extinction) in New York, compared to 51.08% (SE = 10.60, persistence) and 73.67% (SE = 5.70, extinction) in Vermont. Across species, thresholds were found at 19.45-87.96% forest cover for persistence and 50.82-91.02% for extinction dynamics. Through an approach that allows for broad-scale comparisons of threshold responses, we show that species vary in their threshold responses with regard to habitat amount, and that differences between even nearby regions can be pronounced. We present both ecological and methodological factors that may contribute to the different model results, but propose that regardless of the reasons behind these differences, our results merit a warning that

The Bird Community Resilience Index: a novel remote sensing-based biodiversity variable for quantifying ecological integrity

Science.gov (United States)

Michel, N. L.; Wilsey, C.; Burkhalter, C.; Trusty, B.; Langham, G.

2017-12-01

Scalable indicators of biodiversity change are critical to reporting overall progress towards national and global targets for biodiversity conservation (e.g. Aichi Targets) and sustainable development (SDGs). These essential biodiversity variables capitalize on new remote sensing technologies and growth of community science participation. Here we present a novel biodiversity metric quantifying resilience of bird communities and, by extension, of their associated ecological communities. This metric adds breadth to the community composition class of essential biodiversity variables that track trends in condition and vulnerability of ecological communities. We developed this index for use with North American grassland birds, a guild that has experienced stronger population declines than any other avian guild, in order to evaluate gains from the implementation of best management practices on private lands. The Bird Community Resilience Index was designed to incorporate the full suite of species-specific responses to management actions, and be flexible enough to work across broad climatic, land cover, and bird community gradients (i.e., grasslands from northern Mexico through Canada). The Bird Community Resilience Index consists of four components: density estimates of grassland and arid land birds; weighting based on conservation need; a functional diversity metric to incorporate resiliency of bird communities and their ecosystems; and a standardized scoring system to control for interannual variation caused by extrinsic factors (e.g., climate). We present an analysis of bird community resilience across ranches in the Northern Great Plains region of the United States. As predicted, Bird Community Resilience was higher in lands implementing best management practices than elsewhere. While developed for grassland birds, this metric holds great potential for use as an Essential Biodiversity Variable for community composition in a variety of habitat.

Tamarix as habitat for birds: Implications for riparian restoration in the Southwestern United States

Science.gov (United States)

Sogge, M.K.; Sferra, S.J.; Paxton, E.H.

2008-01-01

Exotic vegetation has become a major habitat component in many ecosystems around the world, sometimes dramatically changing the vegetation community structure and composition. In the southwestern United States, riparian ecosystems are undergoing major changes in part due to the establishment and spread of the exotic Tamarix (saltcedar, tamarisk). There are concerns about the suitability of Tamarix as habitat for birds. Although Tamarix habitats tend to support fewer species and individuals than native habitats, Arizona Breeding Bird Atlas data and Birds of North America accounts show that 49 species use Tamarix as breeding habitat. Importantly, the relative use of Tamarix and its quality as habitat vary substantially by geographic location and bird species. Few studies have examined how breeding in Tamarix actually affects bird survivorship and productivity; recent research on Southwestern Willow Flycatchers has found no negative effects from breeding in Tamarix habitats. Therefore, the ecological benefits and costs of Tamarix control are difficult to predict and are likely to be species specific and site specific. Given the likelihood that high-quality native riparian vegetation will not develop at all Tamarix control sites, restoration projects that remove Tamarix but do not assure replacement by high-quality native habitat have the potential to reduce the net riparian habitat value for some local or regional bird populations. Therefore, an assessment of potential negative impacts is important in deciding if exotic control should be conducted. In addition, measurable project objectives, appropriate control and restoration techniques, and robust monitoring are all critical to effective restoration planning and execution. ?? 2008 Society for Ecological Restoration International.

Sea Surface Temperatures Mediated by the El Niño-Southern Oscillation Affect Birds Breeding in Temperate Coastal Rain Forests

Directory of Open Access Journals (Sweden)

Anthony J. Gaston

2005-12-01

Full Text Available We studied the timing of breeding and juvenile/adult ratios among songbirds in temperate rain forests over four years on the Haida Gwaii (Queen Charlotte Islands archipelago, British Columbia. In May 1998, air temperatures in Haida Gwaii were above average, whereas in 1999 they were the lowest in 20 yr: temperatures in the other two years were closer to normal, although 2001 was almost as cold as 1999. Temperatures closely followed the patterns of sea surface temperatures created by the 1997-1998 El Niño, i.e., warm, event and the subsequent strong La Niña, i.e., cool, event. Timing of breeding, as measured by the first capture of juveniles or by direct observations of hatching, varied by approximately 19 d between the earliest (1998 and latest (1999 years. In 1998, the proportion of juveniles among birds trapped increased steeply as soon as young birds began to appear. In other years, the rate of increase was slower. In 1999, the peak proportions of hatching-year individuals among the foliage-gleaning insectivores, i.e., the Orange-crowned Warbler (Vermivora celata, Townsend's Warbler (Dendroica townsendi, and the Golden-crowned Kinglet (Regulus satrapa, were lower than in other years, with almost no young Orange-crowned Warblers captured at all. The pattern of variation in the timing of breeding and in the proportion of hatching-year individuals trapped fitted the temperature data well, although rainfall may also have contributed. We concluded that changes mediated by El Niño-Southern Oscillation (ENSO in sea surface temperatures off northern British Columbia, through their effects on air temperatures, had a strong effect on the breeding of forest birds, to the point of causing nearly complete reproductive failure for one species in 1999. An intensification of the ENSO cycle could lead to more erratic reproduction for some species.

Energy crop cultivations of reed canary grass - An inferior breeding habitat for the skylark, a characteristic farmland bird species

Energy Technology Data Exchange (ETDEWEB)

Vepsaelaeinen, Ville [Finnish Museum of Natural History, P.O. Box 17, University of Helsinki, FI-00014 Helsinki (Finland)

2010-07-15

Here, I present the first comparison of the abundance of farmland birds in energy grass fields and in cereal-dominated conventionally cultivated fields (CCFs). I demonstrate that in boreal farmland, skylark (Alauda arvensis) densities were significantly lower in reed canary grass (RCG) (Phalaris arundinacea) fields than in CCFs. I found that during the early breeding season RCG fields and CCFs are equally good habitats, but over the ensuing couple of weeks RCG rapidly grows too tall and dense for field-nesting species. Consequently, RCG is an inferior habitat for skylark for laying replacement clutches (after failure of first nesting) or for a second clutch after one successful nesting. The results imply that if RCG cultivation is to be expanded, the establishment of large monocultures should be avoided in farmland landscapes; otherwise the novel habitat may affect detrimentally the seriously depleted skylark population, and probably also other field-nesting bird species with similar breeding habitats. (author)

Bird observations in Severnaya Zemlya, Siberia

NARCIS (Netherlands)

de ext. Korte, J.; Volkov, A.E; Gavrilo, M.V

Fieldwork in different parts of Severnaya Zemlya in 1985, 1991, 1992 and 1993 and aerial surveys in 1994 revealed a limited bird fauna with a total of 17 breeding species. The most numerous breeding birds are cliff-nesting seabirds, comprising little auk (Alle alle), 10 000-80 000 pairs; kittiwake

Environmental conditions during breeding modify the strength of mass-dependent carry-over effects in a migratory bird.

Directory of Open Access Journals (Sweden)

Xavier A Harrison

Full Text Available In many animals, processes occurring in one season carry over to influence reproductive success and survival in future seasons. The strength of such carry-over effects is unlikely to be uniform across years, yet our understanding of the processes that are capable of modifying their strength remains limited. Here we show that female light-bellied Brent geese with higher body mass prior to spring migration successfully reared more offspring during breeding, but only in years where environmental conditions during breeding were favourable. In years of bad weather during breeding, all birds suffered reduced reproductive output irrespective of pre-migration mass. Our results suggest that the magnitude of reproductive benefits gained by maximising body stores to fuel breeding fluctuates markedly among years in concert with conditions during the breeding season, as does the degree to which carry-over effects are capable of driving variance in reproductive success among individuals. Therefore while carry-over effects have considerable power to drive fitness asymmetries among individuals, our ability to interpret these effects in terms of their implications for population dynamics is dependent on knowledge of fitness determinants occurring in subsequent seasons. 

Altitudinal patterns in breeding bird species richness and density in relation to climate, habitat heterogeneity, and migration influence in a temperate montane forest (South Korea).

Science.gov (United States)

Kim, Jin-Yong; Lee, Sanghun; Shin, Man-Seok; Lee, Chang-Hoon; Seo, Changwan; Eo, Soo Hyung

2018-01-01

Altitudinal patterns in the population ecology of mountain bird species are useful for predicting species occurrence and behavior. Numerous hypotheses about the complex interactions among environmental factors have been proposed; however, these still remain controversial. This study aimed to identify the altitudinal patterns in breeding bird species richness or density and to test the hypotheses that climate, habitat heterogeneity (horizontal and vertical), and heterospecific attraction in a temperate forest, South Korea. We conducted a field survey of 142 plots at altitudes between 200 and 1,400 m a.s.l in the breeding season. A total of 2,771 individuals from 53 breeding bird species were recorded. Altitudinal patterns of species richness and density showed a hump-shaped pattern, indicating that the highest richness and density could be observed at moderate altitudes. Models constructed with 13 combinations of six variables demonstrated that species richness was positively correlated with vertical and horizontal habitat heterogeneity. Density was positively correlated with vertical, but not horizontal habitat heterogeneity, and negatively correlated with migratory bird ratio. No significant relationships were found between spring temperature and species richness or density. Therefore, the observed patterns in species richness support the hypothesis that habitat heterogeneity, rather than climate, is the main driver of species richness. Also, neither habitat heterogeneity nor climate hypotheses fully explains the observed patterns in density. However, vertical habitat heterogeneity does likely help explain observed patterns in density. The heterospecific attraction hypothesis did not apply to the distribution of birds along the altitudinal gradient. Appropriate management of vertical habitat heterogeneity, such as vegetation cover, should be maintained for the conservation of bird diversity in this area.

Monitoring breeding and migration of neotropical migratory birds at Point Loma, San Diego County, California, 5-year summary, 2011–15

Science.gov (United States)

Lynn, Suellen; Madden, Melanie C.; Kus, Barbara E.

2017-04-27

Executive SummaryWe operated a bird banding station on the Point Loma peninsula in western San Diego County, California, during spring and summer from 2011 to 2015. The station was established in 2010 as part of a long-term monitoring program for neotropical migratory birds during spring migration and for breeding birds as part of the Monitoring Avian Productivity and Survivorship (MAPS) program.During spring migration (April and May), 2011–15, we captured 1,760 individual birds of 54 species, 91 percent (1,595) of which were newly banded, fewer than 1 percent (3) of which were recaptures that were banded in previous years, and 9 percent (143 hummingbirds, 2 hawks, and 17 other birds) of which we released unbanded. We observed an additional 22 species that were not captured. Thirty-four individuals were captured more than once. Bird capture rate averaged 0.49 ± 0.07 captures per net-hour (range 0.41–0.56). Species richness per day averaged 6.87 ± 0.33. Cardellina pusilla (Wilson’s warbler) was the most abundant spring migrant captured, followed by Empidonax difficilis (Pacific-slope flycatcher), Vireo gilvus (warbling vireo), Zonotrichia leucophrys (white-crowned sparrow), and Selasphorus rufus (rufous hummingbird). Captures of white-crowned sparrow decreased, and captures of Pacific-slope flycatcher increased, over the 5 years of our study. Fifty-six percent of known-sex individuals were male and 44 percent were female. The peak number of new species arriving per day ranged from April 1 (2013-six species) to April 16 (2012-five species). A significant correlation was determined between the number of migrants captured each day per net-hour and the density of echoes on the Next-Generation Radar (NEXRAD) images across all 5 years, and in each year except 2014. NEXRAD radar imagery appears to be a useful tool for detecting pulses in migration.Our results indicate that Point Loma provides stopover habitat during migration for 76 migratory species, including 20

Re-shuffling of species with climate disruption: a no-analog future for California birds?

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Diana Stralberg

2009-09-01

Full Text Available By facilitating independent shifts in species' distributions, climate disruption may result in the rapid development of novel species assemblages that challenge the capacity of species to co-exist and adapt. We used a multivariate approach borrowed from paleoecology to quantify the potential change in California terrestrial breeding bird communities based on current and future species-distribution models for 60 focal species. Projections of future no-analog communities based on two climate models and two species-distribution-model algorithms indicate that by 2070 over half of California could be occupied by novel assemblages of bird species, implying the potential for dramatic community reshuffling and altered patterns of species interactions. The expected percentage of no-analog bird communities was dependent on the community scale examined, but consistent geographic patterns indicated several locations that are particularly likely to host novel bird communities in the future. These no-analog areas did not always coincide with areas of greatest projected species turnover. Efforts to conserve and manage biodiversity could be substantially improved by considering not just future changes in the distribution of individual species, but including the potential for unprecedented changes in community composition and unanticipated consequences of novel species assemblages.

To breed or not to breed: a seabird's response to extreme climatic events.

Science.gov (United States)

Cubaynes, Sarah; Doherty, Paul F; Schreiber, E A; Gimenez, Olivier

2011-04-23

Intermittent breeding is an important life-history strategy that has rarely been quantified in the wild and for which drivers remain unclear. It may be the result of a trade-off between survival and reproduction, with individuals skipping breeding when breeding conditions are below a certain threshold. Heterogeneity in individual quality can also lead to heterogeneity in intermittent breeding. We modelled survival, recruitment and breeding probability of the red-footed booby (Sula sula), using a 19 year mark-recapture dataset involving more than 11,000 birds. We showed that skipping breeding was more likely in El-Niño years, correlated with an increase in the local sea surface temperature, supporting the hypothesis that it may be partly an adaptive strategy of birds to face the trade-off between survival and reproduction owing to environmental constraints. We also showed that the age-specific probability of first breeding attempt was synchronized among different age-classes and higher in El-Niño years. This result suggested that pre-breeders may benefit from lowered competition with experienced breeders in years of high skipping probabilities.

Fire effects on the composition of a bird community in an amazonian Savanna (Brazil

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R. Cintra

Full Text Available The effects of fire on the composition of a bird community were investigated in an Amazonian savanna near Alter-do-Chão, Pará (Brazil. Mist-net captures and visual counts were used to assess species richness and bird abundance pre- and post-fire in an approximately 20 ha area. Visual counts along transects were used to survey birds in an approximately 2000 ha area in a nearby area. Results using the same method of ordination analysis (multidimensional scaling showed significant effects of fire in the 20 ha and 2000 ha areas and strongly suggest direct effects on bird community composition. However, the effects were different at different spatial scales and/or in different years, indicating that the effects of fire vary spatially and/or temporally. Bird community composition pre-fire was significantly different from that found post-fire. Using multiple regression analysis it was found that the numbers of burned and unburned trees were not significantly related to either bird species richness or bird abundance. Two months after the fire, neither bird species richness nor bird abundance was significantly related to the number of flowering trees (Lafoensia pacari or fruiting trees (Byrsonima crassifolia. Since fire is an annual event in Alter-do-Chão and is becoming frequent in the entire Amazon, bird community composition in affected areas could be constantly changing in time and space.

Bird communities in sun and shade coffee farms in Kenya

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C. Smith

2015-07-01

Full Text Available Agricultural expansion to meet rising crop demand is one of the greatest threats to terrestrial biodiversity. Coffee, one of the most valuable trade items in tropical countries, can provide both economic livelihood and wildlife habitat. Previous work, conducted primarily on Neotropical coffee farms, indicates that birds are generally more abundant and diverse in farms with a canopy of shade trees, though regional variation exists. To date, few studies have examined birds on coffee farms in Africa, which contains 20% of the world’s coffee acreage. We studied differences in the bird communities between sun and shade monoculture coffee in central Kenya, and we examined effects of vegetation on bird abundance and diversity. Sun coffee had higher species richness and abundances of all major guilds (omnivores, insectivores, and granivores, and showed low community similarity to shade. Unlike findings from the Neotropics, canopy cover appeared to have a negative influence on all guilds, while understory volume of weeds increased bird abundance and species richness with a similar magnitude as canopy cover. These differences highlight the need for further studies in the general East Africa region with a wider variety of shade coffee systems.

Too risky to settle: avian community structure changes in response to perceived predation risk on adults and offspring

Science.gov (United States)

Hua, Fangyuan; Fletcher, Robert J.; Sieving, Kathryn E.; Dorazio, Robert M.

2013-01-01

Predation risk is widely hypothesized as an important force structuring communities, but this potential force is rarely tested experimentally, particularly in terrestrial vertebrate communities. How animals respond to predation risk is generally considered predictable from species life-history and natural-history traits, but rigorous tests of these predictions remain scarce. We report on a large-scale playback experiment with a forest bird community that addresses two questions: (i) does perceived predation risk shape the richness and composition of a breeding bird community? And (ii) can species life-history and natural-history traits predict prey community responses to different types of predation risk? On 9 ha plots, we manipulated cues of three avian predators that preferentially prey on either adult birds or offspring, or both, throughout the breeding season. We found that increased perception of predation risk led to generally negative responses in the abundance, occurrence and/or detection probability of most prey species, which in turn reduced the species richness and shifted the composition of the breeding bird community. Species-level responses were largely predicted from the key natural-history trait of body size, but we did not find support for the life-history theory prediction of the relationship between species' slow/fast life-history strategy and their response to predation risk.

Multi-scale associations between vegetation cover and woodland bird communities across a large agricultural region.

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Karen Ikin

Full Text Available Improving biodiversity conservation in fragmented agricultural landscapes has become an important global issue. Vegetation at the patch and landscape-scale is important for species occupancy and diversity, yet few previous studies have explored multi-scale associations between vegetation and community assemblages. Here, we investigated how patch and landscape-scale vegetation cover structure woodland bird communities. We asked: (1 How is the bird community associated with the vegetation structure of woodland patches and the amount of vegetation cover in the surrounding landscape? (2 Do species of conservation concern respond to woodland vegetation structure and surrounding vegetation cover differently to other species in the community? And (3 Can the relationships between the bird community and the woodland vegetation structure and surrounding vegetation cover be explained by the ecological traits of the species comprising the bird community? We studied 103 woodland patches (0.5 - 53.8 ha over two time periods across a large (6,800 km(2 agricultural region in southeastern Australia. We found that both patch vegetation and surrounding woody vegetation cover were important for structuring the bird community, and that these relationships were consistent over time. In particular, the occurrence of mistletoe within the patches and high values of woody vegetation cover within 1,000 ha and 10,000 ha were important, especially for bird species of conservation concern. We found that the majority of these species displayed similar, positive responses to patch and landscape vegetation attributes. We also found that these relationships were related to the foraging and nesting traits of the bird community. Our findings suggest that management strategies to increase both remnant vegetation quality and the cover of surrounding woody vegetation in fragmented agricultural landscapes may lead to improved conservation of bird communities.

The Effects of Exurbanization on Bird and Macroinvertebrate Communities in Deciduous Forests on the Cumberland Plateau, Tennessee

Directory of Open Access Journals (Sweden)

Jordan M. Casey

2009-01-01

Full Text Available To investigate the potential causes of changes to bird communities in exurban areas, we examined the relationship between bird and macroinvertebrate communities in exurbanized forest. We randomly located sampling points across a gradient of exurbanization. We used point counts to quantify bird communities and sweep netting, soil cores, pitfalls, and frass collectors to quantify macroinvertebrates. Bird communities had higher richness and abundance in exurban areas compared to undeveloped forests, and lost some species of conservation concern but gained others. The macroinvertebrate community was slightly more abundant in exurban areas, with a slight shift in taxonomic composition. The abundance of macroinvertebrates in soil cores (but not pitfalls predicted the abundance of ground-foraging birds. The abundance of macroinvertebrates in sweep nets was not associated with the abundance of aerial insectivore birds. Exurbanization therefore appears to change bird and macroinvertebrate communities, but to a lesser extent than agricultural forest fragmentation or intensive urbanization.

Rural–urban gradient and land use in a millenary metropolis: how urbanization affects avian functional groups and the role of old villas in bird assemblage patterning

OpenAIRE

L. Vignoli; S. Scirè; M. A. Bologna

2013-01-01

Urbanization generally leads to a complex environmental gradient, ranging from almost undisturbed natural areas to highly modified urban landscapes. Here we analyse the effects of a rural–urban gradient on breeding bird communities and functional species groups in remnant natural and semi-natural areas of Rome. A total of 69 breeding bird species were found in the study area. Species richness decreased with increasing urbanization at two spatial scales: the point count...

Response of bird community structure to habitat management in piñon-juniper woodland-sagebrush ecotones

Science.gov (United States)

Knick, Steven T.; Hanser, Steven E.; Grace, James B.; Hollenbeck, Jeff P.; Leu, Matthias

2017-01-01

Piñon (Pinus spp.) and juniper (Juniperus spp.) woodlands have been expanding their range across the intermountain western United States into landscapes dominated by sagebrush (Artemisia spp.) shrublands. Management actions using prescribed fire and mechanical cutting to reduce woodland cover and control expansion provided opportunities to understand how environmental structure and changes due to these treatments influence bird communities in piñon-juniper systems. We surveyed 43 species of birds and measured vegetation for 1–3 years prior to treatment and 6–7 years post-treatment at 13 locations across Oregon, California, Idaho, Nevada, and Utah. We used structural equation modeling to develop and statistically test our conceptual model that the current bird assembly at a site is structured primarily by the previous bird community with additional drivers from current and surrounding habitat conditions as well as external regional bird dynamics. Treatment reduced woodland cover by >5% at 80 of 378 survey sites. However, habitat change achieved by treatment was highly variable because actual disturbance differed widely in extent and intensity. Biological inertia in the bird community was the strongest single driver; 72% of the variation in the bird assemblage was explained by the community that existed seven years earlier. Greater net reduction in woodlands resulted in slight shifts in the bird community to one having ecotone or shrubland affinities. However, the overall influence of woodland changes from treatment were relatively small and were buffered by other extrinsic factors. Regional bird dynamics did not significantly influence the structure of local bird communities at our sites. Our results suggest that bird communities in piñon-juniper woodlands can be highly stable when management treatments are conducted in areas with more advanced woodland development and at the level of disturbance measured in our study.

Bird communities in two oceanic island forests fragmented by roads ...

African Journals Online (AJOL)

Although most studies on road effects on birds have been conducted on continental grounds, road fragmentation on oceanic islands is often heavier. We assessed variation in bird communities near (≤ 25 m) and far (>100 m) from forest roads dividing laurel and pine forests on Tenerife, Canary Islands. Line transects were ...

Bird communities and environmental correlates in southern Oregon and northern California, USA

Science.gov (United States)

Jaime L. Stephens; Eric C. Dinger; John D. Alexander; Sean R. Mohren; C. John Ralph; Daniel A. Sarr

2016-01-01

We examined avian community ecology in the Klamath Ecoregion and determined that individual bird species co-exist spatially to form 29 statistically distinguishable bird groups. We identified climate, geography, and vegetation metrics that are correlated with these 29 bird groups at three scales: Klamath Ecoregion, vegetation formation (agriculture, conifer, mixed...

Adaptation of bird communities to farmland abandonment in a mountain landscape.

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João Lopes Guilherme

Full Text Available Widespread farmland abandonment has led to significant landscape transformations of many European mountain areas. These semi-natural multi-habitat landscapes are important reservoirs of biodiversity and their abandonment has important conservation implications. In multi-habitat landscapes the adaptation of communities depends on the differential affinity of the species to the available habitats. We use nested species-area relationships (SAR to model species richness patterns of bird communities across scales in a mountain landscape, in NW Portugal. We compare the performance of the classic-SAR and the countryside-SAR (i.e. multi-habitat models at the landscape scale, and compare species similarity decay (SSD at the regional scale. We find a considerable overlap of bird communities in the different land-uses (farmland, shrubland and oak forest at the landscape scale. Analysis of the classic and countryside SAR show that specialist species are strongly related to their favourite habitat. Farmland and shrubland have higher regional SSD compared to oak forests. However, this is due to the opportunistic use of farmlands by generalist birds. Forest specialists display significant regional turnover in oak forest. Overall, the countryside-SAR model had a better fit to the data showing that habitat composition determines species richness across scales. Finally, we use the countryside-SAR model to forecast bird diversity under four scenarios of land-use change. Farmland abandonment scenarios show little impact on bird diversity as the model predicts that the complete loss of farmland is less dramatic, in terms of species diversity loss, than the disappearance of native Galicio-Portuguese oak forest. The affinities of species to non-preferred habitats suggest that bird communities can adapt to land-use changes derived from farmland abandonment. Based on model predictions we argue that rewilding may be a suitable management option for many European mountain

Changes in bird communities of Admiralty Bay, King George Island (West Antarctic: insights from monitoring data (1977–1996

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Sierakowski Kazimierz

2017-06-01

Full Text Available The paper summarizes results of twenty years of seabird observations carried out between 1977 and 1996 on the western shore of Admiralty Bay (King George Island, South Shetlands, Antarctic. Changes in population size, distribution and phenology of the breeding species as well as the appearance of non-breeding species are reported. A total of 34 species of birds were observed, including 13 breeding species. Among the non-breeding species, four were observed to visit the site regularly, six rarely, and the remaining 11 were observed only occasionally. Among breeding populations, three Pygoscelis penguin species, the main krill consumers, were most numerous. The Adélie Penguin (P. adeliae dominated among the penguins nesting in the investigated areas, reaching 23,661 breeding pairs in 1978. Two other penguin species were less abundant with population sizes of approximately 7,200 breeding pairs for the Chinstrap Penguin (P. antarcticus and 3,100 breeding pairs for the Gentoo Penguin (P. papua in the same year. During the following two decades, breeding populations of pygoscelid species experienced a declining trend and their numbers were reduced by 68.0% for Chinstrap, 67.1% for Gentoo, and 33.9% for Adélie Penguins. The data reported here represent a unique reference basis and provide valuable information about indicator species, suitable for comparison with contemporary observations of bird populations in the Antarctic Peninsula region, a place of rapidly occurring climate changes and intensive harvesting of marine living resources.

Population ecology of the mallard: II. Breeding habitat conditions, size of the breeding populations, and production indices

Science.gov (United States)

Pospahala, Richard S.; Anderson, David R.; Henny, Charles J.

1974-01-01

This report, the second in a series on a comprehensive analysis of mallard population data, provides information on mallard breeding habitat, the size and distribution of breeding populations, and indices to production. The information in this report is primarily the result of large-scale aerial surveys conducted during May and July, 1955-73. The history of the conflict in resource utilization between agriculturalists and wildlife conservation interests in the primary waterfowl breeding grounds is reviewed. The numbers of ponds present during the breeding season and the midsummer period and the effects of precipitation and temperature on the number of ponds present are analyzed in detail. No significant cycles in precipitation were detected and it appears that precipitation is primarily influenced by substantial seasonal and random components. Annual estimates (1955-73) of the number of mallards in surveyed and unsurveyed breeding areas provided estimates of the size and geographic distribution of breeding mallards in North America. The estimated size of the mallard breeding population in North America has ranged from a high of 14.4 million in 1958 to a low of 7.1 million in 1965. Generally, the mallard breeding population began to decline after the 1958 peak until 1962, and remained below 10 million birds until 1970. The decline and subsequent low level of the mallard population between 1959 and 1969 .generally coincided with a period of poor habitat conditions on the major breeding grounds. The density of mallards was highest in the Prairie-Parkland Area with an average of nearly 19.2 birds per square mile. The proportion of the continental mallard breeding population in the Prairie-Parkland Area ranged from 30% in 1962 to a high of 600/0 in 1956. The geographic distribution of breeding mallards throughout North America was significantly related to the number of May ponds in the Prairie-Parkland Area. Estimates of midsummer habitat conditions and indices to

Climate change leads to decreasing bird migration distances

NARCIS (Netherlands)

Visser, M.E.; Perdeck, A.C.; van Balen, J.H.; Both, C.

2009-01-01

Global climate change has led to warmer winters in NW Europe, shortening the distance between suitable overwintering areas and the breeding areas of many bird species. Here we show that winter recovery distances have decreased over the past seven decades, for birds ringed during the breeding season

Climate change leads to decreasing bird migration distances

NARCIS (Netherlands)

Visser, Marcel E.; Perdeck, Albert C.; van Balen, Johan H.; Both, Christiaan

Global climate change has led to warmer winters in NW Europe, shortening the distance between suitable overwintering areas and the breeding areas of many bird species. Here we show that winter recovery distances have decreased over the past seven decades, for birds ringed during the breeding season

Status and distribution of migrating and breeding marine birds in north Lebanon

International Nuclear Information System (INIS)

Jarade, Gh.R.

2017-01-01

The study of marine birds in the northern part of Lebanon recorded 2681 individuals, distributed over 86 species. Among them 35 are foreshore species, 18 coastal, 6 maritime, 9 ducks, 6 herons, 9 various saltwater related species and 3 terrestrial. The highest density is shown by the yellow-legged Gull Larus michahellis and common blackheaded gull Chroicocephalus ridibundus. The globally vulnerable yelkouan shearwater Puffinus yelkouan, an endemic species to the Mediterranean, appears on the 9th rank in the classification of seabird species from the more to the least abundant, highlighting as such, beside other 6 globally near threatened species, the role that Lebanon can play in improving the conservation status of these species. Regarding the phenological status of species, 48 are passage migrant/winter visitors, 31 passage migrants, 5 winter visitors and 2 vagrant species. The surveys revealed that three coastal seabird species (Armenian gull Larus armenicus, slender-billed gull Chroicocephalus genei and sandwich tern Thalasseus sandvicensis) and one ubiquist species (Eurasian Golden Plover Pluvialis apricaria) are not rare as it was believed in previous papers but fairly common winter visitors. The study identified the yellow-legged gull breeding population to be 160 couples, and confirmed the second and third breeding records of the little ringed plover Charadrius dubius.(author)

Social information in nest colonisation and occupancy in a long-lived, solitary breeding bird.

Science.gov (United States)

Václav, Radovan; Valera, Francisco; Martínez, Teresa

2011-03-01

Recent work increasingly reveals the importance of social information in individual dispersal decisions, population dynamics and conservation. Much of the knowledge gained to date comes from studies on short-lived and/or densely breeding species. In contrast, our understanding of the processes involved in nest-site selection for long-lived, solitary breeding species is insufficient. We increased nest-site availability by nest-box supplementation over a 5-year period in a population of a long-lived, solitary, secondary-cavity nesting bird, the European roller Coracias garrulus, breeding in natural cavities and human constructions. We tested the nest limitation and the inadvertent conspecific social information hypothesis in order to study the dynamics and mechanisms of abandonment of previously used nests and the colonisation of new ones. Our data lend support to the nest-limitation hypothesis both in terms of quantity-population and the size of breeding clusters increased, and suitability--the majority of pairs used and re-occupied nest-boxes. Nevertheless, the use of natural cavities did not decrease after 5 years. At the between-patch scale, rollers were revealed to colonise nest-boxes based on conspecific social attraction, namely distance to the nearest neighbour in the same season. Despite the unpredictability of patch productivity, at the within--patch scale, the selection of previously unoccupied cavities was consistent with the performance-based conspecific attraction hypothesis. Philopatry could account for the repeated use of cavities, because nests that were used for two successive years were more likely to also be reused in the subsequent season.

The Effects of Exurbanization on Bird and Macro invertebrate Communities in Deciduous Forests on the Cumberland Plateau, Tennessee

International Nuclear Information System (INIS)

Casey, J.M.; Wilson, M.E.; Haskell, D.G.; Hollingshead, N.

2009-01-01

To investigate the potential causes of changes to bird communities in exurban areas, we examined the relationship between bird and macro invertebrate communities in exurbanized forest. We randomly located sampling points across a gradient of exurbanization. We used point counts to quantify bird communities and sweep netting, soil cores, pitfalls, and frass collectors to quantify macro invertebrates. Bird communities had higher richness and abundance in exurban areas compared to undeveloped forests, and lost some species of conservation concern but gained others. The macro invertebrate community was slightly more abundant in exurban areas, with a slight shift in taxonomic composition. The abundance of macro invertebrates in soil cores (but not pitfalls) predicted the abundance of ground-foraging birds. The abundance of macro invertebrates in sweep nets was not associated with the abundance of aerial insectivore birds. Exurbanization therefore appears to change bird and macro invertebrate communities, but to a lesser extent than agricultural forest fragmentation or intensive urbanization.

Bird community structure in riparian environments in Cai River, Rio Grande do Sul, Brazil

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Jaqueline Brummelhaus

2012-06-01

Full Text Available Urbanization produces changes in riparian environments, causing effects in the structure of bird communities, which present different responses to the impacts. We compare species richness, abundance, and composition of birds in riparian environments with different characteristics in Cai River, Rio Grande do Sul, Brazil. We carried out observations in woodland, grassland, and urban environments, between September 2007 and August 2008. We listed 130 bird species, 29 species unique to woodland environment, and an endangeredspecies: Triclaria malachitacea. Bird abundance differed from woodland (n = 426 individuals to urban environments (n = 939 individuals (F2,6 = 7.315; P = 0.025. Species composition and feeding guilds differed significantly in the bird community structures among these three riparian environments. In the grassland and urban environments there were more generalist insectivorous species, while in the woodland environments we find more leaf and trunk insectivorous species and frugivorous species, sensitive to human impacts. Bird species can be biological quality indicators and they contribute to ecosystems performing relevant functions. With the knowledge on bird community structure and their needs, it is possible to implement management practices for restoration of degraded riparian environments.

Avian influenza prevalence among hunter-harvested birds in a remote Canadian First Nation community.

Science.gov (United States)

Liberda, Eric N; Meldrum, Richard; Charania, Nadia A; Davey, Robert; Tsuji, Leonard Js

2017-01-01

Avian influenza virus (AIV) prevalence has been associated with wild game and other bird species. The contamination of these birds may pose a greater risk to those who regularly hunt and consumed infected species. Due to resident concerns communicated by local Band Council, hunter-harvested birds from a remote First Nation community in subArctic Ontario, Canada were assessed for AIV. Hunters, and especially those who live a subsistence lifestyle, are at higher risk of AIV exposure due to their increased contact with wild birds, which represent an important part of their diet. Cloacal swabs from 304 harvested game birds representing several species of wild birds commonly hunted and consumed in this First Nation community were analyzed for AIV using real-time reverse transcription polymerase chain reaction. Subtyping was performed using reverse transcription polymerase chain reaction. Sequences were assembled using Lasergene, and the sequences were compared to Genbank. In total, 16 of the 304 cloacal swab samples were positive for AIV. Of the 16 positive samples, 12 were found in mallard ducks, 3 were found in snow geese (wavies), and 1 positive sample was found in partridge. The AIV samples were subtyped, when possible, and found to be positive for the low pathogenic avian influenza virus subtypes H3 and H4. No samples were positive for subtypes of human concern, namely H5 and H7. This work represents the first AIV monitoring program results of hunter-harvested birds in a remote subsistence First Nation community. Community-level surveillance of AIV in remote subsistence hunting communities may help to identify future risks, while educating those who may have the highest exposure about proper handling of hunted birds. Ultimately, only low pathogenic strains of AIV were found, but monitoring should be continued and expanded to safeguard those with the highest exposure risk to AIV.

Mapping global diversity patterns for migratory birds.

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Marius Somveille

Full Text Available Nearly one in five bird species has separate breeding and overwintering distributions, and the regular migrations of these species cause a substantial seasonal redistribution of avian diversity across the world. However, despite its ecological importance, bird migration has been largely ignored in studies of global avian biodiversity, with few studies having addressed it from a macroecological perspective. Here, we analyse a dataset on the global distribution of the world's birds in order to examine global spatial patterns in the diversity of migratory species, including: the seasonal variation in overall species diversity due to migration; the contribution of migratory birds to local bird diversity; and the distribution of narrow-range and threatened migratory birds. Our analyses reveal a striking asymmetry between the Northern and Southern hemispheres, evident in all of the patterns investigated. The highest migratory bird diversity was found in the Northern Hemisphere, with high inter-continental turnover in species composition between breeding and non-breeding seasons, and extensive regions (at high latitudes where migratory birds constitute the majority of the local avifauna. Threatened migratory birds are concentrated mainly in Central and Southern Asia, whereas narrow-range migratory species are mainly found in Central America, the Himalayas and Patagonia. Overall, global patterns in the diversity of migratory birds indicate that bird migration is mainly a Northern Hemisphere phenomenon. The asymmetry between the Northern and Southern hemispheres could not have easily been predicted from the combined results of regional scale studies, highlighting the importance of a global perspective.

Oak Ridge Reservation Bird Records and Population Trends

Energy Technology Data Exchange (ETDEWEB)

Roy, W. K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giffen, N. R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wade, M. C. [CDM Smith (United States); Haines, A. M. [Xcel Engineering, Inc.(United States); Evans, J. W. [Tennessee WIldlife Resources Agency (WRA), Nashville, TN (United States); Jett, R. T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2014-09-01

Bird data have been collected through surveys, environmental assessments, and other observations for decades in the Oak Ridge National Environmental Research Park, located on the US Department of Energy’s Oak Ridge Reservation (ORR) in East Tennessee. Birds were recorded in a variety of habitats, including wetlands, interior forests, grasslands, ponds, corridors, forest edges, and more. Most of the information was gathered from waterfowl surveys conducted from 1990 to 2008, from Partners in Flight (PIF) breeding bird surveys conducted from 1995 to 2013, and from past publications and research on Reservation birds. We have also included our own observations and, in a few instances, credible observations of ORR birds of which we have been made aware through eBird or discussions with area ornithologists and bird watchers. For the period 1950-2014, we were able to document 228 species of birds on the ORR. Several of these species are known from historic records only, while others were not known to have ever occurred on the Reservation until recently. This report does not include PIF breeding bird data from the 2014 season or any records after July 2014. Twenty-two species--approximately 10% of the total number of species observed--have state-listed status in Tennessee as endangered, threatened, or in need of management. Of the 228 species we documented, 120 are believed to be breeding birds on the ORR.

Oak Ridge Reservation Bird Records and Population Trends

Energy Technology Data Exchange (ETDEWEB)

Roy, W. Kelly [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Giffen, Neil R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Wade, Murray [CDM Smith, Inc., Knoxville, TN (United States); Haines, Angelina [Xcel Engineering, Inc., Oak Ridge, TN (United States); Evans, James W. [Tennessee Wildlife Resources Agency, Nashville, TN (United States); Jett, Robert Trent [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2014-11-01

Bird data have been collected through surveys, environmental assessments, and other observations for decades in the Oak Ridge National Environmental Research Park, located on the US Department of Energy s Oak Ridge Reservation (ORR) in East Tennessee. Birds were recorded in a variety of habitats, including wetlands, interior forests, grasslands, ponds, corridors, forest edges, and more. Most of the information was gathered from waterfowl surveys conducted from 1990 to 2008, from Partners in Flight (PIF) breeding bird surveys conducted from 1995 to 2013, and from past publications and research on Reservation birds. We have also included our own observations and, in a few instances, credible observations of ORR birds of which we have been made aware through eBird or discussions with area ornithologists and bird watchers. For the period 1950 2014, we were able to document 228 species of birds on the ORR. Several of these species are known from historic records only, while others were not known to have ever occurred on the Reservation until recently. This report does not include PIF breeding bird data from the 2014 season or any records after July 2014. Twenty-two species approximately 10% of the total number of species observed have state-listed status in Tennessee as endangered, threatened, or in need of management. Of the 228 species we documented, 120 are believed to be breeding birds on the ORR.

Breeding biology of a winter-breeding procellariiform in the North Atlantic, the Macaronesian shearwater Puffinus lherminieri baroli.

Science.gov (United States)

Fagundes, Ana Isabel; Ramos, Jaime A; Ramos, Urtelinda; Medeiros, Renata; Paiva, Vitor H

2016-10-01

The breeding success of burrow-nesting seabirds may be influenced by both nest site characteristics and oceanographic conditions influencing food availability at sea. In this study we describe the breeding biology of the winter-breeding Macaronesian shearwater (Puffinus lherminieri baroli), including nest site characteristics and interspecific competition. We also evaluate the possible effects of changing oceanographic conditions on breeding phenology and breeding success. The study was carried out over two breeding seasons on two islands in the North Atlantic Ocean, Cima Islet and Selvagem Grande. Oceanographic characteristics differed between years. On a regional scale, the North Atlantic Oscillation (NAO) index was low and negative in 2011, and on a local scale, birds used areas with significantly lower values of chlorophyll a concentration and significantly higher values of sea surface temperature anomalies. Hatching success was higher in 2012 than in 2011. At both colonies, egg cracking was the main cause of hatching failure, but in 2011 several eggs on Selvagem Grande were deserted. In 2012 birds laid earlier and chicks had longer wings and were heavier. At both colonies, nests that were deeper, were sheltered from prevailing winds and had small chambers and a soil substrate had a higher probability of being used successfully by the birds. Nests occupied solely by Macaronesian shearwaters were much deeper and had less volume than nests shared with other species. Our study suggests that the breeding success of Macaronesian shearwaters is strongly related to nest site characteristics and that at-sea environmental conditions exert a strong influence on reproductive parameters, with birds breeding in a poor year (evaluated in terms of lower marine productivity) laying much later and their chicks growing at a slower rate than in a good year. The influence of nest site characteristics and environmental conditions may be very important for understanding the breeding

Impact of wind turbines on birds

International Nuclear Information System (INIS)

Clausager, I.; Nohr, H.

1996-01-01

The paper is a review of the present knowledge on impacts of wind turbines on birds, requested by the Danish Ministry of the Environment and Energy. The main conclusions of the review are, that in nearly all the studies so far the numbers of birds recorded colliding with wind turbines have been limited. Some studies indicate that stationary (breeding) birds inside the wind turbine area in the short run habituate to wind turbines, especially the noise and visual impacts, and that the risk for collision becomes low. However, some of the few more long term studies indicate that a negative impact may occur in later generations of breeding birds. In some studies a disturbance effect on bird species, which temporarily stay inside a wind turbine area in order to forage or rest, is observed. The degree of impact is species-specific. An effect is typically recorded inside a zone of up to 250-800 m, with geese and waders as the most sensitive groups of birds. (author)

Sound settlement: noise surpasses land cover in explaining breeding habitat selection of secondary cavity-nesting birds.

Science.gov (United States)

Kleist, Nathan J; Guralnick, Robert P; Cruz, Alexander; Francis, Clinton D

2017-01-01

Birds breeding in heterogeneous landscapes select nest sites by cueing in on a variety of factors from landscape features and social information to the presence of natural enemies. We focus on determining the relative impact of anthropogenic noise on nest site occupancy, compared to amount of forest cover, which is known to strongly influence the selection process. We examine chronic, industrial noise from natural gas wells directly measured at the nest box as well as site-averaged noise, using a well-established field experimental system in northwestern New Mexico. We hypothesized that high levels of noise, both at the nest site and in the environment, would decrease nest box occupancy. We set up nest boxes using a geospatially paired control and experimental site design and analyzed four years of occupancy data from four secondary cavity-nesting birds common to the Colorado Plateau. We found different effects of noise and landscape features depending on species, with strong effects of noise observed in breeding habitat selection of Myiarchus cinerascens, the Ash-throated Flycatcher, and Sialia currucoides, the Mountain Bluebird. In contrast, the amount of forest cover less frequently explained habitat selection for those species or had a smaller standardized effect than the acoustic environment. Although forest cover characterization and management is commonly employed by natural resource managers, our results show that characterizing and managing the acoustic environment should be an important tool in protected area management. © 2016 by the Ecological Society of America.

Influence of call broadcast timing within point counts and survey duration on detection probability of marsh breeding birds

Directory of Open Access Journals (Sweden)

Douglas C. Tozer

2017-12-01

Full Text Available The Standardized North American Marsh Bird Monitoring Protocol recommends point counts consisting of a 5-min passive observation period, meant to be free of broadcast bias, followed by call broadcasts to entice elusive species to reveal their presence. Prior to this protocol, some monitoring programs used point counts with broadcasts during the first 5 min of 10-min counts, and have since used 15-min counts with an initial 5-min passive period (P1 followed by 5 min of broadcasts (B and a second 5-min passive period (P2 to ensure consistency across years and programs. Influence of timing of broadcasts within point counts and point count duration, however, have rarely been assessed. Using data from 23,973 broadcast-assisted 15-min point counts conducted throughout the Great Lakes-St. Lawrence region between 2008 and 2016 by Bird Studies Canada's Marsh Monitoring Program and Central Michigan University's Great Lakes Coastal Wetland Monitoring Program, we estimated detection probabilities of individuals for 14 marsh breeding bird species during P1B compared to BP2, P1 compared to P2, and P1B compared to P1BP2. For six broadcast species and American Bittern (Botaurus lentiginosus, we found no significant difference in detection during P1B compared to BP2, and no significant difference in four of the same seven species during P1 compared to P2. We observed small but significant differences in detection for 7 of 14 species during P1B compared to P1BP2. We conclude that differences in timing of broadcasts causes no bias based on counts from entire 10-minute surveys, although P1B should be favored over BP2 because the same amount of effort in P1B avoids broadcast bias in all broadcast species, and 10-min surveys are superior to 15-min surveys because modest gains in detection of some species does not warrant the additional effort. We recommend point counts consisting of 5 min of passive observation followed by broadcasts, consistent with the standardized

Seasonal patterns in reproductive success of temperate-breeding birds: Experimental tests of the date and quality hypotheses.

Science.gov (United States)

Harriman, Vanessa B; Dawson, Russell D; Bortolotti, Lauren E; Clark, Robert G

2017-04-01

For organisms in seasonal environments, individuals that breed earlier in the season regularly attain higher fitness than their late-breeding counterparts. Two primary hypotheses have been proposed to explain these patterns: The quality hypothesis contends that early breeders are of better phenotypic quality or breed on higher quality territories, whereas the date hypothesis predicts that seasonally declining reproductive success is a response to a seasonal deterioration in environmental quality. In birds, food availability is thought to drive deteriorating environmental conditions, but few experimental studies have demonstrated its importance while also controlling for parental quality. We tested predictions of the date hypothesis in tree swallows ( Tachycineta bicolor ) over two breeding seasons and in two locations within their breeding range in Canada. Nests were paired by clutch initiation date to control for parental quality, and we delayed the hatching date of one nest within each pair. Subsequently, brood sizes were manipulated to mimic changes in per capita food abundance, and we examined the effects of manipulations, as well as indices of environmental and parental quality, on nestling quality, fledging success, and return rates. Reduced reproductive success of late-breeding individuals was causally related to a seasonal decline in environmental quality. Declining insect biomass and enlarged brood sizes resulted in nestlings that were lighter, in poorer body condition, structurally smaller, had shorter and slower growing flight feathers and were less likely to survive to fledge. Our results provide evidence for the importance of food resources in mediating seasonal declines in offspring quality and survival.

Food preferences of winter bird communities in different forest types.

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Swen C Renner

Full Text Available Food availability for forest birds is a function of habitat type, forest management regime, and season. In winter, it is also impacted by variations in the weather. In the current study we assessed the food preferences of wild bird populations in two types of forest (spruce and beech during the months of November 2010 to April 2011 in the Schwäbische Alb Biodiversity Exploratory, south-western Germany. Our aim was to investigate whether local bird communities preferred fat-rich, carbohydrate-rich or wild fruits and to determine how forest structure, seasonality and local weather conditions affected food preferences. We found higher bird activity in beech forests for the eleven resident species. We observed a clear preference for fat-rich food for all birds in both forest types. Snow cover affected activity at food stations but did not affect food preferences. Periods of extreme low temperatures increased activity.

French citizens monitoring ordinary birds provide tools for conservation and ecological sciences

Science.gov (United States)

Jiguet, Frédéric; Devictor, Vincent; Julliard, Romain; Couvet, Denis

2012-10-01

Volunteer-based standardized monitoring of birds has been widely implemented in Europe and North America. In France, a breeding bird survey is running since 1989 and offers keen birdwatchers to count spring birds annually during 5 min exactly on 10 fix points within a randomly selected square. The first goal of such breeding bird surveys is to measure temporal trends in order to detect possible species declines. Combining annual indices of species sharing ecological affinities or a protected/red list status further provides biodiversity indicators for policy makers. Because the sampling effort is similar among sites, and because the initial selection of monitored sites is random, the temporal trends can be considered representative of national trends, and spatial comparisons of the obtained metrics are possible. Species abundance, community richness but also community specialization and average trophic level can be estimated for each site and each year and further related to the wide range of habitat and landscape characteristics and to agricultural or forestry practices. The large number of sites allows overcoming the opposition between adaptive and passive monitoring, making such schemes fitted to adaptive monitoring. This provides opportunities to determine which type of management or practices favour biodiversity. The comparison of population fate or community dynamics across a wide range of climates and temperatures, e.g. from southern to northern Europe, revealed how European birds are already affected by climate change. Bird communities are shifting northwards, but at a slower rate than temperatures, while bird populations have larger growth rates away from their hot thermal limit. Finally, such large-scale long-term monitoring data on a complete taxonomic group (Aves) is original and offers the opportunity to compare different measures of biological diversity, such as taxonomic, phylogenetic and functional diversity. Such a citizen science scheme is an

Species-specific variation in nesting and postfledging resource selection for two forest breeding migrant songbirds

Science.gov (United States)

Julianna M. A. Jenkins; Frank R. Thompson; John Faaborg; Andrew J. Kroll

2017-01-01

Habitat selection is a fundamental component of community ecology, population ecology, and evolutionary biology and can be especially important to species with complex annual habitat requirements, such as migratory birds. Resource preferences on the breeding grounds may change during the postfledging period for migrant songbirds, however, the degree to which selection...

Pre- and post-experimental manipulation assessments confirm the increase in number of birds due to the addition of nest boxes

Directory of Open Access Journals (Sweden)

Cecilia Cuatianquiz Lima

2016-03-01

Full Text Available Secondary cavity nesting (SCN birds breed in holes that they do not excavate themselves. This is possible where there are large trees whose size and age permit the digging of holes by primary excavators and only rarely happens in forest plantations, where we expected a deficit of both breeding holes and SCN species. We assessed whether the availability of tree cavities influenced the number of SCNs in two temperate forest types, and evaluated the change in number of SCNs after adding nest boxes. First, we counted all cavities within each of our 25-m radius sampling points in mature and young forest plots during 2009. We then added nest boxes at standardised locations during 2010 and 2011 and conducted fortnightly bird counts (January–October 2009–2011. In 2011 we added two extra plots of each forest type, where we also conducted bird counts. Prior to adding nest boxes, counts revealed more SCNs in mature than in young forest. Following the addition of nest boxes, the number of SCNs increased significantly in the points with nest boxes in both types of forest. Counts in 2011 confirmed the increase in number of birds due to the addition of nest boxes. Given the likely benefits associated with a richer bird community we propose that, as is routinely done in some countries, forest management programs preserve old tree stumps and add nest boxes to forest plantations in order to increase bird numbers and bird community diversity.

Pre- and post-experimental manipulation assessments confirm the increase in number of birds due to the addition of nest boxes.

Science.gov (United States)

Cuatianquiz Lima, Cecilia; Macías Garcia, Constantino

2016-01-01

Secondary cavity nesting (SCN) birds breed in holes that they do not excavate themselves. This is possible where there are large trees whose size and age permit the digging of holes by primary excavators and only rarely happens in forest plantations, where we expected a deficit of both breeding holes and SCN species. We assessed whether the availability of tree cavities influenced the number of SCNs in two temperate forest types, and evaluated the change in number of SCNs after adding nest boxes. First, we counted all cavities within each of our 25-m radius sampling points in mature and young forest plots during 2009. We then added nest boxes at standardised locations during 2010 and 2011 and conducted fortnightly bird counts (January-October 2009-2011). In 2011 we added two extra plots of each forest type, where we also conducted bird counts. Prior to adding nest boxes, counts revealed more SCNs in mature than in young forest. Following the addition of nest boxes, the number of SCNs increased significantly in the points with nest boxes in both types of forest. Counts in 2011 confirmed the increase in number of birds due to the addition of nest boxes. Given the likely benefits associated with a richer bird community we propose that, as is routinely done in some countries, forest management programs preserve old tree stumps and add nest boxes to forest plantations in order to increase bird numbers and bird community diversity.

Pre- and post-experimental manipulation assessments confirm the increase in number of birds due to the addition of nest boxes

Science.gov (United States)

Cuatianquiz Lima, Cecilia

2016-01-01

Secondary cavity nesting (SCN) birds breed in holes that they do not excavate themselves. This is possible where there are large trees whose size and age permit the digging of holes by primary excavators and only rarely happens in forest plantations, where we expected a deficit of both breeding holes and SCN species. We assessed whether the availability of tree cavities influenced the number of SCNs in two temperate forest types, and evaluated the change in number of SCNs after adding nest boxes. First, we counted all cavities within each of our 25-m radius sampling points in mature and young forest plots during 2009. We then added nest boxes at standardised locations during 2010 and 2011 and conducted fortnightly bird counts (January–October 2009–2011). In 2011 we added two extra plots of each forest type, where we also conducted bird counts. Prior to adding nest boxes, counts revealed more SCNs in mature than in young forest. Following the addition of nest boxes, the number of SCNs increased significantly in the points with nest boxes in both types of forest. Counts in 2011 confirmed the increase in number of birds due to the addition of nest boxes. Given the likely benefits associated with a richer bird community we propose that, as is routinely done in some countries, forest management programs preserve old tree stumps and add nest boxes to forest plantations in order to increase bird numbers and bird community diversity. PMID:26998410

Receivers matter: the meaning of alarm calls and competition for nest sites in a bird community.

Science.gov (United States)

Parejo, Deseada; Avilés, Jesús M; Expósito-Granados, Mónica

2018-04-11

Animal communities may constitute information networks where individuals gain information on predation risk by eavesdropping on alarm calls of other species. However, communities include species in different trophic levels, and it is not yet known how the trophic level of the receiver influences the informative value of a call. Furthermore, no empirical study has yet tested how increased competition may influence the value of alarm calls for distinct receivers. Here, we identify the importance of alarm calls emitted by a small owl, the little owl (Athene noctua), on the structure of a cavity-nesting bird community including mesopredators and primary prey under variable levels of competition for nest holes. Competitors sharing top predators with the callers and prey of the callers interpreted alarm and non-alarm calls differently. Competitors chose preferentially alarm and non-alarm patches over control patches to breed, while prey selected alarm patches. In contrast, competition for nest sites affected habitat selection of prey species more than that of competitors of the callers. This study provides support for a changing value of alarm calls and competition for nest sites for distinct receivers related to niche overlapping among callers and eavesdroppers, therefore, calling attention to possible cascading effects by the use of information in natural communities.

Seasonal bird traffic between Grand Teton National Park and western Mexico

Science.gov (United States)

Martin L. Cody

2005-01-01

This paper presents data on variations in the breeding densities of birds in Grand Teton National Park, Wyoming, and evaluates these variations among years, habitats, and as functions of the migratory status of the breeding birds. Breeding opportunities certainly vary with the extremely variable weather conditions in the park year-to-year, and part of the variation in...

The effects of forest-savanna-grassland gradients on bird communities of Chiquitano Dry Forests domain, in western Brazil.

Science.gov (United States)

Godoi, Mauricio N; Souza, Edivaldo O DE

2016-01-01

Different vegetation types are distributed in mountains according to altitude, topography and soil. The composition and structure of bird communities in these areas can change in relation to the vegetation gradient, with particular communities occupying each habitat type. In this study we present the changes in composition, species richness and bird abundance over the gradient of forests, savannas and altitudinal grasslands of Maciço do Urucum, a mountainous region located in the Chiquitano Dry Forests domain in western Brazil. We recorded 165 bird species through qualitative and quantitative methods. Forested savannas, riparian forests and submontane forests presented the highest richness and abundance of birds, while arboreal savannas and altitudinal grasslands had intermediate and low values, respectively. The bird composition was similar between riparian and submontane forests, while other vegetation types present more dissimilar bird communities. Our results show differences in composition, richness and bird abundance among the vegetation types present at Maciço do Urucum, and highlight an important function of vegetation gradients for the conservation of bird communities in mountains. Additionally, this is the first study of the bird communities in the Brazilian Chiquitano Dry Forests, an important domain in the west of Brazil which has been poorly studied.

ECOLOGICAL RESEARCH ON THE BREEDING AVIFAUNA OF THE DÂMBOVNIC AND SUSENI LAKES AREA

Directory of Open Access Journals (Sweden)

Maria Denisa Conete

2016-12-01

Full Text Available Our research study was conducted in the area of the Dâmbovnic and Suseni lakes (a square of 2x2 km, two artificially created lakes. We identified 105 breeding species belonging to 13 orders, 39 families and 74 genera; 97 (92,4% of them are confirmed breeding species and 8 (7,6 % are probable breeding species. The results of the research on the Dâmbovnic and Suseni lakes area were compared and related to the data from the Atlas of the Romanian breeding species. By relating them to the Atlas data, we noted that 83 of the 100 breeding species cited in the Atlas were also recorded during our study; 22 new breeding species were identified (19 of them are confirmed breeding species and 3 are probable breeding species. The species that nest mainly in the reed beds (Ixobrychus minutus, Anas platyrhynchos, Fulica atra, Gallinula chloropus, Aythya ferina, Acrocephalus arundinaceus and in the ecotones, marginal areas stand out among the wetland-dependent species through their higher numbers of individuals. Chroicocephalus ridibundus and Himantopus himantopus were observed to nest in the Argeş county for the first time. Most of them are constant and euconstant species (78 species, the results reflecting the abundance of resources in the area during the nesting period. The species showing increasing trends in their breeding population had a significant share (57 %, because the attractiveness of these lakes for birds has continuously grown, being correlated with the ecological restoration of the degraded wetland areas and the emergenge of dense vegetation (thus creating new nesting places, the diversity of the habitat, the existence of ecotone areas, the diversification of the aquatic trophic resources and last but not least the reduced interaction between the local population and the bird communities in the lakes area. The anthropogenic influence is manifested through aggressive agriculture (the use of pesticides and fertilizers, etc. and more recently

Effects of wind-energy facilities on breeding grassland bird distributions.

Science.gov (United States)

Shaffer, Jill A; Buhl, Deborah A

2016-02-01

The contribution of renewable energy to meet worldwide demand continues to grow. Wind energy is one of the fastest growing renewable sectors, but new wind facilities are often placed in prime wildlife habitat. Long-term studies that incorporate a rigorous statistical design to evaluate the effects of wind facilities on wildlife are rare. We conducted a before-after-control-impact (BACI) assessment to determine if wind facilities placed in native mixed-grass prairies displaced breeding grassland birds. During 2003-2012, we monitored changes in bird density in 3 study areas in North Dakota and South Dakota (U.S.A.). We examined whether displacement or attraction occurred 1 year after construction (immediate effect) and the average displacement or attraction 2-5 years after construction (delayed effect). We tested for these effects overall and within distance bands of 100, 200, 300, and >300 m from turbines. We observed displacement for 7 of 9 species. One species was unaffected by wind facilities and one species exhibited attraction. Displacement and attraction generally occurred within 100 m and often extended up to 300 m. In a few instances, displacement extended beyond 300 m. Displacement and attraction occurred 1 year after construction and persisted at least 5 years. Our research provides a framework for applying a BACI design to displacement studies and highlights the erroneous conclusions that can be made without the benefit of adopting such a design. More broadly, species-specific behaviors can be used to inform management decisions about turbine placement and the potential impact to individual species. Additionally, the avoidance distance metrics we estimated can facilitate future development of models evaluating impacts of wind facilities under differing land-use scenarios. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Beyond breeding area management

DEFF Research Database (Denmark)

Pedersen, Lykke; Thorup, Kasper; Tøttrup, Anders P.

Every year, billions of songbirds migrate thousands of kilometres between their European breeding grounds and African overwintering area. As migratory birds are dependent on resources at a number of sites varying in both space and time, they are likely to be more vulnerable to environmental chang...... and provide important information for conservation management of migratory birds....

Weather effects on avian breeding performance and implications of climate change

Science.gov (United States)

Skagen, Susan K.; Yackel Adams, Amy A.

2012-01-01

The influence of recent climate change on the world’s biota has manifested broadly, resulting in latitudinal range shifts, advancing dates of arrival of migrants and onset of breeding, and altered community relationships. Climate change elevates conservation concerns worldwide because it will likely exacerbate a broad range of identified threats to animal populations. In the past few decades, grassland birds have declined faster than other North American avifauna, largely due to habitat threats such as the intensification of agriculture. We examine the effects of local climatic variations on the breeding performance of a bird endemic to the shortgrass prairie, the Lark Bunting (Calamospiza melanocorys) and discuss the implications of our findings relative to future climate predictions. Clutch size, nest survival, and productivity all positively covaried with seasonal precipitation, yet relatively intense daily precipitation events temporarily depressed daily survival of nests. Nest survival was positively related to average temperatures during the breeding season. Declining summer precipitation may reduce the likelihood that Lark Buntings can maintain stable breeding populations in eastern Colorado although average temperature increases of up to 38C (within the range of this study) may ameliorate declines in survival expected with drier conditions. Historic climate variability in the Great Plains selects for a degree of vagility and opportunism rather than strong site fidelity and specific adaptation to local environments. These traits may lead to northerly shifts in distribution if climatic and habitat conditions become less favorable in the drying southern regions of the Great Plains. Distributional shifts in Lark Buntings could be constrained by future changes in land use, agricultural practices, or vegetative communities that result in further loss of shortgrass prairie habitats.

Taxonomic and functional diversity of farmland bird communities across Europe: effects of biogeography and agricultural intensification

NARCIS (Netherlands)

Guerrero, I.; Morales, M.B.; Onate, J.J.; Aavik, T.; Bengtsson, J.; Berendse, F.; Geiger, F.

2011-01-01

Abstract In eight European study sites (in Spain, Ireland, Netherlands, Germany, Poland, Estonia and Sweden), abundance of breeding farmland bird territories was obtained from 500 9 500 m survey plots (30 per area, N = 240) using the mapping method. Two analyses were performed: (I) a Canonical

Nest trampling and ground nesting birds: Quantifying temporal and spatial overlap between cattle activity and breeding redshank.

Science.gov (United States)

Sharps, Elwyn; Smart, Jennifer; Mason, Lucy R; Jones, Kate; Skov, Martin W; Garbutt, Angus; Hiddink, Jan G

2017-08-01

Conservation grazing for breeding birds needs to balance the positive effects on vegetation structure and negative effects of nest trampling. In the UK, populations of Common redshank Tringa totanus breeding on saltmarshes declined by >50% between 1985 and 2011. These declines have been linked to changes in grazing management. The highest breeding densities of redshank on saltmarshes are found in lightly grazed areas. Conservation initiatives have encouraged low-intensity grazing at nest trampling. If livestock distribution is not spatially or temporally homogenous but concentrated where and when redshank breed, rates of nest trampling may be much higher than expected based on livestock density alone. By GPS tracking cattle on saltmarshes and monitoring trampling of dummy nests, this study quantified (i) the spatial and temporal distribution of cattle in relation to the distribution of redshank nesting habitats and (ii) trampling rates of dummy nests. The distribution of livestock was highly variable depending on both time in the season and the saltmarsh under study, with cattle using between 3% and 42% of the saltmarsh extent and spending most their time on higher elevation habitat within 500 m of the sea wall, but moving further onto the saltmarsh as the season progressed. Breeding redshank also nest on these higher elevation zones, and this breeding coincides with the early period of grazing. Probability of nest trampling was correlated to livestock density and was up to six times higher in the areas where redshank breed. This overlap in both space and time of the habitat use of cattle and redshank means that the trampling probability of a nest can be much higher than would be expected based on standard measures of cattle density. Synthesis and applications : Because saltmarsh grazing is required to maintain a favorable vegetation structure for redshank breeding, grazing management should aim to keep livestock away from redshank nesting habitat between mid

Bird communities of the arctic shrub tundra of Yamal: habitat specialists and generalists.

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Vasiliy Sokolov

Full Text Available BACKGROUND: The ratio of habitat generalists to specialists in birds has been suggested as a good indicator of ecosystem changes due to e.g. climate change and other anthropogenic perturbations. Most studies focusing on this functional component of biodiversity originate, however, from temperate regions. The Eurasian Arctic tundra is currently experiencing an unprecedented combination of climate change, change in grazing pressure by domestic reindeer and growing human activity. METHODOLOGY/PRINCIPAL FINDINGS: Here we monitored bird communities in a tundra landscape harbouring shrub and open habitats in order to analyse bird habitat relationships and quantify habitat specialization. We used ordination methods to analyse habitat associations and estimated the proportions of specialists in each of the main habitats. Correspondence Analysis identified three main bird communities, inhabiting upland, lowland and dense willow shrubs. We documented a stable structure of communities despite large multiannual variations of bird density (from 90 to 175 pairs/km(2. Willow shrub thickets were a hotspot for bird density, but not for species richness. The thickets hosted many specialized species whose main distribution area was south of the tundra. CONCLUSION/SIGNIFICANCE: If current arctic changes result in a shrubification of the landscape as many studies suggested, we would expect an increase in the overall bird abundance together with an increase of local specialists, since they are associated with willow thickets. The majority of these species have a southern origin and their increase in abundance would represent a strengthening of the boreal component in the southern tundra, perhaps at the expense of species typical of the subarctic zone, which appear to be generalists within this zone.

Bird communities of gambel oak: a descriptive analysis

Science.gov (United States)

Andreas Leidolf; Michael L. Wolfe; Rosemary L. Pendleton

2000-01-01

Gambel oak (Quercus gambelii Nutt.) covers 3.75 million hectares (9.3 million acres) of the western United States. This report synthesizes current knowledge on the composition, structure, and habitat relationships of gambel oak avian communities. It lists life history attributes of 183 bird species documented from gambel oak habitats of the western...

Breeding birds on organic and conventional arable farms

NARCIS (Netherlands)

Kragten, Steven

2009-01-01

As a result of agricultural intensification, farmland bird populations have been declining dramatically over the past decades. Organic farming is often mentioned to be a possible solution to stop these declines. In order to see whether farmland birds really benefit from organic farming a study was

The influence of local- and landscape-level factors on wetland breeding birds in the Prairie Pothole Region of North and South Dakota

Science.gov (United States)

Igl, Lawrence D.; Shaffer, Jill A.; Johnson, Douglas H.; Buhl, Deborah A.

2017-08-17

We examined the relationship between local- (wetland) and landscape-level factors and breeding bird abundances on 1,190 depressional wetlands in the Prairie Pothole Region of North and South Dakota during the breeding seasons in 1995–97. The surveyed wetlands were selected from five wetland classes (alkali, permanent, semipermanent, seasonal, or temporary), two wetland types (natural or restored), and two landowner groups (private or Federal). We recorded 133 species of birds in the surveyed wetlands during the 3 years. We analyzed the nine most common (or focal) species (that is, species that were present in 25 percent or more of the 1,190 wetlands): the Red-winged Blackbird (Agelaius phoeniceus), Blue-winged Teal (Anas discors), Mallard (Anas platyrhynchos), American Coot (Fulica americana), Gadwall (Anas strepera), Common Yellowthroat (Geothlypis trichas), Yellow-headed Blackbird (Xanthocephalus xanthocephalus), Northern Shoveler (Anas clypeata), and Savannah Sparrow (Passerculus sandwichensis). Our results emphasize the ecological value of all wetland classes, natural and restored wetlands, and publicly and privately owned wetlands in this region, including wetlands that are generally smaller and shallower (that is, temporary and seasonal wetlands) and thus most vulnerable to drainage. Blue-winged Teal, Northern Shoveler, Gadwall, Common Yellowthroat, and Red-winged Blackbird had higher abundances on Federal than on private wetlands. Abundances differed among wetland classes for seven of the nine focal species: Blue-winged Teal, Northern Shoveler, Mallard, American Coot, Common Yellowthroat, Yellow-headed Blackbird, Red-winged Blackbird. American Coot had higher abundances on restored wetlands than on natural wetlands overall, and Gadwall and Common Yellowthroat had higher abundances on private restored wetlands than on private natural wetlands. The Common Yellowthroat was the only species that had higher abundances on restored private wetlands than on

Patterns of distribution, abundance, and change over time in a subarctic marine bird community

Science.gov (United States)

Cushing, Daniel A.; Roby, Daniel D.; Irons, David B.

2018-01-01

Over recent decades, marine ecosystems of Prince William Sound (PWS), Alaska, have experienced concurrent effects of natural and anthropogenic perturbations, including variability in the climate system of the northeastern Pacific Ocean. We documented spatial and temporal patterns of variability in the summer marine bird community in relation to habitat and climate variability using boat-based surveys of marine birds conducted during the period 1989-2012. We hypothesized that a major factor structuring marine bird communities in PWS would be proximity to the shoreline, which is theorized to relate to aspects of food web structure. We also hypothesized that shifts in physical ecosystem drivers differentially affected nearshore-benthic and pelagic components of PWS food webs. We evaluated support for our hypotheses using an approach centered on community-level patterns of spatial and temporal variability. We found that an environmental gradient related to water depth and distance from shore was the dominant factor spatially structuring the marine bird community. Responses of marine birds to this onshore-offshore environmental gradient were related to dietary specialization, and separated marine bird taxa by prey type. The primary form of temporal variability over the study period was monotonic increases or decreases in abundance for 11 of 18 evaluated genera of marine birds; 8 genera had declined, whereas 3 had increased. The greatest declines occurred in genera associated with habitats that were deeper and farther from shore. Furthermore, most of the genera that declined primarily fed on pelagic prey resources, such as forage fish and mesozooplankton, and few were directly affected by the 1989 Exxon Valdez oil spill. Our observations of synchronous declines are indicative of a shift in pelagic components of PWS food webs. This pattern was correlated with climate variability at time-scales of several years to a decade.

Patterns of distribution, abundance, and change over time in a subarctic marine bird community

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Cushing, Daniel; Roby, Daniel D.; Irons, David B.

2017-01-01

Over recent decades, marine ecosystems of Prince William Sound (PWS), Alaska, have experienced concurrent effects of natural and anthropogenic perturbations, including variability in the climate system of the northeastern Pacific Ocean. We documented spatial and temporal patterns of variability in the summer marine bird community in relation to habitat and climate variability using boat-based surveys of marine birds conducted during the period 1989–2012. We hypothesized that a major factor structuring marine bird communities in PWS would be proximity to the shoreline, which is theorized to relate to aspects of food web structure. We also hypothesized that shifts in physical ecosystem drivers differentially affected nearshore-benthic and pelagic components of PWS food webs. We evaluated support for our hypotheses using an approach centered on community-level patterns of spatial and temporal variability. We found that an environmental gradient related to water depth and distance from shore was the dominant factor spatially structuring the marine bird community. Responses of marine birds to this onshore-offshore environmental gradient were related to dietary specialization, and separated marine bird taxa by prey type. The primary form of temporal variability over the study period was monotonic increases or decreases in abundance for 11 of 18 evaluated genera of marine birds; 8 genera had declined, whereas 3 had increased. The greatest declines occurred in genera associated with habitats that were deeper and farther from shore. Furthermore, most of the genera that declined primarily fed on pelagic prey resources, such as forage fish and mesozooplankton, and few were directly affected by the 1989 Exxon Valdez oil spill. Our observations of synchronous declines are indicative of a shift in pelagic components of PWS food webs. This pattern was correlated with climate variability at time-scales of several years to a decade.

Off-road sampling reveals a different grassland bird community than roadside sampling: implications for survey design and estimates to guide conservation

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Troy I. Wellicome

2014-06-01

Full Text Available Grassland bird species continue to decline steeply across North America. Road-based surveys such as the North American Breeding Bird Survey (BBS are often used to estimate trends and population sizes and to build species distribution models for grassland birds, although roadside survey counts may introduce bias in estimates because of differences in habitats along roadsides and in off-road surveys. We tested for differences in land cover composition and in the avian community on 21 roadside-based survey routes and in an equal number of adjacent off-road walking routes in the grasslands of southern Alberta, Canada. Off-road routes (n = 225 point counts had more native grassland and short shrubs and less fallow land and road area than the roadside routes (n = 225 point counts. Consequently, 17 of the 39 bird species differed between the two route types in frequency of occurrence and relative abundance, measured using an indicator species analysis. Six species, including five obligate grassland species, were more prevalent at off-road sites; they included four species listed under the Canadian federal Species At Risk Act or listed by the Committee on the Status of Endangered Wildlife in Canada: Sprague's Pipit (Anthus spragueii, Baird's Sparrow (Ammodramus bairdii, the Chestnut-collared Longspur (Calcarius ornatus, and McCown's Longspur (Rhynchophanes mccownii. The six species were as much as four times more abundant on off-road sites. Species more prevalent along roadside routes included common species and those typical of farmland and other human-modified habitats, e.g., the European Starling (Sturnus vulgaris, the Black-billed Magpie (Pica hudsonia, and the House Sparrow (Passer domesticus. Differences in avian community composition between roadside and off-road surveys suggest that the use of BBS data when generating population estimates or distribution models may overestimate certain common species and underestimate others of conservation

Potential of pest regulation by insectivorous birds in Mediterranean woody crops.

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José M Rey Benayas

Full Text Available Regulation of agricultural pests managing their natural enemies represents an alternative to chemical pesticides. We assessed the potential of insectivorous birds as pest regulators in woody crops located in central Spain. A total of 417 nest boxes installed in five field study sites (one vineyard, two fruit orchards, and two olive groves were monitored for use and breeding of insectivorous birds and other species for four consecutive years (2013-2016. At all field sites except the two olive groves, where birds never occupied the nest boxes, predation experiments were conducted with Greater wax moth (Galleria mellonella sentinel caterpillars, and food consumption by birds was estimated. Nesting of insectivorous birds, chiefly Great tit (Parus major, and sparrows (Passer domesticus and P. montanus increased over time, averaging 60% per field site in the vineyard and fruit orchards by the fourth year. Use of nest boxes by sparrows and by Garden dormouse (Eliomys quercinus was high at the fruit orchards (70% and the vineyard (30%, respectively. Micro-habitat characteristics (nest box level and meso-habitat characteristics (patch level strongly affected use of nest boxes and bird breeding (i.e. number of laid eggs and produced chicks in different years. Distance to natural or semi-natural vegetation did not consistently affect bird breeding, nor did we see consistent evidence of competition between adjacent breeding birds. Predation rates of sentinel caterpillars were approximately one-third higher near boxes with nesting birds (31.51 ± 43.13% than at paired distant areas without nest boxes (22.45% ± 38.58%. Food consumption by insectivorous birds per ha and breeding season were conservatively estimated to range from 0.02 kg in one fruit orchard to 0.15 kg in the vineyard. We conclude that installation of nest boxes in Mediterranean woody crops enhances populations of insectivorous birds that regulate pests, but that the effects are moderate and

Effects of exotic fish farms on bird communities in lake and marine ecosystems

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Jiménez, Jaime E.; Arriagada, Aldo M.; Fontúrbel, Francisco E.; Camus, Patricio A.; Ávila-Thieme, M. Isidora

2013-08-01

Salmon farming is a widespread activity around the world, also known to promote diverse environmental effects on aquatic ecosystems. However, information regarding the impact of salmon farming on bird assemblages is notably scarce. We hypothesize that salmon farming, by providing food subsidies and physical structures to birds, will change their local community structure. To test this hypothesis, we conducted a seasonal monitoring of bird richness, abundance, and composition at paired salmon pen and control plots in two marine and two lake sites in southern Chile, from fall 2002 to summer 2004. Overall, salmon farming had no significant effects on species richness, but bird abundance was significantly and noticeably higher in salmon pens than in controls. Such aggregation was mainly accounted for by the trophic guilds of omnivores, diving piscivores, carrion eaters, and perching piscivores, but not by invertebrate feeders, herbivores, and surface feeders. Species composition was also significantly and persistently different between salmon pens and controls within each lake or marine locality. The patterns described above remained consistent across environment types and seasons indicating that salmon farming is changing the community structure of birds in both lake and marine habitats by promoting functional and aggregation responses, particularly by favoring species with broader niches. Such local patterns may thus anticipate potential threats from the ongoing expansion of the salmon industry to neighboring areas in Chile, resulting in regional changes of bird communities, toward a less diverse one and dominated by opportunistic, common, and generalist species such as gulls, vultures, and cormorants.

Breeding in a den of thieves : Pros and cons of nesting close to egg predators

NARCIS (Netherlands)

de Fouw, Jimmy; Bom, Roeland A.; Klaassen, Raymond H. G.; Muskens, Gerard J. D. M.; de Vries, Peter P.; Popov, Igor Yu.; Kokorev, Yakov I.; Ebbinge, Barwolt S.; Nolet, Bart A.

Breeding success of many Arctic-breeding bird populations varies with lemming cycles due to prey switching behavior of generalist predators. Several bird species breed on islands to escape from generalist predators like Arctic fox Vulpes lagopus, but little is known about how these species interact.

Breeding in a den of thieves: pros and cons of nesting close to egg predators

NARCIS (Netherlands)

de Fouw, J.; Bom, R.A.; Klaassen, R.H.G.; Müskens, G.J.D.M.; de Vries, P.P.; Popov, I.Yu.; Kokorev, Y.I.; Ebbinge, B.S.; Nolet, B.A.

Breeding success of many Arctic-breeding bird populations varies with lemming cycles due to prey switching behavior of generalist predators. Several bird species breed on islands to escape from generalist predators like Arctic fox Vulpes lagopus, but little is known about how these species interact.

Breeding in a den of thieves: pros and cons of nesting close to egg predators.

NARCIS (Netherlands)

De Fouw, J.; Bom, R. A.; Klaassen, R.; Müskens, G.J.D.M.; De Vries, P.P.; Popov, I.Y.; Kokorev, Y.I.; Ebbinge, B.S.; Nolet, B.A.

2016-01-01

Breeding success of many Arctic-breeding bird populations varies with lemming cycles due to prey switching behavior of generalist predators. Several bird species breed on islands to escape from generalist predators like Arctic fox Vulpes lagopus, but little is known about how these species interact.

Community occupancy before-after-control-impact (CO-BACI) analysis of Hurricane Gudrun on Swedish forest birds.

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Russell, James C; Stjernman, Martin; Lindström, Åke; Smith, Henrik G

2015-04-01

Resilience of ecological communities to perturbation is important in the face of increased global change from anthropogenic stressors. Monitoring is required to detect the impact of, and recovery from, perturbations, and before-after-control-impact (BACI) analysis provides a powerful framework in this regard. However, species in a community are not observed with perfect detection, and occupancy analysis is required to correct for imperfect detectability of species. We present a Bayesian community occupancy before-after-control-impact (CO-BACI) framework to monitor ecological community response to perturbation when constituent species are imperfectly detected. We test the power of the model to detect changes in community composition following an acute perturbation with simulation. We then apply the model to a study of the impact of a large hurricane on the forest bird community of Sweden, using data from the national bird survey scheme. Although simulation shows the model can detect changes in community occupancy following an acute perturbation, application to a Swedish forest bird community following a major hurricane detected no change in community occupancy despite widespread forest loss. Birds with landscape occupancy less than 50% required correcting for detectability. We conclude that CO-BACI analysis is a useful tool that can incorporate rare species in analyses and detect occupancy changes in ecological communities following perturbation, but, because it does not include abundance, some impacts may be overlooked.

Variation in melatonin receptors (Mel(1a) and Mel(1b)) and androgen receptor (AR) expression in the spleen of a seasonally breeding bird, Perdicula asiatica.

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Yadav, S K; Haldar, C; Singh, S S

2011-12-01

Daily variation in the peripheral level of melatonin plays a major role in integrating reproduction and environmental information for seasonally breeding birds. However, the variation in immunity and reproduction has never been assessed in any avian species on a 24 h time scale. Therefore, to understand the relationship between immune function and reproductive phases in a seasonally breeding bird, Perdicula asiatica, the Indian jungle bush quail, we studied the daily variation of melatonin and testosterone levels along with expression of their receptors Mel(1a), Mel(1b), and androgen receptor in the spleen during the reproductively active phase. Immunocytochemistry for the melatonin receptors Mel(1a) and Mel(1b) presented a differential distribution pattern. Western blot of splenic protein suggested a daily rhythm of melatonin receptors, while acrophases for the two melatonin receptors Mel(1a) and Mel(1b) differed by 4 h, suggesting that the expression of the receptors may peak at different times, causing more of either Mel(1a) or Mel(1b) to be available at a particular time to mediate function. The circulatory melatonin level correlated with percentage stimulation ratio of splenocytes and plasma interleukin-2 level, but did not correlate with testosterone or androgen receptor, suggesting that melatonin could be a major hormone imparting a time-of-day effect on the modulation of immune function in a seasonally breeding bird during the reproductively active phase. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

The impact of nature-based tourism on bird communities: a case study in Pallas-Yllästunturi National Park.

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Huhta, Esa; Sulkava, Pekka

2014-05-01

Nature-based tourism and recreation within and close to protected areas may have negative environmental impacts on biodiversity due to urban development, landscape fragmentation, and increased disturbance. We conducted a 3-year study of disturbances of birds induced by nature-based tourism over a recreational gradient in the Pallas-Yllästunturi National Park and its surroundings in northern Finland. Bird assemblages were studied in highly disturbed areas close to the park (a ski resort, villages, and accommodation areas) and in campfire sites, along hiking routes (recreational areas) and in a forest (control area) within the park. Compared with the forest, the disturbed urbanized areas had higher abundances of human-associated species, corvid species, cavity and building nesters, and edge species. The abundances of managed forest species were higher in campfire sites than in the forest. Hiking trails and campfire sites did not have a negative impact on open-nesting bird species. The most likely reason for this outcome is that most campfire sites were situated at forest edges; this species group prefers managed forests and forest edge as a breeding habitat. The abundances of virgin forest species did not differ among the areas studied. The results of the study suggest that the current recreation pressure has not caused substantial changes in the forest bird communities within the National Park. We suggest that the abundances of urban exploiter species could be used as indicators to monitor the level and changes of urbanization and recreational pressure at tourist destinations.

The Impact of Nature-Based Tourism on Bird Communities: A Case Study in Pallas-Yllästunturi National Park

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Huhta, Esa; Sulkava, Pekka

2014-05-01

Nature-based tourism and recreation within and close to protected areas may have negative environmental impacts on biodiversity due to urban development, landscape fragmentation, and increased disturbance. We conducted a 3-year study of disturbances of birds induced by nature-based tourism over a recreational gradient in the Pallas-Yllästunturi National Park and its surroundings in northern Finland. Bird assemblages were studied in highly disturbed areas close to the park (a ski resort, villages, and accommodation areas) and in campfire sites, along hiking routes (recreational areas) and in a forest (control area) within the park. Compared with the forest, the disturbed urbanized areas had higher abundances of human-associated species, corvid species, cavity and building nesters, and edge species. The abundances of managed forest species were higher in campfire sites than in the forest. Hiking trails and campfire sites did not have a negative impact on open-nesting bird species. The most likely reason for this outcome is that most campfire sites were situated at forest edges; this species group prefers managed forests and forest edge as a breeding habitat. The abundances of virgin forest species did not differ among the areas studied. The results of the study suggest that the current recreation pressure has not caused substantial changes in the forest bird communities within the National Park. We suggest that the abundances of urban exploiter species could be used as indicators to monitor the level and changes of urbanization and recreational pressure at tourist destinations.

Breeding Double-crested Cormorants and Wading Birds on Isla Alcatraz, Sonora, México

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Jennifer N. Duberstein; Virginia Jimenez-Serrania; Tad A. Pfister; Kirsten E. Lindquist; Lorayne Meltzer

2005-01-01

Isla Alcatraz is a small volcanic island in the Eastern Midriff Island region of the Gulf of California, approximately 1.4 km from the fishing community of Bahía de Kino, Sonora, México. The island falls under the protection of the Gulf Island Reserve system for wildlife and migratory birds. Isla Alcatraz is home to one of the largest Double-crested Cormorant (

Chewing lice from wild birds in northern Greece.

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Diakou, Anastasia; Pedroso Couto Soares, José Bernardo; Alivizatos, Haralambos; Panagiotopoulou, Maria; Kazantzidis, Savas; Literák, Ivan; Sychra, Oldřich

2017-10-01

Greece represents an important area for wild birds due to its geographical position and habitat diversity. Although the bird species in Greece are well recorded, the information about the chewing lice that infest them is practically non-existent. Thus, the aim of the present study was to record the species of lice infesting wild birds in northern Greece and furthermore, to associate the infestation prevalence with factors such as the age, sex, migration and social behaviour of the host as well as the time of the year. In total 729 birds, (belonging to 9 orders, 32 families and 68 species) were examined in 7 localities of northern Greece, during 9 ringing sessions from June 2013 until October 2015. Eighty (11%) of the birds were found to be infested with lice. In 31 different bird species, 560 specimens of lice, belonging to 33 species were recorded. Mixed infestations were recorded in 11 cases where birds were infested with 2-3 different lice species. Four new host-parasite associations were recorded i.e. Menacanthus curuccae from Acrocephalus melanopogon, Menacanthus agilis from Cettia cetti, Myrsidea sp. from Acrocephalus schoenobaenus, and Philopretus citrinellae from Spinus spinus. Moreover, Menacanthus sinuatus was detected on Poecile lugubris, rendering this report the first record of louse infestation in this bird species. The statistical analysis of the data collected showed no association between parasitological parameters (prevalence, mean and median intensity and mean abundance) in two different periods of the year (breeding vs post-breeding season). However, there was a statistically significant difference in the prevalence of infestation between a) migrating and sedentary passerine birds (7.4% vs 13.2%), b) colonial and territorial birds (54.5% vs 9.6%), and c) female and male birds in breeding period (2.6% vs 15.6%). Copyright © 2017. Published by Elsevier B.V.

The Significance of Mating System and Nonbreeding Behavior to Population and Forest Patch Use by Migrant Birds

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Eugene S. Morton; Bridget J. M. Stutchbury

2005-01-01

Migratory birds are birds of two worlds, breeding in the temperate zone then living as tropical birds for most of the year. We show two aspects of this unique biology that are important considerations for their conservation. First, habitat selection for breeding must include their need for extra-pair mating opportunities. Second, non-breeding distributions in tropical...

COMPLEX EVALUATION OF THE NUMBER DYNAMICS OF COLONIAL WATERBIRD COMMUNITIES (THE CASE OF SOME ISLANDS OF SIVASH REGION

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Matsyura A.V.

2011-12-01

quantitative data on breeding birds will be the next step of the study of the island birds’ turnover. The results of the analysis of population dynamics assist to count the minimal population size for the colonization of new islands and stable existence of bird communities. Detailed analysis will allow to estimate the effect of competition on population and to determine the competitive variability inside and between the species breeding on islands.

Effects of Patagonian pine forestry on native breeding birds

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Moises Pescador

2014-12-01

Full Text Available Aim of the study: The objective is to assess the influences of the tree stand age and other forestry management practices on species richness, composition, and distribution of the Patagonian pine plantation bird assemblages. Area of Study: The work was carried out in forested plots of Ponderosa pine located at the Lanín National Park (Patagonia, Argentina.Material and Methods: Birds were sampled using 25 m fixed radius point counts, at four plots varying in age, management, and forest structure. Main Results: A total of 2090 individuals belonging to 34 bird species were observed, their numbers vary significantly depending on the different modes of plantation management. The population density of the 14 most abundant bird species was compared among the four plantation plots and ten species don’t show statistically significant differences in their population density among the different forest plots. The California Quail, the White-Crested Elaenia and the Southern House Wren showed higher densities in pine plantations with lower tree densities and fewer cutting treatments. The Diuca Finch had high densities in the younger plantations not subjected to any treatment. Research highlights: Most of these bird species are opportunistic and a few are found more regularly in these non-native woods than in other native forested or afforested areas. Our data suggest that a mixed scenario based on a mosaic of plantation with patches of native deciduous forest may help maximize the bird diversity in the management of northwestern Patagonian plantation landscapes.Keywords: Bird population; diversity; exotic plantations; Patagonia; tree-age.

DNA Barcoding of Birds at a Migratory Hotspot in Eastern Turkey Highlights Continental Phylogeographic Relationships.

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Raşit Bilgin

Full Text Available The combination of habitat loss, climate change, direct persecution, introduced species and other components of the global environmental crisis has resulted in a rapid loss of biodiversity, including species, population and genetic diversity. Birds, which inhabit a wide spectrum of different habitat types, are particularly sensitive to and indicative of environmental changes. The Caucasus endemic bird area, part of which covers northeastern Turkey, is one of the world's key regions harboring a unique bird community threatened with habitat loss. More than 75% of all bird species native to Turkey have been recorded in this region, in particular along the Kars-Iğdır migratory corridor, stopover, wintering and breeding sites along the Aras River, whose wetlands harbor at least 264 bird species. In this study, DNA barcoding technique was used for evaluating the genetic diversity of land bird species of Aras River Bird Paradise at the confluence of Aras River and Iğdır Plains key biodiversity areas. Seventy three COI sequences from 33 common species and 26 different genera were newly generated and used along with 301 sequences that were retrieved from the Barcoding of Life Database (BOLD. Using the sequences obtained in this study, we made global phylogeographic comparisons to define four categories of species, based on barcoding suitability, intraspecific divergence and taxonomy. Our findings indicate that the landbird community of northeastern Turkey has a genetical signature mostly typical of northern Palearctic bird communities while harboring some unique variations. The study also provides a good example of how DNA barcoding can build upon its primary mission of species identification and use available data to integrate genetic variation investigated at the local scale into a global framework. However, the rich bird community of the Aras River wetlands is highly threatened with the imminent construction of the Tuzluca Dam by the government.

Effect of geolocators on migration and subsequent breeding performance of a long-distance passerine migrant.

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Debora Arlt

Full Text Available Geolocators are small light-weight data loggers used to track individual migratory routes, and their use has increased exponentially in birds. However, the effects of geolocators on individual performance are still poorly known. We studied geolocator effects on a long-distance migrating passerine bird, the northern wheatear (Oenanthe oenanthe L.. We asked the general question of whether geolocators affect migratory behaviour and subsequent reproductive performance of small passerines by comparing arrival time, breeding time, breeding success and survival of geolocator versus control birds of known identity and breeding history. During two years geolocator birds (n=37 displayed a lower apparent survival (30% as compared to controls (45%, n=164. Furthermore, returning geolocator birds (n=12 arrived on average 3.5 days later, started laying eggs 6.3 days later, and had lower nest success (25% than control birds (78%. Our results suggest that geolocators affect migratory performance with carry-over effects to the timing of breeding and reproductive success in the subsequent breeding season. We discuss the implications of such geolocator effects for the study of migratory strategies of small passerines in general and suggest how to identify and investigate such effects in the future.

Occupancy dynamics in a tropical bird community: unexpectedly high forest use by birds classified as non-forest species

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Ruiz-Gutierrez, Viviana; Zipkin, Elise F.; Dhondt, Andre A.

2010-01-01

1. Worldwide loss of biodiversity necessitates a clear understanding of the factors driving population declines as well as informed predictions about which species and populations are at greatest risk. The biggest threat to the long-term persistence of populations is the reduction and changes in configuration of their natural habitat. 2. Inconsistencies have been noted in the responses of populations to the combined effects of habitat loss and fragmentation. These have been widely attributed to the effects of the matrix habitats in which remnant focal habitats are typically embedded. 3. We quantified the potential effects of the inter-patch matrix by estimating occupancy and colonization of forest and surrounding non-forest matrix (NF). We estimated species-specific parameters using a dynamic, multi-species hierarchical model on a bird community in southwestern Costa Rica. 4. Overall, we found higher probabilities of occupancy and colonization of forest relative to the NF across bird species, including those previously categorized as open habitat generalists not needing forest to persist. Forest dependency was a poor predictor of occupancy dynamics in our study region, largely predicting occupancy and colonization of only non-forest habitats. 5. Our results indicate that the protection of remnant forest habitats is key for the long-term persistence of all members of the bird community in this fragmented landscape, including species typically associated with open, non-forest habitats. 6.Synthesis and applications. We identified 39 bird species of conservation concern defined by having high estimates of forest occupancy, and low estimates of occupancy and colonization of non-forest. These species survive in forest but are unlikely to venture out into open, non-forested habitats, therefore, they are vulnerable to the effects of habitat loss and fragmentation. Our hierarchical community-level model can be used to estimate species-specific occupancy dynamics for focal

Role of Brazilian zoos in ex situ bird conservation: from 1981 to 2005.

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Azevedo, Cristiano S; Young, Robert J; Rodrigues, Marcos

2011-01-01

Zoos may play an important role in conservation when they maintain and breed large numbers of animals that are threatened with extinction. Bird conservation is in a privileged situation owing to the extensive biological information available about this class. Annual inventories produced by the "Sociedade de Zoológicos do Brasil" in the years 1981, 1990, 2000, and 2005 were analyzed. Variables, such as the number of zoos per geographic region; number of birds held; number of bird species in each IUCN threat category; number of exotic and native bird species; number of potentially breeding bird species; number of bird species in each order; and number of threatened bird species breeding, were analyzed. Brazilian zoos kept more than 350 bird species. The number of bird species and specimens held by the Brazilian Zoos increased from 1981 to 2000, but decreased in 2005. The same pattern was observed for the number of species in each IUCN threat category. Results showed that the potential of the Brazilian zoos in bird conservation needs to be enhanced because they maintain threatened species but do not implement systematic genetic, reproductive, or behavioral management protocols for most species. © 2010 Wiley Periodicals, Inc.

The importance of agricultural lands for Himalayan birds in winter.

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Elsen, Paul R; Kalyanaraman, Ramnarayan; Ramesh, Krishnamurthy; Wilcove, David S

2017-04-01

The impacts of land-use change on biodiversity in the Himalayas are poorly known, notwithstanding widespread deforestation and agricultural intensification in this highly biodiverse region. Although intact primary forests harbor many Himalayan birds during breeding, a large number of bird species use agricultural lands during winter. We assessed how Himalayan bird species richness, abundance, and composition during winter are affected by forest loss stemming from agriculture and grazing. Bird surveys along 12 elevational transects within primary forest, low-intensity agriculture, mixed subsistence agriculture, and intensively grazed pastures in winter revealed that bird species richness and abundance were greatest in low-intensity and mixed agriculture, intermediate in grazed pastures, and lowest in primary forest at both local and landscape scales; over twice as many species and individuals were recorded in low-intensity agriculture than in primary forest. Bird communities in primary forests were distinct from those in all other land-use classes, but only 4 species were unique to primary forests. Low-, medium-, and high-intensity agriculture harbored 32 unique species. Of the species observed in primary forest, 80% had equal or greater abundance in low-intensity agricultural lands, underscoring the value of these lands in retaining diverse community assemblages at high densities in winter. Among disturbed landscapes, bird species richness and abundance declined as land-use intensity increased, especially in high-intensity pastures. Our results suggest that agricultural landscapes are important for most Himalayan bird species in winter. But agricultural intensification-especially increased grazing-will likely result in biodiversity losses. Given that forest reserves alone may inadequately conserve Himalayan birds in winter, comprehensive conservation strategies in the region must go beyond protecting intact primary forests and ensure that low-intensity agricultural

Population structure of Pacific Common Eiders breeding in Alaska

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Petersen, M.R.; Flint, P.L.

2002-01-01

We used satellite telemetry to study the migration routes and wintering areas of two allopatric breeding populations of Pacific Common Eiders (Somateria mollissima v-nigrum) in Alaska: the Yukon-Kuskokwim Delta, and the western Beaufort Sea coast. Only 6% (2 of 36) of females wintered within the wintering area of the other breeding population. Both breeding populations wintered in the closest available ice-free habitat, perhaps to minimize migratory distance. Two Beaufort Sea females wintered in areas used by Yukon-Kuskokwim Delta females, implying potential gene flow among breeding areas. Yet, we conclude that these two populations are largely geographically isolated throughout the annual cycle and the environmental factors influencing survival and reproduction likely differ between these groups of birds. Thus, regardless of the potential gene flow among breeding populations, we suggest that birds from these two breeding areas should be managed as separate populations. ?? The Cooper Ornithological Society 2002.

Vegetation moderates impacts of tourism usage on bird communities along roads and hiking trails.

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Wolf, Isabelle D; Hagenloh, Gerald; Croft, David B

2013-11-15

Bird communities inhabiting ecosystems adjacent to recreational tracks may be adversely affected by disturbance from passing tourism traffic, vehicle-related mortality, habitat alteration and modified biotic relationships such as the increase of strong competitors. This study investigated the effects of tourist usage of roads vs. hiking trails on bird communities in gorges of the Flinders Ranges, a popular South Australian tourist destination in the arid-lands. High tourist usage along roads decreased the individual abundance and species richness of birds relative to low usage trails. The decrease in species richness, though less pronounced, also occurred at high-usage sites along trails. Changes in the species response to recreational disturbance/impacts varied depending on the ecology of the species. Bigger, more competitive birds with a generalist diet were overrepresented at high-usage sites along roads and trails. Species using microhabitats in lower vegetation layers were more sensitive. However, structural and floristic complexity of vegetation was a more important factor influencing bird abundance than tourist usage. Sites with a better developed shrub and tree layer sustained higher species abundance and richer communities. Importantly, vegetation qualities moderated the negative effect of high usage on the individual abundance of birds along roads, to the extent that such an effect was absent at sites with the best developed shrub and tree layer. To protect avifauna along recreational tracks in arid-lands gorges, we recommend the closure of some gorges or sections for vehicle or any access. Further, open space particularly for camping needs to be minimized as it creates areas of high tourist usage with modified habitat that provides birds with little buffer from disturbance. Copyright © 2013 Elsevier Ltd. All rights reserved.

Use of the superpopulation approach to estimate breeding population size: An example in asynchronously breeding birds

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Williams, K.A.; Frederick, P.C.; Nichols, J.D.

2011-01-01

Many populations of animals are fluid in both space and time, making estimation of numbers difficult. Much attention has been devoted to estimation of bias in detection of animals that are present at the time of survey. However, an equally important problem is estimation of population size when all animals are not present on all survey occasions. Here, we showcase use of the superpopulation approach to capture-recapture modeling for estimating populations where group membership is asynchronous, and where considerable overlap in group membership among sampling occasions may occur. We estimate total population size of long-legged wading bird (Great Egret and White Ibis) breeding colonies from aerial observations of individually identifiable nests at various times in the nesting season. Initiation and termination of nests were analogous to entry and departure from a population. Estimates using the superpopulation approach were 47-382% larger than peak aerial counts of the same colonies. Our results indicate that the use of the superpopulation approach to model nesting asynchrony provides a considerably less biased and more efficient estimate of nesting activity than traditional methods. We suggest that this approach may also be used to derive population estimates in a variety of situations where group membership is fluid. ?? 2011 by the Ecological Society of America.

Workshop: Western hemisphere network of bird banding programs

Science.gov (United States)

Celis-Murillo, A.

2007-01-01

Purpose: To promote collaboration among banding programs in the Americas. Introduction: Bird banding and marking provide indispensable tools for ornithological research, management, and conservation of migratory birds on migratory routes, breeding and non-breeding grounds. Many countries and organizations in Latin America and the Caribbean are in the process of developing or have expressed interest in developing national banding schemes and databases to support their research and management programs. Coordination of developing and existing banding programs is essential for effective data management, reporting, archiving and security, and most importantly, for gaining a fuller understanding of migratory bird conservation issues and how the banding data can help. Currently, there is a well established bird-banding program in the U.S.A. and Canada, and programs in other countries are being developed as well. Ornithologists in many Latin American countries and the Caribbean are interested in using banding and marking in their research programs. Many in the ornithological community are interested in establishing banding schemes and some countries have recently initiated independent banding programs. With the number of long term collaborative and international initiatives increasing, the time is ripe to discuss and explore opportunities for international collaboration, coordination, and administration of bird banding programs in the Western Hemisphere. We propose the second ?Western Hemisphere Network of Bird Banding Programs? workshop, in association with the SCSCB, to be an essential step in the progress to strengthen international partnerships and support migratory bird conservation in the Americas and beyond. This will be the second multi-national meeting to promote collaboration among banding programs in the Americas (the first meeting was held in October 8-9, 2006 in La Mancha, Veracruz, Mexico). The Second ?Western Hemisphere Network of Bird Banding Programs

Effect of urbanization on bird community in riparian environments in Caí River, Rio Grande do Sul, Brazil

Directory of Open Access Journals (Sweden)

Jaqueline Brummelhaus

2012-02-01

Full Text Available http://dx.doi.org/10.5007/2175-7925.2012v25n2p81 Urbanization produces changes in riparian environments causing effects in the structure of bird communities, which respond differently to impacts. We compare richness, abundance and composition of birds in riparian environments with different urbanization gradients in Caí River, Rio Grande do Sul. We conducted observations in woodland, grassland and urban environments, between September/2007 and August/2008. We recorded 130 bird species, 29 species unique to woodland environments, including an endangered species: Triclaria malachitacea. Bird abundance differed between woodland and urban environments (426 individuals in woodland, 721 in grassland and 939 in urban. Species composition and feeding guilds contributed significantly to differentiation of bird community structures in these three riparian environments. In open environments (grassland and urban we recorded more generalist feeding guilds and bird species, while in riparian woodland environments, we find guilds and species more sensitive to human impacts. Bird species may be biological quality indicators and contribute to natural economy. With the knowledge of bird community structure and their needs, it is possible to establish management practices for riparian restoration of degraded environments in the region.

Birds Communities at Mangrove of Batu Ampar, Kubu Raya District, West Kalimantan Province

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Jarwadi Budi Hernowo

2016-08-01

Full Text Available Batu Ampar mangrove is an important bird habitat especially for birds which have relation to mangrove ecosystem in West Kalimantan. The research was conducted in February to March 2007, at mangrove Batu Ampar demo site. Sampling was done to get representative area for bird survey. The 19 transects were chosen as sampling site to collect bird data such as species and number of individual. Bird surveys were carried out using Reconnaissance method and index point of abundance (IPA count method. The length of each transect was approximately 500 m. The results showed that the bird community's structure dominated by insectivorous birds represented approximately 60 % of total bird's species at mangrove Batu Ampar demo site. The abundance numbers of the individual with the bird's species has relation pattern like J opposite. Percentage of dominant bird species was approximately 11%, those are such as stork billed kingfisher, white-collared kingfisher, common iora, chestnuts-rumped babbler, Strip-Tit Babbler, magpie robin, ashy tailorbird, mangrove blue flycatcher, pied fantail, mangrove whistler, Brown-throated Sunbird and Cooper-Throated Sunbird. Vertical structure of mangrove vegetation was used by birds at mangrove Batu Ampar demo site is mainly B stratum, and it used around 60% birds species. Based on dendrogram analysis there were 5 cluster birds species. The mangrove bird specialists found at sampling area were mangrove blue flycatcher and Cooper throated sunbird.

Community-based livestock breeding programmes: essentials and examples.

Science.gov (United States)

Mueller, J P; Rischkowsky, B; Haile, A; Philipsson, J; Mwai, O; Besbes, B; Valle Zárate, A; Tibbo, M; Mirkena, T; Duguma, G; Sölkner, J; Wurzinger, M

2015-04-01

Breeding programmes described as community-based (CBBP) typically relate to low-input systems with farmers having a common interest to improve and share their genetic resources. CBBPs are more frequent with keepers of small ruminants, in particular smallholders of local breeds, than with cattle, pigs or chickens with which farmers may have easier access to alternative programmes. Constraints that limit the adoption of conventional breeding technologies in low-input systems cover a range of organizational and technical aspects. The analysis of 8 CBBPs located in countries of Latin-America, Africa and Asia highlights the importance of bottom-up approaches and involvement of local institutions in the planning and implementation stages. The analysis also reveals a high dependence of these programmes on organizational, technical and financial support. Completely self-sustained CBBPs seem to be difficult to realize. There is a need to implement and document formal socio-economic evaluations of CBBPs to provide governments and other development agencies with the information necessary for creating sustainable CBBPs at larger scales. © 2015 Blackwell Verlag GmbH.

Bird community structure in riparian environments in Cai River, Rio Grande do Sul, Brazil

OpenAIRE

Jaqueline Brummelhaus; Marcia Suelí Bohn; Maria Virginia Petry

2012-01-01

Urbanization produces changes in riparian environments, causing effects in the structure of bird communities, which present different responses to the impacts. We compare species richness, abundance, and composition of birds in riparian environments with different characteristics in Cai River, Rio Grande do Sul, Brazil. We carried out observations in woodland, grassland, and urban environments, between September 2007 and August 2008. We listed 130 bird species, 29 species unique to woodland e...

Temporal bird community dynamics are strongly affected by landscape fragmentation in a Central American tropical forest region

Science.gov (United States)

Blandón, A.C.; Perelman, S.B.; Ramírez, M.; López, A.; Javier, O.; Robbins, Chandler S.

2016-01-01

Habitat loss and fragmentation are considered the main causes of species extinctions, particularly in tropical ecosystems. The objective of this work was to evaluate the temporal dynamics of tropical bird communities in landscapes with different levels of fragmentation in eastern Guatemala. We evaluated five bird community dynamic parameters for forest specialists and generalists: (1) species extinction, (2) species turnover, (3) number of colonizing species, (4) relative species richness, and (5) a homogeneity index. For each of 24 landscapes, community dynamic parameters were estimated from bird point count data, for the 1998–1999 and 2008–2009 periods, accounting for species’ detection probability. Forest specialists had higher extinction rates and a smaller number of colonizing species in landscapes with higher fragmentation, thus having lower species richness in both time periods. Alternatively, forest generalists elicited a completely different pattern, showing a curvilinear association to forest fragmentation for most parameters. Thus, greater community dynamism for forest generalists was shown in landscapes with intermediate levels of fragmentation. Our study supports general theory regarding the expected negative effects of habitat loss and fragmentation on the temporal dynamics of biotic communities, particularly for forest specialists, providing strong evidence from understudied tropical bird communities.

Bird on the wire: Landscape planning considering costs and benefits for bird populations coexisting with power lines.

Science.gov (United States)

D'Amico, Marcello; Catry, Inês; Martins, Ricardo C; Ascensão, Fernando; Barrientos, Rafael; Moreira, Francisco

2018-02-24

Power-line grids are increasingly expanding worldwide, as well as their negative impacts on avifauna, namely the direct mortality through collision and electrocution, the reduction of breeding performance, and the barrier effect. On the other hand, some bird species can apparently benefit from the presence of power lines, for example perching for hunting purposes or nesting on electricity towers. In this perspective essay, we reviewed the scientific literature on both costs and benefits for avifauna coexisting with power lines. Overall, we detected a generalized lack of studies focusing on these costs or benefits at a population level. We suggest that a switch in research approach to a larger spatio-temporal scale would greatly improve our knowledge about the actual effects of power lines on bird populations. This research approach would facilitate suitable landscape planning encompassing both mitigation of costs and promotion of benefits for bird populations coexisting with power lines. For example, the strategic route planning of electricity infrastructures would limit collision risk or barrier effects for threatened bird populations. Concurrently, this strategic route planning would promote the range expansion of threatened populations of other bird species, by providing nesting structures in treeless but potentially suitable landscapes. We suggest establishing a collaborative dialogue among the scientific community, governments, and electricity companies, with the aim to produce a win-win scenario in which both biodiversity conservation and infrastructure development are integrated in a common strategy.

Analysis of long-term forest bird monitoring data from national forests of the western Great Lakes Region

Science.gov (United States)

Gerald J. Niemi; Robert W. Howe; Brian R. Sturtevant; Linda R. Parker; Alexis R. Grinde; Nicholas P. Danz; Mark D. Nelson; Edmund J. Zlonis; Nicholas G. Walton; Erin E. Gnass Giese; Sue M. Lietz

2016-01-01

Breeding bird communities in forests of the western Great Lakes region are among the most diverse in North America, but the forest environment in this region has changed dramatically during the past 150 years. To address concerns about loss of biodiversity due to ongoing forest harvesting and to better inform forest planning, researchers have systematically monitored...

Forecasting biodiversity in breeding birds using best practices

Science.gov (United States)

Taylor, Shawn D.; White, Ethan P.

2018-01-01

Biodiversity forecasts are important for conservation, management, and evaluating how well current models characterize natural systems. While the number of forecasts for biodiversity is increasing, there is little information available on how well these forecasts work. Most biodiversity forecasts are not evaluated to determine how well they predict future diversity, fail to account for uncertainty, and do not use time-series data that captures the actual dynamics being studied. We addressed these limitations by using best practices to explore our ability to forecast the species richness of breeding birds in North America. We used hindcasting to evaluate six different modeling approaches for predicting richness. Hindcasts for each method were evaluated annually for a decade at 1,237 sites distributed throughout the continental United States. All models explained more than 50% of the variance in richness, but none of them consistently outperformed a baseline model that predicted constant richness at each site. The best practices implemented in this study directly influenced the forecasts and evaluations. Stacked species distribution models and “naive” forecasts produced poor estimates of uncertainty and accounting for this resulted in these models dropping in the relative performance compared to other models. Accounting for observer effects improved model performance overall, but also changed the rank ordering of models because it did not improve the accuracy of the “naive” model. Considering the forecast horizon revealed that the prediction accuracy decreased across all models as the time horizon of the forecast increased. To facilitate the rapid improvement of biodiversity forecasts, we emphasize the value of specific best practices in making forecasts and evaluating forecasting methods. PMID:29441230

Forecasting biodiversity in breeding birds using best practices

Directory of Open Access Journals (Sweden)

David J. Harris

2018-02-01

Full Text Available Biodiversity forecasts are important for conservation, management, and evaluating how well current models characterize natural systems. While the number of forecasts for biodiversity is increasing, there is little information available on how well these forecasts work. Most biodiversity forecasts are not evaluated to determine how well they predict future diversity, fail to account for uncertainty, and do not use time-series data that captures the actual dynamics being studied. We addressed these limitations by using best practices to explore our ability to forecast the species richness of breeding birds in North America. We used hindcasting to evaluate six different modeling approaches for predicting richness. Hindcasts for each method were evaluated annually for a decade at 1,237 sites distributed throughout the continental United States. All models explained more than 50% of the variance in richness, but none of them consistently outperformed a baseline model that predicted constant richness at each site. The best practices implemented in this study directly influenced the forecasts and evaluations. Stacked species distribution models and “naive” forecasts produced poor estimates of uncertainty and accounting for this resulted in these models dropping in the relative performance compared to other models. Accounting for observer effects improved model performance overall, but also changed the rank ordering of models because it did not improve the accuracy of the “naive” model. Considering the forecast horizon revealed that the prediction accuracy decreased across all models as the time horizon of the forecast increased. To facilitate the rapid improvement of biodiversity forecasts, we emphasize the value of specific best practices in making forecasts and evaluating forecasting methods.

Eastern wood-pewee (Contopus virens) breeding demography across a gradient of savanna, woodland, and forest in the Missouri Ozarks

Science.gov (United States)

Sarah W. Kendrick; Frank R. Thompson; Jennifer L. Reidy

2013-01-01

Better knowledge of bird response to savanna and woodland restoration is needed to inform management of these communities. We related temporal and habitat variables to breeding demography and densities of the Eastern Wood-Pewee (Contopus virens) across a gradient of savanna, woodland, and forest. We determined nest success, clutch size, young fledged...

Plant and Bird Presence Strongly Influences the Microbial Communities in Soils of Admiralty Bay, Maritime Antarctica

Science.gov (United States)

Teixeira, Lia C. R. S.; Yeargeau, Etienne; Balieiro, Fabiano C.; Piccolo, Marisa C.; Peixoto, Raquel S.; Greer, Charles W.; Rosado, Alexandre S.

2013-01-01

Understanding the environmental factors that shape microbial communities is crucial, especially in extreme environments, like Antarctica. Two main forces were reported to influence Antarctic soil microbes: birds and plants. Both birds and plants are currently undergoing relatively large changes in their distribution and abundance due to global warming. However, we need to clearly understand the relationship between plants, birds and soil microorganisms. We therefore collected rhizosphere and bulk soils from six different sampling sites subjected to different levels of bird influence and colonized by Colobanthus quitensis and Deschampsia antarctica in Admiralty Bay, King George Island, Maritime Antarctic. Microarray and qPCR assays targeting 16S rRNA genes of specific taxa were used to assess microbial community structure, composition and abundance and analyzed with a range of soil physico-chemical parameters. The results indicated significant rhizosphere effects in four out of the six sites, including areas with different levels of bird influence. Acidobacteria were significantly more abundant in soils with little bird influence (low nitrogen) and in bulk soil. In contrast, Actinobacteria were significantly more abundant in the rhizosphere of both plant species. At two of the sampling sites under strong bird influence (penguin colonies), Firmicutes were significantly more abundant in D. antarctica rhizosphere but not in C. quitensis rhizosphere. The Firmicutes were also positively and significantly correlated to the nitrogen concentrations in the soil. We conclude that the microbial communities in Antarctic soils are driven both by bird and plants, and that the effect is taxa-specific. PMID:23840411

Plant and bird presence strongly influences the microbial communities in soils of Admiralty Bay, Maritime Antarctica.

Science.gov (United States)

Teixeira, Lia C R S; Yeargeau, Etienne; Balieiro, Fabiano C; Piccolo, Marisa C; Peixoto, Raquel S; Greer, Charles W; Rosado, Alexandre S

2013-01-01

Understanding the environmental factors that shape microbial communities is crucial, especially in extreme environments, like Antarctica. Two main forces were reported to influence Antarctic soil microbes: birds and plants. Both birds and plants are currently undergoing relatively large changes in their distribution and abundance due to global warming. However, we need to clearly understand the relationship between plants, birds and soil microorganisms. We therefore collected rhizosphere and bulk soils from six different sampling sites subjected to different levels of bird influence and colonized by Colobanthus quitensis and Deschampsia antarctica in Admiralty Bay, King George Island, Maritime Antarctic. Microarray and qPCR assays targeting 16S rRNA genes of specific taxa were used to assess microbial community structure, composition and abundance and analyzed with a range of soil physico-chemical parameters. The results indicated significant rhizosphere effects in four out of the six sites, including areas with different levels of bird influence. Acidobacteria were significantly more abundant in soils with little bird influence (low nitrogen) and in bulk soil. In contrast, Actinobacteria were significantly more abundant in the rhizosphere of both plant species. At two of the sampling sites under strong bird influence (penguin colonies), Firmicutes were significantly more abundant in D. antarctica rhizosphere but not in C. quitensis rhizosphere. The Firmicutes were also positively and significantly correlated to the nitrogen concentrations in the soil. We conclude that the microbial communities in Antarctic soils are driven both by bird and plants, and that the effect is taxa-specific.

Plant and bird presence strongly influences the microbial communities in soils of Admiralty Bay, Maritime Antarctica.

Directory of Open Access Journals (Sweden)

Lia C R S Teixeira

Full Text Available Understanding the environmental factors that shape microbial communities is crucial, especially in extreme environments, like Antarctica. Two main forces were reported to influence Antarctic soil microbes: birds and plants. Both birds and plants are currently undergoing relatively large changes in their distribution and abundance due to global warming. However, we need to clearly understand the relationship between plants, birds and soil microorganisms. We therefore collected rhizosphere and bulk soils from six different sampling sites subjected to different levels of bird influence and colonized by Colobanthus quitensis and Deschampsia antarctica in Admiralty Bay, King George Island, Maritime Antarctic. Microarray and qPCR assays targeting 16S rRNA genes of specific taxa were used to assess microbial community structure, composition and abundance and analyzed with a range of soil physico-chemical parameters. The results indicated significant rhizosphere effects in four out of the six sites, including areas with different levels of bird influence. Acidobacteria were significantly more abundant in soils with little bird influence (low nitrogen and in bulk soil. In contrast, Actinobacteria were significantly more abundant in the rhizosphere of both plant species. At two of the sampling sites under strong bird influence (penguin colonies, Firmicutes were significantly more abundant in D. antarctica rhizosphere but not in C. quitensis rhizosphere. The Firmicutes were also positively and significantly correlated to the nitrogen concentrations in the soil. We conclude that the microbial communities in Antarctic soils are driven both by bird and plants, and that the effect is taxa-specific.

Negative range size-abundance relationships in Indo-Pacific bird communities

DEFF Research Database (Denmark)

Hart Reeve, Andrew; Borregaard, Michael Krabbe; Fjeldså, Jon

2016-01-01

and environmental stability create selection pressures that favor narrowly specialized species, which could drive these non-positive relationships. To test this idea, we measured the range size-abundance relationships of eleven bird communities in mature and degraded forest on four islands in the Indo...

Prevalence of coccidiosis among village and exotic breed of chickens in Maiduguri, Nigeria

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Jallailudeen Rabana Lawal

2016-06-01

Full Text Available Aim: Coccidiosis is an important enteric parasitic disease of poultry associated with significant economic losses to poultry farmers worldwide. This survey was conducted from June 2014 through July 2015 with the main goal of investigating the prevalence and associated risk factors of coccidiosis among village and exotic breeds of chickens in Maiduguri, Northeastern Nigeria. Materials and Methods: A total of 600 fecal samples from live and slaughtered birds comprising 284 young, 141, growers and 175 adult birds; 379 male and 221 female birds; 450 exotic and 150 local breeds of birds were randomly collected either as bird’s fresh droppings or cutting open an eviscerated intestine of slaughtered birds, while noting their age, sex, and breeds. Samples were analyzed using standard parasitological methods and techniques. Results: An overall prevalence rate of 31.8% (95% confidence interval: 28.07-35.52 was obtained. Higher prevalence rates were recorded in growing birds 58.9% (50.78-67.02, female birds 35.3% (29.00-41.60, exotic birds 42.4% (37.83- 46.97, and broiler birds 68.7% (61.28-76.12. Similarly, higher infection rates were also observed among birds sampled from Mairi ward 66.7% (56.03-77.37, intensive management system 46.5% (41.61-51.39, and constructed local cages 54.0% (46.02-61.98. The difference in prevalence of coccidiosis among age groups, breeds, among exotic breeds, sampling locations, husbandry management systems, and litter management systems was statistically significant (0.05 of infection rates was observed in sex. Conclusion: Coccidiosis is endemic in both commercial and backyard poultry farms in Maiduguri due to poor management practices encouraging Eimeria oocysts build-up. It is therefore, recommended that poultry farmers should practice strict biosecurity measures on their farms, creating awareness on the prevalence of coccidiosis, routine vaccination against coccidiosis and educating poultry farmers on the need for

Montane-breeding bird distribution and abundance across national parks of southwestern Alaska

Science.gov (United States)

Amundson, Courtney L.; Handel, Colleen M.; Ruthrauff, Daniel R.; Tibbitts, T. Lee; Gill, Robert E.

2018-01-01

Between 2004 and 2008, biologists conducted an inventory of breeding birds during May–June primarily in montane areas (>100 m above sea level) in Aniakchak National Monument and Preserve (Aniakchak NMP), Katmai National Park and Preserve (Katmai NPP), and Lake Clark National Park and Preserve (Lake Clark NPP) in southwestern Alaska. Observers conducted 1,021 point counts along 169 transects within 63 10-km × 10-km plots that were randomly selected and stratified by ecological subsection. We created hierarchical N-mixture models to estimate detection probability and abundance for 15 species, including 12 passerines, 2 galliforms, and 1 shorebird. We first modeled detection probability relative to observer, date within season, and proportion of dense vegetation cover around the point, then modeled abundance as a function of land cover composition (proportion of seven coarse-scale land cover types) within 300 m of the survey point. Land cover relationships varied widely among species but most showed selection for low to tall shrubs (0.2–5 m tall) and an avoidance of alpine and 2 dwarf shrub–herbaceous cover types. After adjusting for species not observed, we estimated a minimum of 107 ± 9 species bred in the areas surveyed within the three parks combined. Species richness was negatively associated with elevation and associated land cover types. At comparable levels of survey effort (n = 721 birds detected), species richness was greatest in Lake Clark NPP (75 ± 12 species), lowest in Aniakchak NMP (45 ± 6 species), and intermediate at Katmai NPP (59 ± 10 species). Species richness was similar at equivalent survey effort (n = 973 birds detected) within the Lime Hills, Alaska Range, and Alaska Peninsula ecoregions (68 ± 8; 79 ± 11; 67 ± 11, respectively). Species composition was similar across all three parks and across the three major ecoregions (Alaska Range, Alaska Peninsula, Lime Hills) that encompass them. Our results provide baseline estimates of

Identifying key conservation threats to Alpine birds through expert knowledge

Science.gov (United States)

Pedrini, Paolo; Brambilla, Mattia; Rolando, Antonio; Girardello, Marco

2016-01-01

Alpine biodiversity is subject to a range of increasing threats, but the scarcity of data for many taxa means that it is difficult to assess the level and likely future impact of a given threat. Expert opinion can be a useful tool to address knowledge gaps in the absence of adequate data. Experts with experience in Alpine ecology were approached to rank threat levels for 69 Alpine bird species over the next 50 years for the whole European Alps in relation to ten categories: land abandonment, climate change, renewable energy, fire, forestry practices, grazing practices, hunting, leisure, mining and urbanization. There was a high degree of concordance in ranking of perceived threats among experts for most threat categories. The major overall perceived threats to Alpine birds identified through expert knowledge were land abandonment, urbanization, leisure and forestry, although other perceived threats were ranked highly for particular species groups (renewable energy and hunting for raptors, hunting for gamebirds). For groups of species defined according to their breeding habitat, open habitat species and treeline species were perceived as the most threatened. A spatial risk assessment tool based on summed scores for the whole community showed threat levels were highest for bird communities of the northern and western Alps. Development of the approaches given in this paper, including addressing biases in the selection of experts and adopting a more detailed ranking procedure, could prove useful in the future in identifying future threats, and in carrying out risk assessments based on levels of threat to the whole bird community. PMID:26966659

Identifying key conservation threats to Alpine birds through expert knowledge

Directory of Open Access Journals (Sweden)

Dan E. Chamberlain

2016-02-01

Full Text Available Alpine biodiversity is subject to a range of increasing threats, but the scarcity of data for many taxa means that it is difficult to assess the level and likely future impact of a given threat. Expert opinion can be a useful tool to address knowledge gaps in the absence of adequate data. Experts with experience in Alpine ecology were approached to rank threat levels for 69 Alpine bird species over the next 50 years for the whole European Alps in relation to ten categories: land abandonment, climate change, renewable energy, fire, forestry practices, grazing practices, hunting, leisure, mining and urbanization. There was a high degree of concordance in ranking of perceived threats among experts for most threat categories. The major overall perceived threats to Alpine birds identified through expert knowledge were land abandonment, urbanization, leisure and forestry, although other perceived threats were ranked highly for particular species groups (renewable energy and hunting for raptors, hunting for gamebirds. For groups of species defined according to their breeding habitat, open habitat species and treeline species were perceived as the most threatened. A spatial risk assessment tool based on summed scores for the whole community showed threat levels were highest for bird communities of the northern and western Alps. Development of the approaches given in this paper, including addressing biases in the selection of experts and adopting a more detailed ranking procedure, could prove useful in the future in identifying future threats, and in carrying out risk assessments based on levels of threat to the whole bird community.

Breeding biology of passerines in a subtropical montane forest in northwestern Argentina

Science.gov (United States)

Auer, S.K.; Bassar, R.D.; Fontaine, J.J.; Martin, T.E.

2007-01-01

The breeding ecology of south temperate bird species is less widely known than that of north temperate species, yet because they comprise a large portion of the world's avian diversity, knowledge of their breeding ecology can contribute to a more comprehensive understanding of the geographic diversity of avian reproductive traits and life history strategies. We provide the first detailed examination of the reproductive strategies of 18 forest passerines of subtropical, northwestern Argentina. Mean clutch sizes were smaller and egg mass was greater than for north temperate birds, but differed among species and nest types, with cavity-nesters having larger clutches than species with open-cup and enclosed nests. Across all species, the average breeding season duration was 50 days; thus, the common perception that southern species have smaller clutch sizes because of longer breeding seasons is not supported in this community. Daily nest predation rates were influenced by nest type, cavity nests suffering the least from predation, as found in north temperate systems. Only females incubated eggs in all but one species, whereas both parents fed and cared for nestlings in all species. Mean nest attentiveness was low compared to north temperate passerines. Mean hourly nestling feeding rates differed among species and were negatively related to nest predation risk. In short, coexisting species in this subtropical forest varied in their life history strategies, in part correlated with variation in nest predation risk, but also differing from north temperate species. ?? The Cooper Ornithological Society 2007.

Bird communities of contrasting semi-natural habitats of Lac bay, Bonaire, during the fall migration season, 2011

NARCIS (Netherlands)

Debrot, A.O.; Bemmelen, van R.S.A.; Ligon, J.

2013-01-01

The mangrove and seagrass lagoon of Lac Bay on Bonaire covers an area of roughly 700 ha. It is home to endangered green sea turtles, Chelonia mydas, and the Caribbean queen conch, Strombus gigas, and is a roosting and breeding area for several birds. Based on its nature values this 7 km2 bay has

Calcium, snails, and birds: a case study

Directory of Open Access Journals (Sweden)

R. Mänd

2000-10-01

Full Text Available Recent studies have shown that wild birds breeding in acidified areas have difficulties with obtaining sufficient calcium for their eggshells, and that the cause of it is the shortage of land snails. Many birds have to search for Ca-rich snail shells on a daily basis during egg production. Molluscs depend on litter calcium, which has decreased due to acidification of the environment. Calcium limitation may be a widespread phenomenon also in non-acidified, naturally Ca-poor areas. The problem is that while in the latter areas the time for development of specific adaptations may have been sufficient, then in acidified areas, on the contrary, calcium shortage is a recent phenomenon. Therefore, since the extent of calcium limitation in non-acidified areas is hard to derive from observational data, experimental approach is needed. We provide experimental evidence that specific calcium deficit does affect reproductive traits also in the birds breeding in naturally base-poor habitats. Our study was conducted in a heterogeneous woodland area in Estonia containing deciduous forest patches as well as base-poor pine forest with low snail abundance. Ca supplementation, using snail shell and chicken eggshell fragments, was carried out for pied flycatchers and great tits. Extra calcium affected positively several reproductive traits like egg volume and eggshell thickness, start of breeding, and fledglings’ parameters. The negative relationship between calcium availability and lay-date suggests that birds adjust their breeding tactics to conditions of Ca deficiency, for example, by postponing laying.

Low Impact of Avian Pox on Captive-Bred Houbara Bustard Breeding Performance.

Science.gov (United States)

Le Loc'h, Guillaume; Souley, Mam-Noury Amadou; Bertagnoli, Stéphane; Paul, Mathilde C

2017-01-01

Avian pox, a disease caused by avipoxviruses, is a major cause of decline of some endangered bird species. While its impact has been assessed in several species in the wild, effects of the disease in conservation breeding have never been studied. Houbara bustard species ( Chlamydotis undulata and Chlamydotis macqueenii ), whose populations declined in the last decades, have been captive bred for conservation purposes for more than 20 years. While mortality and morbidity induced by avipoxviruses can be controlled by appropriate management, the disease might still affect bird breeding performance and jeopardize the production objectives of conservation programs. Impacts of the disease was studied during two outbreaks in captive-bred juvenile Houbara bustards in Morocco in 2009-2010 and 2010-2011, by modeling the effect of the disease on individual breeding performance (male display and female egg production) of 2,797 birds during their first breeding season. Results showed that the impact of avian pox on the ability of birds to reproduce and on the count of displays or eggs is low and mainly non-significant. The absence of strong impact compared to what could be observed in other species in the wild may be explained by the controlled conditions provided by captivity, especially the close veterinary monitoring of each bird. Those results emphasize the importance of individual management to prevent major disease emergence and their effects in captive breeding of endangered species.

RESEARCH STUDY ON THE BREEDING AVIFAUNA OF THE BASCOV RESERVOIR

Directory of Open Access Journals (Sweden)

Maria Denisa Conete

2015-12-01

Full Text Available The author conducted an ornithological study in the Bascov Reservoir area (a square of 2x2 km and observed 102 breeding species; 83 (81% of them are certain breeding species and 19 (19% are probable breeding species. The results of the research were cumulated with those found in the Atlas of the breeding species of Romania. By relating them with the Atlas data, we noted that 83 of the 100 breeding species cited in the Atlas were again recorded during our study. Nineteen new breeding species were identified. Among the species dependent on wetlands, mention should be made of Ixobrychus minutus, Anas platyrhynchos, Fulica atra, Gallinula chloropus, Aythya ferina, etc., with relatively large numbers of individuals. The analysis showed a relatively larger number (66 of euconstant and constant species, which confirmed the wealth of food resources in the area during the nesting period. The specific richness on the Bascov Lake is represented by 119 species, a number that is consistent with the availability of the food resources and nesting places, as well as the somewhat fluctuating presence of predators (stray dogs, and the anthropocentric disturbance (sound and chemical pollution, etc.. The yearly increase in the number of reed clusters, the expansion of the surface of the islets, the emergence of bushes and trees, the ageing of the existing trees have led to a certain yearly increase in the number of breeding individuals in 45 species. But the anthropogenic influence in the area has eventually contributed to a decrease in the number of birds, both as a number of species and as a number of individuals. The study has also shown that in the farmland bird species the number of individuals is in decline. Most of the breeding species - 75 (representing 74% in the area under research are migratory. Eighteen breeding species (17.64% are listed in Annex I of the Birds Directive. The presence of the key breeding species in the area under research must be

Conservation Action Based on Threatened Species Capture Taxonomic and Phylogenetic Richness in Breeding and Wintering Populations of Central Asian Birds

Science.gov (United States)

Schweizer, Manuel; Ayé, Raffael; Kashkarov, Roman; Roth, Tobias

2014-01-01

Although phylogenetic diversity has been suggested to be relevant from a conservation point of view, its role is still limited in applied nature conservation. Recently, the practice of investing conservation resources based on threatened species was identified as a reason for the slow integration of phylogenetic diversity in nature conservation planning. One of the main arguments is based on the observation that threatened species are not evenly distributed over the phylogenetic tree. However this argument seems to dismiss the fact that conservation action is a spatially explicit process, and even if threatened species are not evenly distributed over the phylogenetic tree, the occurrence of threatened species could still indicate areas with above average phylogenetic diversity and consequently could protect phylogenetic diversity. Here we aim to study the selection of important bird areas in Central Asia, which were nominated largely based on the presence of threatened bird species. We show that although threatened species occurring in Central Asia do not capture phylogenetically more distinct species than expected by chance, the current spatially explicit conservation approach of selecting important bird areas covers above average taxonomic and phylogenetic diversity of breeding and wintering birds. We conclude that the spatially explicit processes of conservation actions need to be considered in the current discussion of whether new prioritization methods are needed to complement conservation action based on threatened species. PMID:25337861

Avian Alert - a bird migration early warning system

NARCIS (Netherlands)

van Gasteren, H.; Shamoun-Baranes, J.; Ginati, A.; Garofalo, G.

2008-01-01

Every year billions of birds migrate from breeding areas to their wintering ranges, some travelling over 10,000 km. Stakeholders interested in aviation flight safety, spread of disease, conservation, education, urban planning, meteorology, wind turbines and bird migration ecology are interested in

Performance and bone morphometry of two breeds of finishing ...

African Journals Online (AJOL)

The birds were brooded for 3 weeks and thereafter acclimatized for one week in their respective housing systems (deep litter and outdoor run). Each of the housing systems was allotted 90 chicks per breed with three replicates of 15 birds each. The birds were fed same quality and quantity of feed ad libitum and given water ...

Avian community responses to juniper woodland structure and thinning treatments on the Colorado Plateau

Science.gov (United States)

Crow, Claire; van Riper, Charles

2011-01-01

Federal land managers are increasingly implementing fuels-reduction treatments throughout the western United States with objectives of ecological restoration and fire hazard reduction in pinyon-juniper (Pinus spp.-Juniperus spp.) woodlands. The pinyon-juniper woodland ecosystem complex is highly variable across the western landscape, as is bird community composition. We investigated relations between breeding birds and vegetation characteristics in modified pinyon-juniper woodlands at three sites (BLM, USFS, NPS) on the Colorado Plateau. During the breeding seasons of 2005 and 2006, we surveyed birds and measured vegetation in 74 study plots. These plots were each 3.1 hectares (ha; 7.6 acres), located across the range of natural variation, with 41 control sites and 33 plots in areas previously thinned by hand-cutting or chaining. We found that relations of avian pinyon-juniper specialists and priority species to vegetation characteristics were generally in agreement with the findings of previous studies and known nesting and feeding habits of those birds. Relatively high density of pinyon pines was important to species richness and abundance in 6 of 14 species. Abundance of all species was related to treatment method, and we found no difference in bird communities at chaining and hand-cut sites.

POPULATION SIZE OF AUTOCHTHONOUS AND LOCALLY ADAPTED HEN’S BREEDS ON AREA OF THE SLOVAK REPUBLIC

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J. WEIS

2009-10-01

Full Text Available On basic certificates about acceptation of Oravka Plymouth Rock, Rhode Island, New Hampshire, White Leghorn, Brown Leghorn and Sussex, controlled flocks of Slovak Union of Breeders, we analyzed total number of birds, number of breeding males, number of breeding females and effective population size by Simon and Buchenauer (1993 and we evaluated the populations of observed hen’s breeds to categorisations by Scherf (2000. The highest number of birds we recorded at breed New Hampshire from observed hen’s breeds. Average total number of animals in period of year 2003 - 2008 was 1373 birds with average effective population size 445.103. However, the population of New Hampshire poultry in Slovakia was evaluating by massive decrease in last years as a endangered - maintained breed for which an active conservation programme is in place. By contrast, the smallest number of animals was detected at breed White Leghorn with average total number 18.83 birds in period of year 2003 - 2008 and average effective population size 6.605. The breed White Leghorn in Slovakia we categorized to critical breed. National legislation on Slovakia has been created, the fist experience is being gathered and the European legislation is coming in practice. The conditions for the development and preservation of endangered breeds of poultry in Slovak Republic in the long term are being put in place by means of creative and well aimed utilisation of European and national legislation.

Mangrove bird community of Paranaguá Bay - Paraná, Brazil

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Luiz Augusto Macedo Mestre

2007-01-01

Full Text Available This study describes the mangrove bird community of Paranaguá Bay in Paraná - South Brazil. Seasonal surveys were conducted during September 1997 to September 1998 at three sites in Paranaguá Bay. Frequencies and abundances of birds were registered in 200m transects and one hour point counts. A total of 81 bird species were observed in the three sampling sites. Most of the bird species in Paranaguá mangroves are fruits, seeds and arthropods consumers, and predators of flying insects. The most frequent and abundant species were Egretta caerulea, Ceryle torquata, Chloroceryle amazona, Pitangus sulphuratus, Turdus amaurochalinus and Parula pitiayumi. The bird community of these three sites is composed mainly by forest bird species. The mangroves of Paranaguá Bay shelter one of the richest avifauna of Brazilian mangroves. Differences between sampling sites could be related to the proximity of the Paranaguá city and human impacts in the areas. Only in the most disturbed site were observed Passer domesticus and large flocks of Coragyps atratus. This study contributed to the knowledge of mangrove communities, and could be an important basis to fluvial-marine conservation plans in Paraná- Brazil.Este estudo teve como objetivos caracterizar a comunidade de aves de manguezais na baía de Paranaguá e comparar descritivamente a comunidade das três áreas amostradas, diferentes em relação à proximidade de centros urbanos. Foram amostradas sazonalmente, entre setembro de 1997 a setembro 1998, três áreas de manguezais a diferentes distâncias da cidade e do porto de Paranaguá. A avifauna foi registrada em transectos de 200m no interior dos manguezais e em observações de 1 hora em pontos fixos. Foram determinadas freqüência, abundancia relativa e densidade de espécies em cada área. Foram observadas 81 espécies de aves nas três áreas de manguezais. As guildas mais significativas foram das espécies consumidoras de frutos, sementes e artr

Waterbird flight initiation distances at Barberspan Bird Sanctuary, South Africa

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Carina Coetzer

2017-05-01

Full Text Available With tourism in South Africa expanding, the number of avitourists increases. The increase in infrastructure and human activities in protected areas, if not managed properly, can be harmful to birds. Flight initiation distances (FID can be used as a method to monitor habituation to disturbances. This study was performed at the Barberspan Bird Sanctuary, North West province, South Africa, to determine the levels of habituation among waterbirds and make appropriate recommendations regarding the management of the reserve. Our results indicated a 0.29 m increase in FID per gram reported mean biomass. Compared with conspecific or congeneric birds from Australia, Europe and North America, South African birds have relatively larger FIDs to human disturbance, which may indicate lower habituation. We also calculated buffer zones based on the maximum FID of the waterbirds for three mass groups. These buffer zones were then matched with the spatial distribution of the birds along the shoreline. We recommend that the mean FID for the blacksmith lapwing, Vanellus armatus (62 m, can be used as approach distance outside the breeding season in areas where the birds are sparsely distributed and 104 m during the breeding season in breeding areas. A large buffer of 200 m is suggested for areas with threatened, sensitive and skittish species. However, it is still preferable for avitourists to use the bird hides along the shores. Conservation implications: This study provides information for conservation management at Barberspan, based on typical birder activity. Smaller birds would need smaller buffer zones, while larger birds need much greater distances from observers to minimise disturbance. Similar studies can be applied elsewhere.

Ground-nesting marine birds and potential for human disturbance in Glacier Bay National Park

Science.gov (United States)

Arimitsu, Mayumi L.; Romano, Marc D.; Piatt, John F.; Piatt, John F.; Gende, S.M.

2004-01-01

Glacier Bay National Park and Preserve contains a diverse assemblage of marine birds that use the area for nesting, foraging and molting. The abundance and diversity of marine bird species in Glacier Bay is unmatched in the region, due in part to the geomorphic and successional characteristics that result in a wide array of habitat types (Robards and others, 2003). The opportunity for proactive management of these species is unique in Glacier Bay National Park because much of the suitable marine bird nesting habitat occurs in areas designated as wilderness. Ground-nesting marine birds are vulnerable to human disturbance wherever visitors can access nest sites during the breeding season. Human disturbance of nest sites can be significant because intense parental care is required for egg and hatchling survival, and repeated disturbance can result in reduced productivity (Leseberg and others, 2000). Temporary nest desertion by breeding birds in disturbed areas can lead to increased predation on eggs and hatchlings by conspecifics or other predators (Bolduc and Guillemette, 2003). Human disturbance of ground-nesting birds may also affect incubation time and adult foraging success, which in turn can alter breeding success (Verhulst and others, 2001). Furthermore, human activity can potentially cause colony failure when disturbance prevents the initiation of nesting (Hatch, 2002). There is management concern about the susceptibility of breeding birds to disturbance from human activities, but little historical data has been collected on the distribution of ground-nesting marine birds in Glacier Bay. This report summarizes results obtained during two years of a three-year study to determine the distribution of ground-nesting marine birds in Glacier Bay, and the potential for human disturbance of those nesting birds.

Interspecific and intraspecific spatial separation by birds breeding in nest boxes

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Denis C. Deeming

2017-12-01

Full Text Available Nest boxes can be seen as a conservation tool for improving low-grade nesting habitat but it is unclear how sympatric species using boxes establish a spatial distribution relative to conspecifics and heterospecifics. This study determined the distances between nest boxes occupied by Blue Tits (Cyanistes caeruleus and Great Tits (Parus major in two British woodlands to ascertain whether spatial distribution was affected by species and, if it was, whether there were reproductive consequences of this breeding distribution. Occupancy of nest boxes at two woodland sites were recorded on an annual basis between 2010 and 2014, inclusive. Distances between nest boxes, and reproductive activity, were recorded. Even if nest boxes showed a clumped distribution in the woodlands, the occupancy of the boxes was random. Not all boxes were used and the minimum distance between occupied boxes was at least twice the distance between boxes in general. Blue Tits tended to have greater distances between boxes containing conspecifics but distances between boxes containing heterospecifics were generally of comparable lengths. Reproductive output was only affected in relation to clutch size for Blue Tits nesting at one site. Nest boxes that aim to improve habitats that lack suitable nesting sites should be placed to reflect actual dispersal distances of the focal bird species.

Pied Flycatchers Ficedula hypoleuca travelling from Africa to breed in Europe : differential effects of winter and migration conditions on breeding date

NARCIS (Netherlands)

Both, Christiaan; Sanz, Juan Jose; Artemyev, Aleksandr V.; Blaauw, Bert; Cowie, Richard J.; Dekhuizen, Aarnoud J.; Enemar, Anders; Jarvinen, Antero; Nyholm, N. Erik I.; Potti, Jaime; Ravussin, Pierre-Alain; Silverin, Bengt; Slater, Fred M.; Sokolov, Leonid V.; Visser, Marcel E.; Winkel, Wolfgang; Wright, Jonathan; Zang, Herwig

2006-01-01

In most bird species there is only a short time window available for optimal breeding due to variation in ecological conditions in a seasonal environment. Long-distance migrants must travel before they start breeding, and conditions at the wintering grounds and during migration may affect travelling

Pied Flycatchers Ficedula hypoleuca travelling from Africa to breed in Europe: differential effects of winter and migration conditions on breeding date

NARCIS (Netherlands)

Both, C.; Sanz, J.J.; Artemyev, A.V.; Blaauw, B.; Cowie, R.J.; Dekhuijzen, A.J.; Enemar, A.; Järvinen, A.; Nyholm, N.E.I.; Potti, J.; Ravussin, P.-A.; Silverin, B.; Slater, F.M.; Sokolov, L.V.; Visser, M.E.; Winkel, W.; Wright, J.; Zang, H.

2006-01-01

In most bird species there is only a short time window available for optimal breeding due to variation in ecological conditions in a seasonal environment. Long-distance migrants must travel before they start breeding, and conditions at the wintering grounds and during migration may affect travelling

SPECIES DIVERSITY AND STABILITY OF BIRD COMMUNITIES

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Matsyura M.V.

2011-12-01

Full Text Available When comparing the suggested stability indicators, we obtained statistically significant correlations for indicators of annual stability of species and total number and standard deviation of the logarithm of the number. Annual Stability Index can be applied with a high degree of reliability as a characteristic of the averaged structure of the community and its pyramid of abundances. The results of correlation analysis confirm our assumptions about the correlation between stability over the years and indices of species diversity and relative uniformity.The final task of the study was to create a mathematical model of stability, where the independent variables are the indices of species diversity. The calculation of these indices allows forecasting birds’ community stability. According to the result of multiple regression for the indicators of diversity and stability of the breeding birds’ community highest correlation coefficients were obtained fro Shannon index and Simpson's dominance Index.Community stability could be determined by its overall species diversity. When considering the stability of community its diversity should be considered as a combination of uniformity of their total number and number of species. The most suitable predictors for the community stability were the nonparametric index of dominance and information-statistical indices, since they considered simultaneously evenness and richness. The community stability is subject of the complexity of its internal communications pattern.

Forest Plant and Bird Communities in the Lau Group, Fiji

Science.gov (United States)

Franklin, Janet; Steadman, David W.

2010-01-01

Background We examined species composition of forest and bird communities in relation to environmental and human disturbance gradients on Lakeba (55.9 km2), Nayau (18.4 km2), and Aiwa Levu (1.2 km2), islands in the Lau Group of Fiji, West Polynesia. The unique avifauna of West Polynesia (Fiji, Tonga, Samoa) has been subjected to prehistoric human-caused extinctions but little was previously known about this topic in the Lau Group. We expected that the degree of human disturbance would be a strong determinant of tree species composition and habitat quality for surviving landbirds, while island area would be unrelated to bird diversity. Methodology/Principal Findings All trees >5 cm diameter were measured and identified in 23 forest plots of 500 m2 each. We recognized four forest species assemblages differentiated by composition and structure: coastal forest, dominated by widely distributed species, and three forest types with differences related more to disturbance history (stages of secondary succession following clearing or selective logging) than to environmental gradients (elevation, slope, rockiness). Our point counts (73 locations in 1 or 2 seasons) recorded 18 of the 24 species of landbirds that exist on the three islands. The relative abundance and species richness of birds were greatest in the forested habitats least disturbed by people. These differences were due mostly to increased numbers of columbid frugivores and passerine insectivores in forests on Lakeba and Aiwa Levu. Considering only forested habitats, the relative abundance and species richness of birds were greater on the small but completely forested (and uninhabited) island of Aiwa Levu than on the much larger island of Lakeba. Conclusions/Significance Forest disturbance history is more important than island area in structuring both tree and landbird communities on remote Pacific islands. Even very small islands may be suitable for conservation reserves if they are protected from human

Vulnerability of shortgrass prairie bird assemblages to climate change

Science.gov (United States)

Skagen, Susan K.; Dreitz, Victoria; Conrey, Reesa Y.; Yackel, Amy; Panjabi, Arvind O.; Knuffman, Lekha

2016-01-01

The habitats and resources needed to support grassland birds endemic to North American prairie ecosystems are seriously threatened by impending climate change. To assess the vulnerability of grassland birds to climate change, we consider various components of vulnerability, including sensitivity, exposure, and adaptive capacity (Glick et al. 2011). Sensitivity encompasses the innate characteristics of a species and, in this context, is related to a species’ tolerance to changes in weather patterns. Groundnesting birds, including prairie birds, are particularly responsive to heat waves combined with drought conditions, as revealed by abundance and distribution patterns (Albright et al. 2010). To further assess sensitivity, we estimated reproductive parameters of nearly 3000 breeding attempts of a suite of prairie birds relative to prevailing weather. Fluctuations in weather conditions in eastern Colorado, 1997-2014, influenced breeding performance of a suite of avian species endemic to the shortgrass prairie, many of which have experienced recent population declines. High summer temperatures and intense rain events corresponded with lower nest survival for most species. Although dry conditions favored nest survival of Burrowing Owls and Mountain Plovers (Conrey 2010, Dreitz et al. 2012), drought resulted in smaller clutch sizes and lower nest survival for passerines (Skagen and Yackel Adams 2012, Conrey et al. in review). Declining summer precipitation may reduce the likelihood that some passerine species can maintain stable breeding populations in this region of the shortgrass prairie.

Biosecurity and bird movement practices in upland game bird facilities in the United States.

Science.gov (United States)

Slota, Katharine E; Hill, Ashley E; Keefe, Thomas J; Bowen, Richard A; Pabilonia, Kristy L

2011-06-01

Since 1996, the emergence of Asian-origin highly pathogenic avian influenza subtype H5N1 has spurred great concern for the global poultry industry. In the United States, there is concern over the potential of a foreign avian disease incursion into the country. Noncommercial poultry operations, such as upland game bird facilities in the United States, may serve as a potential source of avian disease introduction to other bird populations including the commercial poultry industry, backyard flocks, or wildlife. In order to evaluate how to prevent disease transmission from these facilities to other populations, we examined biosecurity practices and bird movement within the upland game bird industry in the United States. Persons that held a current permit to keep, breed, or release upland game birds were surveyed for information on biosecurity practices, flock and release environments, and bird movement parameters. Biosecurity practices vary greatly among permit holders. Many facilities allow for interaction between wild birds and pen-reared birds, and there is regular long-distance movement of live adult birds among facilities. Results suggest that upland game bird facilities should be targeted for biosecurity education and disease surveillance efforts.

Bateman's Principle in Cooperatively Breeding Vertebrates: The Effects of Non-breeding Alloparents on Variability in Female and Male Reproductive Success.

Science.gov (United States)

Hauber, Mark E; Lacey, Eileen A

2005-11-01

The sex-specific slopes of Bateman's gradients have important implications for understanding animal mating systems, including patterns of sexual selection and reproductive competition. Intersexual differences in the fitness benefits derived from mating with multiple partners are expected to yield distinct patterns of reproductive success for males and females, with variance in direct fitness predicted to be greater among males. These analyses assume that typically all adults are reproductive and that failure to produce offspring is non-adaptive. Among some species of cooperatively breeding birds and mammals, however, non-breeding adult alloparents are common and may comprise the majority of individuals in social groups. The presence of a large number of non-breeding adults, particularly when coupled with greater social suppression of reproduction among females, may alter the relative variance in direct fitness between the sexes, thereby generating an apparent contradiction to Bateman's Paradigm. To explore quantitatively the effects of non-breeding alloparents on variance in reproductive success, we used genetic estimates of parentage and reproductive success drawn from the literature to calculate the relative variability in direct fitness for females and males in alloparental and "other" societies of birds and mammals. Our analyses indicate that in mammals and, to a lesser extent, in birds, variability in direct fitness is greater among females in species characterized by the presence of non-breeding alloparents. These data suggest that social interactions, including social suppression of reproduction, are powerful determinants of individual direct fitness that may modify sex-specific patterns of reproductive variance from those described by Bateman.

Changing nest placement of Hawaiian Common Amakihi during the breeding cycle

Science.gov (United States)

van Riper, Charles; Kern, M. D.; Sogge, M. K.

1993-01-01

We studied the nesting behavior of the Common Amakihi (Hemignathus virens) from 1970-1981 on the island of Hawaii to determine if the species alters nest placement over a protracted 9-month breeding season. Birds preferentially chose the southwest quadrant of trees in which to build nests during all phases of the breeding season. It appeared that ambient temperature (Ta) was a contributing factor to differential nest placement between early and late phases of the annual breeding cycle. When Ta is low during the early (December-March) breeding period, Common Amakihi selected exposed nesting locations that benefitted them with maximum solar insolation. However, in the later phase of the breeding period (April-July) when Ta was much higher, renesting birds selected nest sites deeper in the canopy in significantly taller trees. This is one of the few documented examples in which a species changes location of nest during a breeding season, thus allowing exploitation of temporally differing microclimatic conditions.

Recreational Trails Reduce the Density of Ground-Dwelling Birds in Protected Areas

Science.gov (United States)

Thompson, Bill

2015-05-01

Recreational disturbance associated with trails has been identified as one of the major factors causing a decline of native biodiversity within protected areas. However, despite the negative impacts that recreation can have on biodiversity, providing public access to nature is critical for the future of the conservation of biodiversity. As such, many protected area managers are looking for tools to help maintain a balance between public access and biodiversity conservation. The objectives of this study were to examine the impacts of recreational trails on forest-dwelling bird communities in eastern North America, identify functional guilds which are particularly sensitive to recreational trails, and derive guidelines for trail design to assist in managing the impacts of recreational trails on forest-dwelling birds. Trails within 24 publicly owned natural areas were mapped, and breeding bird communities were described with the use of point count surveys. The density of forest birds, particularly of those species which nest or forage on the ground, were significantly positively influenced by the amount of trail-free refuge habitat. Although management options to control trail use in non-staffed protected areas are limited, this study suggests that protected area managers could design and maintain a trail network that would minimize impacts on resident wildlife, while providing recreational opportunities for visitors, by designing their trail network to maximize the area of trail-free habitat.

Recreational trails reduce the density of ground-dwelling birds in protected areas.

Science.gov (United States)

Thompson, Bill

2015-05-01

Recreational disturbance associated with trails has been identified as one of the major factors causing a decline of native biodiversity within protected areas. However, despite the negative impacts that recreation can have on biodiversity, providing public access to nature is critical for the future of the conservation of biodiversity. As such, many protected area managers are looking for tools to help maintain a balance between public access and biodiversity conservation. The objectives of this study were to examine the impacts of recreational trails on forest-dwelling bird communities in eastern North America, identify functional guilds which are particularly sensitive to recreational trails, and derive guidelines for trail design to assist in managing the impacts of recreational trails on forest-dwelling birds. Trails within 24 publicly owned natural areas were mapped, and breeding bird communities were described with the use of point count surveys. The density of forest birds, particularly of those species which nest or forage on the ground, were significantly positively influenced by the amount of trail-free refuge habitat. Although management options to control trail use in non-staffed protected areas are limited, this study suggests that protected area managers could design and maintain a trail network that would minimize impacts on resident wildlife, while providing recreational opportunities for visitors, by designing their trail network to maximize the area of trail-free habitat.

Avian Alert - a bird migration early warning system

OpenAIRE

van Gasteren, H.; Shamoun-Baranes, J.; Ginati, A.; Garofalo, G.

2008-01-01

Every year billions of birds migrate from breeding areas to their wintering ranges, some travelling over 10,000 km. Stakeholders interested in aviation flight safety, spread of disease, conservation, education, urban planning, meteorology, wind turbines and bird migration ecology are interested in information on bird movements. Collecting and disseminating useful information about such mobile creatures exhibiting diverse behaviour is no simple task. However, ESA’s Integrated Application Promo...

Sexual selection affects local extinction and turnover in bird communities

Science.gov (United States)

Doherty, P.F.; Sorci, G.; Royle, J. Andrew; Hines, J.E.; Nichols, J.D.; Boulinier, T.

2003-01-01

Predicting extinction risks has become a central goal for conservation and evolutionary biologists interested in population and community dynamics. Several factors have been put forward to explain risks of extinction, including ecological and life history characteristics of individuals. For instance, factors that affect the balance between natality and mortality can have profound effects on population persistence. Sexual selection has been identified as one such factor. Populations under strong sexual selection experience a number of costs ranging from increased predation and parasitism to enhanced sensitivity to environmental and demographic stochasticity. These findings have led to the prediction that local extinction rates should be higher for species/populations with intense sexual selection. We tested this prediction by analyzing the dynamics of natural bird communities at a continental scale over a period of 21 years (1975-1996), using relevant statistical tools. In agreement with the theoretical prediction, we found that sexual selection increased risks of local extinction (dichromatic birds had on average a 23% higher local extinction rate than monochromatic species). However, despite higher local extinction probabilities, the number of dichromatic species did not decrease over the period considered in this study. This pattern was caused by higher local turnover rates of dichromatic species, resulting in relatively stable communities for both groups of species. Our results suggest that these communities function as metacommunities, with frequent local extinctions followed by colonization. Anthropogenic factors impeding dispersal might therefore have a significant impact on the global persistence of sexually selected species.

Eimeria tenella: host specificity in gallinaceous birds.

Science.gov (United States)

Vetterling, J M

1976-02-01

Eight species representing 8 genera of gallinaceous birds were used: Alectoris graeca; Colinus virginianus; Coturnix coturnix; Gallus gallus; Meleagris gallopavo; Numidia meleagris; Pavo cristatus; Phasianus colchicus. Three week-old birds were dosed with sporulated oocysts of Eimeria tenella Beltsville strain. At 4, 24, 48, 72, 96, 120 and 144, and 168 hr after inoculation, 1-3 infected birds and uninoculated controls of each species were killed by cardiac exsanguination. Pieces of intestines were fixed and examined for stages of E. tenella as stained paraffin sections or indirect fluorescent antibody preparations. Oocyst counts were made in droppings collected for the first 6 days of the patent period. Sporozoites were found in the lamina propria of some birds of 5 species at 4 hr postinoculation, but no stages were found thereafter except in the breeds of G. gallus and A. gracea. At 144 and 168 hr postinoculation, a few macrogametes were found in the ceca of 2 A. gracea, but no oocysts were found in the feces. No statistical difference was found between the number of oocysts produced/bird in the breeds of G. gallus examined. It is evident from these observations the E. tenella did not complete its life cycle in several close phylogenetic relatives of G. gallus, even though in other studies this parasite was found to complete its life cycle in cell cultures derived from the same birds.

Effects of management practices on grassland birds: Grasshopper Sparrow

Science.gov (United States)

Dechant, Jill A.; Sondreal, Marriah L.; Johnson, Douglas H.; Igl, Lawrence D.; Goldade, Christopher M.; Nenneman, Melvin P.; Euliss, Betty R.

1998-01-01

Information on the habitat requirements and effects of habitat management on grassland birds were summarized from information in more than 5,500 published and unpublished papers. A range map is provided to indicate the relative densities of the species in North America, based on Breeding Bird Survey (BBS) data. Although birds frequently are observed outside the breeding range indicated, the maps are intended to show areas where managers might concentrate their attention. It may be ineffectual to manage habitat at a site for a species that rarely occurs in an area. The species account begins with a brief capsule statement, which provides the fundamental components or keys to management for the species. A section on breeding range outlines the current breeding distribution of the species in North America, including areas that could not be mapped using BBS data. The suitable habitat section describes the breeding habitat and occasionally microhabitat characteristics of the species, especially those habitats that occur in the Great Plains. Details on habitat and microhabitat requirements often provide clues to how a species will respond to a particular management practice. A table near the end of the account complements the section on suitable habitat, and lists the specific habitat characteristics for the species by individual studies. A special section on prey habitat is included for those predatory species that have more specific prey requirements. The area requirements section provides details on territory and home range sizes, minimum area requirements, and the effects of patch size, edges, and other landscape and habitat features on abundance and productivity. It may be futile to manage a small block of suitable habitat for a species that has minimum area requirements that are larger than the area being managed. The Brown-headed Cowbird (Molothrus ater) is an obligate brood parasite of many grassland birds. The section on cowbird brood parasitism summarizes rates

Neuroendocrine regulation of gonadotropin secretion in seasonally breeding birds

Directory of Open Access Journals (Sweden)

Takayoshi eUbuka

2013-03-01

Full Text Available Seasonally breeding birds detect environmental signals, such as light, temperature, food availability and presence of mates to time reproduction. Hypothalamic neurons integrate external and internal signals, and regulate reproduction by releasing neurohormones to the pituitary gland. The pituitary gland synthesizes and releases gonadotropins which in turn act on the gonads to stimulate gametogenesis and sex steroid secretion. Accordingly, how gonadotropin secretion is controlled by the hypothalamus is key to our understanding of the mechanisms of seasonal reproduction. A hypothalamic neuropeptide, gonadotropin-releasing hormone (GnRH, activates reproduction by stimulating gonadotropin synthesis and release. Another hypothalamic neuropeptide, gonadotropin-inhibitory hormone (GnIH, inhibits gonadotropin synthesis and release directly by acting on the pituitary gland or indirectly by decreasing the activity of GnRH neurons. Therefore, the next step to understand seasonal reproduction is to investigate how the activities of GnRH and GnIH neurons in the hypothalamus and their receptors in the pituitary gland are regulated by external and internal signals. It is possible that locally-produced triiodothyronine resulting from the action of type 2 iodothyronine deiodinase on thyroxine stimulates the release of gonadotropins, perhaps by action on GnRH neurons. The function of GnRH neurons is also regulated by transcription of the GnRH gene. Melatonin, a nocturnal hormone, stimulates the synthesis and release of GnIH and GnIH may therefore regulate a daily rhythm of gonadotropin secretion. GnIH may also temporally suppress gonadotropin secretion when environmental conditions are unfavorable. Environmental and social milieus fluctuate seasonally in the wild. Accordingly, complex interactions of various neuronal and hormonal systems need to be considered if we are to understand the mechanisms underlying seasonal reproduction.

Maternal genealogical patterns of chicken breeds sampled in Europe.

Science.gov (United States)

Lyimo, C M; Weigend, A; Msoffe, P L; Hocking, P M; Simianer, H; Weigend, S

2015-08-01

The aim of this study was to investigate the maternal genealogical pattern of chicken breeds sampled in Europe. Sequence polymorphisms of 1256 chickens of the hypervariable region (D-loop) of mitochondrial DNA (mtDNA) were used. Median-joining networks were constructed to establish evolutionary relationships among mtDNA haplotypes of chickens, which included a wide range of breeds with different origin and history. Chicken breeds which have had their roots in Europe for more than 3000 years were categorized by their founding regions, encompassing Mediterranean type, East European type and Northwest European type. Breeds which were introduced to Europe from Asia since the mid-19th century were classified as Asian type, and breeds based on crossbreeding between Asian breeds and European breeds were classified as Intermediate type. The last group, Game birds, included fighting birds from Asia. The classification of mtDNA haplotypes was based on Liu et al.'s (2006) nomenclature. Haplogroup E was the predominant clade among the European chicken breeds. The results showed, on average, the highest number of haplotypes, highest haplotype diversity, and highest nucleotide diversity for Asian type breeds, followed by Intermediate type chickens. East European and Northwest European breeds had lower haplotype and nucleotide diversity compared to Mediterranean, Intermediate, Game and Asian type breeds. Results of our study support earlier findings that chicken breeds sampled in Europe have their roots in the Indian subcontinent and East Asia. This is consistent with historical and archaeological evidence of chicken migration routes to Europe. © 2015 Stichting International Foundation for Animal Genetics.

Experimental evidence of human recreational disturbance effects on bird-territory establishment.

Science.gov (United States)

Bötsch, Yves; Tablado, Zulima; Jenni, Lukas

2017-07-12

The worldwide increase in human outdoor activities raises concerns for wildlife. Human disturbances, even at low levels, are likely to impact species during sensitive periods of the annual cycle. However, experimental studies during the putative sensitive period of territory establishment of birds which not only investigate low disturbance levels, but which also exclude the effect of habitat modification (e.g. walking trails) are lacking. Here, we experimentally disturbed birds in forest plots by walking through twice a day during territory establishment. Later we compared the breeding bird community of experimentally disturbed plots with that of undisturbed control plots. We discovered that the number of territories (-15.0%) and species richness (-15.2%) in disturbed plots were substantially reduced compared with control plots. Species most affected included those sensitive to human presence (assessed by flight-initiation distances), open-cup nesters and above-ground foragers. Long-distance migrants, however, were unaffected due to their arrival after experimental disturbance took place. These findings highlight how territory establishment is a sensitive period for birds, when even low levels of human recreation may be perceived as threatening, and alter settlement decisions. This can have important implications for the conservation of species, which might go unnoticed when focusing only on already established birds. © 2017 The Author(s).

Wetland Plants of Great Salt Lake, A Guide to Identification, Communities, & Bird Habitat

OpenAIRE

Downard, Rebekah; Frank, Maureen; Perkins, Jennifer; Kettenring, Karin; Larese-Casanova, Mark

2017-01-01

Wetland Plants of Great Salt Lake: a guide to identification, communities, & bird habitat is a wetland plant identification guide, resulting from collaborative research efforts about Great Salt Lake (GSL) wetland conditions and bird habitat. Dr. Rebekah Downard collected dissertation field data from GSL wetlands during 2012–2015, the majority of which informed this work. Dr. Maureen Frank contributed her guide to GSL wetland vegetation and how to manage native plants as high-quality habitat f...

Phylogeny and species traits predict bird detectability

Science.gov (United States)

Solymos, Peter; Matsuoka, Steven M.; Stralberg, Diana; Barker, Nicole K. S.; Bayne, Erin M.

2018-01-01

Avian acoustic communication has resulted from evolutionary pressures and ecological constraints. We therefore expect that auditory detectability in birds might be predictable by species traits and phylogenetic relatedness. We evaluated the relationship between phylogeny, species traits, and field‐based estimates of the two processes that determine species detectability (singing rate and detection distance) for 141 bird species breeding in boreal North America. We used phylogenetic mixed models and cross‐validation to compare the relative merits of using trait data only, phylogeny only, or the combination of both to predict detectability. We found a strong phylogenetic signal in both singing rates and detection distances; however the strength of phylogenetic effects was less than expected under Brownian motion evolution. The evolution of behavioural traits that determine singing rates was found to be more labile, leaving more room for species to evolve independently, whereas detection distance was mostly determined by anatomy (i.e. body size) and thus the laws of physics. Our findings can help in disentangling how complex ecological and evolutionary mechanisms have shaped different aspects of detectability in boreal birds. Such information can greatly inform single‐ and multi‐species models but more work is required to better understand how to best correct possible biases in phylogenetic diversity and other community metrics.

Monitoring Forsmark - Bird monitoring in Forsmark 2012

Energy Technology Data Exchange (ETDEWEB)

Green, Martin [Dept of Biology, Lund Univ., Lund (Sweden)

2013-03-15

This report summarizes the monitoring of selected listed (Swedish Red List and/or the EU Birds directive) breeding birds in Forsmark 2002 - 2012. Monitoring of eleven listed species was conducted in the regional model area, including the candidate area in 2012 in the same way as in earlier years. The results from 2012 generally follow patterns recorded in earlier years. 2012 was in general a better bird year compared to 2010 and 2011 and most species (82%) showed increasing or stable numbers from 2011 to 2012. Only two species (18%) decreased in numbers between the last two years. All in all, six species (55 %, black-throated diver, honey buzzard, black grouse, ural owl, wryneck and red-backed shrike) show no significant trends since the start of the bird monitoring (2002/2003/2004 depending on species). During this period three species (27 %, white-tailed eagle, osprey and lesser spotted woodpecker) have increased in numbers while just two (18 %, capercaillie and hazelhen) have decreased. A new pair of black-throated divers was discovered in 2012 and seven resident pairs were registered. Breeding success was very good, the second best during the study period. Population development follows the national pattern, but breeding success seems to be better in Forsmark than in the country as a whole. Honey buzzards and ospreys occurred in good numbers, and breeding success for ospreys was good. No signs of successful breedings of honey buzzards were recorded, but this may mean little as no detailed monitoring of breeding success is made for this species. The white-tailed eagles had their best breeding year since the start of the SKB bird monitoring, meaning that during the last two years local breeding success has been back at the level recorded before the site investigations started. The three grouse species (black grouse, capercaillie and hazelhen) again showed somewhat varying patterns between the last two years as well as in the long run. The black grouse increased

Monitoring Forsmark-Bird monitoring in Forsmark 2012

International Nuclear Information System (INIS)

Green, Martin

2013-03-01

This report summarizes the monitoring of selected listed (Swedish Red List and/or the EU Birds directive) breeding birds in Forsmark 2002 - 2012. Monitoring of eleven listed species was conducted in the regional model area, including the candidate area in 2012 in the same way as in earlier years. The results from 2012 generally follow patterns recorded in earlier years. 2012 was in general a better bird year compared to 2010 and 2011 and most species (82%) showed increasing or stable numbers from 2011 to 2012. Only two species (18%) decreased in numbers between the last two years. All in all, six species (55 %, black-throated diver, honey buzzard, black grouse, ural owl, wryneck and red-backed shrike) show no significant trends since the start of the bird monitoring (2002/2003/2004 depending on species). During this period three species (27 %, white-tailed eagle, osprey and lesser spotted woodpecker) have increased in numbers while just two (18 %, capercaillie and hazelhen) have decreased. A new pair of black-throated divers was discovered in 2012 and seven resident pairs were registered. Breeding success was very good, the second best during the study period. Population development follows the national pattern, but breeding success seems to be better in Forsmark than in the country as a whole. Honey buzzards and ospreys occurred in good numbers, and breeding success for ospreys was good. No signs of successful breedings of honey buzzards were recorded, but this may mean little as no detailed monitoring of breeding success is made for this species. The white-tailed eagles had their best breeding year since the start of the SKB bird monitoring, meaning that during the last two years local breeding success has been back at the level recorded before the site investigations started. The three grouse species (black grouse, capercaillie and hazelhen) again showed somewhat varying patterns between the last two years as well as in the long run. The black grouse increased

Breeding latitude drives individual schedules in a trans-hemispheric migrant bird

NARCIS (Netherlands)

Conklin, J.R.; Battley, Phil F.; Potter, Murray A.; Fox, James W.

2010-01-01

Despite clear benefits of optimal arrival time on breeding grounds, migration schedules may vary with an individual bird’s innate quality, non-breeding habitat or breeding destination. Here, we show that for the bar-tailed godwit (Limosa lapponica baueri), a shorebird that makes the longest known

The Effects of Different Forest Loggings on Forest Birds Community Composition in Shastkolateh Forest, Gorgan

Directory of Open Access Journals (Sweden)

F. Parsaei

2014-06-01

Full Text Available The species composition of a bird community is dependent upon many factors. Within any geographic area, vegetation structure may be the most important factor. The changes of bird community composition based on foraging behavior in relation to 3 different harvesting systems, including strip cutting, group selection logging, and single tree selection logging, was evaluated in a virgin area in this study. Birds and environmental variables were detected within 103 circle sampling plots with 25m radius. Based on the results, 4 groups of birds were observed in treatments based on the foraging behavior. Group 1 was ground foragers, group 2 consisted of foliage gleaning, group 3 included flycatchers, and group 4 represented bark foraging. The first group had the highest abundance in the strip treatment. The second group in group selection treatment, and the third and fourth groups had the highest abundance in the virgin area and then, in single tree selection treatment. The first group showed the highest correlation with shrub and herb or grass layer, stone cover and the number of trees 10-20m in height. The second, third and fourth groups showed the highest correlation with the number of trees>20m in height, basal areas, dead trees number, and the number of fagus trees. The results showed the single cutting treatment had a relatively minor effect on mature forest bird species and were more appropriate and sustainable methods to reduce the negative effects of forest harvesting on the birds.

Environmental species sorting dominates forest-bird community assembly across scales.

Science.gov (United States)

Özkan, Korhan; Svenning, Jens-Christian; Jeppesen, Erik

2013-01-01

Environmental species sorting and dispersal are seen as key factors in community assembly, but their relative importance and scale dependence remain uncertain, as the extent to which communities are consistently assembled throughout their biomes. To address these issues, we analysed bird metacommunity structure in a 1200-km(2) forested landscape (Istranca Forests) in Turkish Thrace at the margin of the Western Palaearctic (WP) temperate-forest biome. First, we used spatial regressions and Mantel tests to assess the relative importance of environmental and spatial factors as drivers of local species richness and composition within the metacommunity. Second, we analysed species' abundance-occupancy relationship across the metacommunity and used null models to assess whether occupancy is determined by species' environmental niches. Third, we used generalized linear models to test for links between species' metacommunity-wide occupancy and their broader WP regional populations and assessed whether these links are consistent with environmental species sorting. There was strong environmental control on local species richness and composition patterns within the metacommunity, but non-environmental spatial factors had also an important joint role. Null model analyses on randomized communities showed that species' occupancy across the metacommunity was strongly determined by species' environmental niches, with occupancy being related to niche position marginality. Species' metacommunity-wide occupancy correlated with their local abundance as well as with their range size and total abundance for the whole WP, suggesting that the same assembly mechanisms act consistently across local to regional scales. A species specialization index that was estimated by bird species' habitat use across France, incorporating both niche position and breadth, was significantly related to species' occupancy and abundance at both metacommunity and WP regional scales. Hence, the same niche

Impact of nest sanitation on the immune system of parents and nestlings in a passerine bird.

Science.gov (United States)

Evans, Jessica K; Griffith, Simon C; Klasing, Kirk C; Buchanan, Katherine L

2016-07-01

Bacterial communities are thought to have fundamental effects on the growth and development of nestling birds. The antigen exposure hypothesis suggests that, for both nestlings and adult birds, exposure to a diverse range of bacteria would select for stronger immune defences. However, there are relatively few studies that have tested the immune/bacterial relationships outside of domestic poultry. We therefore sought to examine indices of immunity (microbial killing ability in naive birds, which is a measure of innate immunity, and the antibody response to sheep red blood cells, which measures adaptive immunity) in both adult and nestling zebra finches (Taeniopygia guttata). We did this throughout breeding and between reproductive attempts in nests that were experimentally manipulated to change the intensity of bacterial exposure. Our results suggest that nest sanitation and bacterial load affected measures of the adaptive immune system, but not the innate immune parameters tested. Adult finches breeding in clean nests had a lower primary antibody response to sheep red blood cells, particularly males, and a greater difference between primary and secondary responses. Adult microbial killing of Escherichia coli decreased as parents moved from incubation to nestling rearing for both nest treatments; however, killing of Candida albicans remained consistent throughout. In nestlings, both innate microbial killing and the adaptive antibody response did not differ between nest environments. Together, these results suggest that exposure to microorganisms in the environment affects the adaptive immune system in nesting birds, with exposure upregulating the antibody response in adult birds. © 2016. Published by The Company of Biologists Ltd.

Response of Bird Community to Various Plantation Forests in Gunung Walat, West Java, Indonesia

Directory of Open Access Journals (Sweden)

Aronika Kaban

2017-04-01

Full Text Available Different plantation forests possibly harbor different bird communities. This study was aimed to reveal responses of bird community to the different plantation (Schima wallichii, Agathis loranthifolia, Pinus merkusii, and mixed plantation, identify species shared in all plantation, and species confined to a particular plantation. The study site was plantation forests, using the point count method for 64 effective hours. There were 40 bird species (maximum prediction 52 in all forest plantations and each type had 26–31 species. Number of individuals, species density, and diversity index in Schima plantation were higher, followed by Agathis, Pinus, and mixed plantations. Mixed plantation could have harbored more species based on the prediction by Chao. Although there were some differences in tree species, tree sizes, and tree heights, the response of bird composition in all plantations was not differed (93–81% similarity probably because of the short distances among the forests, the abundance of food insects, and the same late-successional stages. There were 15 (37.5% widely distributed species in all forest types. Eight species were confined only to a specific forest type. Four species were considered true confined species, namely Javan sunbird (Schima forest, Grey-cheeked bulbul (in Pinus, Crescent-chested babbler (Agathis, and Mountain white-eye (Agathis.

Zoonotic diseases in pet birds – a short review

OpenAIRE

Boseret, Géraldine; Saegerman, Claude

2012-01-01

The term « Pet bird » designates birds housed and breeded for an exclusively ornamental use. This category includes mainly Passeriformes (canaries, finches…) and Psittaciformes (parrots, parakeets…), and is a not-so-well known vet’s clientship fraction. Many families indeed own their « kitchen canary », which represent a lucrative business for pet shops or local breeders (e.a. via birds fairs and markets). Besides, some birds are bred for their very high value; for example, in the case of can...

Commonness and ecology, but not bigger brains, predict urban living in birds.

Science.gov (United States)

Dale, Svein; Lifjeld, Jan T; Rowe, Melissah

2015-04-11

Several life history and ecological variables have been reported to affect the likelihood of species becoming urbanized. Recently, studies have also focused on the role of brain size in explaining ability to adapt to urban environments. In contrast, however, little is known about the effect of colonization pressure from surrounding areas, which may confound conclusions about what makes a species urban. We recorded presence/absence data for birds in 93 urban sites in Oslo (Norway) and compared these with species lists generated from 137 forest and 51 farmland sites surrounding Oslo which may represent source populations for colonization. We found that the frequency (proportion of sites where present) of a species within the city was strongly and positively associated with its frequency in sites surrounding the city, as were both species breeding habitat and nest site location. In contrast, there were generally no significant effects of relative brain mass or migration on urban occupancy. Furthermore, analyses of previously published data showed that urban density of birds in six other European cities was also positively and significantly associated with density in areas outside cities, whereas relative brain mass showed no such relationship. These results suggest that urban bird communities are primarily determined by how frequently species occurred in the surrounding landscapes and by features of ecology (i.e. breeding habitat and nest site location), whereas species' relative brain mass had no significant effects.

[Response of forest bird communities to forest gap in winter in southwestern China].

Science.gov (United States)

Zhao, Dong-Dong; Wu, Ying-Huan; Lu, Zhou; Jiang, Guang-Wei; Zhou, Fang

2013-06-01

Although forest gap ecology is an important field of study, research remains limited. By plot setting and point counted observation, the response of birds to forest gaps in winter as well as bird distribution patterns in forest gaps and intact canopies were studied in a north tropical monsoon forest of southwestern China from November 2011 to February 2012 in the Fangcheng Golden Camellia National Nature Reserve, Guangxi. The regression equation of bird species diversity to habitat factor was Y1=0.611+0.002 X13+0.043 X2+0.002 X5-0.003 X8+0.006 X10+0.008 X1 and the regression equation of bird species dominance index to habitat factor was Y3=0.533+0.001 X13+0.019 X2+0.002 X3-0.017 X4+0.002 X1. There were 45 bird species (2 orders and 13 families) recorded in the forest gap, accounting for 84.9% of all birds (n=45), with an average of 9.6 species (range: 2-22). Thirty-nine bird species (5 orders and 14 families) were recorded in non-gap areas, accounting for 73.6% of all birds (n=39), with an average of 5.3 species (range: 1-12). These results suggested that gap size, arbor average height (10 m from gap margin), arbor quantity (10 m from gap margin), shrub quantity (10 m from gap margin), herbal average coverage (1 m from gap margin) and bare land ratio were the key forest gap factors that influenced bird diversities. On the whole, bird diversity in the forest gap was greater than in the intact canopy. Spatial distributions in the forest gaps were also observed in the bird community. Most birds foraged in the "middle" and "canopy" layers in the vertical stratification. In addition, "nearly from" and "close from" contained more birds in relation to horizontal stratification. Feeding niche differentiation was suggested as the main reason for these distribution patterns.

Scale dependence of biotic homogenisation by urbanisation: a comparison of urban bird communities between central Argentina and northern Finland

Directory of Open Access Journals (Sweden)

Leveau Lucas M.

2017-12-01

Full Text Available Recent studies showed contrasting results about the homogenising force of urbanisation on bird community composition at large and regional scales. We studied whether urbanisation promotes the homogenisation of wintering bird communities and if this varies when comparing towns located within a specific region and towns located in two different biomes of two countries. We used both similarity indices based on the presence/absence data and the abundance data in comparing communities. Processes governing bird community dissimilarity between urbanisation levels were examined with the partitioning of Sörensen index in species turnover and nestedness. We made bird surveys in town centres and suburban habitats of three cities located in the Pampean region of Argentina and in the boreal region of Finland using a single-visit study plot method. Rarefacted species richness did not differ amongst the town centres between the countries, but it was higher in the suburban areas of Argentina than in Finland. At the country-level comparison, we found a higher similarity amongst the town centres than amongst the suburban areas; whereas at the regional comparison, similarity between town centres was comparable to the similarity between suburban areas. The use of an abundance-based index produced a higher similarity between town centre communities of both countries than when using a presence-based index. The dissimilarity between habitats in Argentina was related to nestedness and to species turnover in Finland. Our results indicate that urban-based biotic homogenisation of bird communities is dependent on the scale used, being more evident when comparing cities of different biomes where the same and abundant bird species, such as sparrows and doves, dominate. At the regional scale, quite a high beta-diversity can still be found within urban habitats. Processes of community dissimilarity between urban habitats may differ according to the regional pool of species

Bird community in an Araucaria forest fragment in relation to changes in the surrounding landscape in Southern Brazil

Directory of Open Access Journals (Sweden)

Pedro Scherer-Neto

2012-12-01

Full Text Available The dynamics of the bird community in a small forest fragment was evaluated along seven years in relation to changes in the surrounding landscape. The study area is an Araucaria forest fragment in Southern Brazil (state of Paraná. The sampling period covered the years 1988 through 1994 and the mark-release-recapture method was utilized. The landscape analysis was based on Landsat TM images, and changes in exotic tree plantations, native forest, open areas (agriculture, pasture, bare soil, and abandoned field, and "capoeira"(native vegetation < 2 m were quantified. The relationship between landscape changes and changes in abundance diversity of forest birds, open-area birds, forest-edge birds, and bamboo specialists was evaluated. Richness estimates were run for each year studied. The richness recorded in the study area comprised 96 species. The richness estimates were 114, 118 and 110 species for Chao 1, Jackknife 1 and Bootstrap, respectively. The bird community varied in species richness, abundance and diversity from year to year. As for species diversity, 1991, 1993 and 1994 were significantly different from the other years. Changes in the landscape contributed to the increase in abundance and richness for the groups of forest, open-area and bamboo-specialist species. An important factor discussed was the effect of the flowering of "taquara" (Poaceae, which contributed significantly to increasing richness of bamboo seed eaters, mainly in 1992 and 1993. In general, the results showed that landscape changes affected the dynamics and structure of the bird community of this forest fragment over time, and proved to have an important role in conservation of the avian community in areas of intensive forestry and agricultural activities.

Windturbines and meadow birds in Germany - results of a 7 years BACI-study and a literature review

Energy Technology Data Exchange (ETDEWEB)

Reichenbach, Marc; Steinborn, Hanjo

2011-07-01

Full text: In many parts of Germany meadow birds - either breeding or staging - are the species most affected by wind farms planned in open agricultural areas. A 7 year BACI-study (before-after-control-impact) in the south of East Frisia, Lower Saxony, investigated the influence of wind turbines on several meadow bird species. The parameters analysed comprised population trends, spatial distribution and behaviour in relation to turbine distance, breeding success as well as the influence of certain habitat parameters like type of agricultural use and the distance to woods and hedges. The results show, that breeding birds are generally less sensitive to wind turbines than staging birds. Significant reductions of breeding lapwing density occurred only up to a distance of 100 m. Curlews however showed a reduction of resting and grooming behaviour up to a distance of 250 m. Other species like meadow pipit, skylark and stonechat showed no indications of displacement. An impact of wind turbines on breeding success could not be detected. Breeding lapwings showed a strong preference for certain types of crops, which led to spatial aggregations irrespective of turbine proximity. In staging birds a much more obvious displacement up to about 400 m could be detected. The results are consistent with a number of other German studies on possible displacement effects in different bird species. Lapwing and skylark are among the best studied species whereas staging geese tend to be the most sensitive ones. In conclusion the siting of wind farms must not only be guided by occurrence of endangered species named on national or regional Red Lists but also by the species-specific sensitivity against the disturbance effects of wind turbines. (Author)

Do Birds Avoid Railroads as Has Been Found for Roads?

Science.gov (United States)

Wiącek, Jarosław; Polak, Marcin; Filipiuk, Maciej; Kucharczyk, Marek; Bohatkiewicz, Janusz

2015-09-01

The construction of railway lines usually has a negative effect on the natural environment: habitats are destroyed, collisions with trains cause deaths, and the noise and vibrations associated with rail traffic disturb the lives of animals. Cases are known, however, where the opposite holds true: a railway line has a positive effect on the fauna in its vicinity. In this study, we attempted to define the influence of a busy railway line on a breeding community of woodland birds. Birds were counted using the point method at 45 observation points located at three different distances (30, 280, 530 m) from the tracks. At each point, we determined the habitat parameters and the intensity of noise. In total, 791 individual birds of 42 species were recorded on the study plot. Even though the noise level fell distinctly with increasing distance from the tracks, the abundance of birds and the number of species were the highest near the railway line. Moreover, insectivorous species displayed a clear preference for the vicinity of the line. The noise from the trains did not adversely affect the birds on the study plot. The environmental conditions created by the edge effect meant that the birds preferred the neighborhood of the tracks: the more diverse habitats near the tracks supplied attractive nesting and foraging niches for many species of birds. Trains passing at clear intervals acted as point sources of noise and did not elicit any negative reactions on the part of the birds; this stands in contrast to busy roads, where the almost continuous flow of traffic in practice constitutes a linear source of noise.

Conserving migratory land birds in the new world: do we know enough?

Science.gov (United States)

Faaborg, John; Holmes, Richard T; Anders, Angela D; Bildstein, Keith L; Dugger, Katie M; Gauthreaux, Sidney A; Heglund, Patricia; Hobson, Keith A; Jahn, Alex E; Johnson, Douglas H; Latta, Steven C; Levey, Douglas J; Marra, Peter P; Merkord, Christopher L; Nol, Erica; Rothstein, Stephen I; Sherry, Thomas W; Sillett, T Scott; Thompson, Frank R; Warnock, Nils

2010-03-01

Migratory bird needs must be met during four phases of the year: breeding season, fall migration, wintering, and spring migration; thus, management may be needed during all four phases. The bulk of research and management has focused on the breeding season, although several issues remain unsettled, including the spatial extent of habitat influences on fitness and the importance of habitat on the breeding grounds used after breeding. Although detailed investigations have shed light on the ecology and population dynamics of a few avian species, knowledge is sketchy for most species. Replication of comprehensive studies is needed for multiple species across a range of areas, Information deficiencies are even greater during the wintering season, when birds require sites that provide security and food resources needed for survival and developing nutrient reserves for spring migration and, possibly, reproduction. Research is needed on many species simply to identify geographic distributions, wintering sites, habitat use, and basic ecology. Studies are complicated, however, by the mobility of birds and by sexual segregation during winter. Stable-isotope methodology has offered an opportunity to identify linkages between breeding and wintering sites, which facilitates understanding the complete annual cycle of birds. The twice-annual migrations are the poorest-understood events in a bird's life. Migration has always been a risky undertaking, with such anthropogenic features as tall buildings, towers, and wind generators adding to the risk. Species such as woodland specialists migrating through eastern North America have numerous options for pausing during migration to replenish nutrients, but some species depend on limited stopover locations. Research needs for migration include identifying pathways and timetables of migration, quality and distribution of habitats, threats posed by towers and other tall structures, and any bottlenecks for migration. Issues such as human

Abdim\\'s Stork Ciconia abdimii in Niger: population size, breeding ...

African Journals Online (AJOL)

–4, n = 36), suggesting a total post-fledging population of c. 83 500 birds (95% CL ± 51 267), excluding any non-breeding (sub)adults. The home range of six satellite-tagged breeders in 2003 was 10–120 km2 (median 36 km2); birds adjacent ...

What drives cooperative breeding?

Directory of Open Access Journals (Sweden)

Walter D Koenig

2017-06-01

Full Text Available Cooperative breeding, in which more than a pair of conspecifics cooperate to raise young at a single nest or brood, is widespread among vertebrates but highly variable in its geographic distribution. Particularly vexing has been identifying the ecological correlates of this phenomenon, which has been suggested to be favored in populations inhabiting both relatively stable, productive environments and in populations living under highly variable and unpredictable conditions. Griesser et al. provide a novel approach to this problem, performing a phylogenetic analysis indicating that family living is an intermediate step between nonsocial and cooperative breeding birds. They then examine the ecological and climatic conditions associated with these different social systems, concluding that cooperative breeding emerges when family living is favored in highly productive environments, followed secondarily by selection for cooperative breeding when environmental conditions deteriorate and within-year variability increases. Combined with recent work addressing the fitness consequences of cooperative breeding, Griesser et al.'s contribution stands to move the field forward by demonstrating that the evolution of complex adaptations such as cooperative breeding may only be understood when each of the steps leading to it are identified and carefully integrated.

Birds and Aircraft on Midway Islands, 1959-63 Investigations

Science.gov (United States)

Robbins, C.S.

1966-01-01

At Midway Naval Station, 1.100 miles west-northwest of Honolulu, military aircraft collide with flying albatrosses at the rate of about 300 to 400 per year. One aircraft out of every five that hits an albatross on takeoff either aborts (stops before it is airborne), or dumps fuel and returns for appraisal of damage. About 70,000 pairs of Laysan albatrosses and 7,000 pairs of blackfooted albatrosses nest at Midway in any given year. The population is declining. Two-thirds or more of the birds of breeding age nest each year. The minimum breeding age recorded is 5 years (each species), but many individuals do not nest until at least 7 years of age. Young birds begin to return to Midway at 3 years of age and are found more frequently as breeding age approaches. They come ashore more frequently in March and April (the high bird strike months) than in midwinter. Even in midwinter the number of 'walkers' (birds not on nests) may comprise more than 40 percent of the albatrosses present on Sand Island, Midway. Maximum longevity of the Laysan albatross is believed to exceed 40 years; 6 out of 99 birds banded as breeding adults (7+ years old) were still alive 24 years after banding. Control methods tested experimentally include disturbance, gunfire, other sounds, radar beams, smoke, odors, destruction of nests, eggs, chicks, and adults, moving of birds, eggs, and chicks, erection of obstacles to flight, and habitat management. Habitat management (leveling and hardsurfacing of shoulders of runways) has been the most effective. Albatrosses were counted over the runways at 10 locations in 1957, 1958, and 1960 to determine the effects of wind direction, wind speed, and topography on the numbers of flying birds. Birds were most concentrated in areas where rising air currents were created as winds blew against dunes or tall trees. Soaring and strike rate both increased with greater wind speeds. There was a highly significant correlation between strike frequency and wind direction

Food abundance explains the breeding season of a tropical ...

African Journals Online (AJOL)

The timing of breeding in birds is a life-history trait that generally depends on food availability, but other factors may play a role, particularly in tropical areas where food availability is less seasonal than in temperate or polar areas. We studied the factors affecting the breeding season of the Crab Plover Dromas ardeola, ...

Factors influencing the breeding success of Cape Gannets Morus ...

African Journals Online (AJOL)

In the 2002/2003 breeding season at Malgas Island, South Africa, 125 nests of Cape Gannets Morus capensis, of which at least one partner was of known age, were monitored. The age of birds at these nests ranged from five to 22 years. At five nests, the ages of both partners were known; ages were similar for birds ...

American Exceptionalism: Population Trends and Flight Initiation Distances in Birds from Three Continents

Science.gov (United States)

Møller, Anders Pape; Samia, Diogo S. M.; Weston, Mike A.; Guay, Patrick-Jean; Blumstein, Daniel T.

2014-01-01

Background All organisms may be affected by humans' increasing impact on Earth, but there are many potential drivers of population trends and the relative importance of each remains largely unknown. The causes of spatial patterns in population trends and their relationship with animal responses to human proximity are even less known. Methodology/Principal Finding We investigated the relationship between population trends of 193 species of bird in North America, Australia and Europe and flight initiation distance (FID); the distance at which birds take flight when approached by a human. While there is an expected negative relationship between population trend and FID in Australia and Europe, we found the inverse relationship for North American birds; thus FID cannot be used as a universal predictor of vulnerability of birds. However, the analysis of the joint explanatory ability of multiple drivers (farmland breeding habitat, pole-most breeding latitude, migratory habit, FID) effects on population status replicated previously reported strong effects of farmland breeding habitat (an effect apparently driven mostly by European birds), as well as strong effects of FID, body size, migratory habit and continent. Farmland birds are generally declining. Conclusions/Significance Flight initiation distance is related to population trends in a way that differs among continents opening new research possibilities concerning the causes of geographic differences in patterns of anti-predator behavior. PMID:25226165

Tornadic storm avoidance behavior in breeding songbirds

Science.gov (United States)

Streby, Henry M.; Kramer, Gunnar R.; Peterson, Sean M.; Lehman, Justin A.; Buehler, David A.; Andersen, David E.

2015-01-01

Migration is a common behavior used by animals of many taxa to occupy different habitats during different periods. Migrant birds are categorized as either facultative (i.e., those that are forced to migrate by some proximal cue, often weather) or obligate (i.e., those that migrate on a regular cycle). During migration, obligate migrants can curtail or delay flights in response to inclement weather or until favorable winds prevail, and they can temporarily reorient or reverse direction when ecological or meteorological obstacles are encountered. However, it is not known whether obligate migrants undertake facultative migrations and make large-scale movements in response to proximal cues outside of their regular migration periods. Here, we present the first documentation of obligate long-distance migrant birds undertaking a facultative migration, wherein breeding golden-winged warblers (Vermivora chrysoptera) carrying light-level geolocators performed a >1,500 km 5-day circumvention of a severe tornadic storm. The birds evacuated their breeding territories >24 hr before the arrival of the storm and atmospheric variation associated with it. The probable cue, radiating >1,000 km from tornadic storms, perceived by birds and influencing bird behavior and movements, is infrasound (i.e., sound below the range of human hearing). With the predicted increase in severity and frequency of similar storms as anthropogenic climate change progresses, understanding large-scale behavioral responses of animals to such events will be an important objective of future research.

Joint review of related contracts on bird populations in the Ravenglass Estuary

International Nuclear Information System (INIS)

Anderson, N.; Evans, P.R.; Lowe, V.P.W.

1987-10-01

Black-headed Gulls breeding at Ravenglass (and at other coastal sites in Cumbria) fed exclusively inland during the breeding season and so they and their young could not have acquired any radionuclides present in the estuarine muds and invertebrates. Levels in the invertebrates and in gull tissues were low; they were slightly higher in Shelducks, which feed on estuarine invertebrates but have nested successfully at Ravenglass in recent years. Gulls and two other ground-nesting bird species have suffered severe disturbance and predation by foxes in recent springs at Ravenglass; Shelducks nest in burrows and have escaped such effects. Levels of radionuclides in birds, particularly gulls, are too low to have caused breeding failures at Ravenglass. (author)

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.

Phenological shifts conserve thermal niches in North American birds and reshape expectations for climate-driven range shifts.

Science.gov (United States)

Socolar, Jacob B; Epanchin, Peter N; Beissinger, Steven R; Tingley, Morgan W

2017-12-05

Species respond to climate change in two dominant ways: range shifts in latitude or elevation and phenological shifts of life-history events. Range shifts are widely viewed as the principal mechanism for thermal niche tracking, and phenological shifts in birds and other consumers are widely understood as the principal mechanism for tracking temporal peaks in biotic resources. However, phenological and range shifts each present simultaneous opportunities for temperature and resource tracking, although the possible role for phenological shifts in thermal niche tracking has been widely overlooked. Using a canonical dataset of Californian bird surveys and a detectability-based approach for quantifying phenological signal, we show that Californian bird communities advanced their breeding phenology by 5-12 d over the last century. This phenological shift might track shifting resource peaks, but it also reduces average temperatures during nesting by over 1 °C, approximately the same magnitude that average temperatures have warmed over the same period. We further show that early-summer temperature anomalies are correlated with nest success in a continental-scale database of bird nests, suggesting avian thermal niches might be broadly limited by temperatures during nesting. These findings outline an adaptation surface where geographic range and breeding phenology respond jointly to constraints imposed by temperature and resource phenology. By stabilizing temperatures during nesting, phenological shifts might mitigate the need for range shifts. Global change ecology will benefit from further exploring phenological adjustment as a potential mechanism for thermal niche tracking and vice versa.

Understanding soaring bird migration through interactions and decisions at the individual level

NARCIS (Netherlands)

van Loon, E.E.; Shamoun-Baranes, J.; Bouten, W.; Davis, S.L.

2011-01-01

Many soaring bird species migrate southwards in autumn from their breeding grounds in Europe and Central Asia towards their wintering grounds. Our knowledge about interactions between migrating birds, thermal selection during migration and mechanisms that lead to flocking or convergent travel

Bird community changes in response to single and repeated fires in a lowland tropical rainforest of eastern Borneo

NARCIS (Netherlands)

Slik, J.W.F.; Balen, van S.

2006-01-01

Our current understanding of bird community responses to tropical forest fires is limited and strongly geographically biased towards South America. Here we used the circular plot method to carry out complete bird inventories in undisturbed, once burned (1998) and twice burned forests (1983 and 1998)

growth and development of the reproduction organs of breeding

African Journals Online (AJOL)

Theodore Olivier

assumptions that the breeding ostrich will lay an egg every second day and eat 2 kg feed per day. A study by. Olivier et al (2009) revealed that female birds can consume up to 3.7 kg feed per day in an ad libitum situation. Under controlled conditions birds are fed only 2.5 kg feed/d (Brand & Gous, 2006). Each female.

How birds weather the weather: avian migration in the mid-latitudes

NARCIS (Netherlands)

Kemp, M.U.

2012-01-01

The life cycle of many bird species involves the twice-annual movement between a breeding ground and a wintering ground that we refer to as `migration'. To complete these journeys, birds must successfully navigate many obstacles including a dynamic atmosphere. To make optimal use of this

The effects of organic inputs to estuaries on overwintering bird populations and communities

International Nuclear Information System (INIS)

Green, P.T.; Hill, D.A.; Clark, N.A.

1992-01-01

This study investigates the relationship between changes in organic inputs to river estuaries and other coastal intertidal areas, and changes in the populations of waterfowl in these habitats. This is done in the context of tidal barrage construction, where barrage construction and operation may coincide with the cleaning of estuarine water. A thorough review of the literature is undertaken to determine the current status of knowledge of bird/organic-enrichment interactions. The use of multivariate statistics for identifying gradients in similarity between bird communities (specifically waders) of different estuaries, irrespective of geographic locations is investigated. (UK)

Captive breeding and reintroduction of the oriental pied hornbill (Anthracoceros albirostris) in Khao Kheow Open Zoo, Thailand.

Science.gov (United States)

Chaiyarat, Rattanawat; Kongprom, Urarikha; Manathamkamon, Darika; Wanpradab, Sunan; Sangarang, Satean

2012-01-01

This article discusses two related issues of the captive breeding and reintroduction of the Oriental pied hornbill (Anthracoceros albirostris) in order to increase its population in the natural habitats. Oriental pied hornbills were bred in Khao Kheow Open Zoo. Three pairs were separated and kept in breeding cages. Females occupied artificial nests between February and April 2005-2007. Eggs were laid and incubated between February and March each year from 2005 to 2007. Nestlings hatched in late March and left the nest in late April 2005-2007. Each breeding pair was fed with approximately 400 g of food each day. All three pairs reproduced resulting in mature offspring of seven in 2005, six in 2006, and five in 2007. Four of sixteen 3-year-old birds were randomly selected and equipped with a GPS receiver on their backs. Activities of the birds attached and unattached with GPS were not significantly different. The first two birds (one female, one male with GPS) were reintroduced on August 5, 2006, and another nine birds (four birds with GPS) were reintroduced on December 26, 2006. The average home range of these reintroduced birds was 0.13 km(2) . Their foods consisted of wild plants and animals in the home range. The first reintroduced pair was able to breed naturally by laying and hatching eggs in an artificial nest. Two juveniles left the nest in April 2008. These results indicate that both captive breeding and reintroduction are potentially important ways to increase the population of the Oriental pied hornbill in natural habitats. © 2011 Wiley Periodicals, Inc.

Nest-site competition between invasive and native cavity nesting birds and its implication for conservation.

Science.gov (United States)

Charter, Motti; Izhaki, Ido; Ben Mocha, Yitzchak; Kark, Salit

2016-10-01

Nesting cavities are often a limited resource that multiple species use. There is an ongoing discussion on whether invasive cavity nesting birds restrict the availability of this key limited resource. While the answer to this question has important conservation implications, little experimental work has been done to examine it. Here, we aimed to experimentally test whether alien cavity nesting birds affect the occupancy of cavities and the resulting breeding success of native cavity breeders in a large urban park located in Tel Aviv, Israel. Over three breeding seasons, we manipulated the entry size of nest boxes and compared the occupancy and breeding success of birds in nest boxes of two treatments. These included nest boxes with large-entrance and small-entrance holes. The large-entrance holes allowed access for both the native and invasive birds (the two main aliens in the park are the common mynas and rose-ringed parakeets). The smaller-entrance boxes, on the other hand, allowed only the smaller sized native cavity breeders (great tits and house sparrows) to enter the boxes but prevented the alien species from entering. We found that the large-entrance nest boxes were occupied by five different bird species, comprising three natives (great tit, house sparrow, Scops owl) and two invasive species (common myna, rose-ringed parakeet) while the small-entrance boxes were only occupied by the two native species. The alien common mynas and rose-ringed parakeets occupied 77.5% of the large-entrance nest boxes whereas native species, mainly great tits, occupied less than 9% of the large-entrance boxes and 36.5% of the small-entrance boxes. When examining the occupancy of those cavities that were not occupied by the aliens, natives occupied both the small and large-entrance nest boxes equally. Three quarters (78%) of the great tits breeding in the large-entrance boxes were usurped by common mynas during the breeding season and as a result breeding success was

The effect of the Sep wind park near Oosterbierum, Friesland, The Netherlands, on birds

International Nuclear Information System (INIS)

Winkelman, J.E.

1992-01-01

The title study concerns the period 1984-1991. The wind park consists of 18 three-bladed 300 kW horizontal axis wind turbines of 35 meters height, and a rotor diameter of 30 meters, seven meteorological towers, and three cluster and control buildings. Aspects studied included disturbance of breeding, resting or feeding, and migrating birds, behavior of birds approaching the wind turbines during the day and night, and bird victims due to collision with the wind turbines and the meteorological towers. In this report attention is paid to the disturbance of the bird's biotope. The results show that four species of grassland birds, breeding in the park, were hardly disturbed by the wind turbines. For feeding and resting birds, however, disturbance effects were noted, even at a distance of 500 meters from the outside wind turbine array. The present number of bird species reduced 60-95%, dependent on the species, after the wind park was put into operation. Also the behavior of migrating birds was influenced by the wind park, showed in clustering of groups or avoiding the wind park, sometimes up to 67% of the birds did so. It is therefore recommended not to implement new wind parks in important bird migration and bird feeding or bird resting areas. Bird popular areas, however, are mostly windy areas. 15 figs., 25 tabs., 56 app., 128 refs

Potential breeding distributions of U.S. birds predicted with both short-term variability and long-term average climate data.

Science.gov (United States)

Bateman, Brooke L; Pidgeon, Anna M; Radeloff, Volker C; Flather, Curtis H; VanDerWal, Jeremy; Akçakaya, H Resit; Thogmartin, Wayne E; Albright, Thomas P; Vavrus, Stephen J; Heglund, Patricia J

2016-12-01

Climate conditions, such as temperature or precipitation, averaged over several decades strongly affect species distributions, as evidenced by experimental results and a plethora of models demonstrating statistical relations between species occurrences and long-term climate averages. However, long-term averages can conceal climate changes that have occurred in recent decades and may not capture actual species occurrence well because the distributions of species, especially at the edges of their range, are typically dynamic and may respond strongly to short-term climate variability. Our goal here was to test whether bird occurrence models can be predicted by either covariates based on short-term climate variability or on long-term climate averages. We parameterized species distribution models (SDMs) based on either short-term variability or long-term average climate covariates for 320 bird species in the conterminous USA and tested whether any life-history trait-based guilds were particularly sensitive to short-term conditions. Models including short-term climate variability performed well based on their cross-validated area-under-the-curve AUC score (0.85), as did models based on long-term climate averages (0.84). Similarly, both models performed well compared to independent presence/absence data from the North American Breeding Bird Survey (independent AUC of 0.89 and 0.90, respectively). However, models based on short-term variability covariates more accurately classified true absences for most species (73% of true absences classified within the lowest quarter of environmental suitability vs. 68%). In addition, they have the advantage that they can reveal the dynamic relationship between species and their environment because they capture the spatial fluctuations of species potential breeding distributions. With this information, we can identify which species and guilds are sensitive to climate variability, identify sites of high conservation value where climate

Radionuclides and the birds at Ravenglass

International Nuclear Information System (INIS)

Lowe, V.P.W.

1991-01-01

Since 1983 concern has been expressed about the apparent decline in numbers of birds in the Ravenglass estuary in west Cumbria, particularly of the black-headed gull colony on the Drigg dunes, and suggestions have been made that this decline might be due to excessive radiation in the birds' food and their general environment. Twelve species of marine invertebrates from Ravenglass, known to be important foods for birds, were analysed, and further samples were taken from sites along the west Cumbrian coast. None of these samples showed excessive contamination with any of the radionuclides analysed. Analysis of a sample of bird carcasses from the area showed oystercatchers (Haematopus ostralegus) and shelduck (Tadorna tadorna) to have some of the highest concentrations of 137 Cs in their tissues; yet their breeding success and populations were not affected. Black-headed gulls were found to be feeding mainly inland, and were the least contaminated with radionuclides of all the birds at Ravenglass, yet this species and its breeding success were in decline. Calculations of the total dose equivalent rate to the whole body of the most contaminated black-headed gull amounted to 9.8 x 10 -4 mSv h -1 (∼ 8.4 x 10 -4 mGy h -1 , whole-body absorbed dose rate), and the background exposure dose was of the order of 8.3 x 10 -4 mGy h -1 . As a minimum chronic dose of 1000 mGy day -1 has been found necessary to retard growth of nestling birds, and 9600 mGy over 20 days of incubation to cause the death of 50% of embryos in black-headed gulls' eggs, the concentrations of radionuclides in the foods, body tissues and general environment were at least three orders of magnitude too low to have had any effects. (author)

Plants, birds and butterflies: short-term responses of species communities to climate warming vary by taxon and with altitude.

Science.gov (United States)

Roth, Tobias; Plattner, Matthias; Amrhein, Valentin

2014-01-01

As a consequence of climate warming, species usually shift their distribution towards higher latitudes or altitudes. Yet, it is unclear how different taxonomic groups may respond to climate warming over larger altitudinal ranges. Here, we used data from the national biodiversity monitoring program of Switzerland, collected over an altitudinal range of 2500 m. Within the short period of eight years (2003-2010), we found significant shifts in communities of vascular plants, butterflies and birds. At low altitudes, communities of all species groups changed towards warm-dwelling species, corresponding to an average uphill shift of 8 m, 38 m and 42 m in plant, butterfly and bird communities, respectively. However, rates of community changes decreased with altitude in plants and butterflies, while bird communities changed towards warm-dwelling species at all altitudes. We found no decrease in community variation with respect to temperature niches of species, suggesting that climate warming has not led to more homogenous communities. The different community changes depending on altitude could not be explained by different changes of air temperatures, since during the 16 years between 1995 and 2010, summer temperatures in Switzerland rose by about 0.07°C per year at all altitudes. We discuss that land-use changes or increased disturbances may have prevented alpine plant and butterfly communities from changing towards warm-dwelling species. However, the findings are also consistent with the hypothesis that unlike birds, many alpine plant species in a warming climate could find suitable habitats within just a few metres, due to the highly varied surface of alpine landscapes. Our results may thus support the idea that for plants and butterflies and on a short temporal scale, alpine landscapes are safer places than lowlands in a warming world.

Transmission of influenza reflects seasonality of wild birds across the annual cycle

Science.gov (United States)

Hill, Nichola J.; Ma, Eric J.; Meixell, Brandt W.; Lindberg, Mark S.; Boyce, Walter M.; Runstadler, Jonathan A.

2016-01-01

Influenza A Viruses (IAV) in nature must overcome shifting transmission barriers caused by the mobility of their primary host, migratory wild birds, that change throughout the annual cycle. Using a phylogenetic network of viral sequences from North American wild birds (2008–2011) we demonstrate a shift from intraspecific to interspecific transmission that along with reassortment, allows IAV to achieve viral flow across successive seasons from summer to winter. Our study supports amplification of IAV during summer breeding seeded by overwintering virus persisting locally and virus introduced from a wide range of latitudes. As birds migrate from breeding sites to lower latitudes, they become involved in transmission networks with greater connectivity to other bird species, with interspecies transmission of reassortant viruses peaking during the winter. We propose that switching transmission dynamics may be a critical strategy for pathogens that infect mobile hosts inhabiting regions with strong seasonality.

Transformation in the diversity of avifauna under the influence of recreational load

Directory of Open Access Journals (Sweden)

T. V. Shupova

2017-02-01

Full Text Available This article examines the bird community of a large reservoir and its surrounding area , located in the central part of a large city in the northern part of the steppe zone of Ukraine. The city, Krivoy Rog, has a population of over 700,000 people. Large areas of the city have undergone dramatic transformation. Industrial and and residential areas of the city are located around the reservoir. The shores of the reservoirs are subject to recreational loading. The natural landscape here is a combination of steppe habitats and scubland.. The material for this study was collected in the breeding seasons of 1996, 1999, 2012, 2015. The number and distribution of birds were determined by registrations of birds along transects. The diversity index, dominance and evenness of species distribution in the breeding bird communities were compared for different habitats and different years. In breeding season 73 bird species belonging to 15 orders were found on the territory of the reservoir. Of these, 62 species bred, and 11 more used the area for foraging but bred in adjacent habitats. 24 species were present in winter. The average density of the breeding birds per species increased from 1.8 ± 0.4 pairs/km of survey route in 1996 to 3.2 ± 0.8 pairs/km in 2015. The dominant species in the breeding bird communities were Passer montanus L., Sturnus vulgaris L., Parus major L., Fulica atra L., Podiceps cristatus L. In the period 1996–1999 the habitat conditions in the territory of the water reservoir changed. These changes were associated with mass recreation of city residents here. The changes resulted in a stressful situation for the habitats and the bird communities. The changes resulted in an imbalance in the development of the bird communities. Since 2012 the birds adapted to the new environmental conditions and formed a new community. By 2015, the species diversity of birds had increased, the degree of pressure on the dominant species and the species

Husbandry, breeding practices, and production constraints of camel in the pastoral communities of Afar and Somali, Ethiopia

Directory of Open Access Journals (Sweden)

Yosef Tadesse

2014-12-01

Full Text Available The objectives of this paper were to identify and describe husbandry practices, herd structure, owners’ trait preferences, breeding practices, and production constraints of camel in the two major camel rearing pastoral communities, viz. Afar and Somali, to generate baseline information that would help to plan possible breed improvement strategies and options for the different camel populations. The study sites were selected purposively while households from each of the sites randomly. Data were collected using formal questionnaires and focus group discussion. Results showed that average camel population per household was higher in Mille (28.06±2.27, Gode (27.51±2.02, and Moyale (24.07±2.13 districts. Female camel populations with age of >1 year contributes 78-83% of the total camel herd population in all the study districts. Higher number of female animals in the herd in the arid environment means providing continuous supply of milk and allows a rapid recovery of herd numbers after a disease outbreak or drought occurrence. This shows that pastoralists breeding objectives are in relation to the arid environment and female population in the herd. Most of the pastoral communities utilize a single breeding male camel per 40-50 female camels and this will affect productivity and heterogeneity of camel population. With regard to trait preference, all pastoral communities ranked milk yield as the first trait of choice, except Liben district in which adaptation trait was the primary preference. Growth trait ranked second in Mille, Gode, Liben, and Jijiga pastoral communities where as adaptation trait ranked second in Amibara and Shinille pastoral communities. The major camel production constraints were feed, diseases, and lack of water in that order and the major cause of the constraints was the recurrent drought occurred during the past 2-3 decades in the two regions. Therefore, in planning and implementation of the breeding strategies for small

Coordinating across scales: Building a regional marsh bird monitoring program from national and state Initiatives

Science.gov (United States)

Shriver, G.W.; Sauer, J.R.

2008-01-01

Salt marsh breeding bird populations (rails, bitterns, sparrows, etc.) in eastern North America are high conservation priorities in need of site specific and regional monitoring designed to detect population changes over time. The present status and trends of these species are unknown but anecdotal evidence of declines in many of the species has raised conservation concerns. Most of these species are listed as conservation priorities on comprehensive wildlife plans throughout the eastern U.S. National Wildlife Refuges, National Park Service units, and other wildlife conservation areas provide important salt marsh habitat. To meet management needs for these areas, and to assist regional conservation planning, survey designs are being developed to estimate abundance and population trends for these breeding bird species. The primary purpose of this project is to develop a hierarchical sampling frame for salt marsh birds in Bird Conservation Region (BCR) 30 that will provide the ability to estimate species population abundances on 1) specific sites (i.e. National Parks and National Wildlife Refuges), 2) within states or regions, and 3) within BCR 30. The entire breeding range of Saltmarsh Sharp-tailed and Coastal Plain Swamp sparrows are within BCR 30, providing an opportunity to detect population trends within the entire breeding ranges of two priority species.

Constant and seasonal drivers of bird communities in a wind farm: implications for conservation

Directory of Open Access Journals (Sweden)

Zuzanna M. Rosin

2016-07-01

Full Text Available Background. One of the most difficult challenges for conservation biology is to reconcile growing human demands for resources with the rising need for protecting nature. Wind farms producing renewable energy have been recognised to be a threat for birds, but clear directives for environmental planning are still missing. Methods. Point counts were performed to study the relationship between eight environmental variables and bird populations in different parts of a year on the largest Polish wind farm between March 2011 and February 2013. Variables potentially related to species richness (Chao 1 estimator and the abundance of the entire bird community as well as five selected farmland species were analysed with the use of generalized linear mixed models. Results. Some associations between the studied variables and bird populations were season/year specific, while others had a constant direction (positive or negative across seasons and/or years. The latter were distance to the nearest turbine, field size, number of wind turbines, proximity of settlements and water bodies. Spatial autocorrelation and counting time were significantly correlated with bird population estimates but the directions of these relationships varied among seasons and years. Associations between abundance of individual species and environmental variables were species-specific. Conclusions. The results demonstrated a constant negative relationship between wind turbine proximity and bird numbers. Other environmental variables, such as field size, proximity of settlements and water bodies that also had constant associations with bird populations across seasons may be taken into account when minimizing adverse effects of wind farm development on birds or choosing optimal locations of new turbines.

Constant and seasonal drivers of bird communities in a wind farm: implications for conservation.

Science.gov (United States)

Rosin, Zuzanna M; Skórka, Piotr; Szymański, Paweł; Tobolka, Marcin; Luczak, Andrzej; Tryjanowski, Piotr

2016-01-01

Background. One of the most difficult challenges for conservation biology is to reconcile growing human demands for resources with the rising need for protecting nature. Wind farms producing renewable energy have been recognised to be a threat for birds, but clear directives for environmental planning are still missing. Methods. Point counts were performed to study the relationship between eight environmental variables and bird populations in different parts of a year on the largest Polish wind farm between March 2011 and February 2013. Variables potentially related to species richness (Chao 1 estimator) and the abundance of the entire bird community as well as five selected farmland species were analysed with the use of generalized linear mixed models. Results. Some associations between the studied variables and bird populations were season/year specific, while others had a constant direction (positive or negative) across seasons and/or years. The latter were distance to the nearest turbine, field size, number of wind turbines, proximity of settlements and water bodies. Spatial autocorrelation and counting time were significantly correlated with bird population estimates but the directions of these relationships varied among seasons and years. Associations between abundance of individual species and environmental variables were species-specific. Conclusions. The results demonstrated a constant negative relationship between wind turbine proximity and bird numbers. Other environmental variables, such as field size, proximity of settlements and water bodies that also had constant associations with bird populations across seasons may be taken into account when minimizing adverse effects of wind farm development on birds or choosing optimal locations of new turbines.

Accumulation features of persistent organochlorines in resident and migratory birds from Asia

International Nuclear Information System (INIS)

Kunisue, Tatsuya; Watanabe, Mafumi; Subramanian, Annamalai; Sethuraman, Alagappan; Titenko, Alexei M.; Qui, Vo; Prudente, Maricar; Tanabe, Shinsuke

2003-01-01

Accumulation features of persistent organochlorines in migratory birds from Asia did not necessarily reflect only the pollution in the sampling area. - Concentrations of organochlorine contaminants including polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexane isomers (HCHs), chlordane compounds (CHLs), hexachlorobenzene (HCB) were determined in the resident and migratory birds, which were collected from India, Japan, Philippines, Russia (Lake Baikal) and Vietnam. Accumulation patterns of organochlorine concentrations in resident birds suggested that the predominant contaminants of each country were as follows: Japan-PCBs Philippines-PCBs and CHLs, India-HCHs and DDTs, Vietnam-DDTs, and Lake Baikal-PCBs and DDTs. The migratory birds from Philippines and Vietnam retained mostly the highest concentrations of DDTs among the organochlorines analyzed, indicating the presence of stopover and breeding grounds of those birds in China and Russia. On the other hand, migratory birds from India and Lake Baikal showed different patterns of organochlorine residues, reflecting that each species has inherent migratory routes and thus has exposure to different contaminants. Species which have breeding grounds around the Red Sea and Persian Gulf showed high levels of PCBs, indicating the presence of areas heavily polluted by PCBs in the Middle East

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.

Ecology of Avian Influenza Virus in Wild Birds in Tropical Africa.

Science.gov (United States)

Gaidet, Nicolas

2016-05-01

Several ecologic factors have been proposed to describe the mechanisms whereby host ecology and the environment influence the transmission of avian influenza viruses (AIVs) in wild birds, including bird's foraging behavior, migratory pattern, seasonal congregation, the rate of recruitment of juvenile birds, and abiotic factors. However, these ecologic factors are derived from studies that have been conducted in temperate or boreal regions of the Northern Hemisphere. These factors cannot be directly translated to tropical regions, where differences in host ecology and seasonality may produce different ecologic interactions between wild birds and AIV. An extensive dataset of AIV detection in wildfowl and shorebirds sampled across tropical Africa was used to analyze how the distinctive ecologic features of Afrotropical regions may influence the dynamics of AIV transmission in wild birds. The strong seasonality of rainfall and surface area of wetlands allows testing of how the seasonality of wildfowl ecology (reproduction phenology and congregation) is related to AIV seasonal dynamics. The diversity of the African wildfowl community provides the opportunity to investigate the respective influence of migratory behavior, foraging behavior, and phylogeny on species variation in infection rate. Large aggregation sites of shorebirds in Africa allow testing for the existence of AIV infection hot spots. We found that the processes whereby host ecology influence AIV transmission in wild birds in the Afrotropical context operate through ecologic factors (seasonal drying of wetlands and extended and nonsynchronized breeding periods) that are different than the one described in temperate regions, hence, resulting in different patterns of AIV infection dynamics.

Effect of urbanization on bird community in riparian environments in Caí River, Rio Grande do Sul, Brazil

OpenAIRE

Brummelhaus, Jaqueline; Bohn, Márcia Sueli; Petry, Maria Virginia

2012-01-01

http://dx.doi.org/10.5007/2175-7925.2012v25n2p81 Urbanization produces changes in riparian environments causing effects in the structure of bird communities, which respond differently to impacts. We compare richness, abundance and composition of birds in riparian environments with different urbanization gradients in Caí River, Rio Grande do Sul. We conducted observations in woodland, grassland and urban environments, between September/2007 and August/2008. We recorded 130 bird species, 29...

Dataset of Passerine bird communities in a Mediterranean high mountain (Sierra Nevada, Spain).

Science.gov (United States)

Pérez-Luque, Antonio Jesús; Barea-Azcón, José Miguel; Álvarez-Ruiz, Lola; Bonet-García, Francisco Javier; Zamora, Regino

2016-01-01

In this data paper, a dataset of passerine bird communities is described in Sierra Nevada, a Mediterranean high mountain located in southern Spain. The dataset includes occurrence data from bird surveys conducted in four representative ecosystem types of Sierra Nevada from 2008 to 2015. For each visit, bird species numbers as well as distance to the transect line were recorded. A total of 27847 occurrence records were compiled with accompanying measurements on distance to the transect and animal counts. All records are of species in the order Passeriformes. Records of 16 different families and 44 genera were collected. Some of the taxa in the dataset are included in the European Red List. This dataset belongs to the Sierra Nevada Global-Change Observatory (OBSNEV), a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area.

El Grupo Cerúleo: Cooperation for Non-breeding Season Conservation of the Cerulean Warbler

Science.gov (United States)

David Mehlman; Paul. Hamel

2010-01-01

Without collaboration, conservation is impossible for long-distance migrants such as the Cerulean Warbler, a declining forest breeding bird in North America that overwinters in the Andes Mountains of South America. The Cerulean Warbler, one of the fastest declining woodland birds of eastern North America, is considered Vulnerable by BirdLife international, in the...

Conservation Priorities for Terrestrial Birds in the Northeastern United States

Science.gov (United States)

Kenneth V. Rosenberg; Jeffrey V. Wells

2005-01-01

As part of the Partners in Flight (PIF) bird-conservation planning process, we assessed breeding land bird species according to seven categories of population vulnerability to derive a priority species pool in each of 12 physiographic areas that overlap the northeastern U.S. We then grouped species into the following habitat-species suites: (1) boreal-mountaintop...

Assessing the effect of agricultural land abandonment on bird communities in southern-eastern Europe.

Science.gov (United States)

Zakkak, Sylvia; Radovic, Andreja; Nikolov, Stoyan C; Shumka, Spase; Kakalis, Lefteris; Kati, Vassiliki

2015-12-01

Agricultural land abandonment is recognized as a major environmental threat in Europe, being particularly pronounced in south-eastern Europe, where knowledge on its effects is limited. Taking the Balkan Peninsula as a case study, we investigated agricultural abandonment impact on passerine communities at regional level. We set up a standard methodology for site selection (70 sites) and data collection, along a well-defined forest-encroachment gradient that reflects land abandonment in four countries: Albania, Bulgaria, Croatia and Greece. Regardless the different socio-economic and political histories in the Balkans that led to diverse land abandonment patterns in space and time, rural abandonment had a consistent negative effect on bird communities, while regional-level analysis revealed patterns that were hidden at local level. The general trends were an increase of forest-dwelling bird species at the expense of farmland birds, the decline of overall bird species richness, as well as the decline of Species of European Conservation Concern (SPECs) richness and abundance. Many farmland bird species declined with land abandonment, whereas few forest species benefited from the process. In conclusion, our results support CAP towards hampering rural land abandonment and preserving semi-open rural mosaics in remote upland areas, using a suite of management measures carefully tailored to local needs. The maintenance of traditional rural landscapes should be prioritized in the Balkans, through the timely identification of HNV farmland that is most prone to abandonment. We also suggest that coordinated transnational research is needed, for a better assessment of conservation options in remote rural landscapes at European scale, including the enhancement of wild grazers' populations as an alternative in areas where traditional land management is rather unlikely to be re-established. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biodiversity conservation in an anthropized landscape: Trees, not patch size drive, bird community composition in a low-input agro-ecosystem.

Science.gov (United States)

Mellink, Eric; Riojas-López, Mónica E; Cárdenas-García, Melinda

2017-01-01

One of the most typical agro-ecosystems in the Llanos de Ojuelos, a semi-arid region of central Mexico, is that of fruit-production orchards of nopales (prickly pear cacti). This perennial habitat with complex vertical structure provides refuge and food for at least 112 species of birds throughout the year. Nopal orchards vary in their internal structure, size and shrub/tree composition, yet these factors have unknown effects on the animals that use them. To further understand the conservation potential of this agro-ecosystem, we evaluated the effects of patch-size and the presence of trees on bird community composition, as well as several habitat variables, through an information-theoretical modelling approach. Community composition was obtained through a year of census transects in 12 orchards. The presence of trees in the orchards was the major driver of bird communities followed by seasonality; bird communities are independent of patch size, except for small orchard patches that benefit black-chin sparrows, which are considered a sensitive species. At least 55 species of six trophic guilds (insectivores, granivores, carnivores, nectivores, omnivores, and frugivores) used the orchards. Orchards provide adequate habitat and food resources for several sensitive species of resident and migratory sparrows. The attributes that make orchards important for birds: trees, shrubs, herb seeds, and open patches can be managed to maintain native biodiversity in highly anthropized regions with an urgent need to find convergence between production and biological conservation.

Detailed description of the Ócsa Bird Ringing Station, Hungary

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Csörgő Tibor

2016-12-01

Full Text Available The present paper acts as an introduction to a series that will describe the exploratory analyses of migration phenology and morphometrics of the most common passerine species at the Ócsa Bird Ringing Station. This station is situated in the Ócsa Landscape Protection Area that belongs to the Duna–Ipoly National Park, Hungary. The area is somewhat cooler and more humid than the surrounding agricultural fields and tree plantations, covered by a mosaic of diverse hygrophilous vegetation patches. Bird trapping is mostly based on Japanese mist-net lines crossing different plant communities. During the period of 1984–2015, a total of 422,862 birds were trapped and ringed here, while 202,739 local, 1,235 within country, and 443 foreign recaptures were also recorded. Each bird is characterized by the following data: location and time of capture, species, age, sex, scores of fat, pectoral muscle, wing tip abrasion, and moult, length of wing, 3rd primary, and tail, and body mass. After subjected to a rigorous quality check, digital data are deposited in the archive of the Hungarian Bird Ringing Centre, and the EURING data base. From time to time, other research projects also utilized the accessibility of wild birds captured here, thus collection of blood samples, ecto- and endoparasites was carried out at the station. The relatively long time span, large number of species and individuals, and the readily available environmental (weather, vegetation, etc. data makes the avian data collected here a suitable base for studies of various disciplines like capture methodology, habitat preferences, breeding, migration, and wintering, effects of weather and climate change, and epidemiology of viruses and parasites.

Ethnobotanic importance of plants used in pigeon-breeding in Eastern Spain

OpenAIRE

Belda, Antonio; Cort?s, Carolina; Peir?, Victoriano

2013-01-01

Background: The importance that birds of the Columbidae family have had throughout history is visible on the Mediterranean coast. Pigeon fancying is the art of breeding and training carrier pigeons and currently, several breeds exist. The sport of racing pigeons consists in covering a distance at maximum possible speed. However, pigeon breeding has another modality called “sport pigeon”, where several males follow a female. This study focusses on ethnobotanical knowledge of native and exotic ...

Rapid adjustment of bird community compositions to local climatic variations and its functional consequences.

Science.gov (United States)

Gaüzère, Pierre; Jiguet, Frédéric; Devictor, Vincent

2015-09-01

The local spatial congruence between climate changes and community changes has rarely been studied over large areas. We proposed one of the first comprehensive frameworks tracking local changes in community composition related to climate changes. First, we investigated whether and how 12 years of changes in the local composition of bird communities were related to local climate variations. Then, we tested the consequences of this climate-induced adjustment of communities on Grinnellian (habitat-related) and Eltonian (function-related) homogenization. A standardized protocol monitoring spatial and temporal trends of birds over France from 2001 to 2012 was used. For each plot and each year, we used the spring temperature and the spring precipitations and calculated three indices reflecting the thermal niche, the habitat specialization, and the functional originality of the species within a community. We then used a moving-window approach to estimate the spatial distribution of the temporal trends in each of these indices and their congruency with local climatic variations. Temperature fluctuations and community dynamics were found to be highly variable in space, but their variations were finely congruent. More interestingly, the community adjustment to temperature variations was nonmonotonous. Instead, unexplained fluctuations in community composition were observed up to a certain threshold of climate change intensity, above which a change in community composition was observed. This shift corresponded to a significant decrease in the relative abundance of habitat specialists and functionally original species within communities, regardless of the direction of temperature change. The investigation of variations in climate and community responses appears to be a central step toward a better understanding of climate change effects on biodiversity. Our results suggest a fine-scale and short-term adjustment of community composition to temperature changes. Moreover

Sex-Specific Habitat Utilization and Differential Breeding Investments in Christmas Island Frigatebirds throughout the Breeding Cycle.

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Janos C Hennicke

Full Text Available In seabirds, equal bi-parental care is the rule, as it is considered crucial for raising chicks successfully because seabirds forage in an environment with unpredictable and highly variable food supply. Frigatebirds forage in poor tropical waters, yet males reduce and even stop parental care soon after chick brooding, leaving the female to provision the chick alone for an extended fledging period. Using bird-borne tracking devices, male and female Christmas Island Frigatebirds (Fregata andrewsi were investigated during the brooding, late chick rearing and post-fledging period to examine whether sexes exhibit foraging strategies that may be linked to differential breeding investments. During brooding, males and females showed similar foraging behaviour under average marine productivity of oceanic waters close to the colony, but males shifted to more distant and more productive habitats when conditions deteriorated to continue with reduced chick provisioning. During the late chick rearing period, females progressively increased their foraging range to the more distant but productive marine areas that only males had visited during brooding. Birds spent the non-breeding period roosting in highly productive waters of the Sunda Shelf. The sex-specific utilisation of three different foraging habitats with different primary productivity (oceanic, coastal, and shelf areas allowed for temporal and spatial segregation in the exploitation of favourable habitats which seems to enable each sex to optimise its foraging profitability. In addition, post-fledging foraging movements of females suggest a biennial breeding cycle, while limited information on males suggests the possibility of an annual breeding cycle.

First report and breeding record of the Chinese Crested Tern Thalasseus bernsteini on the Korean Peninsula

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Se-Kyu Song

2017-06-01

Full Text Available The Chinese Crested Tern Thalasseus bernsteini is a critically endangered species (as designated by the IUCN (International Union for Conservation of Nature and Natural Resources. This report expands the known breeding grounds of these birds eastward. An individual of the Chinese Crested Tern was first observed at an uninhabited island of Jeollanam-do in Korea on April 28, 2016. On May 9, 2016 five Chinese Crested Terns (consisting of 2 breeding pairs and a single bird were observed. Nests from the breeding pairs were found, at a distance of 0.6 m from each other; each pair was observed incubating one egg in the nest. To our knowledge, this is the easternmost record of breeding grounds for the Chinese Crested Tern.

Road networks predict human influence on Amazonian bird communities.

Science.gov (United States)

Ahmed, Sadia E; Lees, Alexander C; Moura, Nárgila G; Gardner, Toby A; Barlow, Jos; Ferreira, Joice; Ewers, Robert M

2014-11-22

Road building can lead to significant deleterious impacts on biodiversity, varying from direct road-kill mortality and direct habitat loss associated with road construction, to more subtle indirect impacts from edge effects and fragmentation. However, little work has been done to evaluate the specific effects of road networks and biodiversity loss beyond the more generalized effects of habitat loss. Here, we compared forest bird species richness and composition in the municipalities of Santarém and Belterra in Pará state, eastern Brazilian Amazon, with a road network metric called 'roadless volume (RV)' at the scale of small hydrological catchments (averaging 3721 ha). We found a significant positive relationship between RV and both forest bird richness and the average number of unique species (species represented by a single record) recorded at each site. Forest bird community composition was also significantly affected by RV. Moreover, there was no significant correlation between RV and forest cover, suggesting that road networks may impact biodiversity independently of changes in forest cover. However, variance partitioning analysis indicated that RV has partially independent and therefore additive effects, suggesting that RV and forest cover are best used in a complementary manner to investigate changes in biodiversity. Road impacts on avian species richness and composition independent of habitat loss may result from road-dependent habitat disturbance and fragmentation effects that are not captured by total percentage habitat cover, such as selective logging, fire, hunting, traffic disturbance, edge effects and road-induced fragmentation. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Road networks predict human influence on Amazonian bird communities

Science.gov (United States)

Ahmed, Sadia E.; Lees, Alexander C.; Moura, Nárgila G.; Gardner, Toby A.; Barlow, Jos; Ferreira, Joice; Ewers, Robert M.

2014-01-01

Road building can lead to significant deleterious impacts on biodiversity, varying from direct road-kill mortality and direct habitat loss associated with road construction, to more subtle indirect impacts from edge effects and fragmentation. However, little work has been done to evaluate the specific effects of road networks and biodiversity loss beyond the more generalized effects of habitat loss. Here, we compared forest bird species richness and composition in the municipalities of Santarém and Belterra in Pará state, eastern Brazilian Amazon, with a road network metric called ‘roadless volume (RV)’ at the scale of small hydrological catchments (averaging 3721 ha). We found a significant positive relationship between RV and both forest bird richness and the average number of unique species (species represented by a single record) recorded at each site. Forest bird community composition was also significantly affected by RV. Moreover, there was no significant correlation between RV and forest cover, suggesting that road networks may impact biodiversity independently of changes in forest cover. However, variance partitioning analysis indicated that RV has partially independent and therefore additive effects, suggesting that RV and forest cover are best used in a complementary manner to investigate changes in biodiversity. Road impacts on avian species richness and composition independent of habitat loss may result from road-dependent habitat disturbance and fragmentation effects that are not captured by total percentage habitat cover, such as selective logging, fire, hunting, traffic disturbance, edge effects and road-induced fragmentation. PMID:25274363

Testing bird response to roads on a rural environment: A case study from Central Italy

Science.gov (United States)

Morelli, Federico; Jerzak, Leszek; Pruscini, Fabio; Santolini, Riccardo; Benedetti, Yanina; Tryjanowski, Piotr

2015-11-01

The construction of roads is currently well spread in many parts of our world and impacts strongly on wildlife distribution. Some bird species avoid, while other prefer to be in the vicinity of these human structures. However, studies on roads effects on birds, in terms of strength or direction of these effects, are scarce. Therefore, in a study carried out in Central Italy we tested the responses of different bird species to roads at a local spatial scale, using generalized linear models (GLM). Analysis were conducted on a large dataset (more than 1400 sampled sites, mainly on rural environments). Both positive and negative effects of roads on birds were found for bird species of close or semi-close environments, while the negative effects of roads were negligible for bird species of open and semi-open environments. This fact suggest that roads can be a source of "functional heterogeneity" on semi-open environments, providing marginal habitats, hedgerows and residual vegetation typical of roadsides, offering breeding and feeding habitat for some bird species. The proposed methodology provide a useful explorative tool, in order to develop conservation policies to preserve the biodiversity, mainly in rural landscapes. The outputs of GLM can be used as inputs in ecological planning: direction and strength of the effects of roads on bird species are adequate to estimate the response of bird community, up front to the presence of new structures, or identifying which of them should be mitigated to reduce negative effects on the biodiversity.

Dataset of Passerine bird communities in a Mediterranean high mountain (Sierra Nevada, Spain)

Science.gov (United States)

Pérez-Luque, Antonio Jesús; Barea-Azcón, José Miguel; Álvarez-Ruiz, Lola; Bonet-García, Francisco Javier; Zamora, Regino

2016-01-01

Abstract In this data paper, a dataset of passerine bird communities is described in Sierra Nevada, a Mediterranean high mountain located in southern Spain. The dataset includes occurrence data from bird surveys conducted in four representative ecosystem types of Sierra Nevada from 2008 to 2015. For each visit, bird species numbers as well as distance to the transect line were recorded. A total of 27847 occurrence records were compiled with accompanying measurements on distance to the transect and animal counts. All records are of species in the order Passeriformes. Records of 16 different families and 44 genera were collected. Some of the taxa in the dataset are included in the European Red List. This dataset belongs to the Sierra Nevada Global-Change Observatory (OBSNEV), a long-term research project designed to compile socio-ecological information on the major ecosystem types in order to identify the impacts of global change in this area. PMID:26865820

Blood lead concentrations in Alaskan tundra swans: linking breeding and wintering areas with satellite telemetry.

Science.gov (United States)

Ely, Craig R; Franson, J Christian

2014-04-01

Tundra swans (Cygnus columbianus) like many waterfowl species are susceptible to lead (Pb) poisoning, and Pb-induced mortality has been reported from many areas of their wintering range. Little is known however about Pb levels throughout the annual cycle of tundra swans, especially during summer when birds are on remote northern breeding areas where they are less likely to be exposed to anthropogenic sources of Pb. Our objective was to document summer Pb levels in tundra swans throughout their breeding range in Alaska to determine if there were population-specific differences in blood Pb concentrations that might pose a threat to swans and to humans that may consume them. We measured blood Pb concentrations in tundra swans at five locations in Alaska, representing birds that winter in both the Pacific Flyway and Atlantic Flyway. We also marked swans at each location with satellite transmitters and coded neck bands, to identify staging and wintering sites and determine if winter site use correlated with summer Pb concentrations. Blood Pb levels were generally low (<0.2 μg/ml) in swans across all breeding areas. Pb levels were lower in cygnets than adults, suggesting that swans were likely exposed to Pb on wintering areas or on return migration to Alaska, rather than on the summer breeding grounds. Blood Pb levels varied significantly across the five breeding areas, with highest concentrations in birds on the North Slope of Alaska (wintering in the Atlantic Flyway), and lowest in birds from the lower Alaska Peninsula that rarely migrate south for winter.

Cryptococcosis outbreak in psittacine birds in Brazil.

Science.gov (United States)

Raso, T F; Werther, K; Miranda, E T; Mendes-Giannini, M J S

2004-08-01

An outbreak of cryptococcosis occurred in a breeding aviary in São Paulo, Brazil. Seven psittacine birds (of species Charmosyna papou, Lorius lory, Trichoglossus goldiei, Psittacula krameri and Psittacus erithacus) died of disseminated cryptococcosis. Incoordination, progressive paralysis and difficulty in flying were seen in five birds, whereas superficial lesions coincident with respiratory alterations were seen in two birds. Encapsulated yeasts suggestive of Cryptococcus sp. were seen in faecal smears stained with India ink in two cases. Histological examination of the birds showed cryptococcal cells in various tissues, including the beak, choana, sinus, lungs, air sacs, heart, liver, spleen, kidneys, intestines and central nervous system. High titres of cryptococcal antigen were observed in the serum of an affected bird. In this case, titres increased during treatment and the bird eventually died. Yeasts were isolated from the nasal mass, faeces and liver of one bird. Cryptococcus neoformans var. gattii serovar B was identified based on biochemical, physiological and serological tests. These strains were resistant (minimum inhibitory concentration 64 microg/ml) to fluconazole. This is the first report of C. neoformans var. gattii occurring in psittacine birds in Brazil.

A 'slow pace of life' in Australian old-endemic passerine birds is not accompanied by low basal metabolic rates.

Science.gov (United States)

Bech, Claus; Chappell, Mark A; Astheimer, Lee B; Londoño, Gustavo A; Buttemer, William A

2016-05-01

Life history theory suggests that species experiencing high extrinsic mortality rates allocate more resources toward reproduction relative to self-maintenance and reach maturity earlier ('fast pace of life') than those having greater life expectancy and reproducing at a lower rate ('slow pace of life'). Among birds, many studies have shown that tropical species have a slower pace of life than temperate-breeding species. The pace of life has been hypothesized to affect metabolism and, as predicted, tropical birds have lower basal metabolic rates (BMR) than temperate-breeding birds. However, many temperate-breeding Australian passerines belong to lineages that evolved in Australia and share 'slow' life-history traits that are typical of tropical birds. We obtained BMR from 30 of these 'old-endemics' and ten sympatric species of more recently arrived passerine lineages (derived from Afro-Asian origins or introduced by Europeans) with 'faster' life histories. The BMR of 'slow' temperate-breeding old-endemics was indistinguishable from that of new-arrivals and was not lower than the BMR of 'fast' temperate-breeding non-Australian passerines. Old-endemics had substantially smaller clutches and longer maximal life spans in the wild than new arrivals, but neither clutch size nor maximum life span was correlated with BMR. Our results suggest that low BMR in tropical birds is not functionally linked to their 'slow pace of life' and instead may be a consequence of differences in annual thermal conditions experienced by tropical versus temperate species.

Arthropod abundance and seasonal bird use of bottomland forest harvest gaps

Science.gov (United States)

Christopher E. Moorman; Liessa T. Woen; John C. Kilgo; James L. Hanula; Scott Horn; Michael D. Ulyshen

2012-01-01

We investigated the influence of arthropod abundance and vegetation structure on shifts in avian use of canopy gap, gap edge, and surrounding forest understory in a bottomland hardwood forest in the Upper Coastal Plain of South Carolina. We compared captures of foliage-gleaning birds among locations during four periods (spring migration, breeding, post-breeding, and...

Invasive alien birds in Denmark

DEFF Research Database (Denmark)

Fox, Anthony David; Heldbjerg, Henning; Nyegaard, Timme

2015-01-01

Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to such bird species in Denmark. A new European Union Regulation...... on Invasive Alien Species implemented in January 2015 establishes a framework for actions to combat alien species, which requires Member States to prevent the spread of alien species, provide early warning and rapid responses to their presence and management of established alien species where they occur. We...... show the importance of mechanisms such as DOF’s (Dansk Ornitologisk Forening, BirdLife Denmark) Atlas project, Common Bird Census (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already...

Invasive alien birds in Denmark

DEFF Research Database (Denmark)

Nyegaard, Timme; Heldbjerg, Henning; Fox, Anthony David

Avian Introduced Alien Species (IAS) constitute a threat to the integrity of native biodiversity, the economy and human health, so here we briefly review some of the problems posed by such species around the world in relation to bird species in Denmark. A new European Union Regulation on Invasive...... Alien Species implemented in January 2015 requires a framework for actions to combat alien species, which requires Member States to prevent the spread of alien species, provide early warning and rapid responses to their presence and management of established alien species where they occur. We show...... the importance of mechanisms such as DOFs (Danish Ornithological Society, BirdLife Denmark) Atlas project, Common Bird Monitoring (breeding and wintering species) and DOFbasen to contribute data on the current geographical and numerical distribution of the few serious alien avian species already present...

Birds of a Great Basin Sagebrush Habitat in East-Central Nevada

OpenAIRE

United States Department of Agriculture, Forest Service

1992-01-01

Breeding bird populations ranged from 3.35 to 3.48 individuals/ha over a 3-year study conducted from 1981 to 1983. Brewer's sparrows, sage sparrows, sage thrashers, and black-throated sparrows were numerically dominant. Horned larks and western meadowlarks were less common. Results are compared with bird populations in Great Basin sagebrush habitats elsewhere in the United States.

Complete breeding failures in ivory gull following unusual rainy storms in North Greenland

Directory of Open Access Journals (Sweden)

Glenn Yannic

2014-03-01

Full Text Available Natural catastrophic events such as heavy rainfall and windstorms may induce drastic decreases in breeding success of animal populations. We report the impacts of summer rainfalls on the reproductive success of ivory gull (Pagophila eburnea in north-east Greenland. On two occasions, at Amdrup Land in July 2009 and at Station Nord in July 2011, we observed massive ivory gull breeding failures following violent rainfall and windstorms that hit the colonies. In each colony, all of the breeding birds abandoned their eggs or chicks during the storm. Juvenile mortality was close to 100% at Amdrup Land in 2009 and 100% at Station Nord in 2011. Our results show that strong winds associated with heavy rain directly affected the reproductive success of some Arctic bird species. Such extreme weather events may become more common with climate change and represent a new potential factor affecting ivory gull breeding success in the High Arctic.

Projecting climate effects on birds and reptiles of the Southwestern United States

Science.gov (United States)

van Riper, Charles; Hatten, James R.; Giermakowski, J. Tomasz; Mattson, David; Holmes, Jennifer A.; Johnson, Matthew J.; Nowak, Erika M.; Ironside, Kirsten; Peters, Michael; Heinrich, Paul; Cole, K.L.; Truettner, C.; Schwalbe, Cecil R.

2014-01-01

We modeled the current and future breeding ranges of seven bird and five reptile species in the Southwestern United States with sets of landscape, biotic (plant), and climatic global circulation model (GCM) variables. For modeling purposes, we used PRISM data to characterize the climate of the Western United States between 1980 and 2009 (baseline for birds) and between 1940 and 2009 (baseline for reptiles). In contrast, we used a pre-selected set of GCMs that are known to be good predictors of southwestern climate (five individual and one ensemble GCM), for the A1B emission scenario, to characterize future climatic conditions in three time periods (2010–39; 2040–69; and, 2070–99). Our modeling approach relied on conceptual models for each target species to inform selection of candidate explanatory variables and to interpret the ecological meaning of developed probabilistic distribution models. We employed logistic regression and maximum entropy modeling techniques to create a set of probabilistic models for each target species. We considered climatic, landscape, and plant variables when developing and testing our probabilistic models. Climatic variables included the maximum and minimum mean monthly and seasonal temperature and precipitation for three time periods. Landscape features included terrain ruggedness and insolation. We also considered plant species distributions as candidate explanatory variables where prior ecological knowledge implicated a strong association between a plant and animal species. Projected changes in range varied widely among species, from major losses to major gains. Breeding bird ranges exhibited greater expansions and contractions than did reptile species. We project range losses for Williamson’s sapsucker and pygmy nuthatch of a magnitude that could move these two species close to extinction within the next century. Although both species currently have a relatively limited distribution, they can be locally common, and neither

Sex and migratory strategy influence corticosterone levels in winter-grown feathers, with positive breeding effects in a migratory pelagic seabird.

Science.gov (United States)

Pérez, Cristóbal; Granadeiro, José Pedro; Dias, Maria P; Catry, Paulo

2016-08-01

To overcome unpredictable stressful transitory events, animals trigger an allostatic response involving the hypothalamic-pituitary-adrenal cortex. This hormonal response, which involves the release of glucocorticoids which in turn mediate between the main physiological mechanisms that regulate the energetic demands and resource allocation trade-off with behavioural responses to environmental perturbations and may ultimately lead to variation in fitness. We have used the Cory's shearwater Calonectris borealis, a sexually dimorphic pelagic seabird with a partial migratory strategy, as a model bird species to analyse a number of traits related to the stress response. We investigated whether the activation of a stressful response, mediated by corticosterone, during the wintering period (1) correlated with the previous breeding success, (2) was affected by the migratory behaviour of male birds and (3) had consequences in the fitness of the birds. Corticosterone levels in feathers grown overwinter were analysed in 61 adult birds during three consecutive migratory periods (2009-2012) and in 14 immature birds in the wintering period 2010-2011. Moreover, the levels of corticosterone were analysed in experimental birds which were freed from their reproductive duties and compared with control birds which raised fledglings to the end of the breeding period. The results show that the levels of corticosterone were sex dependent, differed between years and were affected by the migratory strategy performed by the birds. The activation of the stressful response over the wintering period generated residual carry-over effects that positively affected the reproductive output in the subsequent breeding stage, a phenomenon previously undescribed in a long-lived pelagic seabird. Our study provides evidence that the analysis of corticosterone from feathers is a useful tool to evaluate carry-over effects in birds far away from breeding sites, opening new possibilities for future studies in

Short Note: New breeding locality for Crowned Cormorant

Directory of Open Access Journals (Sweden)

P.A. Whittington

2004-12-01

Full Text Available The Crowned Cormorant Phalacrocorax coronatus is endemic to the southern African subregion with an estimated population of about 2700 pairs, breeding at 48 localities between Walvis Bay, Namibia and Cape Agulhas, South Africa (Crawford et al. 1994, Crawford 1997. The easternmost point at which breeding has previously been recorded is 2 km west of Aasfontein (34°46'S, 19°50'E, where 35 nests were recorded in January 1981 (Crawford et al. 1982. Non-breeding birds have been seen further to the east as far as Holkom Meester se Baai (34°23'S, 21°49'E (Crawford et al. 1982.

Avian cooperative breeding: Old hypotheses and new directions.

Science.gov (United States)

Heinsohn, R G; Cockburn, A; Mulder, R A

1990-12-01

In cooperatively breeding birds, individuals that appear capable of reproducing on their own may instead assist others with their breeding efforts. Research into avian cooperative breeding has attempted to reconcile the apparent altruism of this behaviour with maximization of inclusive fitness. Most explanations of cooperative breeding have suggested that philopatry is enforced by ecological constraints, such as a shortage of resources critical to breeding. Non-dispersers may then benefit both directly and indirectly from contributing at the nest. Recent research has shown that such benefits may be sufficient to promote philopatry, without the need for ecological constraints, and emphasizes that consideration of both costs and benefits of philopatry is essential for a comprehensive approach to the problem. The growing body of data from long-term studies of different species should combine with an improved phylogenetic perspective on cooperative breeding, to provide a useful base for future comparative analyses and experimentation. Copyright © 1990. Published by Elsevier Ltd.

Breeding performance in the Italian chicken breed Mericanel della Brianza

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Stefano P. Marelli

2010-11-01

Full Text Available In Italy, 90 local avian breeds were described, the majority (61% were classified extinct and only 8.9 % still diffused. Therefore, efforts for conservation of Italian avian breeds are urgently required. The aim of this study was to record the breeding performance of the Italian breed Mericanel della Brianza and multiply a small population, in order to develop a conservation program. Fourteen females and 8 males were available at the beginning of the reproductive season in 2009 and organized in 8 families (1 male/1-2 females kept in floor pens. Birds received a photoperiod of 14L:10D and fed ad libitum. Breeding performance was recorded from March to June. Egg production and egg weight were recorded daily; eggs were set every 2 weeks and fertility, embryo mortality and hatchability were recorded. Mean egg production was 37% and mean egg weight was 34±3.49 g. High fertility values were recorded in the first three settings, from 94 to 87%, and the overall mean fertility value was 81.6%. Overall hatchability was only 49.6% due to a high proportion of dead embryos. Embryo mortality occurred mainly between day 2 and 7 of incubation and during hatch. Highest hatchability values were recorded in setting 1 and 2, 69 and 60% respectively, and a great decrease was found in the following settings. Great variations in egg production, fertility, hatchability and embryo mortality were found among families. The present results are the basic knowledge on reproductive parameters necessary to improve the reproductive efficiency of the breed within a conservation plan.

Trading up: the fitness consequences of divorce in monogamous birds.

Science.gov (United States)

Culina, Antica; Radersma, Reinder; Sheldon, Ben C

2015-11-01

Social and genetic mating systems play an important role in natural and sexual selection, as well as in the dynamics of populations. In socially monogamous species different genetic mating patterns appear when individuals mate outside the breeding pair within a breeding season (extra-pair mating) or when they change partners between two breeding seasons (widowing or divorce). Divorce can be defined as having occurred when two previously paired individuals are alive during the next breeding season and at least one of them has re-mated with a new partner. In socially monogamous birds divorce is widespread, but it is not clear whether it is a behavioural adaptation to improve the quality of a mating decision or whether, alternatively, it results as a non-selected consequence of other processes: existing studies suggest a heterogeneous set of results with respect to this central question. This heterogeneity could result from a number of factors, ranging from the methodological approaches used, to population- or species-specific characters. In this review we use phylogenetic meta-analyses to assess the evidence that divorce is adaptive (in terms of breeding success) across 64 species of socially monogamous birds. Second, we explore biological and methodological reasons for the heterogeneity in the results of previous studies. Results of our analyses supported the hypothesis that divorce is, in general, an adaptive behavioural strategy as: (1) divorce is triggered by relatively low breeding success; (2) there is a positive change in breeding success as a result of divorce. More specifically, while controlling for methodological moderators, we show that: (i) earlier stages of breeding are better predictors of divorce than later stages (r = 0.231; 95% CI: 0.061-0.391 for clutch size; similar for laying date); (ii) females benefited from divorce more than males in terms of increasing breeding success between successive breeding attempts, with different stages of the

Malaria knowledge and agricultural practices that promote mosquito breeding in two rural farming communities in Oyo State, Nigeria

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Oshiname Frederick O

2010-04-01

Full Text Available Abstract Background Agricultural practices such as the use of irrigation during rice cultivation, the use of ponds for fish farming and the storage of water in tanks for livestock provide suitable breeding grounds for anthropophylic mosquitoes. The most common anthropophylic mosquito in Nigeria which causes much of the morbidity and mortality associated with malaria is the anopheles mosquito. Farmers are therefore at high risk of malaria - a disease which seriously impacts on agricultural productivity. Unfortunately information relating to agricultural practices and farmers' behavioural antecedent factors that could assist malaria programmers plan and implement interventions to reduce risk of infections among farmers is scanty. Farmers' knowledge about malaria and agricultural practices which favour the breeding of mosquitoes in Fashola and Soku, two rural farming communities in Oyo State were therefore assessed in two rural farming communities in Oyo State. Methods This descriptive cross-sectional study involved the collection of data through the use of eight Focus Group Discussions (FGDs and the interview of 403 randomly selected farmers using semi-structured questionnaires. These sets of information were supplemented with observations of agricultural practices made in 40 randomly selected farms. The FGD data were recorded on audio-tapes, transcribed and subjected to content analysis while the quantitative data were analyzed using descriptive and inferential statistics. Results Most respondents in the two communities had low level of knowledge of malaria causation as only 12.4% stated that mosquito bite could transmit the disease. Less than half (46.7% correctly mentioned the signs and symptoms of malaria as high body temperature, body pains, headache, body weakness and cold/fever. The reported main methods for preventing mosquito bites in the farming communities included removal of heaps of cassava tuber peelings (62.3%, bush burning

Bird-community responses to habitat creation in a long-term, large-scale natural experiment.

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Whytock, Robin C; Fuentes-Montemayor, Elisa; Watts, Kevin; Barbosa De Andrade, Patanjaly; Whytock, Rory T; French, Paul; Macgregor, Nicholas A; Park, Kirsty J

2018-04-01

Ecosystem function and resilience are compromised when habitats become fragmented due to land-use change. This has led to national and international conservation strategies aimed at restoring habitat extent and improving functional connectivity (i.e., maintaining dispersal processes). However, biodiversity responses to landscape-scale habitat creation and the relative importance of spatial and temporal scales are poorly understood, and there is disagreement over which conservation strategies should be prioritized. We used 160 years of historic post-agricultural woodland creation as a natural experiment to evaluate biodiversity responses to habitat creation in a landscape context. Birds were surveyed in 101 secondary, broadleaf woodlands aged 10-160 years with ≥80% canopy cover and in landscapes with 0-17% broadleaf woodland cover within 3000 m. We used piecewise structural equation modeling to examine the direct and indirect relationships between bird abundance and diversity, ecological continuity, patch characteristics, and landscape structure and quantified the relative conservation value of local and landscape scales for bird communities. Ecological continuity indirectly affected overall bird abundance and species richness through its effects on stand structure, but had a weaker influence (effect size near 0) on the abundance and diversity of species most closely associated with woodland habitats. This was probably because woodlands were rapidly colonized by woodland generalists in ≤10 years (minimum patch age) but were on average too young (median 50 years) to be colonized by woodland specialists. Local patch characteristics were relatively more important than landscape characteristics for bird communities. Based on our results, biodiversity responses to habitat creation depended on local- and landscape-scale factors that interacted across time and space. We suggest that there is a need for further studies that focus on habitat creation in a landscape

Breeding Bird Community Continues to Colonize Riparian Buffers Ten Years after Harvest.

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Scott F Pearson

Full Text Available Riparian ecosystems integrate aquatic and terrestrial communities and often contain unique assemblages of flora and fauna. Retention of forested buffers along riparian habitats is a commonly employed practice to reduce potential negative effects of land use on aquatic systems. However, very few studies have examined long-term population and community responses to buffers, leading to considerable uncertainty about effectiveness of this practice for achieving conservation and management outcomes. We examined short- (1-2 years and long-term (~10 years avian community responses (occupancy and abundance to riparian buffer prescriptions to clearcut logging silvicultural practices in the Pacific Northwest USA. We used a Before-After-Control-Impact experimental approach and temporally replicated point counts analyzed within a Bayesian framework. Our experimental design consisted of forested control sites with no harvest, sites with relatively narrow (~13 m forested buffers on each side of the stream, and sites with wider (~30 m and more variable width unharvested buffer. Buffer treatments exhibited a 31-44% increase in mean species richness in the post-harvest years, a pattern most evident 10 years post-harvest. Post-harvest, species turnover was much higher on both treatments (63-74% relative to the controls (29%. We did not find evidence of local extinction for any species but found strong evidence (no overlap in 95% credible intervals for an increase in site occupancy on both Narrow (short-term: 7%; long-term 29% and Wide buffers (short-term: 21%; long-term 93% relative to controls after harvest. We did not find a treatment effect on total avian abundance. When assessing relationships between buffer width and site level abundance of four riparian specialists, we did not find strong evidence of reduced abundance in Narrow or Wide buffers. Silviculture regulations in this region dictate average buffer widths on small and large permanent streams that

Nesting ecology of grassland birds following a wildfire in the southern Great Plains

Science.gov (United States)

Roberts, Anthony J.; Boal, Clint W.; Whitlaw, Heather A.

2017-01-01

We studied the response of nesting grassland birds occupying short-grass and mixed-grass prairie sites 2 and 3 y following two, large-scale wildfires that burned ≥360,000 ha in the Texas Panhandle in March 2006. Nest success was greater on burned plots compared to unburned plots, though this varied by species and year. Woody vegetation cover was greater around nests on unburned plots compared to burned plots for Cassin's sparrow (Peucaea cassinii) and lark sparrow (Chondestes grammacus). Cassin's sparrows and lark sparrows nested in more-woody vegetation than did grasshopper sparrows (Ammodramus savannarum), and woody vegetation was reduced following the wildfires. The wildfires appear to have had few if any negative influences on the avian community 3 years postfire. This may be due to grassland breeding birds being adapted to landscapes in which, historically, periodic disturbance (e.g., wildfire, intensive grazing by bison [Bison bison]) resulted in vegetation heterogeneity.

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.

The relations between forest fragmentation and bird community body size and biodiversity and bird community body size.

OpenAIRE

Hopman, F.

2017-01-01

Bachelor thesis Future Planet Studies, major biologie ABSTRACT Animal species with a larger body-size tend to have larger home ranges than small-bodied animals. Therefore it is likely that they are more affected by habitat fragmentation than small-bodied species. Body size of birds also seems to have a negative relation with species richness. This research has therefore looked into whether birds with a larger body-size are more sensitive to habitat fragmentation caused by forest...

Impacts of Potential Oak Forest Change on Breeding Birds in Northwestern Arkansas

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Douglas A. James

2004-01-01

Birds found on existing census routes in the Ozark region of northwestern Arkansas were used to predict avifaunal changes that could occur in the area due to oak-hickory forest degradation caused by red oak borer beetle infestations. The two census routes used passed through high elevation forests where red oaks thrive the best. Analysis showed that 21 bird species...

Arctic sea ice a major determinant in Mandt's black guillemot movement and distribution during non-breeding season

Science.gov (United States)

Divoky, G.J.; Douglas, David C.; Stenhouse, I. J.

2016-01-01

Mandt's black guillemot (Cepphus grylle mandtii) is one of the few seabirds associated in all seasons with Arctic sea ice, a habitat that is changing rapidly. Recent decreases in summer ice have reduced breeding success and colony size of this species in Arctic Alaska. Little is known about the species' movements and distribution during the nine month non-breeding period (September–May), when changes in sea ice extent and composition are also occurring and predicted to continue. To examine bird movements and the seasonal role of sea ice to non-breeding Mandt's black guillemots, we deployed and recovered (n = 45) geolocators on individuals at a breeding colony in Arctic Alaska during 2011–2015. Black guillemots moved north to the marginal ice zone (MIZ) in the Beaufort and Chukchi seas immediately after breeding, moved south to the Bering Sea during freeze-up in December, and wintered in the Bering Sea January–April. Most birds occupied the MIZ in regions averaging 30–60% sea ice concentration, with little seasonal variation. Birds regularly roosted on ice in all seasons averaging 5 h d−1, primarily at night. By using the MIZ, with its roosting opportunities and associated prey, black guillemots can remain in the Arctic during winter when littoral waters are completely covered by ice.

Breeding in a den of thieves: pros and cons of nesting close to egg predators

NARCIS (Netherlands)

de Fouw, J; Bom, R.A.; Klaassen, R.H.G.; Müskens, G.J. D. M.; de Vries, P.P.; Popov, I.Y.; Kokorev, Y.I.; Ebbinge, B.S.; Nolet, B.A.

2016-01-01

Breeding success of many Arctic-breedingbird populations varies with lemming cycles dueto prey switching behavior of generalist predators. Several bird species breed on islands to escape fromgeneralist predators like Arctic fox Vulpes lagopus, but little is known about how these species interact.We

Birds of Somalia: new records, range extensions and observations ...

African Journals Online (AJOL)

Due to recent political instability and unrest across the Horn of Africa region,. Somaliland (the ... and peak bird breeding season (Ash & Miskell 1998). We entered Somaliland over- .... Blue-cheeked Bee-eater Merops persicus. A group of c.

Vulnerability of birds to climate change in California's Sierra Nevada

OpenAIRE

Rodney B. Siegel; Peter Pyle; James H. Thorne; Andrew J. Holguin; Christine A. Howell; Sarah Stock; Morgan W. Tingley

2014-01-01

In a rapidly changing climate, effective bird conservation requires not only reliable information about the current vulnerability of species of conservation concern, but also credible projections of their future vulnerability. Such projections may enable managers to preempt or reduce emerging climate-related threats through appropriate habitat management. We used NatureServe's Climate Change Vulnerability Index (CCVI) to predict vulnerability to climate change of 168 bird species that breed i...

Agriculture modifies the seasonal decline of breeding success in a tropical wild bird population

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Cartwright, Samantha J; Nicoll, Malcolm A C; Jones, Carl G; Tatayah, Vikash; Norris, Ken

2014-01-01

Habitat conversion for agriculture is a major driver of biodiversity loss, but our understanding of the demographic processes involved remains poor. We typically investigate the impacts of agriculture in isolation even though populations are likely to experience multiple, concurrent changes in the environment (e.g. land and climate change). Drivers of environmental change may interact to affect demography, but the mechanisms have yet to be explored fully in wild populations. Here, we investigate the mechanisms linking agricultural land use with breeding success using long-term data for the formerly Critically Endangered Mauritius kestrel Falco punctatus, a tropical forest specialist that also occupies agricultural habitats. We specifically focused on the relationship between breeding success, agriculture and the timing of breeding because the latter is sensitive to changes in climatic conditions (spring rainfall) and enables us to explore the interactive effects of different (land and climate) drivers of environmental change. Breeding success, measured as egg survival to fledging, declines seasonally in this population, but we found that the rate of this decline became increasingly rapid as the area of agriculture around a nest site increased. If the relationship between breeding success and agriculture was used in isolation to estimate the demographic impact of agriculture, it would significantly under-estimate breeding success in dry (early) springs and over-estimate breeding success in wet (late) springs. Analysis of prey delivered to nests suggests that the relationship between breeding success and agriculture might be due, in part, to spatial variation in the availability of native, arboreal geckos. Synthesis and applications. Agriculture modifies the seasonal decline in breeding success in this population. As springs are becoming wetter in our study area and since the kestrels breed later in wetter springs, the impact of agriculture on breeding success will

Population genetic structure and long-distance dispersal of a recently expanding migratory bird.

Science.gov (United States)

Ramos, Raül; Song, Gang; Navarro, Joan; Zhang, Ruiying; Symes, Craig T; Forero, Manuela G; Lei, Fumin

2016-06-01

Long-distance dispersal events and their derivable increases of genetic diversity have been highlighted as important ecological and evolutionary determinants that improve performances of range-expanding species. In the context of global environmental change, specific dispersal strategies have to be understood and foreseen if we like to prevent general biodiversity impoverishment or the spread of allochthonous diseases. We explored the genetic structure and potential population mixing on the recently range-expanding European bee-eater Merops apiaster. In addition, the species is suspected of harbouring and disseminating the most relevant disease for bees and apiculture, Nosema microsporidia. In agreement with complementary ringing recovery data and morphometric measurements, genetic results on two mitochondrial genes and 12 microsatellites showed a reasonably well-structured population partitioning along its breeding distribution. Microsatellite results indicated that not only did a few birds recently disperse long distance during their return migrations and change their natal breeding areas, but also that a group of allochthonous birds together founded a new colony. Although we did not provide evidence on the direct implication of birds in the widespread of Nosema parasites, our finding on the long-distance dispersal of bird flocks between remote breeding colonies adds concern about the role of European bee-eaters in the spread of such disease at a large, inter-continental scale. Copyright © 2016 Elsevier Inc. All rights reserved.

Experimental dissociation of individual quality, food and timing of breeding effects on double-brooding in a migratory songbird.

Science.gov (United States)

O'Brien, Erin L; Dawson, Russell D

2013-07-01

Annual reproductive success in many species is influenced by the number of breeding attempts within a season. Although previous studies have shown isolated effects of female quality, food, and timing of breeding on the probability of female birds producing second broods, to our knowledge, none have tested the relative importance of multiple factors and their interactions using simultaneous manipulations within populations of free-living birds. In this study, we show that individual quality and timing of breeding interact to affect the probability of double-brooding in female mountain bluebirds (Sialia currucoides). High-quality females (those that naturally initiated clutches early in the season) were more likely to double-brood, regardless of whether their hatching date was advanced or delayed, whereas later breeding, lower quality females were much less likely to double-brood when their first attempt was delayed. This indicates that annual fecundity of poorer quality (or younger) female bluebirds may be more sensitive to seasonal variation in environmental conditions. In addition, birds that were provided with supplemental food throughout first breeding attempts were more likely to double-brood in one of the study years, suggesting that female bluebirds may be energetically limited in their capacity to initiate a second brood. Females that had their first brood delayed also had a shorter inter-brood interval and were moulting fewer feathers during second broods compared to controls, while females in better condition showed more advanced moult in second breeding attempts. Taken together, our results demonstrate the combined effects of age- or individual quality-mediated energetic trade-offs between current and future reproduction, and between investments in offspring and self-maintenance, on annual fecundity of female birds.

Short-term hurricane impacts on a neotropical community of marked birds and implications for early-stage community resilience.

Science.gov (United States)

Johnson, Andrew B; Winker, Kevin

2010-11-30

Populations in fragmented ecosystems risk extirpation through natural disasters, which must be endured rather than avoided. Managing communities for resilience is thus critical, but details are sketchy about the capacity for resilience and its associated properties in vertebrate communities. We studied short-term resilience in a community of individually marked birds, following this community through the catastrophic destruction of its forest habitat by Hurricane Iris in Belize, Central America. We sampled for 58 d immediately before the storm, 28 d beginning 11 d after Hurricane Iris, and for 69 d approximately one year later. Our data showed that the initial capacity for resilience was strong. Many banded individuals remained after the storm, although lower post-hurricane recapture rates revealed increased turnover among individuals. Changes occurred in community dynamics and in abundances among species and guilds. Survivors and immigrants both were critical components of resilience, but in a heterogeneous, species-specific manner. Delayed effects, including higher fat storage and increased species losses, were evident one year later.

Increasingly urban Marabou Storks start breeding four months early ...

African Journals Online (AJOL)

Traditionally, a bird of savannas, breeding in those areas is timed so that the growing young are in the nest during the December to February drier period, when food ... Further understanding of this unusual situation will benefit from continued ...

Human recreation alters behaviour profiles of non-breeding birds on open-coast sandy shores

Science.gov (United States)

Schlacher, Thomas A.; Nielsen, Tara; Weston, Michael A.

2013-02-01

Sandy beaches are primarily valued for their amenity and property values rather than for their ecological functions and properties. Some human usage of beaches potentially conflicts with the conservation and management of wildlife, such as beach-dwelling birds, on sandy shorelines. Because responses by birds to environmental change, including disturbance by humans, often involve behaviours that carry fitness costs, we quantify behaviour profiles of birds in relation to human occurrence along 200 km of sandy shoreline in Eastern Australia, including the large conservation area of Fraser Island. Disturbance to birds on these shores was considerable: 1) birds encountered motorized vehicles (cars, trucks, buses etc.) during 80% of focal bird observation bouts, 2) birds were flushed in over half (up to 86% in individual species) of all bouts, and 3) individuals spent, on average, one-third of their time on disturbance-related behaviours; this was particularly prevalent for Crested Terns (Thalasseus bergii) which were alert 42% of the time and spent 12% of their time escaping from human stimuli. Overall, this study demonstrated that motorized traffic is the prime agent of disturbance to birds on these beaches, resulting in frequent and time-consuming escape behaviours. These findings also emphasize that management of vehicle-based recreation on beaches needs to be re-aligned to meet conservation requirements in addition to providing leisure opportunities in National Parks and beyond; we identify some salient issue for this development: a) encouragement of social norms that promote environmentally benign beach use not involving motor vehicles, b) creation of spatial refuges for beach wildlife from traffic and other non-compatible uses, and c) investment in developing complementary management actions such as effective set-back distances.

Breeding status affects the hormonal and metabolic response to acute stress in a long-lived seabird, the king penguin.

Science.gov (United States)

Viblanc, Vincent A; Gineste, Benoit; Robin, Jean-Patrice; Groscolas, René

2016-09-15

Stress responses are suggested to physiologically underlie parental decisions promoting the redirection of behaviour away from offspring care when survival is jeopardized (e.g., when facing a predator). Besides this classical view, the "brood-value hypothesis" suggests that parents' stress responses may be adaptively attenuated to increase fitness, ensuring continued breeding when the relative value of the brood is high. Here, we test the brood-value hypothesis in breeding king penguins (Aptenodytes patagonicus), long-lived seabirds for which the energy commitment to reproduction is high. We subjected birds at different breeding stages (courtship, incubation and chick brooding) to an acute 30-min capture stress and measured their hormonal (corticosterone, CORT) and metabolic (non-esterified fatty acid, NEFA) responses to stress. We found that CORT responses were markedly attenuated in chick-brooding birds when compared to earlier stages of breeding (courtship and incubation). In addition, NEFA responses appeared to be rapidly attenuated in incubating and brooding birds, but a progressive increase in NEFA plasma levels in courting birds suggested energy mobilization to deal with the threat. Our results support the idea that stress responses may constitute an important life-history mechanism mediating parental reproductive decisions in relation to their expected fitness outcome. Copyright © 2016 Elsevier Inc. All rights reserved.

Spatio-temporal trends in the predation of large gulls by peregrine falcons (Falco peregrinus in an insular breeding population

Directory of Open Access Journals (Sweden)

Sutton Luke J.

2017-12-01

Full Text Available Individual diet specialization occurs in many populations of generalist predators, with specific individuals developing specialist strategies in their feeding behaviour. Intraspecific resource partitioning is hypothesised to be common amongst species in higher trophic levels where competition for resources is intense, and a key driver in breeding success and community structure. Though well-studied in other predators, there is sparse data on ecological specialization in raptors, which are important drivers of community and trophic structure. In this study, the breeding season diet of an insular population of peregrine falcons (Falco peregrinus was determined from indirect analysis of prey remains collected over three years. An unexpected result was the high proportion of large gulls (Laridae, of the genus Larus, in the diet of two breeding pairs of peregrines. Large gulls made up 18.44% by frequency of total prey recorded and 30.81% by biomass. Herring gulls (Larus argentatus were the most common large gull prey, with immatures most frequent (67.95% compared to adults (19.23%. Overall, most gulls predated were immatures (80.77%. Frequency of predation varied between breeding pairs and months, but was consistent over the three years. Most gulls were taken in April (37.17%, followed by May (19.23%, with a smaller peak of immature herring gulls taken in August and September. The pattern of regular predation by peregrines on large gulls is a new observation with important implications for understanding individual diet specialization in raptors, and its effect on bird populations and community structure.

Woody plants and the prediction of climate-change impacts on bird diversity

DEFF Research Database (Denmark)

Kissling, W. Daniel; Field, R.; Korntheuer, H.

2010-01-01

Current methods of assessing climate-induced shifts of species distributions rarely account for species interactions and usually ignore potential differences in response times of interacting taxa to climate change. Here, we used species-richness data from 1005 breeding bird and 1417 woody plant...... species in Kenya and employed model-averaged coefficients from regression models and median climatic forecasts assembled across 15 climate-change scenarios to predict bird species richness under climate change. Forecasts assuming an instantaneous response of woody plants and birds to climate change...... suggested increases in future bird species richness across most of Kenya whereas forecasts assuming strongly lagged woody plant responses to climate change indicated a reversed trend, i.e. reduced bird species richness. Uncertainties in predictions of future bird species richness were geographically...

Functional Traits, Flocking Propensity, and Perceived Predation Risk in an Amazonian Understory Bird Community.

Science.gov (United States)

Martínez, Ari E; Gomez, Juan P; Ponciano, José Miguel; Robinson, Scott K

2016-05-01

Within a community, different species might share similar predation risks, and, thus, the ability of species to signal and interpret heterospecific threat information may determine species' associations. We combined observational, experimental, and phylogenetic approaches to determine the extent to which evolutionary history and functional traits determined flocking propensity and perceived predation risk (response to heterospecific alarm calls) in a lowland Amazonian bird community. We predicted that small birds that feed myopically and out in the open would have higher flocking propensities and account for a higher proportion of positive responses to alarms. Using generalized linear models and the incorporation of phylogeny on data from 56 species, our results suggest that phylogenetic relationships alongside body size, foraging height, vegetation density, and response to alarm calls influence flocking propensity. Conversely, phylogenetic relationships did not influence response to heterospecific alarm calls. Among functional traits, however, foraging strategy, foraging density, and flocking propensity partially explained responses to alarm calls. Our results suggest that flocking propensity and perceived predation risk are positively related and that functional ecological traits and evolutionary history may explain certain species' associations.

Use of Hardwood Tree Species by Birds Nesting in Ponderosa Pine Forests

Science.gov (United States)

Kathryn L. Purcell; Douglas A. Drynan

2008-01-01

We examined the use of hardwood tree species for nesting by bird species breeding in ponderosa pine (Pinus ponderosa) forests in the Sierra National Forest, California. From 1995 through 2002, we located 668 nests of 36 bird species nesting in trees and snags on four 60-ha study sites. Two-thirds of all species nesting in trees or snags used...

Climate impacts on bird and plant communities from altered animal-plant interactions

Science.gov (United States)

Martin, Thomas E.; Maron, John L.

2012-01-01

The contribution of climate change to declining populations of organisms remains a question of outstanding concern. Much attention to declining populations has focused on how changing climate drives phenological mismatches between animals and their food. Effects of climate on plant communities may provide an alternative, but particularly powerful, influence on animal populations because plants provide their habitats. Here, we show that abundances of deciduous trees and associated songbirds have declined with decreasing snowfall over 22 years of study in montane Arizona, USA. We experimentally tested the hypothesis that declining snowfall indirectly influences plants and associated birds by allowing greater over-winter herbivory by elk (Cervus canadensis). We excluded elk from one of two paired snowmelt drainages (10 ha per drainage), and replicated this paired experiment across three distant canyons. Over six years, we reversed multi-decade declines in plant and bird populations by experimentally inhibiting heavy winter herbivory associated with declining snowfall. Moreover, predation rates on songbird nests decreased in exclosures, despite higher abundances of nest predators, demonstrating the over-riding importance of habitat quality to avian recruitment. Thus, our results suggest that climate impacts on plant–animal interactions can have forceful ramifying effects on plants, birds, and ecological interactions.

An overview of migratory birds in Brazil

Directory of Open Access Journals (Sweden)

Marina Somenzari

2018-03-01

Full Text Available Abstract We reviewed the occurrences and distributional patterns of migratory species of birds in Brazil. A species was classified as migratory when at least part of its population performs cyclical, seasonal movements with high fidelity to its breeding grounds. Of the 1,919 species of birds recorded in Brazil, 198 (10.3% are migratory. Of these, 127 (64% were classified as Migratory and 71 (36% as Partially Migratory. A few species (83; 4.3% were classified as Vagrant and eight (0,4% species could not be defined due to limited information available, or due to conflicting data.

Use of multispecies occupancy models to evaluate the response of bird communities to forest degradation associated with logging.

Science.gov (United States)

Carrillo-Rubio, Eduardo; Kéry, Marc; Morreale, Stephen J; Sullivan, Patrick J; Gardner, Beth; Cooch, Evan G; Lassoie, James P

2014-08-01

Forest degradation is arguably the greatest threat to biodiversity, ecosystem services, and rural livelihoods. Therefore, increasing understanding of how organisms respond to degradation is essential for management and conservation planning. We were motivated by the need for rapid and practical analytical tools to assess the influence of management and degradation on biodiversity and system state in areas subject to rapid environmental change. We compared bird community composition and size in managed (ejido, i.e., communally owned lands) and unmanaged (national park) forests in the Sierra Tarahumara region, Mexico, using multispecies occupancy models and data from a 2-year breeding bird survey. Unmanaged sites had on average higher species occupancy and richness than managed sites. Most species were present in low numbers as indicated by lower values of detection and occupancy associated with logging-induced degradation. Less than 10% of species had occupancy probabilities >0.5, and degradation had no positive effects on occupancy. The estimated metacommunity size of 125 exceeded previous estimates for the region, and sites with mature trees and uneven-aged forest stand characteristics contained the highest species richness. Higher estimation uncertainty and decreases in richness and occupancy for all species, including habitat generalists, were associated with degraded young, even-aged stands. Our findings show that multispecies occupancy methods provide tractable measures of biodiversity and system state and valuable decision support for landholders and managers. These techniques can be used to rapidly address gaps in biodiversity information, threats to biodiversity, and vulnerabilities of species of interest on a landscape level, even in degraded or fast-changing environments. Moreover, such tools may be particularly relevant in the assessment of species richness and distribution in a wide array of habitats. © 2014 Society for Conservation Biology.

Corticosterone mediated costs of reproduction link current to future breeding.

Science.gov (United States)

Crossin, Glenn T; Phillips, Richard A; Lattin, Christine R; Romero, L Michael; Williams, Tony D

2013-11-01

Life-history theory predicts that costs are associated with reproduction. One possible mediator of costs involves the secretion of glucocorticoid hormones, which in birds can be measured in feathers grown during the breeding period. Glucocorticoids mediate physiological responses to unpredictable environmental or other stressors, but they can also function as metabolic regulators during more predictable events such as reproduction. Here we show that corticosterone ("Cort") in feathers grown during the breeding season reflects reproductive effort in two Antarctic seabird species (giant petrels, Macronectes spp.). In females of both species, but not males, feather Cort ("fCort") was nearly 1.5-fold higher in successful than failed breeders (those that lost their eggs/chicks), suggesting a cost of successful reproduction, i.e., high fCort levels in females reflect the elevated plasma Cort levels required to support high metabolic demands of chick-rearing. Successful breeding also led to delayed moult prior to winter migration. The fCort levels and pre-migration moult score that we measured at the end of current breeding were predictive of subsequent reproductive effort in the following year. Birds with high fCort and a delayed initiation of moult were much more likely to defer breeding in the following year. Cort levels and the timing of moult thus provide a potential mechanism for the tradeoff between current and future reproduction. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

Breeding biology and reproductive success of the Spectacled ...

African Journals Online (AJOL)

Thirty nests were monitored and incubating birds were marked. Direct observations were made associated with nest building, incubating and nestling periods. Habitat structure was assessed to detect nesting site choice. The breeding episode, from the nest-building stage to fledging of the last chick, lasted on average 45 d.

Resource configuration and abundance affect space use of a cooperatively breeding resident bird

Science.gov (United States)

Richard A. Stanton; Dylan C. Kesler; Frank R. Thompson III

2014-01-01

Movement and space use of birds is driven by activities associated with acquiring and maintaining access to critical resources. Thus, the spatial configuration of resources within home ranges should influence bird movements, and resource values should be relative to their locations. We radio-tracked 22 Brown-headed Nuthatches (Sitta pusilla) and...

Can variation in risk of nest predation explain altitudinal migration in tropical birds?

Science.gov (United States)

Boyle, W Alice

2008-03-01

Migration is among the best studied of animal behaviors, yet few empirical studies have tested hypotheses explaining the ultimate causes of these cyclical annual movements. Fretwell's (1980) hypothesis predicts that if nest predation explains why many tropical birds migrate uphill to breed, then predation risk must be negatively associated with elevation. Data from 385 artificial nests spanning 2,740 m of elevation on the Atlantic slope of Costa Rica show an overall decline in predation with increasing elevation. However, nest predation risk was highest at intermediate elevations (500-650 m), not at lowest elevations. The proportion of nests depredated by different types of predators differed among elevations. These results imply that over half of the altitudinal migrant bird species in this region migrate to safer breeding areas than their non-breeding areas, suggesting that variation in nest predation risk could be an important benefit of uphill migrations of many species.

Monitoring Forsmark. Bird monitoring in Forsmark 2010

Energy Technology Data Exchange (ETDEWEB)

Green, Martin (Dept. of Animal Ecology, Lund Univ. (Sweden))

2010-12-15

This report summarizes the monitoring of selected listed (Swedish Red List and/or the EU Birds Directive) breeding birds in Forsmark 2002-2010. Monitoring of eleven listed species was conducted in the regional model area, including the candidate area in 2010 in the same way as in earlier years. The results from the monitoring in 2010 differed somewhat from results gathered in earlier years. Most monitored species have increased in local numbers during the study years, and from most years continued increases have been reported. Between 2009 and 2010 most species (seven, 64% of the monitored ones) instead decreased in numbers. Only one species (honey buzzard) increased in numbers between the years and in this case this was probably more a result of small moves by certain pairs so that they this year had parts reaching into the regional model area, while in 2009 their territories were outside of this. No dramatic changes in bird numbers were however recorded and all the studied species show stable or increasing local populations over the study period. Number of Black-throated diver pairs was normal and breeding success was good this year. The breeding success of divers has improved considerably over the studied period and the patterns recorded in Forsmark closely follow recorded patterns at the national level. Honey buzzards and ospreys occurred in good numbers, above the average for the whole period, and breeding success was better than in 2009. Even if breeding success of honey buzzards is not monitored in any detail, there were still signs of at least a few successful breedings in the area this year. Breeding success of ospreys was below average, but still within the normal variation for most years. The local white-tailed eagles had a poor breeding season and no young at all were produced within the study area. All three grouse species (black grouse, capercaillie and hazelhen) decreased in numbers between 2009 and 2010. Note however that the large amounts of snow

Monitoring Forsmark. Bird monitoring in Forsmark 2010

International Nuclear Information System (INIS)

Green, Martin

2010-12-01

This report summarizes the monitoring of selected listed (Swedish Red List and/or the EU Birds Directive) breeding birds in Forsmark 2002-2010. Monitoring of eleven listed species was conducted in the regional model area, including the candidate area in 2010 in the same way as in earlier years. The results from the monitoring in 2010 differed somewhat from results gathered in earlier years. Most monitored species have increased in local numbers during the study years, and from most years continued increases have been reported. Between 2009 and 2010 most species (seven, 64% of the monitored ones) instead decreased in numbers. Only one species (honey buzzard) increased in numbers between the years and in this case this was probably more a result of small moves by certain pairs so that they this year had parts reaching into the regional model area, while in 2009 their territories were outside of this. No dramatic changes in bird numbers were however recorded and all the studied species show stable or increasing local populations over the study period. Number of Black-throated diver pairs was normal and breeding success was good this year. The breeding success of divers has improved considerably over the studied period and the patterns recorded in Forsmark closely follow recorded patterns at the national level. Honey buzzards and ospreys occurred in good numbers, above the average for the whole period, and breeding success was better than in 2009. Even if breeding success of honey buzzards is not monitored in any detail, there were still signs of at least a few successful breedings in the area this year. Breeding success of ospreys was below average, but still within the normal variation for most years. The local white-tailed eagles had a poor breeding season and no young at all were produced within the study area. All three grouse species (black grouse, capercaillie and hazelhen) decreased in numbers between 2009 and 2010. Note however that the large amounts of snow

Food abundance does not determine bird use of early-successional habitat.

Energy Technology Data Exchange (ETDEWEB)

Champlin, Tracey B.; Kilgo, John C.; Moorman, Christopher E.

2009-06-01

Abstract. Few attempts have been made to experimentally address the extent to which temporal or spatial variation in food availability influences avian habitat use. We used an experimental approach to investigate whether bird use differed between treated (arthropods reduced through insecticide application) and control (untreated) forest canopy gaps within a bottomland hardwood forest in the Upper Coastal Plain of South Carolina, USA. Gaps were two- to three-year-old group selection timber harvest openings of three sizes (0.13, 0.26, and 0.50 ha). Our study was conducted during four bird use periods (spring migration, breeding, post-breeding, and fall migration) in 2002 and 2003. Arthropods were reduced in treated gaps by 68% in 2002 and 73% in 2003. We used mist-netting captures and foraging attack rates to assess the influence of arthropod abundance on avian habitat use. Evidence that birds responded to arthropod abundance was limited and inconsistent. In 2002, we generally captured more birds in treated gaps of the smallest size (0.13 ha) and fewer birds in treated gaps of the larger sizes. In 2003, we recorded few differences in the number of captures in treated and control gaps. Foraging attack rates generally were lower in treated than in control gaps, indicating that birds were able to adapt to the reduced food availability and remain in treated gaps. We conclude that arthropod abundance was not a proximate factor controlling whether forest birds used our gaps. The abundance of food resources may not be as important in determining avian habitat selection as previous research has indicated, at least for passerines in temperate subtropical regions.

Spatial Variation in Bird Community Composition in Relation to Topographic Gradient and Forest Heterogeneity in a Central Amazonian Rainforest

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Renato Cintra

2012-01-01

Full Text Available We investigated the effects of landscape features and forest structure on the avian community at the Reserva Florestal Adolpho Ducke near Manaus, in the Brazilian Amazon. We sampled the landscape and forest in 72 50 × 50 m plots systematically distributed in the reserve, covering an area of 6,400 ha. The avifauna was sampled using mist nets and acoustic surveys near the plots. We found no significant relationships between landscape features and forest components in the plots and the number of bird species and individuals sampled. Results of Principal Coordinate Analyses, however, showed that bird species composition changes along a topographic gradient (plateau-slope-valley, and also in relation to leaf litter depth and distance to forest streams. We also found compositional differences in the avian community on the eastern and western water basins that compose the reserve. Our results suggest that although most bird species occur throughout the reserve, many species track differences in the landscape and the forest structure.

Ethnobotanic importance of plants used in pigeon-breeding in Eastern Spain.

Science.gov (United States)

Belda, Antonio; Cortés, Carolina; Peiró, Victoriano

2013-05-20

The importance that birds of the Columbidae family have had throughout history is visible on the Mediterranean coast. Pigeon fancying is the art of breeding and training carrier pigeons and currently, several breeds exist. The sport of racing pigeons consists in covering a distance at maximum possible speed. However, pigeon breeding has another modality called "sport pigeon", where several males follow a female. This study focusses on ethnobotanical knowledge of native and exotic plant species that are used for diet, breeding, stimulation, healing illnesses and staining the plumage of pigeons bred in captivity. Using semi-structured interviews, we gathered information about the different plant species traditionally used for pigeon-breeding in the region of Valencia. Background material on remedies for bird illnesses was gathered from folk botanical references, local books and journals.The plant species were collected in the study area, then identified in the laboratory using dichotomous keys and vouchered in the ABH (Herbarium of Alicante University). We used Excel (®) 2003 to perform a simple statistical analysis of the data collected. We collected 56 species of plants (and one variety) that included 29 botanical families. The total number of species was made up of 35 cultivated and 21 wild plants. The most common were Gramineae (14 species), Leguminosae (6 species), and Compositae (4 species). Pigeon breeding is an immensely popular activity in Eastern Spain, and ethnobiological knowledge about breeding pigeons and caring for them is considerable. The names and traditional uses of plants depend on their geographical location, vernacular names serve as an intangible heritage. Feeding, environmental features, and genetic makeup of individuals are relevant aspects in the maintenance of avian health.

Assessment of bird populations in a high quality savanna/woodland: a banding approach

Science.gov (United States)

Wilmore, Sandra L.; Glowacki, Gary A.; Grundel, Ralph

2005-01-01

Between 1999 and 2004, Save the Dunes Conservation Fund's Miller Woods Bird Banding Program monitored migrating and breeding bird populations within a high quality black oak, dry-mesic sand savanna/woodland with ridge and swale topography. The objectives of this program were to collect consistent and reliable demographic and abundance data on the bird populations, to investigate long-term population trends, and to contribute to improved land management decisions at regional and national scales. The technique employed involved capturing birds in mist nets that were deployed for set periods of time at 17 net sites in two banding areas in Miller Woods.

The influence of early age at breeding on reproductive parameters ...

African Journals Online (AJOL)

2002–2006), early-age (2–5 years) Roseate Terns Sterna dougallii nested in more concealed sites than older-age (6–7 years) birds, possibly because of a relatively lower competitive ability. Fledging success and breeding productivity were ...

Inter-annual variability and long-term trends in breeding success in a declining population of migratory swans.

NARCIS (Netherlands)

Wood, K.A.; Newth, J.L.; Hilton, G.M.; Nolet, B.A.; Rees, E.C.

2016-01-01

Population declines among migratory Arctic-breeding birds are a growing concern for conservationists. To inform the conservation of these declining populations, we need to understand how demographic rates such as breeding success are influenced by combinations of extrinsic and intrinsic factors. In

Direct and indirect effects of the most widely implemented Dutch agri-environment schemes on breeding waders

NARCIS (Netherlands)

Verhulst, J.; Kleijn, D.; Berendse, F.

2007-01-01

1. In the Netherlands, agri-environment schemes are an important tool for halting the ongoing decline of meadow birds and, in particular, waders breeding on wet meadows. The effectiveness of the main scheme, postponed mowing, is heavily debated because it does not result in higher breeding

Is there a connection between weather at departure sites, onset of migration and timing of soaring-bird autumn migration in Israel?

NARCIS (Netherlands)

Shamoun-Baranes, J.; van Loon, E.E.; Alon, D.; Alpert, P.; Yom-Tov, Y.; Leshem, Y.

2006-01-01

Aims Different aspects of soaring-bird migration are influenced by weather. However, the relationship between weather and the onset of soaring-bird migration, particularly in autumn, is not clear. Although long-term migration counts are often unavailable near the breeding areas of many soaring birds

Alien invasive birds.

Science.gov (United States)

Brochier, B; Vangeluwe, D; van den Berg, T

2010-08-01

A bird species is regarded as alien invasive if it has been introduced, intentionally or accidentally, to a location where it did not previously occur naturally, becomes capable of establishing a breeding population without further intervention by humans, spreads and becomes a pest affecting the environment, the local biodiversity, the economy and/or society, including human health. European Starling (Sturnus vulgaris), Common Myna (Acridotheres tristis) and Red-vented Bulbul (Pycnonotus cafer) have been included on the list of '100 of the World's Worst Invasive Alien Species', a subset of the Global Invasive Species Database. The 'Delivering Alien Invasive Species Inventories for Europe' project has selected Canada Goose (Branta canadensis), Ruddy Duck (Oxyura jamaicensis), Rose-ringed Parakeet (Psittacula krameri) and Sacred Ibis (Threskiornis aethiopicus) as among 100 of the worst invasive species in Europe. For each of these alien bird species, the geographic range (native and introduced range), the introduction pathway, the general impacts and the management methods are presented.

Environmental and hormonal factors in seasonal breeding in free-living male Indian rose-ringed parakeets (Psittacula krameri).

Science.gov (United States)

Krishnaprasadan, T N; Kotak, V C; Sharp, P J; Schmedemann, R; Haase, E

1988-12-01

Seasonal changes in testicular activity, plasma luteinizing hormone (LH), estradiol (E2), testosterone (T), and 5 alpha-dihydrotestosterone (5 alpha-DHT) were related to pair bond formation, nest building, nest defense, and parental behavior in free-living Indian rose-ringed parakeets (Psittacula krameri) in northwest India. Spermatozoa production occurred between January and March when daylengths were short (10-12 hr) and ambient temperature was seasonally low (8-20 degrees C). At other times of the year the testes were regressed. Plasma LH levels increased during the prebreeding period (September-December) when the birds were forming pairs and selecting or defending nest sites. Plasma LH levels increased further between January and March and decreased to seasonal low values during the post breeding period between April and June when the birds were caring for young. Concentrations of plasma androgens and estrogens were similar during the prebreeding and postbreeding phases of the breeding cycle. During the breeding period, the ratios between plasma 5 alpha-DHT and testosterone and between plasma estradiol and testosterone increased. It is proposed that the absence of marked seasonal changes in plasma steroid levels is related to nest defense behavior which occurs during the prebreeding, breeding, and postbreeding phases of the breeding cycle. Winter breeding makes it possible for the parakeets to avoid competition with other birds for nesting sites, to avoid fledging young during the monsoon period, and to take advantage of the winter pea crop which provides the female with extra nutrients for egg production.

Light pollution is greatest within migration passage areas for nocturnally-migrating birds around the world.

Science.gov (United States)

Cabrera-Cruz, Sergio A; Smolinsky, Jaclyn A; Buler, Jeffrey J

2018-02-19

Excessive or misdirected artificial light at night (ALAN) produces light pollution that influences several aspects of the biology and ecology of birds, including disruption of circadian rhythms and disorientation during flight. Many migrating birds traverse large expanses of land twice every year at night when ALAN illuminates the sky. Considering the extensive and increasing encroachment of light pollution around the world, we evaluated the association of the annual mean ALAN intensity over land within the geographic ranges of 298 nocturnally migrating bird species with five factors: phase of annual cycle, mean distance between breeding and non-breeding ranges, range size, global hemisphere of range, and IUCN category of conservation concern. Light pollution within geographic ranges was relatively greater during the migration season, for shorter-distance migrants, for species with smaller ranges, and for species in the western hemisphere. Our results suggest that migratory birds may be subject to the effects of light pollution particularly during migration, the most critical stage in their annual cycle. We hope these results will spur further research on how light pollution affects not only migrating birds, but also other highly mobile animals throughout their annual cycle.

The reliance on distant resources for egg formation in high Arctic breeding barnacle geese Branta leucopsis

NARCIS (Netherlands)

Hahn, S.M.; Loonen, M.J.J.E.; Klaassen, M.R.J.

2011-01-01

Breeding in the high Arctic is time constrained and animals should therefore start with their annual reproduction as early as possible. To allow for such early reproduction in migratory birds, females arrive at the breeding grounds either with body stores or they try to rapidly develop their eggs

The reliance on distant resources for egg formation in high Arctic breeding barnacle geese Branta leucopsis

NARCIS (Netherlands)

Hahn, Steffen; Loonen, Maarten J. J. E.; Klaassen, Marcel

Breeding in the high Arctic is time constrained and animals should therefore start with their annual reproduction as early as possible. To allow for such early reproduction in migratory birds, females arrive at the breeding grounds either with body stores or they try to rapidly develop their eggs

Relative roles of grey squirrels, supplementary feeding, and habitat in shaping urban bird assemblages.

Science.gov (United States)

Bonnington, Colin; Gaston, Kevin J; Evans, Karl L

2014-01-01

Non-native species are frequently considered to influence urban assemblages. The grey squirrel Sciurus carolinensis is one such species that is widespread in the UK and is starting to spread across Europe; it predates birds' nests and can compete with birds for supplementary food. Using distance sampling across the urbanisation intensity gradient in Sheffield (UK) we test whether urban grey squirrels influence avian species richness and density through nest predation and competition for supplementary food sources. We also assess how urban bird assemblages respond to supplementary feeding. We find that grey squirrels slightly reduced the abundance of breeding bird species most sensitive to squirrel nest predation by reducing the beneficial impact of woodland cover. There was no evidence that grey squirrel presence altered relationships between supplementary feeding and avian assemblage structure. This may be because, somewhat surprisingly, supplementary feeding was not associated with the richness or density of wintering bird assemblages. These associations were positive during the summer, supporting advocacy to feed birds during the breeding season and not just winter, but explanatory capacity was limited. The amount of green space and its quality, assessed as canopy cover, had a stronger influence on avian species richness and population size than the presence of grey squirrels and supplementary feeding stations. Urban bird populations are thus more likely to benefit from investment in improving the availability of high quality habitats than controlling squirrel populations or increased investment in supplementary feeding.

Relative roles of grey squirrels, supplementary feeding, and habitat in shaping urban bird assemblages.

Directory of Open Access Journals (Sweden)

Colin Bonnington

Full Text Available Non-native species are frequently considered to influence urban assemblages. The grey squirrel Sciurus carolinensis is one such species that is widespread in the UK and is starting to spread across Europe; it predates birds' nests and can compete with birds for supplementary food. Using distance sampling across the urbanisation intensity gradient in Sheffield (UK we test whether urban grey squirrels influence avian species richness and density through nest predation and competition for supplementary food sources. We also assess how urban bird assemblages respond to supplementary feeding. We find that grey squirrels slightly reduced the abundance of breeding bird species most sensitive to squirrel nest predation by reducing the beneficial impact of woodland cover. There was no evidence that grey squirrel presence altered relationships between supplementary feeding and avian assemblage structure. This may be because, somewhat surprisingly, supplementary feeding was not associated with the richness or density of wintering bird assemblages. These associations were positive during the summer, supporting advocacy to feed birds during the breeding season and not just winter, but explanatory capacity was limited. The amount of green space and its quality, assessed as canopy cover, had a stronger influence on avian species richness and population size than the presence of grey squirrels and supplementary feeding stations. Urban bird populations are thus more likely to benefit from investment in improving the availability of high quality habitats than controlling squirrel populations or increased investment in supplementary feeding.

Can lowland dry forests represent a refuge from avian malaria for native Hawaiian birds?

Science.gov (United States)

Tucker-Mohl, Katherine; Hart, Patrick; Atkinson, Carter T.

2010-01-01

Hawaii's native birds have become increasingly threatened over the past century. Introduced mosquito borne diseases such as avian malaria may be responsible for the near absence of endemic Hawaiian forest birds in low-elevation habitats. The recent recognition that some native Hawaiian forest birds may be repopulating moist lowland habitats as a result of evolved resistance to this disease has increased the conservation value of these areas. Here, we investigate whether remnant low elevation dry forests on Hawaii Island provide natural 'refuges' from mosquito-transmitted malaria by nature of their low rainfall and absence of suitable natural sources of water for mosquito breeding. Unlike lowland wet forests where high rates of disease transmission may be selecting for disease resistance, lowland dry forests may provide some refuge for native forest birds without natural resistance to malaria. We mistnetted forest birds in two lowland dry forests and tested all native birds by microscopy and serology for avian malaria caused by the Plasmodium relictum parasite. We also conducted surveys for standing water and mosquito larvae. Overall prevalence of infections with Plasmodium relictum in the Hawaii Amakihi Hemignathus virens virens was 15%. Most infected birds had lowlevel parasitemias, suggesting chronic infections. Although avian malaria is present in these lowland dry forest Amakihi populations, infection rates are significantly lower than in wet forest populations at similar elevations. Sources of breeding mosquitoes in these forests appeared to be largely anthropogenic; thus, there is potential to manage dry forests as mosquito-free habitat for Hawaii Amakihi and other Hawaiian forest birds.

Persistence of accuracy of genomic estimated breeding values over generations in layer chickens

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Fernando Rohan

2011-06-01

Full Text Available Abstract Background The predictive ability of genomic estimated breeding values (GEBV originates both from associations between high-density markers and QTL (Quantitative Trait Loci and from pedigree information. Thus, GEBV are expected to provide more persistent accuracy over successive generations than breeding values estimated using pedigree-based methods. The objective of this study was to evaluate the accuracy of GEBV in a closed population of layer chickens and to quantify their persistence over five successive generations using marker or pedigree information. Methods The training data consisted of 16 traits and 777 genotyped animals from two generations of a brown-egg layer breeding line, 295 of which had individual phenotype records, while others had phenotypes on 2,738 non-genotyped relatives, or similar data accumulated over up to five generations. Validation data included phenotyped and genotyped birds from five subsequent generations (on average 306 birds/generation. Birds were genotyped for 23,356 segregating SNP. Animal models using genomic or pedigree relationship matrices and Bayesian model averaging methods were used for training analyses. Accuracy was evaluated as the correlation between EBV and phenotype in validation divided by the square root of trait heritability. Results Pedigree relationships in outbred populations are reduced by 50% at each meiosis, therefore accuracy is expected to decrease by the square root of 0.5 every generation, as observed for pedigree-based EBV (Estimated Breeding Values. In contrast the GEBV accuracy was more persistent, although the drop in accuracy was substantial in the first generation. Traits that were considered to be influenced by fewer QTL and to have a higher heritability maintained a higher GEBV accuracy over generations. In conclusion, GEBV capture information beyond pedigree relationships, but retraining every generation is recommended for genomic selection in closed breeding

Birding 2.0: Citizen Science and Effective Monitoring in the Web 2.0 World

Directory of Open Access Journals (Sweden)

Yolanda F. Wiersma

2010-12-01

Full Text Available The amateur birding community has a long and proud tradition of contributing to bird surveys and bird atlases. Coordinated activities such as Breeding Bird Atlases and the Christmas Bird Count are examples of "citizen science" projects. With the advent of technology, Web 2.0 sites such as eBird have been developed to facilitate online sharing of data and thus increase the potential for real-time monitoring. However, as recently articulated in an editorial in this journal and elsewhere, monitoring is best served when based on a priori hypotheses. Harnessing citizen scientists to collect data following a hypothetico-deductive approach carries challenges. Moreover, the use of citizen science in scientific and monitoring studies has raised issues of data accuracy and quality. These issues are compounded when data collection moves into the Web 2.0 world. An examination of the literature from social geography on the concept of "citizen sensors" and volunteered geographic information (VGI yields thoughtful reflections on the challenges of data quality/data accuracy when applying information from citizen sensors to research and management questions. VGI has been harnessed in a number of contexts, including for environmental and ecological monitoring activities. Here, I argue that conceptualizing a monitoring project as an experiment following the scientific method can further contribute to the use of VGI. I show how principles of experimental design can be applied to monitoring projects to better control for data quality of VGI. This includes suggestions for how citizen sensors can be harnessed to address issues of experimental controls and how to design monitoring projects to increase randomization and replication of sampled data, hence increasing scientific reliability and statistical power.

A global analysis of bird plumage patterns reveals no association between habitat and camouflage

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Marius Somveille

2016-11-01

Full Text Available Evidence suggests that animal patterns (motifs function in camouflage. Irregular mottled patterns can facilitate concealment when stationary in cluttered habitats, whereas regular patterns typically prevent capture during movement in open habitats. Bird plumage patterns have predominantly converged on just four types—mottled (irregular, scales, bars and spots (regular—and habitat could be driving convergent evolution in avian patterning. Based on sensory ecology, we therefore predict that irregular patterns would be associated with visually noisy closed habitats and that regular patterns would be associated with open habitats. Regular patterns have also been shown to function in communication for sexually competing males to stand-out and attract females, so we predict that male breeding plumage patterns evolved in both open and closed habitats. Here, taking phylogenetic relatedness into account, we investigate ecological selection for bird plumage patterns across the class Aves. We surveyed plumage patterns in 80% of all avian species worldwide. Of these, 2,756 bird species have regular and irregular plumage patterns as well as habitat information. In this subset, we tested whether adult breeding/non-breeding plumages in each sex, and juvenile plumages, were associated with the habitat types found within the species’ geographical distributions. We found no evidence for an association between habitat and plumage patterns across the world’s birds and little phylogenetic signal. We also found that species with regular and irregular plumage patterns were distributed randomly across the world’s eco-regions without being affected by habitat type. These results indicate that at the global spatial and taxonomic scale, habitat does not predict convergent evolution in bird plumage patterns, contrary to the camouflage hypothesis.

A global analysis of bird plumage patterns reveals no association between habitat and camouflage.

Science.gov (United States)

Somveille, Marius; Marshall, Kate L A; Gluckman, Thanh-Lan

2016-01-01

Evidence suggests that animal patterns (motifs) function in camouflage. Irregular mottled patterns can facilitate concealment when stationary in cluttered habitats, whereas regular patterns typically prevent capture during movement in open habitats. Bird plumage patterns have predominantly converged on just four types-mottled (irregular), scales, bars and spots (regular)-and habitat could be driving convergent evolution in avian patterning. Based on sensory ecology, we therefore predict that irregular patterns would be associated with visually noisy closed habitats and that regular patterns would be associated with open habitats. Regular patterns have also been shown to function in communication for sexually competing males to stand-out and attract females, so we predict that male breeding plumage patterns evolved in both open and closed habitats. Here, taking phylogenetic relatedness into account, we investigate ecological selection for bird plumage patterns across the class Aves. We surveyed plumage patterns in 80% of all avian species worldwide. Of these, 2,756 bird species have regular and irregular plumage patterns as well as habitat information. In this subset, we tested whether adult breeding/non-breeding plumages in each sex, and juvenile plumages, were associated with the habitat types found within the species' geographical distributions. We found no evidence for an association between habitat and plumage patterns across the world's birds and little phylogenetic signal. We also found that species with regular and irregular plumage patterns were distributed randomly across the world's eco-regions without being affected by habitat type. These results indicate that at the global spatial and taxonomic scale, habitat does not predict convergent evolution in bird plumage patterns, contrary to the camouflage hypothesis.

Arthropod prey for riparian associated birds in headwater forests of the Oregon Coast Range

Science.gov (United States)

Hagar, Joan C.; Li, Judith; Sobota, Janel; Jenkins, Stephanie

2012-01-01

Headwater riparian areas occupy a large proportion of the land base in Pacific Northwest forests, and thus are ecologically and economically important. Although a primary goal of management along small headwater streams is the protection of aquatic resources, streamside habitat also is important for many terrestrial wildlife species. However, mechanisms underlying the riparian associations of some terrestrial species have not been well studied, particularly for headwater drainages. We investigated the diets of and food availability for four bird species associated with riparian habitats in montane coastal forests of western Oregon, USA. We examined variation in the availability of arthropod prey as a function of distance from stream. Specifically, we tested the hypotheses that (1) emergent aquatic insects were a food source for insectivorous birds in headwater riparian areas, and (2) the abundances of aquatic and terrestrial arthropod prey did not differ between streamside and upland areas during the bird breeding season. We found that although adult aquatic insects were available for consumption throughout the study period, they represented a relatively small proportion of available prey abundance and biomass and were present in only 1% of the diet samples from only one of the four riparian-associated bird species. Nonetheless, arthropod prey, comprised primarily of insects of terrestrial origin, was more abundant in streamside than upland samples. We conclude that food resources for birds in headwater riparian areas are primarily associated with terrestrial vegetation, and that bird distributions along the gradient from streamside to upland may be related to variation in arthropod prey availability. Because distinct vegetation may distinguish riparian from upland habitats for riparian-associated birds and their terrestrial arthropod prey, we suggest that understory communities be considered when defining management zones for riparian habitat.

Behavior of emu bird (Dromaius novaehollandiae

Directory of Open Access Journals (Sweden)

V. R. Patodkar

Full Text Available Emu is the second largest living bird of world belonging to order Ratite. This order is of flightless birds with flat breast bone and it includes emu, ostrich, rhea, cassowary and kiwi. Emus are reared commercially in many parts of the world for their meat, oil, skin and feathers, which are of high economic value. The anatomical and physiological features of these birds appear to be suitable for temperate and tropical climatic conditions. Emu is newly introduced species in India. Although emu farming is considered to be economical, we have to study the behavior of emus to increase the profitability by providing housing, feeding and breeding facilities more or less same as that of in wild condition during their rearing in captivity and we will have to carry out comparative study of behavior in captivity as well as in wild condition. [Vet World 2009; 2(11.000: 439-440

The ecology, status, and conservation of marine and shoreline birds on the west coast of Vancouver Island

International Nuclear Information System (INIS)

Vermeer, K.; Butler, R.W.; Morgan, K.H.

1992-01-01

A symposium was held to combine various disciplines to provide a review of current knowledge about the marine biology of the west coast of Vancouver Island, with a particular emphasis on birds. Papers were presented on the physical and biological environment of the study region, the population and breeding ecology of marine and shoreline birds, the distribution of marine and shoreline birds at sea, the effects of oil pollution on the bird population, and the conservation of marine and shoreline birds. Separate abstracts have been prepared for two papers from this symposium

Observations on habitat use, breeding chronology and parental care in Bristle-thighed Curlews on the Seward Peninsula, Alaska

Science.gov (United States)

Gill, R.E.; Lanctot, Richard B.; Mason, J.D.; Handel, Colleen M.

1991-01-01

Results from an intensive survey in 1989 of one of the two known breeding localities of Bristle-thighed Curlews Numenius tahitiensis are reported. During the pre-nesting period birds confined most of their activity to two vegetation communities: shrub meadow tundra and low shrub/tussock tundra. During nesting more than half the Curlews seen were observed on shrub meadow tundra, whilst during brood rearing, use of low shrub/tussock tundra continued to decline in importance as birds attending young increased their use of sedge wet meadows. Despite extensive searches no nests were located; however, observations of broods indicated that nest initiation began around 25 May and that hatching occurred during the last week of June. Detailed observations are presented on the formation of four brood-groups, some of which held different combinations of unrelated adults or young. The adaptive significance of this unusual wader behaviour is discussed.

Heterogeneity of bird communities in a mosaic of habitats on a restinga ecosystem in southeast Brazil

Directory of Open Access Journals (Sweden)

Verônica S. da M. Gomes

Full Text Available ABSTRACT Restinga occurs as a narrow band of coastal habitats throughout the Atlantic Forest, although it presents considerable variation in vegetation structure, which likely contributes to heterogeneity in species inhabiting this endangered ecosystem. The goal of this study is to examine how variation in vegetation and abiotic conditions in the restinga ecosystem may contribute to heterogeneity of bird communities in Restinga de Jurubatiba, Brazil. Temperature, relative humidity, and vegetation structure were sampled to characterize four sites (dry forest, flooded forest, open scrub and closed scrub. Birds were sampled using observations, mist-netting and voice recordings. Results indicate that major differences of all variables occur between forest and scrub in both vegetation and birds. In addition, differences also exist within forests and within scrub, resulting in considerable heterogeneity among sampled areas. Scrub sites were richer in bird species (n = 58 than forest sites (n = 41, while closed scrub had the most species (n = 49. Also, 64% (47 of 73 of bird species were exclusive to forest or scrub habitats. Scrub habitats were more similar to each other than forest habitats. Normalized Difference Vegetation Index (NDVI calculated from satellite images distinguished scrub sites and may be useful to monitor changes in vegetation patches through time. The restinga ecosystem is quite heterogeneous with considerable turnover in bird species composition and differences in vegetation structure. Forest strips may serve as connectors on the landscape and to help maintain species diversity and conservation of forest species. Also, this highly dynamic ecosystem, which includes a mosaic of habitat types, likely promotes resilience of bird populations under changing conditions.

PCB concentrations and metabolism patterns in common terns (Sterna hirundo) from different breeding colonies in the Netherlands

NARCIS (Netherlands)

Brink, van den N.W.; Bosveld, A.T.C.

2001-01-01

PCB levels in blood of common terns (Sterna hirundo) from Terneuzen, a breeding colony in The Netherlands with relatively low breeding success, were significantly higher than in birds from two Dutch reference colonies, one nearby (Oesterdam) and one further away (the Isle of Griend). However, a

Bird surveys at Stokes Point and Philips Bay, Yukon in 1983. No. 40

Energy Technology Data Exchange (ETDEWEB)

Dickson, D L; Dickson, H L; Aiudi, G M

1988-01-01

The distribution, abundance, and habitat preferences of birds were studied at Stokes Point, Phillips Bay and King Point in the northern Yukon in 1983. These data were gathered to assist in decisions about future development of a port to support marine drilling activities in the Beaufort Sea. Nesting bird densities at Stokes Point were similar to those found elsewhere on the Yukon Coastal Plain due to the similarity in habitat. The lagoon at Stokes Point was locally important to molting ducks. Several species occurred in higher densities at Phillips Bay than elsewhere on the Plain, mainly due to the deltas and spits created by rivers flowing into the Bay. These deltas were locally important to such species as molting non-breeding tundra swans, Canada geese, and ducks. During ground surveys in June, habitat was classified into 13 types and the nesting density for each bird species calculated for each habitat type. Overall bird densities were more than 3 times higher in lowland than in upland habitats. Passerine densities and species were highest in the tall shrub type of habitat found primarily in stream and river valleys. The Yukon Coastal Plain is an important nesting area for the stilt sandpiper, which has a limited breeding range. The Plain is also nationally important for nesting long-billed dowitchers and yellow wagtails, both fairly common in the study area but with very limited breeding distribution within Canada. The Plain is also internationally important to fall staging snow geese. 38 refs., 17 figs., 35 tabs.

Speed of spring migration of Tundra Swans Cygnus columbianus in accordance with income or capital breeding strategy?

NARCIS (Netherlands)

Nolet, B.A.

2006-01-01

Large migratory birds may bring along stores in order to survive adverse conditions and produce a clutch upon arrival (‘capital breeders’) or they may acquire all the necessary resources on the breeding grounds (‘income breeders’). Whether birds are capital- or income-breeders may depend on the

Comparative analysis of the intestinal bacterial and RNA viral communities from sentinel birds placed on selected broiler chicken farms.

Directory of Open Access Journals (Sweden)

J Michael Day

Full Text Available There is a great deal of interest in characterizing the complex microbial communities in the poultry gut, and in understanding the effects of these dynamic communities on poultry performance, disease status, animal welfare, and microbes with human health significance. Investigations characterizing the poultry enteric virome have identified novel poultry viruses, but the roles these viruses play in disease and performance problems have yet to be fully characterized. The complex bacterial community present in the poultry gut influences gut development, immune status, and animal health, each of which can be an indicator of overall performance. The present metagenomic investigation was undertaken to provide insight into the colonization of specific pathogen free chickens by enteric microorganisms under field conditions and to compare the pre-contact intestinal microbiome with the altered microbiome following contact with poultry raised in the field. Analysis of the intestinal virome from contact birds ("sentinels" placed on farms revealed colonization by members of the Picornaviridae, Picobirnaviridae, Reoviridae, and Astroviridae that were not present in pre-contact birds or present in proportionally lower numbers. Analysis of the sentinel gut bacterial community revealed an altered community in the post-contact birds, notably by members of the Lachnospiracea/Clostridium and Lactobacillus families and genera. Members of the avian enteric Reoviridae and Astroviridae have been well-characterized and have historically been implicated in poultry enteric disease; members of the Picobirnaviridae and Picornaviridae have only relatively recently been described in the poultry and avian gut, and their roles in the recognized disease syndromes and in poultry performance in general have not been determined. This metagenomic analysis has provided insight into the colonization of the poultry gut by enteric microbes circulating in commercial broiler flocks, and

Helminth communities of two species of piscivorous birds, Ardea alba (Linnaeus) and Nyctanassa violacea (Gmelin) (Ciconiiformes: Ardeidae), in two coastal lagoons from Guerrero state, Mexico.

Science.gov (United States)

Violante-González, Juan; Monks, Scott; Gil-Guerrero, Salvador; Rojas-Herrera, Agustín A; Flores-Rodríguez, Pedro

2012-07-01

The composition and species richness in helminth communities of two species of heron, Ardea alba and Nyctanassa violacea, in two coastal lagoons from Guerrero, Mexico were examined. Nineteen species of helminth (7,804 individuals) were identified in 43 adult birds: 15 digeneans, 1 acanthocephalan, 1 cestode, and 2 nematodes. Eight species co-occurred in herons of both species and lagoons. The prevalence values of seven species and the mean abundance of five species varied significantly between species of birds and between lagoons. The heterophyid, Ascocotyle (Phagicola) longa, was the helminth numerically dominant in the helminth community of A. alba in both lagoons, while the cestode, Parvitaenia cochlearii, dominated the community of N. violacea. At the component community level, species richness varied significantly: 10 species in A. alba from Coyuca to 16 in N. violacea (Tres Palos). All of the birds examined were infected with helminth parasites: three to seven species per host in A. alba from Coyuca, and two to eight species in A. alba and N. violacea from Tres Palos. The results indicate that even though species composition was similar between both species of heron, the structure of their communities was not the same. Differences in the feeding behavior of the birds (day/night habits), as well as local differences in the abundance of species of fish, and infection levels of helminths in each lagoon are suggested as being responsible for the variations registered in the structure of the helminth communities.

Production system and participatory identification of breeding objective traits for indigenous goat breeds of Uganda

NARCIS (Netherlands)

Onzima, R.B.; Gizaw, S.; Kugonza, D.R.; Arendonk, van J.A.M.; Kanis, E.

2018-01-01

The success of breeding programs in improving indigenous livestock breeds in Uganda has hitherto been limited due to lack of involvement of the key stakeholders. Thus, participatory approaches are being promoted for designing community based improvement programs. The aim of this study was to

Production system and participatory identification of breeding objective traits for indigenous goat breeds of Uganda

NARCIS (Netherlands)

Onzima, R.B.; Gizaw, S.; Kugonza, D.R.; Arendonk, van J.A.M.; Kanis, E.

2017-01-01

The success of breeding programs in improving indigenous livestock breeds in Uganda has hitherto been limited due to lack of involvement of the key stakeholders. Thus, participatory approaches are being promoted for designing community based improvement programs. The aim of this study was to

A method for investigating population declines of migratory birds using stable isotopes: origins of harvested lesser scaup in North America.

Directory of Open Access Journals (Sweden)

Keith A Hobson

2009-11-01

Full Text Available Elucidating geographic locations from where migratory birds are recruited into adult breeding populations is a fundamental but largely elusive goal in conservation biology. This is especially true for species that breed in remote northern areas where field-based demographic assessments are logistically challenging.Here we used hydrogen isotopes (deltaD to determine natal origins of migrating hatch-year lesser scaup (Aythya affinis harvested by hunters in the United States from all North American flyways during the hunting seasons of 1999-2000 (n = 412 and 2000-2001 (n = 455. We combined geospatial, observational, and analytical data sources, including known scaup breeding range, deltaD values of feathers from juveniles at natal sites, models of deltaD for growing-season precipitation, and scaup band-recovery data to generate probabilistic natal origin landscapes for individual scaup. We then used Monte Carlo integration to model assignment uncertainty from among individual deltaD variance estimates from birds of known molt origin and also from band-return data summarized at the flyway level. We compared the distribution of scaup natal origin with the distribution of breeding population counts obtained from systematic long-term surveys.Our analysis revealed that the proportion of young scaup produced in the northern (above 60 degrees N versus the southern boreal and Prairie-Parkland region was inversely related to the proportions of breeding adults using these regions, suggesting that despite having a higher relative abundance of breeding adults, the northern boreal region was less productive for scaup recruitment into the harvest than more southern biomes. Our approach for evaluating population declines of migratory birds (particularly game birds synthesizes all available distributional data and exploits the advantages of intrinsic isotopic markers that link individuals to geography.

Checklist of the birds of Kipini Conservancy, Lamu and Tana River ...

African Journals Online (AJOL)

We present here details of the birds we saw in an area whose avifauna has been ..... The absence of immatures suggests no breeding took place in recent years. Pair at base camp ..... Northern Carmine Bee-eater Merops nubicus. Common ...

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.

Vegetation composition and structure influences bird species ...

African Journals Online (AJOL)

Vegetation composition and structure influences bird species community ... variables on bird species diversity and richness of respective foraging guilds, and ... of the species assessed: (1) increasing closed cover due to woody plant density, ...

Variation in the structure of bird nests between northern Manitoba and southeastern Ontario.

Directory of Open Access Journals (Sweden)

Carla A Crossman

Full Text Available Traits that converge in appearance under similar environmental conditions among phylogenetically independent lineages are thought to represent adaptations to local environments. We tested for convergence in nest morphology and composition of birds breeding in two ecologically different locations in Canada: Churchill in northern Manitoba and Elgin in southeastern Ontario. We examined nests from four families of passerine birds (Turdidae: Turdus, Parulidae: Dendroica, Emberizidae: Passerculus and Fringillidae: Carduelis where closely related populations or species breed in both locations. Nests of American Robins, Yellow Warblers, and Carduelis finches had heavier nest masses, and tended to have thicker nest-walls, in northern Manitoba compared with conspecifics or congenerics breeding in southeastern Ontario. Together, all species showed evidence for wider internal and external nest-cup diameters in northern Manitoba, while individual species showed varying patterns for internal nest-cup and external nest depths. American Robins, Yellow Warblers, and Carduelis finches in northern Manitoba achieved heavier nest masses in different ways. American Robins increased all materials in similar proportions, and Yellow Warblers and Common Redpolls used greater amounts of select materials. While changes in nest composition vary uniquely for each species, the pattern of larger nests in northern Manitoba compared to southeastern Ontario in three of our four phylogenetically-independent comparisons suggests that birds are adapting to similar selective pressures between locations.

Variation in the structure of bird nests between northern Manitoba and southeastern Ontario.

Science.gov (United States)

Crossman, Carla A; Rohwer, Vanya G; Martin, Paul R

2011-04-28

Traits that converge in appearance under similar environmental conditions among phylogenetically independent lineages are thought to represent adaptations to local environments. We tested for convergence in nest morphology and composition of birds breeding in two ecologically different locations in Canada: Churchill in northern Manitoba and Elgin in southeastern Ontario. We examined nests from four families of passerine birds (Turdidae: Turdus, Parulidae: Dendroica, Emberizidae: Passerculus and Fringillidae: Carduelis) where closely related populations or species breed in both locations. Nests of American Robins, Yellow Warblers, and Carduelis finches had heavier nest masses, and tended to have thicker nest-walls, in northern Manitoba compared with conspecifics or congenerics breeding in southeastern Ontario. Together, all species showed evidence for wider internal and external nest-cup diameters in northern Manitoba, while individual species showed varying patterns for internal nest-cup and external nest depths. American Robins, Yellow Warblers, and Carduelis finches in northern Manitoba achieved heavier nest masses in different ways. American Robins increased all materials in similar proportions, and Yellow Warblers and Common Redpolls used greater amounts of select materials. While changes in nest composition vary uniquely for each species, the pattern of larger nests in northern Manitoba compared to southeastern Ontario in three of our four phylogenetically-independent comparisons suggests that birds are adapting to similar selective pressures between locations.

Variation in the Structure of Bird Nests between Northern Manitoba and Southeastern Ontario

Science.gov (United States)

Crossman, Carla A.; Rohwer, Vanya G.; Martin, Paul R.

2011-01-01

Traits that converge in appearance under similar environmental conditions among phylogenetically independent lineages are thought to represent adaptations to local environments. We tested for convergence in nest morphology and composition of birds breeding in two ecologically different locations in Canada: Churchill in northern Manitoba and Elgin in southeastern Ontario. We examined nests from four families of passerine birds (Turdidae: Turdus, Parulidae: Dendroica, Emberizidae: Passerculus and Fringillidae: Carduelis) where closely related populations or species breed in both locations. Nests of American Robins, Yellow Warblers, and Carduelis finches had heavier nest masses, and tended to have thicker nest-walls, in northern Manitoba compared with conspecifics or congenerics breeding in southeastern Ontario. Together, all species showed evidence for wider internal and external nest-cup diameters in northern Manitoba, while individual species showed varying patterns for internal nest-cup and external nest depths. American Robins, Yellow Warblers, and Carduelis finches in northern Manitoba achieved heavier nest masses in different ways. American Robins increased all materials in similar proportions, and Yellow Warblers and Common Redpolls used greater amounts of select materials. While changes in nest composition vary uniquely for each species, the pattern of larger nests in northern Manitoba compared to southeastern Ontario in three of our four phylogenetically-independent comparisons suggests that birds are adapting to similar selective pressures between locations. PMID:21552515

Effects of food supplementation on a tropical bird.

Science.gov (United States)

Class, Alexandra M; Moore, Ignacio T

2013-10-01

Tropical birds typically exhibit a 'slow pace of life' relative to higher latitude species. This is often manifested as slow development, low fecundity, and high survival. Following from this, it is predicted that tropical birds may be more likely to trade current reproductive effort to favor self-maintenance, thus supporting survival and future reproduction. To test this idea, we conducted two food supplementation experiments on tropical rufous-collared sparrows (Zonotrichia capensis) in the eastern Andes of Ecuador. In the first experiment, we food-supplemented pairs during the non-breeding life-history stage, and in the second experiment, we food-supplemented pairs that were provisioning fledglings. In both experiments, a larger proportion of food-supplemented birds exhibited pre-basic molt (replacement of feathers) than in a control group. To our knowledge, this is the first study to experimentally demonstrate that a food-supplemented bird invests extra resources into molt, a form of self-maintenance, and contrasts with the majority of food supplementation studies in high latitude birds that show they typically advance the initiation of, or extend the period of, reproduction. Our results are consistent with the syndrome of the slow pace of life in the tropics and support the concept of fundamental differences between temperate-zone and tropical birds.

Bird populations as sentinels of endocrine disrupting chemicals.

Science.gov (United States)

Carere, Claudio; Costantini, David; Sorace, Alberto; Santucci, Daniela; Alleva, Enrico

2010-01-01

Exposure to endocrine disrupting chemicals (EDCs) is a widespread phenomenon in nature. Although the mechanisms of action of EDCs are actively studied, the consequences of endocrine disruption (ED) at the population level and the adaptations evolved to cope with chronic EDC exposure have been overlooked. Birds probably represent the animal taxon most successfully adapted to synanthropic life. Hence, birds share with humans a similar pattern of exposure to xenobiotics. In this article, we review case studies on patterns of behaviour that deviate from the expectation in bird species exposed to EDCs. We provide behavioural and ecological parameters to be used as endpoints of ED; methodological requirements and caveats based on species-specific life-history traits, behavioural repertoires, developmental styles, and possibility of captive breeding; a list of species that could be used as sentinels to assess the quality of man-made environment.