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.

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

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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.

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.

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

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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

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

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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.

Neotropical Migratory Bird Communities in a Developing Pine Plantation

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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...

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

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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.

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.

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.

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

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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

Forest Plant and Bird Communities in the Lau Group, Fiji

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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

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 ...

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

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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

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.

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.

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.

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

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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.

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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.

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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.

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.

Effect of artificial nestboxes on the diversity of secondary cavity-nesting birds and the stability of breeding bird community

OpenAIRE

Wenhong Deng; Wen Liu; Liyuan Yang; Zhen Li

2008-01-01

Artificial nestboxes are widely used in ecological research and conservation practices. However, we know little about the effects of nestboxes on breeding bird communities and their actual conservationvalue to bird communities. We chose two sample plots with similar plant communities in Xiaolongmen National Forest Park, Beijing. Fifty artificial nest-boxes were hung in the experimental plot and the other plot as a control. From March to August in 2007, we monitored artificial nestbox use by s...

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.

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...

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.

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.

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.

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

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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.

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

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

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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...

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

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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.

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

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.

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.

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

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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.

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

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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.

Heterogeneity of bird communities in a mosaic of habitats on a restinga ecosystem in southeast Brazil

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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.

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

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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

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.

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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.

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.

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

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

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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.

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

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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.

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...

Predation risk determines breeding territory choice in a Mediterranean cavity-nesting bird community.

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Parejo, Deseada; Avilés, Jesús M

2011-01-01

Non-direct effects of predation can be an important component of the total effect of predation, modulating animal population and community dynamics. The isolated effects of predation risk on the spatial organisation of the breeding bird community, however, remains poorly studied. We investigated whether an experimentally increased predation risk prior to reproduction affected breeding territory selection and subsequent reproductive strategies in three Mediterranean cavity-nesting birds, i.e., the little owl Athene noctua, European roller Coracias garrulus and scops owl Otus scops. We found that territories used the previous year were more likely to be re-occupied when they belonged to the safe treatment rather than to the risky treatment. The first choice of breeders of all three species was for safe territories over risky ones. When all breeding attempts in the season (i.e., final occupation) were considered, breeders also preferred safe to risky sites. In addition, little owls laid larger eggs in risky territories than in safe territories. Our study provides experimental evidence of a rapid preventive response of the three most abundant species in a cavity-nesting bird community to a short-term manipulation of predation risk. This response highlights the key role of the non-direct effects of predation in modulating avian community organisation.

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

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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.

Physical cognition: birds learn the structural efficacy of nest material.

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Bailey, Ida E; Morgan, Kate V; Bertin, Marion; Meddle, Simone L; Healy, Susan D

2014-06-07

It is generally assumed that birds' choice of structurally suitable materials for nest building is genetically predetermined. Here, we tested that assumption by investigating whether experience affected male zebra finches' (Taeniopygia guttata) choice of nest material. After a short period of building with relatively flexible string, birds preferred to build with stiffer string while those that had experienced a stiffer string were indifferent to string type. After building a complete nest with either string type, however, all birds increased their preference for stiff string. The stiffer string appeared to be the more effective building material as birds required fewer pieces of stiffer than flexible string to build a roofed nest. For birds that raised chicks successfully, there was no association between the material they used to build their nest and the type they subsequently preferred. Birds' material preference reflected neither the preference of their father nor of their siblings but juvenile experience of either string type increased their preference for stiffer string. Our results represent two important advances: (i) birds choose nest material based on the structural properties of the material; (ii) nest material preference is not entirely genetically predetermined as both the type and amount of experience influences birds' choices.

Genetic Structure and Antimicrobial Resistance of Escherichia coli and Cryptic Clades in Birds with Diverse Human Associations.

Science.gov (United States)

Blyton, Michaela D J; Pi, Hongfei; Vangchhia, Belinda; Abraham, Sam; Trott, Darren J; Johnson, James R; Gordon, David M

2015-08-01

The manner and extent to which birds associate with humans may influence the genetic attributes and antimicrobial resistance of their commensal Escherichia communities through strain transmission and altered selection pressures. In this study, we determined whether the distribution of the different Escherichia coli phylogenetic groups and cryptic clades, the occurrence of 49 virulence associated genes, and/or the prevalence of resistance to 12 antimicrobials differed between four groups of birds from Australia with contrasting types of human association. We found that birds sampled in suburban and wilderness areas had similar Escherichia communities. The Escherichia communities of backyard domestic poultry were phylogenetically distinct from the Escherichia communities sourced from all other birds, with a large proportion (46%) of poultry strains belonging to phylogenetic group A and a significant minority (17%) belonging to the cryptic clades. Wild birds sampled from veterinary and wildlife rehabilitation centers (in-care birds) carried Escherichia isolates that possessed particular virulence-associated genes more often than Escherichia isolates from birds sampled in suburban and wilderness areas. The Escherichia isolates from both the backyard poultry and in-care birds were more likely to be multidrug resistant than the Escherichia isolates from wild birds. We also detected a multidrug-resistant E. coli strain circulating in a wildlife rehabilitation center, reinforcing the importance of adequate hygiene practices when handling and caring for wildlife. We suggest that the relatively high frequency of antimicrobial resistance in the in-care birds and backyard poultry is due primarily to the use of antimicrobials in these animals, and we recommend that the treatment protocols used for these birds be reviewed. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

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

A numerical model for bird strike on sidewall structure of an aircraft nose

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Liu Jun

2014-06-01

Full Text Available In order to examine the potential of using the coupled smooth particles hydrodynamic (SPH and finite element (FE method to predict the dynamic responses of aircraft structures in bird strike events, bird-strike tests on the sidewall structure of an aircraft nose are carried out and numerically simulated. The bird is modeled with SPH and described by the Murnaghan equation of state, while the structure is modeled with finite elements. A coupled SPH–FE method is developed to simulate the bird-strike tests and a numerical model is established using a commercial software PAM-CRASH. The bird model shows no signs of instability and correctly modeled the break-up of the bird into particles. Finally the dynamic response such as strains in the skin is simulated and compared with test results, and the simulated deformation and fracture process of the sidewall structure is compared with images recorded by a high speed camera. Good agreement between the simulation results and test data indicates that the coupled SPH–FE method can provide a very powerful tool in predicting the dynamic responses of aircraft structures in events of bird strike.

Animal-habitat relationships in the Knysna Forest, South Africa: discrimination between forest types by birds and invertebrates.

Science.gov (United States)

Koen, J H; Crowe, T M

1987-06-01

Effects of forest plant species composition and physiognomy on bird and invertebrate communities were investigated in three discrete, relatively undisturbed forest types along a dry-wet soil moisture gradient. Using discriminant function analysis, a 100% floristic and a 78% vegetation structural discrimination were obtained between the three forest types. However, the bird communities of these different forest types were very similar in species composition, and had much lower densities than those normally encountered in other, superficially similar forests. Although an 81% discrimination between forest types was attained through analysis of ground surface invertebrates, measures of litter and aerial invertebrate abundance were also of limited use as discriminators. Historical and biogeographic factors, as well as the low nutritional levels in the soil and vegetation may be the causes of low bird and invertebrate density and diversity. It is concluded that floristics and vegetation structure have, at best, a minor influence on bird community structure, and possibly also on invertebrate community structure in the Knysna Forest.

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.

Structural design principles of complex bird songs: a network-based approach.

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Kazutoshi Sasahara

Full Text Available Bird songs are acoustic communication signals primarily used in male-male aggression and in male-female attraction. These are often monotonous patterns composed of a few phrases, yet some birds have extremely complex songs with a large phrase repertoire, organized in non-random fashion with discernible patterns. Since structure is typically associated with function, the structures of complex bird songs provide important clues to the evolution of animal communication systems. Here we propose an efficient network-based approach to explore structural design principles of complex bird songs, in which the song networks--transition relationships among different phrases and the related structural measures--are employed. We demonstrate how this approach works with an example using California Thrasher songs, which are sequences of highly varied phrases delivered in succession over several minutes. These songs display two distinct features: a large phrase repertoire with a 'small-world' architecture, in which subsets of phrases are highly grouped and linked with a short average path length; and a balanced transition diversity amongst phrases, in which deterministic and non-deterministic transition patterns are moderately mixed. We explore the robustness of this approach with variations in sample size and the amount of noise. Our approach enables a more quantitative study of global and local structural properties of complex bird songs than has been possible to date.

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...

Bird Perches Increase Forest Seeds on Puerto Rican Landslides.

Science.gov (United States)

Aaron B. Shiels; Lawrence R. Walker

2003-01-01

Landslides result in the loss of vertical vegetative structure, soil nutrients, and the soil seed bank. These losses impede timely recovery of tropical forest communities. In this study we added bird perches to six Puerto Rican landslides with three types of surfaces (bare, climbing fern, grass) in an effort to facilitate inputs of forest seeds through bird dispersal...

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

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

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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.

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

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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

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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

Birds communities of fragmented forest within highly urbanized landscape in Kuala Lumpur, Malaysia

Science.gov (United States)

Mohd-Taib, F. S.; Rabiatul-Adawiyah, S.; Md-Nor, S.

2014-09-01

Urbanization is one form of forest modification for development purposes. It produces forest fragments scattered in the landscape with different intensity of disturbance. We want to determine the effect of forest fragmentation towards bird community in urbanized landscapes in Kuala Lumpur, namely Sungai Besi Forest Reserve (FR), Bukit Nenas FR and Bukit Sungei Puteh FR. We used mist-netting and direct observation method along established trails. These forests differ in size, vegetation composition and land use history. Results show that these forests show relatively low number of species compared to other secondary forest with only 39 bird species recorded. The largest fragment, Sg. Besi encompassed the highest species richness and abundance with 69% species but lower in diversity. Bukit Nenas, the next smallest fragment besides being the only remaining primary forest has the highest diversity index with 1.866. Bkt. Sg. Puteh the smallest fragment has the lowest species richness and diversity with Shanon diversity index of 1.332. The presence of introduced species such as Corvus splendens (House crow) in all study areas suggest high disturbance encountered by these forests. Nonetheless, these patches comprised of considerably high proportion of native species. In conclusion, different intensity of disturbance due to logging activities and urbanization surrounding the forest directly influenced bird species richness and diversity. These effects however can be compensated by maintaining habitat complexity including high vegetation composition and habitat structure at the landscape level.

Qualitative-quantitative characteristic of bird community of middle course alluvium of the Vah River (Piestany - Nove Mesto); Kvalitativno-kvantitativna charakteristika ornitocenoz aluvia stredneho toku Vahu (Piestany - Nove Mesto nad Vahom)

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Lacko, J. [Univerzita Komenskeho v Bratislave, Prirodovedecka fakulta, Katedra ekologie, 84215 Bratislava (Slovakia); Topercer, J. [Botanicka zahrada Univerzity Komenskeho v Bratislave, pracovisko Blatnica, 03815 Blatnica pri Martine (Slovakia)

2013-04-16

The research focuses on the analysis of structure and dynamics of bird communities in two transects on the Vah river alluvium between cities Piestany and Nove Mesto nad Vahom. The research is aimed on the analysis of species composition, distribution and multitude of aquatic and wetland birds, on the analysis of their seasonal dynamics, inter-annual variability in species composition, diversity and others indicators of birds in these transects. The secondary aim is to find out the main types of disturbances, their intensity, antropogenous effects and others chosen environment variables in these transects of Vah river alluvium. We will utilize statistical analyses from these environmental variables and explain their impact on bird communities of this area. From these findings suitable management measures for the conservation or improvement of conservation status of target species will be derived. (authors)

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.

Assessing the impacts of bait collection on inter-tidal sediment and the associated macrofaunal and bird communities: The importance of appropriate spatial scales.

Science.gov (United States)

Watson, G J; Murray, J M; Schaefer, M; Bonner, A; Gillingham, M

2017-09-01

Bait collection is a multibillion dollar worldwide activity that is often managed ineffectively. For managers to understand the impacts on protected inter-tidal mudflats and waders at appropriate spatial scales macrofaunal surveys combined with video recordings of birds and bait collectors were undertaken at two UK sites. Dug sediment constituted approximately 8% of the surveyed area at both sites and is less muddy (lower organic content) than undug sediment. This may have significant implications for turbidity. Differences in the macrofaunal community between dug and undug areas if the same shore height is compared as well as changes in the dispersion of the community occurred at one site. Collection also induces a 'temporary loss of habitat' for some birds as bait collector numbers negatively correlate with wader and gull abundance. Bait collection changes the coherence and ecological structure of inter-tidal mudflats as well as directly affecting wading birds. However, as β diversity increased we suggest that management at appropriate hectare/site scales could maximise biodiversity/function whilst still supporting collection. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

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.

Urban and rural habitats differ in number and type of bird feeders and in bird species consuming supplementary food.

Science.gov (United States)

Tryjanowski, Piotr; Skórka, Piotr; Sparks, Tim H; Biaduń, Waldemar; Brauze, Tomasz; Hetmański, Tomasz; Martyka, Rafał; Indykiewicz, Piotr; Myczko, Łukasz; Kunysz, Przemysław; Kawa, Piotr; Czyż, Stanisław; Czechowski, Paweł; Polakowski, Michał; Zduniak, Piotr; Jerzak, Leszek; Janiszewski, Tomasz; Goławski, Artur; Duduś, Leszek; Nowakowski, Jacek J; Wuczyński, Andrzej; Wysocki, Dariusz

2015-10-01

Bird feeding is one of the most widespread direct interactions between man and nature, and this has important social and environmental consequences. However, this activity can differ between rural and urban habitats, due to inter alia habitat structure, human behaviour and the composition of wintering bird communities. We counted birds in 156 squares (0.25 km(2) each) in December 2012 and again in January 2013 in locations in and around 26 towns and cities across Poland (in each urban area, we surveyed 3 squares and also 3 squares in nearby rural areas). At each count, we noted the number of bird feeders, the number of bird feeders with food, the type of feeders, additional food supplies potentially available for birds (bread offered by people, bins) and finally the birds themselves. In winter, urban and rural areas differ in the availability of food offered intentionally and unintentionally to birds by humans. Both types of food availability are higher in urban areas. Our findings suggest that different types of bird feeder support only those species specialized for that particular food type and this relationship is similar in urban and rural areas.

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)

Bat and bird diversity along independent gradients of latitude and tree composition in European forests.

Science.gov (United States)

Charbonnier, Yohan M; Barbaro, Luc; Barnagaud, Jean-Yves; Ampoorter, Evy; Nezan, Julien; Verheyen, Kris; Jactel, Hervé

2016-10-01

Species assemblages are shaped by local and continental-scale processes that are seldom investigated together, due to the lack of surveys along independent gradients of latitude and habitat types. Our study investigated changes in the effects of forest composition and structure on bat and bird diversity across Europe. We compared the taxonomic and functional diversity of bat and bird assemblages in 209 mature forest plots spread along gradients of forest composition and vertical structure, replicated in 6 regions spanning from the Mediterranean to the boreal biomes. Species richness and functional evenness of both bat and bird communities were affected by the interactions between latitude and forest composition and structure. Bat and bird species richness increased with broadleaved tree cover in temperate and especially in boreal regions but not in the Mediterranean where they increased with conifer abundance. Bat species richness was lower in forests with smaller trees and denser understorey only in northern regions. Bird species richness was not affected by forest structure. Bird functional evenness increased in younger and denser forests. Bat functional evenness was also influenced by interactions between latitude and understorey structure, increasing in temperate forests but decreasing in the Mediterranean. Covariation between bat and bird abundances also shifted across Europe, from negative in southern forests to positive in northern forests. Our results suggest that community assembly processes in bats and birds of European forests are predominantly driven by abundance and accessibility of feeding resources, i.e., insect prey, and their changes across both forest types and latitudes.

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)

Community structure of waterbirds in several type of wetland utilization in East Coast of Surabaya

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Ragil Siti Rihadini

2013-10-01

Full Text Available Natural wetlands are the natural habitat of waterbirds, but it is very diffi cult to fi nd an unspoiled wetlands without human intervention curently. East coast of Surabaya is wetlands area in Surabaya that most of the region have change into fi shpond and residental. The aims of this reasearch are to determine the community structure of waterbirds in each type of wetland utilization and to determine if the different type of wetland utilization infl uence the community structure of waterbirds in East Coast of Surabaya. Data were collected during August 2012 to January 2013 with point count method. Six sampling plots have been selected. Six sampling plots representing four types of use of wetlands, which are bozem, the former fi shpond, fi shpond with vegetation, and fi shponds without vegetation (fi shpond 1, fi shpond 2 and fi shpond 3. In bozem recorded 19 species of waterbirds (1107 individual, dominated by shorebirds, with a diversity index (H' 1.86, and evenness index (J' 0.63. In former fi shpond recorded 7 species of water birds (168 individual, dominated by rails and moorhen, with H’ = 1.12 and J’ = 0.57. In fi shpond with vegetation recorded 12 species of water birds (137 individual, dominated by large wader, with H’ = 1.85 and J’ = 0.74. In fi shpond 1 recorded 18 species of water birds (299 individual, dominated by terns, with H’ = 1.96 and J’ = 0.68. In fi shpond 2 recorded 9 species of water birds (70 individual, dominated by terns, with H’ = 1.73 and J’ = 0.79. In fi shpond 3 recorded 10 species of water birds (83 individual, dominated by terns, with H’ = 1.84 and J’ = 0.80. Chi-square test showed that X2 count is greater than X2 table with α < 0.05, which indicates that there is a signifi cant difference of the number of individuals of each species and the number of individual of each water birds’ group for each type of use of wetlands, so it can be

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.

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

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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.

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.

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

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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.

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

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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

Road networks predict human influence on Amazonian bird communities.

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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

Diversity and abundance of communities of birds associated to forests semideciduos and pine encino of the National Park Viñales

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Sael Hanoi Pérez Báez

2016-06-01

Full Text Available The present work was carried out in the months of February to April 2009 in the forest semideciduo of the path "Marvel of Viñales" and the formation pine-encino of the Valley Ancón of the National Park Viñales and it pursued as main objective to evaluate the diversity and abundance of the communities of birds and its association grade with both formations. The method of circular parcels of fixed radio was used in 30 points of counts separated to 150 m one of other and for the study of vegetation he/she took like base the methodology proposed by James and Shugart (1970 and Noon (1981 with adaptations, he/she took state fenológico of the vegetable species and they measured different variables of the formation boscosa. They were detected a total of 44 species of birds for the semidesiduo and 42 in Ancón. He/she was association between several species of birds and vegetables of the formations in study, appreciating you increment of S with the Relative Abundance and the decrease of the height of the vegetation with the vegetable density. The communities of birds of the formation of forest semideciduo of the path "Marvels of Viñales" and of the forest of pine encino of "Valley Ancón" presented similar figures of wealth, diversity and equitatividad but they sustained differences in composition and it structures. In both study formations numeric dominancias of Turdus plumbeus and Vireo altiloquus registered and the difference was given by the abundance of Teretistris fernandinae in "Marvels of Viñales" and Tiaris canorus in Valley Ancón. The relationship was demonstrated between ornitocenosis and fitocenosis and several species of birds they associated in more measure to rosy Clusea, Callophilum antillanun, Cuban Quercus, Matayba oppositifolia and Cordovan leathers.

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

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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.

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

Impact of Non-Native Birds on Native Ecosystems: A Global Analysis.

Science.gov (United States)

Martin-Albarracin, Valeria L; Amico, Guillermo C; Simberloff, Daniel; Nuñez, Martin A

2015-01-01

Introduction and naturalization of non-native species is one of the most important threats to global biodiversity. Birds have been widely introduced worldwide, but their impacts on populations, communities, and ecosystems have not received as much attention as those of other groups. This work is a global synthesis of the impact of nonnative birds on native ecosystems to determine (1) what groups, impacts, and locations have been best studied; (2) which taxonomic groups and which impacts have greatest effects on ecosystems, (3) how important are bird impacts at the community and ecosystem levels, and (4) what are the known benefits of nonnative birds to natural ecosystems. We conducted an extensive literature search that yielded 148 articles covering 39 species belonging to 18 families -18% of all known naturalized species. Studies were classified according to where they were conducted: Africa, Asia, Australasia, Europe, North America, South America, Islands of the Indian, of the Pacific, and of the Atlantic Ocean. Seven types of impact on native ecosystems were evaluated: competition, disease transmission, chemical, physical, or structural impact on ecosystem, grazing/ herbivory/ browsing, hybridization, predation, and interaction with other non-native species. Hybridization and disease transmission were the most important impacts, affecting the population and community levels. Ecosystem-level impacts, such as structural and chemical impacts were detected. Seven species were found to have positive impacts aside from negative ones. We provide suggestions for future studies focused on mechanisms of impact, regions, and understudied taxonomic groups.

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...

The role of climate and environmental variables in structuring bird assemblages in the Seasonally Dry Tropical Forests (SDTFs.

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Gabriela Silva Ribeiro Gonçalves

Full Text Available Understanding the processes that influence species diversity is still a challenge in ecological studies. However, there are two main theories to discuss this topic, the niche theory and the neutral theory. Our objective was to understand the importance of environmental and spatial processes in structuring bird communities within the hydrological seasons in dry forest areas in northeastern Brazil. The study was conducted in two National Parks, the Serra da Capivara and Serra das Confusões National Parks, where 36 areas were sampled in different seasons (dry, dry/rainy transition, rainy, rainy/dry transition, in 2012 and 2013. We found with our results that bird species richness is higher in the rainy season and lower during the dry season, indicating a strong influence of seasonality, a pattern also found for environmental heterogeneity. Richness was explained by local environmental factors, while species composition was explained by environmental and spatial factors. The environmental factors were more important in explaining variations in composition. Climate change predictions have currently pointed out frequent drought events and a rise in global temperature by 2050, which would lead to changes in species behavior and to increasing desertification in some regions, including the Caatinga. In addition, the high deforestation rates and the low level of representativeness of the Caatinga in the conservation units negatively affects bird communities. This scenario has demonstrated how climatic factors affect individuals, and, therefore, should be the starting point for conservation initiatives to be developed in xeric environments.

The role of climate and environmental variables in structuring bird assemblages in the Seasonally Dry Tropical Forests (SDTFs).

Science.gov (United States)

Gonçalves, Gabriela Silva Ribeiro; Cerqueira, Pablo Vieira; Brasil, Leandro Schlemmer; Santos, Marcos Pérsio Dantas

2017-01-01

Understanding the processes that influence species diversity is still a challenge in ecological studies. However, there are two main theories to discuss this topic, the niche theory and the neutral theory. Our objective was to understand the importance of environmental and spatial processes in structuring bird communities within the hydrological seasons in dry forest areas in northeastern Brazil. The study was conducted in two National Parks, the Serra da Capivara and Serra das Confusões National Parks, where 36 areas were sampled in different seasons (dry, dry/rainy transition, rainy, rainy/dry transition), in 2012 and 2013. We found with our results that bird species richness is higher in the rainy season and lower during the dry season, indicating a strong influence of seasonality, a pattern also found for environmental heterogeneity. Richness was explained by local environmental factors, while species composition was explained by environmental and spatial factors. The environmental factors were more important in explaining variations in composition. Climate change predictions have currently pointed out frequent drought events and a rise in global temperature by 2050, which would lead to changes in species behavior and to increasing desertification in some regions, including the Caatinga. In addition, the high deforestation rates and the low level of representativeness of the Caatinga in the conservation units negatively affects bird communities. This scenario has demonstrated how climatic factors affect individuals, and, therefore, should be the starting point for conservation initiatives to be developed in xeric environments.

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

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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

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

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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.

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

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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.

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

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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.

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

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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.

HUMIDIFICATION AS A FACTOR OF STRUCTURIAL ORGANIZATION OF BIRD POPULATIONS IN THE WOOD STANDS OF THE BIOSPHERE RESERVE ASKANIA NOVA

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Listopadsky M. A.

2014-04-01

Full Text Available The influence of different humidification types towards appearance of forest vegetation conditions on spatial organization of birds in the wood stands is analyzed. Population density, coefficient of occurrence, and informative connection with six types of soil humidification are given for 53 bird species. The informative estimation of every humidification type is determined for every bird species. Thereby it is definitely a contribution of every gradation of edaphic factor to the structural genesis of dendrophilous bird communities. The strongest informative connection between humidity gradients and the avifauna structure of the wood stands is available in dry edaphotopes for margin representatives and fresh one for typical forest species. These two humidification types play a start function in the structural genesis of some blocks of dendrophilous bird communities per se. It is determined that change of bird species of forest-steppe faunogenetic complex by species from Nemoral complex undergoes in most cases on the border of the gradient between fresh and humid edaphotopes. For 53 species of birds from dendrophilous complex is was revealed that the importance of different levels of soil moisture has a different impact in shaping of the modern structure dendrophilous avifauna. Dry and especially drily edaphotopes determine the spatial structure of the species that are of forest-steppe origin and belong to the representatives of the optional component of dendrophilous bird communities. Wet edafotopes are involved in the formation of the spatial structure of species of predominantly immoral origin and relate to the obligate component of representatives of dendrophilous bitd comminities. Gradient wetting of edaphotopes on the verge of ‘linked’/’fresh’ is restructuring for the bird communities. It takes an optional replacement red communists feature to obligate. Stands rather dry and fresh items currently being the most active formation of

Mass and performance optimization of an airplane wing leading edge structure against bird strike using Taguchi-based grey relational analysis

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Hassan Pahange

2016-08-01

Full Text Available Collisions between birds and aircraft are one of the most dangerous threats to flight safety. In this study, smoothed particles hydrodynamics (SPH method is used for simulating the bird strike to an airplane wing leading edge structure. In order to verify the model, first, experiment of bird strike to a flat aluminum plate is simulated, and then bird impact on an airplane wing leading edge structure is investigated. After that, considering dimensions of wing internal structural components like ribs, skin and spar as design variables, we try to minimize structural mass and wing skin deformation simultaneously. To do this, bird strike simulations to 18 different wing structures are made based on Taguchi’s L18 factorial design of experiment. Then grey relational analysis is used to minimize structural mass and wing skin deformation due to the bird strike. The analysis of variance (ANOVA is also applied and it is concluded that the most significant parameter for the performance of wing structure against impact is the skin thickness. Finally, a validation simulation is conducted under the optimal condition to show the improvement of performance of the wing structure.

Winter Bird Assemblages in Rural and Urban Environments: A National Survey.

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Tryjanowski, Piotr; Sparks, Tim H; Biaduń, Waldemar; Brauze, Tomasz; Hetmański, Tomasz; Martyka, Rafał; Skórka, Piotr; Indykiewicz, Piotr; Myczko, Łukasz; Kunysz, Przemysław; Kawa, Piotr; Czyż, Stanisław; Czechowski, Paweł; Polakowski, Michał; Zduniak, Piotr; Jerzak, Leszek; Janiszewski, Tomasz; Goławski, Artur; Duduś, Leszek; Nowakowski, Jacek J; Wuczyński, Andrzej; Wysocki, Dariusz

2015-01-01

Urban development has a marked effect on the ecological and behavioural traits of many living organisms, including birds. In this paper, we analysed differences in the numbers of wintering birds between rural and urban areas in Poland. We also analysed species richness and abundance in relation to longitude, latitude, human population size, and landscape structure. All these parameters were analysed using modern statistical techniques incorporating species detectability. We counted birds in 156 squares (0.25 km2 each) in December 2012 and again in January 2013 in locations in and around 26 urban areas across Poland (in each urban area we surveyed 3 squares and 3 squares in nearby rural areas). The influence of twelve potential environmental variables on species abundance and richness was assessed with Generalized Linear Mixed Models, Principal Components and Detrended Correspondence Analyses. Totals of 72 bird species and 89,710 individual birds were recorded in this study. On average (± SE) 13.3 ± 0.3 species and 288 ± 14 individuals were recorded in each square in each survey. A formal comparison of rural and urban areas revealed that 27 species had a significant preference; 17 to rural areas and 10 to urban areas. Moreover, overall abundance in urban areas was more than double that of rural areas. There was almost a complete separation of rural and urban bird communities. Significantly more birds and more bird species were recorded in January compared to December. We conclude that differences between rural and urban areas in terms of winter conditions and the availability of resources are reflected in different bird communities in the two environments.

Winter Bird Assemblages in Rural and Urban Environments: A National Survey.

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Piotr Tryjanowski

Full Text Available Urban development has a marked effect on the ecological and behavioural traits of many living organisms, including birds. In this paper, we analysed differences in the numbers of wintering birds between rural and urban areas in Poland. We also analysed species richness and abundance in relation to longitude, latitude, human population size, and landscape structure. All these parameters were analysed using modern statistical techniques incorporating species detectability. We counted birds in 156 squares (0.25 km2 each in December 2012 and again in January 2013 in locations in and around 26 urban areas across Poland (in each urban area we surveyed 3 squares and 3 squares in nearby rural areas. The influence of twelve potential environmental variables on species abundance and richness was assessed with Generalized Linear Mixed Models, Principal Components and Detrended Correspondence Analyses. Totals of 72 bird species and 89,710 individual birds were recorded in this study. On average (± SE 13.3 ± 0.3 species and 288 ± 14 individuals were recorded in each square in each survey. A formal comparison of rural and urban areas revealed that 27 species had a significant preference; 17 to rural areas and 10 to urban areas. Moreover, overall abundance in urban areas was more than double that of rural areas. There was almost a complete separation of rural and urban bird communities. Significantly more birds and more bird species were recorded in January compared to December. We conclude that differences between rural and urban areas in terms of winter conditions and the availability of resources are reflected in different bird communities in the two environments.

DNA barcode detects high genetic structure within neotropical bird species.

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Erika Sendra Tavares

Full Text Available BACKGROUND: Towards lower latitudes the number of recognized species is not only higher, but also phylogeographic subdivision within species is more pronounced. Moreover, new genetically isolated populations are often described in recent phylogenies of Neotropical birds suggesting that the number of species in the region is underestimated. Previous COI barcoding of Argentinean bird species showed more complex patterns of regional divergence in the Neotropical than in the North American avifauna. METHODS AND FINDINGS: Here we analyzed 1,431 samples from 561 different species to extend the Neotropical bird barcode survey to lower latitudes, and detected even higher geographic structure within species than reported previously. About 93% (520 of the species were identified correctly from their DNA barcodes. The remaining 41 species were not monophyletic in their COI sequences because they shared barcode sequences with closely related species (N = 21 or contained very divergent clusters suggestive of putative new species embedded within the gene tree (N = 20. Deep intraspecific divergences overlapping with among-species differences were detected in 48 species, often with samples from large geographic areas and several including multiple subspecies. This strong population genetic structure often coincided with breaks between different ecoregions or areas of endemism. CONCLUSIONS: The taxonomic uncertainty associated with the high incidence of non-monophyletic species and discovery of putative species obscures studies of historical patterns of species diversification in the Neotropical region. We showed that COI barcodes are a valuable tool to indicate which taxa would benefit from more extensive taxonomic revisions with multilocus approaches. Moreover, our results support hypotheses that the megadiversity of birds in the region is associated with multiple geographic processes starting well before the Quaternary and extending to more recent

Window area and development drive spatial variation in bird-window collisions in an urban landscape.

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Hager, Stephen B; Cosentino, Bradley J; McKay, Kelly J; Monson, Cathleen; Zuurdeeg, Walt; Blevins, Brian

2013-01-01

Collisions with windows are an important human-related threat to birds in urban landscapes. However, the proximate drivers of collisions are not well understood, and no study has examined spatial variation in mortality in an urban setting. We hypothesized that the number of fatalities at buildings varies with window area and habitat features that influence avian community structure. In 2010 we documented bird-window collisions (BWCs) and characterized avian community structure at 20 buildings in an urban landscape in northwestern Illinois, USA. For each building and season, we conducted 21 daily surveys for carcasses and nine point count surveys to estimate relative abundance, richness, and diversity. Our sampling design was informed by experimentally estimated carcass persistence times and detection probabilities. We used linear and generalized linear mixed models to evaluate how habitat features influenced community structure and how mortality was affected by window area and factors that correlated with community structure. The most-supported model was consistent for all community indices and included effects of season, development, and distance to vegetated lots. BWCs were related positively to window area and negatively to development. We documented mortalities for 16/72 (22%) species (34 total carcasses) recorded at buildings, and BWCs were greater for juveniles than adults. Based on the most-supported model of BWCs, the median number of annual predicted fatalities at study buildings was 3 (range = 0-52). These results suggest that patchily distributed environmental resources and levels of window area in buildings create spatial variation in BWCs within and among urban areas. Current mortality estimates place little emphasis on spatial variation, which precludes a fundamental understanding of the issue. To focus conservation efforts, we illustrate how knowledge of the structural and environmental factors that influence bird-window collisions can be used to

Window area and development drive spatial variation in bird-window collisions in an urban landscape.

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Stephen B Hager

Full Text Available Collisions with windows are an important human-related threat to birds in urban landscapes. However, the proximate drivers of collisions are not well understood, and no study has examined spatial variation in mortality in an urban setting. We hypothesized that the number of fatalities at buildings varies with window area and habitat features that influence avian community structure. In 2010 we documented bird-window collisions (BWCs and characterized avian community structure at 20 buildings in an urban landscape in northwestern Illinois, USA. For each building and season, we conducted 21 daily surveys for carcasses and nine point count surveys to estimate relative abundance, richness, and diversity. Our sampling design was informed by experimentally estimated carcass persistence times and detection probabilities. We used linear and generalized linear mixed models to evaluate how habitat features influenced community structure and how mortality was affected by window area and factors that correlated with community structure. The most-supported model was consistent for all community indices and included effects of season, development, and distance to vegetated lots. BWCs were related positively to window area and negatively to development. We documented mortalities for 16/72 (22% species (34 total carcasses recorded at buildings, and BWCs were greater for juveniles than adults. Based on the most-supported model of BWCs, the median number of annual predicted fatalities at study buildings was 3 (range = 0-52. These results suggest that patchily distributed environmental resources and levels of window area in buildings create spatial variation in BWCs within and among urban areas. Current mortality estimates place little emphasis on spatial variation, which precludes a fundamental understanding of the issue. To focus conservation efforts, we illustrate how knowledge of the structural and environmental factors that influence bird

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-...

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.

Comparative analysis of the intestinal bacterial and RNA viral communities from sentinel birds placed on selected broiler chicken farms.

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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

Discrete particle swarm optimization for identifying community structures in signed social networks.

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Cai, Qing; Gong, Maoguo; Shen, Bo; Ma, Lijia; Jiao, Licheng

2014-10-01

Modern science of networks has facilitated us with enormous convenience to the understanding of complex systems. Community structure is believed to be one of the notable features of complex networks representing real complicated systems. Very often, uncovering community structures in networks can be regarded as an optimization problem, thus, many evolutionary algorithms based approaches have been put forward. Particle swarm optimization (PSO) is an artificial intelligent algorithm originated from social behavior such as birds flocking and fish schooling. PSO has been proved to be an effective optimization technique. However, PSO was originally designed for continuous optimization which confounds its applications to discrete contexts. In this paper, a novel discrete PSO algorithm is suggested for identifying community structures in signed networks. In the suggested method, particles' status has been redesigned in discrete form so as to make PSO proper for discrete scenarios, and particles' updating rules have been reformulated by making use of the topology of the signed network. Extensive experiments compared with three state-of-the-art approaches on both synthetic and real-world signed networks demonstrate that the proposed method is effective and promising. Copyright © 2014 Elsevier Ltd. All rights reserved.

Linking snake behavior to nest predation in a Midwestern bird community.

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Weatherhead, Patrick J; Carfagno, Gerardo L F; Sperry, Jinelle H; Brawn, Jeffrey D; Robinson, Scott K

2010-01-01

Nest predators can adversely affect the viability of songbird populations, and their impact is exacerbated in fragmented habitats. Despite substantial research on this predator-prey interaction, however, almost all of the focus has been on the birds rather than their nest predators, thereby limiting our understanding of the factors that bring predators and nests into contact. We used radiotelemetry to document the activity of two snake species (rat snakes, Elaphe obsoleta; racers, Coluber constrictor) known to prey on nests in Midwestern bird communities and simultaneously monitored 300 songbird nests and tested the hypothesis that predation risk should increase for nests when snakes were more active and in edge habitat preferred by both snake species. Predation risk increased when rat snakes were more active, for all nests combined and for two of the six bird species for which we had sufficient nests to allow separate analyses. This result is consistent with rat snakes being more important nest predators than racers. We found no evidence, however, that nests closer to forest edges were at greater risk. These results are generally consistent with the one previous study that investigated rat snakes and nest predation simultaneously. The seemingly paradoxical failure to find higher predation risk in the snakes' preferred habitat (i.e., edge) might be explained by the snakes using edges at least in part for non-foraging activities. We propose that higher nest predation in fragmented habitats (at least that attributable to snakes) results indirectly from edges promoting larger snake populations, rather than from edges directly increasing the risk of nest predation by snakes. If so, the notion of edges per se functioning as ecological "traps" merits further study.

Bird communities in two fragments of semideciduos forest in rural São Paulo state

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D. D. Pozza

Full Text Available A quali-quantitative survey was done in two fragments (75 and 100 ha of semideciduous forest in rural São Paulo State. The aim was to characterize the bird community according to richness, abundance, and occurrence frequency in these areas. The qualitative survey showed 145 species in the Estação Ecológica de São Carlos - EESCar (Brotas - and 173 in the Fazenda Santa Cecília - FSC (Patrocínio Paulista, while the quantitative survey showed the presence of 60 and 72 species in EESCar and FSC respectively. The isolation and the lower environmental quality of the EESCar fragment may be responsible for the lower number of species in this area compared to that of FSC. Abundance index value analysis (IPA showed that both areas have a large number of species with low IPA and few species with intermediate or high IPA compared to the pattern observed in other surveys. At FSC, a larger number of occurrences of species in danger of extinction in São Paulo State was also observed. Apparently, the FSC fragment had better environmental quality for sheltering a larger number of species, including the endangered ones. The study of the community of birds is important in planning management and conservation of natural areas.

Bird communities in two fragments of semideciduos forest in rural São Paulo state

Directory of Open Access Journals (Sweden)

Pozza D. D.

2003-01-01

Full Text Available A quali-quantitative survey was done in two fragments (75 and 100 ha of semideciduous forest in rural São Paulo State. The aim was to characterize the bird community according to richness, abundance, and occurrence frequency in these areas. The qualitative survey showed 145 species in the Estação Ecológica de São Carlos - EESCar (Brotas - and 173 in the Fazenda Santa Cecília - FSC (Patrocínio Paulista, while the quantitative survey showed the presence of 60 and 72 species in EESCar and FSC respectively. The isolation and the lower environmental quality of the EESCar fragment may be responsible for the lower number of species in this area compared to that of FSC. Abundance index value analysis (IPA showed that both areas have a large number of species with low IPA and few species with intermediate or high IPA compared to the pattern observed in other surveys. At FSC, a larger number of occurrences of species in danger of extinction in São Paulo State was also observed. Apparently, the FSC fragment had better environmental quality for sheltering a larger number of species, including the endangered ones. The study of the community of birds is important in planning management and conservation of natural areas.

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

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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.

Bird communities as indicators of the impact of changes in agriculture in the Mar Menor catchment area (Murcia, SE Spain)

International Nuclear Information System (INIS)

Farinos, P.; Robledano, F.; Jimenez, M. V.; Zapata Perez, V. M.

2009-01-01

Mediterranean coastal landscapes have suffered significant changes along the last decades due to agricultural intensification and tourism, that have altered the hydrological regime of wetland, as ha occurred in the Mar Menor (Southeast Spain). Such alterations and the consequent changes in nutrient flows are threatening the conservation of these wetlands. We analyze the effects of these ecosystems changes on the bird assemblages, focusing on two especially sensitive communities: water birds and steppe passerines. (Author) 2 refs.

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

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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.

Effects of drought on avian community structure

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Thomas P. Albright; Anna M. Pidgeon; Chadwick D. Rittenhouse; Murray K. Clayton; Curtis H. Flather; Patrick D. Culbert; Brian D. Wardlow; Volker C. Radeloff

2010-01-01

Droughts are expected to become more frequent under global climate change. Avifauna depend on precipitation for hydration, cover, and food. While there are indications that avian communities respond negatively to drought, little is known about the response of birds with differing functional and behavioural traits, what time periods and indicators of drought are most...

Insectivorous Birds and Environmental Factors Across an Edge-Interior Gradient in Tropical Rainforest of Malaysia

OpenAIRE

Abdullah B. Mohd; Mohamed Zakaria; Hossein Varasteh Moradi; Ebil Yusof

2009-01-01

The study objectives were to test: (1) the effects of the edge-interior gradient on understorey insectivorous bird abundance, density and diversity; (2) effects of environmental variables along an edge-interior gradient at population level (i.e., on each sub-guilds and species abundance); (3) possible effects of environmental structure along an edge-interior gradient at community level (i.e., species richness, diversity and total abundance). Fifteen hundred and four birds belonging to ...

Bird community conservation and carbon offsets in western North America.

Science.gov (United States)

Schuster, Richard; Martin, Tara G; Arcese, Peter

2014-01-01

Conservation initiatives to protect and restore valued species and communities in human-dominated landscapes face huge challenges linked to the cost of acquiring habitat. We ask how the sale of forest carbon offsets could reduce land acquisition costs, and how the alternate goals of maximizing α or β-diversity in focal communities could affect the prioritization land parcels over a range of conservation targets. Maximizing total carbon storage and carbon sequestration potential reduced land acquisition costs by up to 48%. Maximizing β rather than α-diversity within forest and savannah bird communities reduced acquisition costs by up to 15%, and when these solutions included potential carbon credit revenues, acquisition cost reductions up to 32% were achieved. However, the total cost of conservation networks increased exponentially as area targets increased in all scenarios. Our results indicate that carbon credit sales have the potential to enhance conservation outcomes in human-dominated landscapes by reducing the net acquisition costs of land conservation in old and maturing forests essential for the persistence of old forest plant and animal communities. Maximizing β versus α-diversity may further reduce costs by reducing the total area required to meet conservation targets and enhancing landscape heterogeneity. Although the potential value of carbon credit sales declined as a fraction of total acquisition costs, even conservative scenarios using a carbon credit value of $12.5/T suggest reductions in acquisition cost of up to $235 M, indicating that carbon credit sales could substantially reduce the costs of conservation.

Opposing Responses of Bird Functional Diversity to Vegetation Structural Diversity in Wet and Dry Forest.

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Holly Sitters

Full Text Available Disturbance regimes are changing worldwide, and the consequences for ecosystem function and resilience are largely unknown. Functional diversity (FD provides a surrogate measure of ecosystem function by capturing the range, abundance and distribution of trait values in a community. Enhanced understanding of the responses of FD to measures of vegetation structure at landscape scales is needed to guide conservation management. To address this knowledge gap, we used a whole-of-landscape sampling approach to examine relationships between bird FD, vegetation diversity and time since fire. We surveyed birds and measured vegetation at 36 landscape sampling units in dry and wet forest in southeast Australia during 2010 and 2011. Four uncorrelated indices of bird FD (richness, evenness, divergence and dispersion were derived from six bird traits, and we investigated responses of these indices and species richness to both vertical and horizontal vegetation diversity using linear mixed models. We also considered the extent to which the mean and diversity of time since fire were related to vegetation diversity. Results showed opposing responses of FD to vegetation diversity in dry and wet forest. In dry forest, where fire is frequent, species richness and two FD indices (richness and dispersion were positively related to vertical vegetation diversity, consistent with theory relating to environmental variation and coexistence. However, in wet forest subject to infrequent fire, the same three response variables were negatively associated with vertical diversity. We suggest that competitive dominance by species results in lower FD as vegetation diversity increases in wet forest. The responses of functional evenness were opposite to those of species richness, functional richness and dispersion in both forest types, highlighting the value of examining multiple FD metrics at management-relevant scales. The mean and diversity of time since fire were uncorrelated

Opposing Responses of Bird Functional Diversity to Vegetation Structural Diversity in Wet and Dry Forest.

Science.gov (United States)

Sitters, Holly; York, Alan; Swan, Matthew; Christie, Fiona; Di Stefano, Julian

2016-01-01

Disturbance regimes are changing worldwide, and the consequences for ecosystem function and resilience are largely unknown. Functional diversity (FD) provides a surrogate measure of ecosystem function by capturing the range, abundance and distribution of trait values in a community. Enhanced understanding of the responses of FD to measures of vegetation structure at landscape scales is needed to guide conservation management. To address this knowledge gap, we used a whole-of-landscape sampling approach to examine relationships between bird FD, vegetation diversity and time since fire. We surveyed birds and measured vegetation at 36 landscape sampling units in dry and wet forest in southeast Australia during 2010 and 2011. Four uncorrelated indices of bird FD (richness, evenness, divergence and dispersion) were derived from six bird traits, and we investigated responses of these indices and species richness to both vertical and horizontal vegetation diversity using linear mixed models. We also considered the extent to which the mean and diversity of time since fire were related to vegetation diversity. Results showed opposing responses of FD to vegetation diversity in dry and wet forest. In dry forest, where fire is frequent, species richness and two FD indices (richness and dispersion) were positively related to vertical vegetation diversity, consistent with theory relating to environmental variation and coexistence. However, in wet forest subject to infrequent fire, the same three response variables were negatively associated with vertical diversity. We suggest that competitive dominance by species results in lower FD as vegetation diversity increases in wet forest. The responses of functional evenness were opposite to those of species richness, functional richness and dispersion in both forest types, highlighting the value of examining multiple FD metrics at management-relevant scales. The mean and diversity of time since fire were uncorrelated with vegetation

Organic matter quantity and source affects microbial community structure and function following volcanic eruption on Kasatochi Island, Alaska

Science.gov (United States)

Zeglin, Lydia H.; Wang, Bronwen; Waythomas, Christopher F.; Rainey, Frederick; Talbot, Sandra L.

2016-01-01

In August 2008, Kasatochi volcano erupted and buried a small island in pyroclastic deposits and fine ash; since then, microbes, plants and birds have begun to re-colonize the initially sterile surface. Five years post-eruption, bacterial 16S rRNA gene and fungal internal transcribed spacer (ITS) copy numbers and extracellular enzyme activity (EEA) potentials were one to two orders of magnitude greater in pyroclastic materials with organic matter (OM) inputs relative to those without, despite minimal accumulation of OM (eruptive surfaces with OM inputs had the highest β-glucosidase, phosphatase, NAGase and cellobiohydrolase activities, and had microbial population sizes approaching those in reference soils. In contrast, the strongest factor determining bacterial community composition was the dominance of plants versus birds as OM input vectors. Although soil pH ranged from 3.9 to 7.0, and %C ranged 100×, differentiation between plant- and bird-associated microbial communities suggested that cell dispersal or nutrient availability are more likely drivers of assembly than pH or OM content. This study exemplifies the complex relationship between microbial cell dispersal, soil geochemistry, and microbial structure and function; and illustrates the potential for soil microbiota to be resilient to disturbance.

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

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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.

Ecological traits influence the phylogenetic structure of bird species co-occurrences worldwide

NARCIS (Netherlands)

Barnagaud, J.-Y.; Kissling, W.D.; Sandel, B.; Eiserhardt, W.L.; Şekercioğlu, Ç.H.; Enquist, B.J.; Tsirogiannis, C.; Svenning, J.-C.

2014-01-01

The extent to which species’ ecological and phylogenetic relatedness shape their co-occurrence patterns at large spatial scales remains poorly understood. By quantifying phylogenetic assemblage structure within geographic ranges of >8000 bird species, we show that global co-occurrence patterns are

A method for evaluating land conservation value by means of a bird community analysis; Valutazione dell`integrita` ecologica del territorio mediante l`analisi di comunita` di uccelli

Energy Technology Data Exchange (ETDEWEB)

Fornasari, Lorenzo; De Carli, Elisabetta; Bottoni, Luciana; Massa, Renato [Milan, Univ. (Italy). Dipt. di Scenze dell`Ambiente e del Territorio

1997-06-01

The present planetary crisis of species extinction is mainly due to habitat loss. Therefore, for its mitigation, it is imperative to identify areas of major conservation concern. To this end, they analysed bird community data, by selecting samples randomly over a large study area. They subjected the samples collected to a cluster analysis to identify `a posteriori` bird communities to be indexed together with their habitats associated. They identified 15 bird community types and were able to characterise each of them by a community conservation index (CCI) taking into account three different components of rarity: habitat selectivity, geographical distribution and abundance. A cluster of four communities was associated with lowland farmland and woodland; another cluster of five was found at higher average altitudes and degree of urbanization; a third one of six showed a montane distribution. This third cluster showed much higher CCI in comparison with the first two. As a conservation tool, CCI points out the events in which selectivity is high and geographical distribution / abundance is restricted. In the study area (the whole of Lombardy) they found that the communities showing high CCI values are mostly associated with habitats of marginal value for human use.

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)

Natural windbreaks sustain bird diversity in a tea-dominated landscape.

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Rachakonda Sreekar

Full Text Available Windbreaks often form networks of forest habitats that improve connectivity and thus conserve biodiversity, but little is known of such effects in the tropics. We determined bird species richness and community composition in windbreaks composed of remnant native vegetation amongst tea plantations (natural windbreaks, and compared it with the surrounding primary forests. Fifty-one, ten-minute point counts were conducted in each habitat type over three days. Despite the limited sampling period, our bird inventories in both natural windbreaks and primary forests were nearly complete, as indicated by bootstrap true richness estimator. Bird species richness and abundance between primary forests and windbreaks were similar, however a difference in bird community composition was observed. Abundances of important functional groups such as frugivores and insectivores did not vary between habitat types but nectarivores were more abundant in windbreaks, potentially as a result of the use of windbreaks as traveling routes, foraging and nesting sites. This preliminary study suggests that natural windbreaks may be important habitats for the persistence of bird species in a production landscape. However, a better understanding of the required physical and compositional characteristics for windbreaks to sustain bird communities is needed for effective conservation management.

Structure and mechanical behavior of bird beaks

Science.gov (United States)

Seki, Yasuaki

The structure and mechanical behavior of Toco toucan (Ramphastos toco) and Wreathed hornbill (Rhyticeros undulatus) beaks were examined. The structure of Toco toucan and Wreathed hornbill beak was found to be a sandwich composite with an exterior of keratin and a fibrous bony network of closed cells made of trabeculae. A distinctive feature of the hornbill beak is its casque formed from cornified keratin layers. The casque is believed to have an acoustic function due to the complex internal structure. The toucan and hornbill beaks have a hollow region that extends from proximal to mid-section. The rhamphotheca is comprised of super-posed polygonal scales (45 mum diameter and 1 mum thickness) fixed by some organic adhesive. The branched intermediate filaments embedded in keratin matrix were discovered by transmission electron microscopy (TEM). The diameter of intermediate laments was ~10 nm. The orientation of intermediate filaments was examined with TEM tomography and the branched filaments were homogeneously distributed. The closed-cell foam is comprised of the fibrous structure of bony struts with an edge connectivity of three or four and the cells are sealed off by the thin membranes. The volumetric structure of bird beak foam was reproduced by computed tomography for finite element modeling.

Street trees reduce the negative effects of urbanization on birds.

Science.gov (United States)

Pena, João Carlos de Castro; Martello, Felipe; Ribeiro, Milton Cezar; Armitage, Richard A; Young, Robert J; Rodrigues, Marcos

2017-01-01

The effects of streets on biodiversity is an important aspect of urban ecology, but it has been neglected worldwide. Several vegetation attributes (e.g. street tree density and diversity) have important effects on biodiversity and ecological processes. In this study, we evaluated the influences of urban vegetation-represented by characteristics of street trees (canopy size, proportion of native tree species and tree species richness)-and characteristics of the landscape (distance to parks and vegetation quantity), and human impacts (human population size and exposure to noise) on taxonomic data and functional diversity indices of the bird community inhabiting streets. The study area was the southern region of Belo Horizonte (Minas Gerais, Brazil), a largely urbanized city in the understudied Neotropical region. Bird data were collected on 60 point count locations distributed across the streets of the landscape. We used a series of competing GLM models (using Akaike's information criterion for small sample sizes) to assess the relative contribution of the different sets of variables to explain the observed patterns. Seventy-three bird species were observed exploiting the streets: native species were the most abundant and frequent throughout this landscape. The bird community's functional richness and Rao's Quadratic Entropy presented values lower than 0.5. Therefore, this landscape was favoring few functional traits. Exposure to noise was the most limiting factor for this bird community. However, the average size of arboreal patches and, especially the characteristics of street trees, were able to reduce the negative effects of noise on the bird community. These results show the importance of adequately planning the urban afforestation process: increasing tree species richness, preserving large trees and planting more native trees species in the streets are management practices that will increase bird species richness, abundance and community functional aspects and

Leveraging disjoint communities for detecting overlapping community structure

International Nuclear Information System (INIS)

Chakraborty, Tanmoy

2015-01-01

Network communities represent mesoscopic structure for understanding the organization of real-world networks, where nodes often belong to multiple communities and form overlapping community structure in the network. Due to non-triviality in finding the exact boundary of such overlapping communities, this problem has become challenging, and therefore huge effort has been devoted to detect overlapping communities from the network.In this paper, we present PVOC (Permanence based Vertex-replication algorithm for Overlapping Community detection), a two-stage framework to detect overlapping community structure. We build on a novel observation that non-overlapping community structure detected by a standard disjoint community detection algorithm from a network has high resemblance with its actual overlapping community structure, except the overlapping part. Based on this observation, we posit that there is perhaps no need of building yet another overlapping community finding algorithm; but one can efficiently manipulate the output of any existing disjoint community finding algorithm to obtain the required overlapping structure. We propose a new post-processing technique that by combining with any existing disjoint community detection algorithm, can suitably process each vertex using a new vertex-based metric, called permanence, and thereby finds out overlapping candidates with their community memberships. Experimental results on both synthetic and large real-world networks show that PVOC significantly outperforms six state-of-the-art overlapping community detection algorithms in terms of high similarity of the output with the ground-truth structure. Thus our framework not only finds meaningful overlapping communities from the network, but also allows us to put an end to the constant effort of building yet another overlapping community detection algorithm. (paper)

Structure and composition of woody vegetation in two important bird areas in southern Zimbabwe

NARCIS (Netherlands)

Gandiwa, P.; Chinoitezvi, E.; Gandiwa, E.

2013-01-01

This study assessed the status of woody vegetation structure and composition in two Important Bird Areas (IBA) i.e. Manjinji Pan and Save-Runde Junction located in southeastern Zimbabwe. The objectives of this study were to: (i) determine the woody vegetation structure and composition of the study

SPECIES DIVERSITY AND STABILITY OF BIRD COMMUNITIES

Directory of Open Access Journals (Sweden)

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.

At the Crossroads: Does the Configuration of Roadside Vegetation Affect Woodland Bird Communities in Rural Landscapes?

Science.gov (United States)

Hall, Mark; Nimmo, Dale; Bennett, Andrew F.

2016-01-01

In agricultural regions worldwide, linear networks of vegetation such as hedges, fencerows and live fences provide habitat for plant and animal species in heavily modified landscapes. In Australia, networks of remnant native vegetation along roadsides are a distinctive feature of many rural landscapes. Here, we investigated the richness and composition of woodland-dependent bird communities in networks of eucalypt woodland vegetation along roadsides, in an agricultural region in which >80% of native woodland and forest vegetation has been cleared. We stratified sites in a) cross sections and b) linear strips of roadside vegetation, to test the influence on woodland birds of site location and configuration in the linear network (the ‘intersection effect’). We also examined the influence of tree size at the site, the amount of wooded vegetation surrounding the site, and the abundance of an aggressive native species, the noisy miner Manorina melanocephala. Birds were surveyed at 26 pairs of sites (cross section or linear strip) on four occasions. A total of 66 species was recorded, including 35 woodland species. The richness of woodland bird species was influenced by site configuration, with more species present at cross sections, particularly those with larger trees (>30 cm diameter). However, the strongest influence on species richness was the relative abundance of the noisy miner. The richness of woodland birds at sites where noisy miners were abundant was ~20% of that where miners were absent. These results recognise the value of networks of roadside vegetation as habitat for woodland birds in depleted agricultural landscapes; but highlight that this value is not realised for much of this vast vegetation network because of the dominance of the noisy miner. Nevertheless, roadside vegetation is particularly important where the configuration of networks create nodes that facilitate movement. Globally, the protection, conservation and restoration of such linear

At the Crossroads: Does the Configuration of Roadside Vegetation Affect Woodland Bird Communities in Rural Landscapes?

Science.gov (United States)

Hall, Mark; Nimmo, Dale; Bennett, Andrew F

2016-01-01

In agricultural regions worldwide, linear networks of vegetation such as hedges, fencerows and live fences provide habitat for plant and animal species in heavily modified landscapes. In Australia, networks of remnant native vegetation along roadsides are a distinctive feature of many rural landscapes. Here, we investigated the richness and composition of woodland-dependent bird communities in networks of eucalypt woodland vegetation along roadsides, in an agricultural region in which >80% of native woodland and forest vegetation has been cleared. We stratified sites in a) cross sections and b) linear strips of roadside vegetation, to test the influence on woodland birds of site location and configuration in the linear network (the 'intersection effect'). We also examined the influence of tree size at the site, the amount of wooded vegetation surrounding the site, and the abundance of an aggressive native species, the noisy miner Manorina melanocephala. Birds were surveyed at 26 pairs of sites (cross section or linear strip) on four occasions. A total of 66 species was recorded, including 35 woodland species. The richness of woodland bird species was influenced by site configuration, with more species present at cross sections, particularly those with larger trees (>30 cm diameter). However, the strongest influence on species richness was the relative abundance of the noisy miner. The richness of woodland birds at sites where noisy miners were abundant was ~20% of that where miners were absent. These results recognise the value of networks of roadside vegetation as habitat for woodland birds in depleted agricultural landscapes; but highlight that this value is not realised for much of this vast vegetation network because of the dominance of the noisy miner. Nevertheless, roadside vegetation is particularly important where the configuration of networks create nodes that facilitate movement. Globally, the protection, conservation and restoration of such linear

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.

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.

Keeping Hawai’i’s forest birds one step ahead of avian diseases in a warming world: a focus on Hakalau Forest National Wildlife Refuge. A case study from the National Conservation and Training Center Structured Decision Making Workshop

Science.gov (United States)

Paxton, Eben H.; Burgett, Jeff; McDonald-Fadden, Eve; Bean, Ellen; Atkinson, Carter T.; Ball, Donna; Cole, Colleen; Crampton, Lisa H.; Kraus, Jim; LaPointe, Dennis A.; Mehrhoff, Loyal; Samuel, Michael D.; Brewer, Donna; Converse, Sarah J.; Morey, Steve

2011-01-01

This report is a product of a one-week workshop on using Structured Decision Making to identify and prioritize conservation actions to address the threat of climate change on Hawaii‟s native forest bird community. Specifically, t his report addresses the issue of global warming ‟s likely role in increasing disease prevalence in upper elevation forests of Hawaii, negatively impacting native bird populations susceptible to the disease but currently disease - free because of the cooler temperatures at high elevations. 

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

Directory of Open Access Journals (Sweden)

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

Spatially modulated structural colour in bird feathers

Science.gov (United States)

Parnell, Andrew J.; Washington, Adam L.; Mykhaylyk, Oleksandr O.; Hill, Christopher J.; Bianco, Antonino; Burg, Stephanie L.; Dennison, Andrew J. C.; Snape, Mary; Cadby, Ashley J.; Smith, Andrew; Prevost, Sylvain; Whittaker, David M.; Jones, Richard A. L.; Fairclough, J. Patrick. A.; Parker, Andrew R.

2015-12-01

Eurasian Jay (Garrulus glandarius) feathers display periodic variations in the reflected colour from white through light blue, dark blue and black. We find the structures responsible for the colour are continuous in their size and spatially controlled by the degree of spinodal phase separation in the corresponding region of the feather barb. Blue structures have a well-defined broadband ultra-violet (UV) to blue wavelength distribution; the corresponding nanostructure has characteristic spinodal morphology with a lengthscale of order 150 nm. White regions have a larger 200 nm nanostructure, consistent with a spinodal process that has coarsened further, yielding broader wavelength white reflectance. Our analysis shows that nanostructure in single bird feather barbs can be varied continuously by controlling the time the keratin network is allowed to phase separate before mobility in the system is arrested. Dynamic scaling analysis of the single barb scattering data implies that the phase separation arrest mechanism is rapid and also distinct from the spinodal phase separation mechanism i.e. it is not gelation or intermolecular re-association. Any growing lengthscale using this spinodal phase separation approach must first traverse the UV and blue wavelength regions, growing the structure by coarsening, resulting in a broad distribution of domain sizes.

Spatially modulated structural colour in bird feathers.

Science.gov (United States)

Parnell, Andrew J; Washington, Adam L; Mykhaylyk, Oleksandr O; Hill, Christopher J; Bianco, Antonino; Burg, Stephanie L; Dennison, Andrew J C; Snape, Mary; Cadby, Ashley J; Smith, Andrew; Prevost, Sylvain; Whittaker, David M; Jones, Richard A L; Fairclough, J Patrick A; Parker, Andrew R

2015-12-21

Eurasian Jay (Garrulus glandarius) feathers display periodic variations in the reflected colour from white through light blue, dark blue and black. We find the structures responsible for the colour are continuous in their size and spatially controlled by the degree of spinodal phase separation in the corresponding region of the feather barb. Blue structures have a well-defined broadband ultra-violet (UV) to blue wavelength distribution; the corresponding nanostructure has characteristic spinodal morphology with a lengthscale of order 150 nm. White regions have a larger 200 nm nanostructure, consistent with a spinodal process that has coarsened further, yielding broader wavelength white reflectance. Our analysis shows that nanostructure in single bird feather barbs can be varied continuously by controlling the time the keratin network is allowed to phase separate before mobility in the system is arrested. Dynamic scaling analysis of the single barb scattering data implies that the phase separation arrest mechanism is rapid and also distinct from the spinodal phase separation mechanism i.e. it is not gelation or intermolecular re-association. Any growing lengthscale using this spinodal phase separation approach must first traverse the UV and blue wavelength regions, growing the structure by coarsening, resulting in a broad distribution of domain sizes.

9 CFR 93.104 - Certificate for pet birds, commercial birds, zoological birds, and research birds.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Certificate for pet birds, commercial birds, zoological birds, and research birds. 93.104 Section 93.104 Animals and Animal Products ANIMAL... (INCLUDING POULTRY) AND ANIMAL PRODUCTS IMPORTATION OF CERTAIN ANIMALS, BIRDS, FISH, AND POULTRY, AND CERTAIN...

Virginia ESI: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, pelagic birds, passerine birds, and gulls...

Terrestrial liming benefits birds in an acidified forest in the northeast.

Science.gov (United States)

Pabian, Sarah E; Brittingham, Margaret C

2007-12-01

Studies in Europe have reported negative effects of acid deposition on forest birds, and research in North America has identified links between forest bird abundance and rates of acid deposition. We examined the bird community in an acidified forest in central Pennsylvania (USA) and evaluated the effects of terrestrial lime application on birds. We used a before-after control-impact (BACI) study design, with one year of observation before (2003) and three years after lime application (2004, 2005, and 2006). Between the 2003 and 2004 field seasons, 4500 kg/ha of dolomitic lime were applied to two of four 100-ha watersheds. Each year, we monitored bird abundance and Ovenbird (Seiurus aurocapilla) eggshell thickness and territory size. Soil and snail abundance data were also collected. The bird community and territory size results indicated that the study area may be providing low-quality habitat for forest birds, perhaps as a result of acid deposition. We found lower forest bird abundances than have been found in less acidified areas of Pennsylvania, and larger Ovenbird territory sizes than have been found in other studies. We found a significant positive relationship between soil calcium and bird abundance, indicating that soil calcium may affect bird abundance. Liming increased soil calcium and pH and led to increased snail and bird abundances. After liming, bird abundance was positively related to snail abundance. No significant changes occurred in Ovenbird territory size or eggshell thickness. Our results suggest that acid deposition could be responsible for reduced bird abundance, and that liming is a potential mitigation technique.

Heterogeneous Landscapes on Steep Slopes at Low Altitudes as Hotspots of Bird Diversity in a Hilly Region of Nepal in the Central Himalayas

Czech Academy of Sciences Publication Activity Database

Basnet, T. B.; Rokaya, Maan Bahadur; Bhattarai, B. P.; Münzbergová, Z.

2016-01-01

Roč. 11, č. 3 (2016), č. článku e0150498. E-ISSN 1932-6203 R&D Projects: GA ČR GB14-36098G Institutional support: RVO:67179843 Keywords : species richness * elevational gradient * habitat heterogeneity * insectivorous birds * forest birds * vegetation structure * protected areas * lowland Nepal * communities * patterns Subject RIV: EH - Ecology, Behaviour Impact factor: 2.806, year: 2016

Birds of a high-altitude cloud forest in Alta Verapaz, Guatemala.

Science.gov (United States)

Eisermann, Knut; Schulz, Ulrich

2005-01-01

The Northern Central American Highlands have been recognized as endemic bird area, but little is known about bird communities in Guatemalan cloud forests. From 1997 to 2001 a total of 142 bird species were recorded between 2000 and 2400 masl in cloud forest and agricultural clearings on Montaña Caquipec (Alta Verapaz, Guatemala). The bird community is described based on line transect counts within the forest. Pooling census data from undisturbed and disturbed forest, the Gray-breasted Wood-Wren (Henicorhina leucophrys) was found to be the most abundant species, followed in descending order by the Common Bush-Tanager (Chlorospingus ophthalmicus), the Paltry Tyrannulet (Zimmerius vilissimus), the Yellowish Flycatcher (Empidonax flavescens), the Ruddy-capped Nightingale-Thrush (Catharus frantzi), and the Amethyst-throated Hummingbird (Lampornis amethystinus). Bird communities in undisturbed and disturbed forest were found to be similar (Serensen similarity index 0.85), indicating low human impact. Of all recorded species, approximately 27% were Nearctic-Neotropical migratory birds. The most abundant one was the Wilson's Warbler (Wilsonia pusilla). The Montaña Caquipec is an important area for bird conservation, which is indicated by the presence of four species listed in the IUCN Red List (Highland Guan Penelopina nigra, Resplendent Quetzal Pharomachrus mocinno, Pink-headed Warbler Ergaticus versicolor, Golden-cheeked Warbler Dendroica chrysoparia), and 42 Mesoamerican endemics, of which 14 species are endemic to the Central American Highlands. The results presented here will be useful as baseline data for a long-term monitoring.

Bird mortality associated with wind turbines at the Buffalo Ridge wind resource area, Minnesota

Science.gov (United States)

Osborn, R.G.; Higgins, K.F.; Usgaard, R.E.; Dieter, C.D.; Neiger, R.D.

2000-01-01

Recent technological advances have made wind power a viable source of alternative energy production and the number of windplant facilities has increased in the United States. Construction was completed on a 73 turbine, 25 megawatt windplant on Buffalo Ridge near Lake Benton, Minnesota in Spring 1994. The number of birds killed at existing windplants in California caused concern about the potential impacts of the Buffalo Ridge facility on the avian community. From April 1994 through Dec. 1995 we searched the Buffalo Ridge windplant site for dead birds. Additionally, we evaluated search efficiency, predator scavenging rates and rate of carcass decomposition. During 20 mo of monitoring we found 12 dead birds. Collisions with wind turbines were suspected for 8 of the 12 birds. During observer efficiency trials searchers found 78.8% of carcasses. Scavengers removed 39.5% of carcasses during scavenging trials. All carcasses remained recognizable during 7 d decomposition trials. After correction for biases we estimated that approximately 36 ?? 12 birds (bird per turbine) were killed at the Buffalo Ridge windplant in 1 y. Although windplants do not appear to be more detrimental to birds than other man-made structures, proper facility sitting is an important first consideration in order to avoid unnecessary fatalities.

Calcium metabolism in birds.

Science.gov (United States)

de Matos, Ricardo

2008-01-01

Calcium is one of the most important plasma constituents in mammals and birds. It provides structural strength and support (bones and eggshell) and plays vital roles in many of the biochemical reactions in the body. The control of calcium metabolism in birds is highly efficient and closely regulated in a number of tissues, primarily parathyroid gland, intestine, kidney, and bone. The hormones with the greatest involvement in calcium regulation in birds are parathyroid hormone, 1,25-dihydroxyvitamin D(3) (calcitriol), and estrogen, with calcitonin playing a minor and uncertain role. The special characteristics of calcium metabolism in birds, mainly associated with egg production, are discussed, along with common clinical disorders secondary to derangements in calcium homeostasis.

The heterogeneity of wooded-agricultural landscape mosaics influences woodland bird community assemblages

OpenAIRE

Neumann, Jessica L.; Griffiths, Geoffrey H.; Foster, Christopher W.; Holloway, Graham J.

2016-01-01

Context\\ud Landscape heterogeneity (the composition and configuration of different landcover types) plays a key role in shaping woodland bird assemblages in wooded-agricultural mosaics. Understanding how species respond to landscape factors could contribute to preventing further decline of woodland bird populations.\\ud Objective\\ud To investigate how woodland birds with different species traits respond to landscape heterogeneity, and to identify whether specific landcover types are important ...

Bird communities following high-severity fire: Response to single and repeat fires in a mixed-evergreen forest, Oregon, USA

Science.gov (United States)

Joseph B. Fontaine; Daniel C. Donato; W. Douglas Robinson; Beverly E. Law; J. Boone Kauffman

2009-01-01

Fire is a widespread natural disturbance agent in most conifer-dominated forests. In light of climate change and the effects of fire exclusion, single and repeated high-severity (stand-replacement) fires have become prominent land management issues. We studied bird communities using point counting in the Klamath-Siskiyou ecoregion of Oregon, USA at various points in...

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

Directory of Open Access Journals (Sweden)

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.

Extreme genetic structure in a social bird species despite high dispersal capacity.

Science.gov (United States)

Morinha, Francisco; Dávila, José A; Bastos, Estela; Cabral, João A; Frías, Óscar; González, José L; Travassos, Paulo; Carvalho, Diogo; Milá, Borja; Blanco, Guillermo

2017-05-01

Social barriers have been shown to reduce gene flow and contribute to genetic structure among populations in species with high cognitive capacity and complex societies, such as cetaceans, apes and humans. In birds, high dispersal capacity is thought to prevent population divergence unless major geographical or habitat barriers induce isolation patterns by dispersal, colonization or adaptation limitation. We report that Iberian populations of the red-billed chough, a social, gregarious corvid with high dispersal capacity, show a striking degree of genetic structure composed of at least 15 distinct genetic units. Monitoring of marked individuals over 30 years revealed that long-distance movements over hundreds of kilometres are common, yet recruitment into breeding populations is infrequent and highly philopatric. Genetic differentiation is weakly related to geographical distance, and habitat types used are overall qualitatively similar among regions and regularly shared by individuals of different populations, so that genetic structure is unlikely to be due solely to isolation by distance or isolation by adaptation. Moreover, most population nuclei showed relatively high levels of genetic diversity, suggesting a limited role for genetic drift in significantly differentiating populations. We propose that social mechanisms may underlie this unprecedented level of genetic structure in birds through a pattern of isolation by social barriers not yet described, which may have driven this remarkable population divergence in the absence of geographical and environmental barriers. © 2017 John Wiley & Sons Ltd.

How does vegetation structure influence woodpeckers and secondary cavity nesting birds in African cork oak forest?

Science.gov (United States)

Segura, Amalia

2017-08-01

The Great Spotted Woodpecker provides important information about the status of a forest in terms of structure and age. As a primary cavity creator, it provides small-medium size cavities for passerines. However, despite its interest as an ecosystem engineer, studies of this species in Africa are scarce. Here, spatially explicit predictive models were used to investigate how forest structural variables are related to both the Great Spotted Woodpecker and secondary cavity nesting birds in Maamora cork oak forest (northwest Morocco). A positive association between Great Spotted Woodpecker and both dead-tree density and large mature trees (>60 cm dbh) was found. This study area, Maamora, has an old-growth forest structure incorporating a broad range of size and condition of live and dead trees, favouring Great Spotted Woodpecker by providing high availability of foraging and excavating sites. Secondary cavity nesting birds, represented by Great Tit, African Blue Tit, and Hoopoe, were predicted by Great Spotted Woodpecker detections. The findings suggest that the conservation of the Maamora cork oak forest could be key to maintaining these hole-nesting birds. However, this forest is threatened by forestry practises and livestock overgrazing and the challenge is therefore to find sustainable management strategies that ensure conservation while allowing its exploitation.

Effects of high latitude protected areas on bird communities under rapid climate change.

Science.gov (United States)

Santangeli, Andrea; Rajasärkkä, Ari; Lehikoinen, Aleksi

2017-06-01

Anthropogenic climate change is rapidly becoming one of the main threats to biodiversity, along with other threats triggered by human-driven land-use change. Species are already responding to climate change by shifting their distributions polewards. This shift may create a spatial mismatch between dynamic species distributions and static protected areas (PAs). As protected areas represent one of the main pillars for preserving biodiversity today and in the future, it is important to assess their contribution in sheltering the biodiversity communities, they were designated to protect. A recent development to investigate climate-driven impacts on biological communities is represented by the community temperature index (CTI). CTI provides a measure of the relative temperature average of a community in a specific assemblage. CTI value will be higher for assemblages dominated by warm species compared with those dominated by cold-dwelling species. We here model changes in the CTI of Finnish bird assemblages, as well as changes in species densities, within and outside of PAs during the past four decades in a large boreal landscape under rapid change. We show that CTI has markedly increased over time across Finland, with this change being similar within and outside PAs and five to seven times slower than the temperature increase. Moreover, CTI has been constantly lower within than outside of PAs, and PAs still support communities, which show colder thermal index than those outside of PAs in the 1970s and 1980s. This result can be explained by the higher relative density of northern species within PAs than outside. Overall, our results provide some, albeit inconclusive, evidence that PAs may play a role in supporting the community of northern species. Results also suggest that communities are, however, shifting rapidly, both inside and outside of PAs, highlighting the need for adjusting conservation measures before it is too late. © 2016 John Wiley & Sons Ltd.

Resilience and stability in bird guilds across tropical countryside

Science.gov (United States)

Karp, Daniel S.; Ziv, Guy; Zook, Jim; Ehrlich, Paul R.; Daily, Gretchen C.

2011-01-01

The consequences of biodiversity decline in intensified agricultural landscapes hinge on surviving biotic assemblages. Maintaining crucial ecosystem processes and services requires resilience to natural and anthropogenic disturbances. However, the resilience and stability of surviving biological communities remain poorly quantified. From a 10-y dataset comprising 2,880 bird censuses across a land-use gradient, we present three key findings concerning the resilience and stability of Costa Rican bird communities. First, seed dispersing, insect eating, and pollinating guilds were more resilient to low-intensity land use than high-intensity land use. Compared with forest assemblages, bird abundance, species richness, and diversity were all ∼15% lower in low-intensity land use and ∼50% lower in high-intensity land use. Second, patterns in species richness generally correlated with patterns in stability: guilds exhibited less variation in abundance in low-intensity land use than in high-intensity land use. Finally, interspecific differences in reaction to environmental change (response diversity) and possibly the portfolio effect, but not negative covariance of species abundances, conferred resilience and stability. These findings point to the changes needed in agricultural production practices in the tropics to better sustain bird communities and, possibly, the functional and service roles that they play. PMID:22160726

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

The Use of Various Vegetation Level by Bird Community on Mbarek Spring, Gedangan, Malang

Directory of Open Access Journals (Sweden)

Suparno Suparno

2018-01-01

Full Text Available Study of correlation between vegetation and birds could show how great the impact of Figs (Ficus spp. towards wildlife. Mbarek spring has a unique microhabitat by Figs. These trees expected to provide a high potential role and benefit related to supporting bird life. This study aims to analyze the use of vegetation by birds in the sphere of Mbarek’s spring microhabitat. Study was held in Mulyosari sub-village, Sumberejo village, Gedangan subdistrict, Malang regency. The study was conducted from 26-29 October 2017. Bird observation point was chosen on Ficus racemosa, known locally as ‘Lo’, which suspected to have a major influence on the presence of birds. Each of observation results were identified, counted, and recorded. Documentation were done incidentally. The results are visualized by descriptive representations of the use of vegetation composition on 4 vegetation classifications : seedling (high = 0-1.5 m, sapling (high≥1.5 m, pole (diameter = 10-20 cm, tree (diameter> 20 cm. Sooty-headed Bulbul (Pycnonotus aurigaster is the dominant bird during observation. Most of birds observed at the canopy  with the activity of sunbathing. Figs became a favorite location for birds to rest and parenting during the day. Sedges (Cyperus sp. is the greatest importance on study site. Keywords: Birds, Figs, Mbarek, Sedges

Lack of nest site limitation in a cavity-nesting bird community

Science.gov (United States)

Jeffry R. Waters; Barry R. Noon; Jared Verner

1990-01-01

We examined the relationship between nest site availability and density of secondary cavitynesting birds by blocking cavities in an oak-pine (Quercus spp.-Pinus sp. ) woodland. In 1986 and 1987we blocked 67 and 106 cavities, respectively, on a 37-ha plot. The combined density of secondary cavity-nesting birds did not decline...

Hunting or habitat? Drivers of waterbird abundance and community structure in agricultural wetlands of southern India.

Science.gov (United States)

Ramachandran, Ramesh; Kumar, Ajith; Gopi Sundar, Kolla S; Bhalla, Ravinder Singh

2017-09-01

The relative impacts of hunting and habitat on waterbird community were studied in agricultural wetlands of southern India. We surveyed wetlands to document waterbird community, and interviewed hunters to document hunting intensity, targeted species, and the motivations for hunting. Our results show that hunting leads to drastic declines in waterbird diversity and numbers, and skew the community towards smaller species. Hunting intensity, water spread, and vegetation cover were the three most important determinants of waterbird abundance and community structure. Species richness, density of piscivorous species, and medium-sized species (31-65 cm) were most affected by hunting. Out of 53 species recorded, 47 were hunted, with a preference for larger birds. Although illegal, hunting has increased in recent years and is driven by market demand. This challenges the widely held belief that waterbird hunting in India is a low intensity, subsistence activity, and undermines the importance of agricultural wetlands in waterbird conservation.

Important bird areas of the Madrean Archipelago: A conservation strategy for avian communities

Science.gov (United States)

Vashti (Tice) Supplee; Jennie MacFarland

2013-01-01

The Important Bird Areas (IBA) Program is a worldwide program through BirdLife International that identifies sites considered to provide important habitats for avian species. Criteria for designation are species abundance, diversity, and range restriction. As the United States Partner of BirdLife International, the National Audubon Society administers the IBA Program...

Exploring differences in stakeholders' perceptions of illegal bird trapping in Cyprus.

Science.gov (United States)

Jenkins, Heather M; Mammides, Christos; Keane, Aidan

2017-11-28

Cyprus is recognised as a hotspot for illegal bird trapping in the Mediterranean basin. A consumer demand for the Eurasian blackcap (Sylvia atricapilla) is driving the use of non-selective trapping methods, resulting in the indiscriminate killing of millions of migratory birds. Efforts to tackle the issue have so far been characterised mostly by a top-down approach, focusing on legislation and enforcement. However, trapping levels are not decreasing and conflict between stakeholder groups is intensifying. To understand why efforts to stop illegal bird trapping have not been effective, we used semi-structured interviews to interview 18 local bird trappers and nine representatives from the pertinent environmental non-governmental organisations (NGOs) and the governmental agencies responsible for enforcing the legislation. We found distinct differences between the views of the local trapping community and the environmental NGOs, particularly on why trapping is occurring and its impact on the avifauna. This disparity has contributed to misrepresentations of both sides and a high degree of conflict, which is potentially proving counterproductive to conservation interventions. In addition, it appears that trappers are a heterogeneous group, likely driven by various motivations besides profit. We argue that stakeholders interested in reducing illegal bird trapping need to develop anti-poaching strategies that aim at minimising the disparity in the views, and subsequently the conflict, acknowledging also that trappers are not a homogenous group, as often treated.

An analytical hierarchical model explaining the robustness and flaw-tolerance of the interlocking barb-barbule structure of bird feathers

Science.gov (United States)

Chen, Qiang; Gorb, Stanislav; Kovalev, Alexander; Li, Zhiyong; Pugno, Nicola

2016-10-01

Feathers can fulfill their aerodynamic function only if the pennaceous vane forms an airfoil stabilized by robust interlocking between barbules. Thus, revealing the robustness of the interlocking mechanical behavior of the barbules is very important to understand the function and long-term resilience of bird feathers. This paper, basing on the small- and large-beam deflection solutions, presents a hierarchical mechanical model for deriving the critical delamination conditions of the interlocking barbules between two adjacent barbs in bird feathers. The results indicate a high robustness and flaw-tolerant design of the structure. This work contributes to the understanding of the mechanical behavior of the robust interlocking barb-barbule structure of the bird feather, and provides a basis for design of feather-inspired materials with robust interlocking mechanism, such as advanced bio-inspired micro-zipping devices.

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

Alabama ESI: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, gulls, and terns...

Maryland ESI: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

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

Science.gov (United States)

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.

Bird diversity along a gradient of fragmented habitats of the Cerrado.

Science.gov (United States)

Jesus, Shayana DE; Pedro, Wagner A; Bispo, Arthur A

2018-01-01

Understanding the factors that affect biodiversity is of central interest to ecology, and essential to species conservation and ecosystems management. We sampled bird communities in 17 forest fragments in the Cerrado biome, the Central-West region of Brazil. We aimed to know the communities structure pattern and the influence of geographical distance and environmental variables on them, along a gradient of fragmented habitats at both local and landscape scales. Eight structural variables of the fragments served as an environmental distance measurement at the local scale while five metrics served as an environmental distance measurement at the landscape scale. Species presence-absence data were used to calculate the dissimilarity index. Beta diversity was calculated using three indices (βsim, βnes and βsor), representing the spatial species turnover, nestedness and total beta diversity, respectively. Spatial species turnover was the predominant pattern in the structure of the communities. Variations in beta diversity were explained only by the environmental variables of the landscape with spatial configuration being more important than the composition. This fact indicates that, in Cerrado of Goiás avian communities structure, deterministic ecological processes associated to differences in species responses to landscape fragmentation are more important than stochastic processes driven by species dispersal.

Cicadas impact bird communication in a noisy tropical rainforest

Science.gov (United States)

Hall, Robert; Ray, William; Beck, Angela; Zook, James

2015-01-01

Many animals communicate through acoustic signaling, and “acoustic space” may be viewed as a limited resource that organisms compete for. If acoustic signals overlap, the information in them is masked, so there should be selection toward strategies that reduce signal overlap. The extent to which animals are able to partition acoustic space in acoustically diverse habitats such as tropical forests is poorly known. Here, we demonstrate that a single cicada species plays a major role in the frequency and timing of acoustic communication in a neotropical wet forest bird community. Using an automated acoustic monitor, we found that cicadas vary the timing of their signals throughout the day and that the frequency range and timing of bird vocalizations closely track these signals. Birds significantly avoid temporal overlap with cicadas by reducing and often shutting down vocalizations at the onset of cicada signals that utilize the same frequency range. When birds do vocalize at the same time as cicadas, the vocalizations primarily occur at nonoverlapping frequencies with cicada signals. Our results greatly improve our understanding of the community dynamics of acoustic signaling and reveal how patterns in biotic noise shape the frequency and timing of bird vocalizations in tropical forests. PMID:26023277

Bird and bat predation services in tropical forests and agroforestry landscapes.

Science.gov (United States)

Maas, Bea; Karp, Daniel S; Bumrungsri, Sara; Darras, Kevin; Gonthier, David; Huang, Joe C-C; Lindell, Catherine A; Maine, Josiah J; Mestre, Laia; Michel, Nicole L; Morrison, Emily B; Perfecto, Ivette; Philpott, Stacy M; Şekercioğlu, Çagan H; Silva, Roberta M; Taylor, Peter J; Tscharntke, Teja; Van Bael, Sunshine A; Whelan, Christopher J; Williams-Guillén, Kimberly

2016-11-01

Understanding distribution patterns and multitrophic interactions is critical for managing bat- and bird-mediated ecosystem services such as the suppression of pest and non-pest arthropods. Despite the ecological and economic importance of bats and birds in tropical forests, agroforestry systems, and agricultural systems mixed with natural forest, a systematic review of their impact is still missing. A growing number of bird and bat exclosure experiments has improved our knowledge allowing new conclusions regarding their roles in food webs and associated ecosystem services. Here, we review the distribution patterns of insectivorous birds and bats, their local and landscape drivers, and their effects on trophic cascades in tropical ecosystems. We report that for birds but not bats community composition and relative importance of functional groups changes conspicuously from forests to habitats including both agricultural areas and forests, here termed 'forest-agri' habitats, with reduced representation of insectivores in the latter. In contrast to previous theory regarding trophic cascade strength, we find that birds and bats reduce the density and biomass of arthropods in the tropics with effect sizes similar to those in temperate and boreal communities. The relative importance of birds versus bats in regulating pest abundances varies with season, geography and management. Birds and bats may even suppress tropical arthropod outbreaks, although positive effects on plant growth are not always reported. As both bats and birds are major agents of pest suppression, a better understanding of the local and landscape factors driving the variability of their impact is needed. © 2015 Cambridge Philosophical Society.

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

Directory of Open Access Journals (Sweden)

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.

Revegetation increase bird diversity in coastal area of Socorejo, Tuban, East Java - Indonesia

Science.gov (United States)

Lestari, Yeni Indah; Edi, Wasito; Alivvy, Alkautsar; Ibadah, Acib Setia; Sari, Fadina Yuliana; Nuraini, Finda; Yanuar, Ahmad; Satriyono, Agus; Riany, Citra Fitrie; Saptarini, Dian; Muzaki, Farid Kamal

2017-06-01

Study to address positive impact of revegetation program to increasing diversity of bird had been conducted in coastal area of Socorejo, Tuban - Indonesia. Field observation conducted during April 2011 (representing pre-revegetation period), April 2015 and May 2016 (representing post-revegetation period). A belt transect (500 meter long and 50 meter width) was used to survey the abundance and species composition of birds community. In general, we identified at least 51 bird species from three observation times. From 2011 to 2016, the numbers of the birds identified are 23, 37 and 37 species; while the Shannon-Wiener diversity indices (H') are 1.865, 2.071 and 2.957, respectively. In addition, there are 11 national or internationally protected species, 3 Indonesian endemic species and 12 migratory species occurred in the area. As a conclusion, the coastal revegetation program provides positive impact by generating habitat function for bird community.

Avian community responses to variability in river hydrology.

Science.gov (United States)

Royan, Alexander; Hannah, David M; Reynolds, S James; Noble, David G; Sadler, Jonathan P

2013-01-01

River flow is a major driver of morphological structure and community dynamics in riverine-floodplain ecosystems. Flow influences in-stream communities through changes in water velocity, depth, temperature, turbidity and nutrient fluxes, and perturbations in the organisation of lower trophic levels are cascaded through the food web, resulting in shifts in food availability for consumer species. River birds are sensitive to spatial and phenological mismatches with aquatic prey following flow disturbances; however, the role of flow as a determinant of riparian ecological structure remains poorly known. This knowledge is crucial to help to predict if, and how, riparian communities will be influenced by climate-induced changes in river flow characterised by more extreme high (i.e. flood) and/or low (i.e. drought) flow events. Here, we combine national-scale datasets of river bird surveys and river flow archives to understand how hydrological disturbance has affected the distribution of riparian species at higher trophic levels. Data were analysed for 71 river locations using a Generalized Additive Model framework and a model averaging procedure. Species had complex but biologically interpretable associations with hydrological indices, with species' responses consistent with their ecology, indicating that hydrological-disturbance has implications for higher trophic levels in riparian food webs. Our quantitative analysis of river flow-bird relationships demonstrates the potential vulnerability of riparian species to the impacts of changing flow variability and represents an important contribution in helping to understand how bird communities might respond to a climate change-induced increase in the intensity of floods and droughts. Moreover, the success in relating parameters of river flow variability to species' distributions highlights the need to include river flow data in climate change impact models of species' distributions.

Edge effect of low-traffic forest roads on bird communities in secondary production forests in central Europe

Czech Academy of Sciences Publication Activity Database

Šálek, M.; Svobodová, Jana; Zasadil, P.

2010-01-01

Roč. 25, č. 7 (2010), s. 1113-1124 ISSN 0921-2973 Institutional research plan: CEZ:AV0Z60930519 Keywords : Biodiversity * Bird assemblages * Czech Republic * Edge effect * Habitat fragmentation * Landscape structure * Point count method Subject RIV: EH - Ecology, Behaviour Impact factor: 3.200, year: 2010

Bird checklist, Guánica Biosphere Reserve, Puerto Rico

Science.gov (United States)

Wayne J. Arendt; John Faaborg; Miguel Canals; Jerry Bauer

2015-01-01

This research note compiles 43 years of research and monitoring data to produce the first comprehensive checklist of the dry forest avian community found within the Guánica Biosphere Reserve. We provide an overview of the reserve along with sighting locales, a list of 185 birds with their resident status and abundance, and a list of the available bird habitats....

Effects of forest fragmentation on nocturnal Asian birds: A case study from Xishuangbanna, China

Science.gov (United States)

DAYANANDA, Salindra K.; GOODALE, Eben; LEE, Myung-bok; LIU, Jia-Jia; MAMMIDES, Christos; PASION, Bonifacio O.; QUAN, Rui-Chang; SLIK, J. W. Ferry; SREEKAR, Rachakonda; TOMLINSON, Kyle W.; YASUDA, Mika

2016-01-01

Owls have the potential to be keystone species for conservation in fragmented landscapes, as the absence of these predators could profoundly change community structure. Yet few studies have examined how whole communities of owls respond to fragmentation, especially in the tropics. When evaluating the effect of factors related to fragmentation, such as fragment area and distance to the edge, on these birds, it is also important in heterogeneous landscapes to ask how ‘location factors’ such as the topography, vegetation and soil of the fragment predict their persistence. In Xishuangbanna, southwest China, we established 43 transects (200 m×60 m) within 20 forest fragments to sample nocturnal birds, both visually and aurally. We used a multimodel inference approach to identify the factors that influence owl species richness, and generalized linear mixed models to predict the occurrence probabilities of each species. We found that fragmentation factors dominated location factors, with larger fragments having more species, and four of eight species were significantly more likely to occur in large fragments. Given the potential importance of these birds on regulating small mammal and other animal populations, and thus indirectly affecting seed dispersal, we suggest further protection of large fragments and programs to increase their connectivity to the remaining smaller fragments. PMID:27265653

Effects of forest fragmentation on nocturnal Asian birds: A case study from Xishuangbanna, China

Directory of Open Access Journals (Sweden)

Salindra K. DAYANANDA

2016-05-01

Full Text Available Owls have the potential to be keystone species for conservation in fragmented landscapes, as the absence of these predators could profoundly change community structure. Yet few studies have examined how whole communities of owls respond to fragmentation, especially in the tropics. When evaluating the effect of factors related to fragmentation, such as fragment area and distance to the edge, on these birds, it is also important in heterogeneous landscapes to ask how ‘location factors’ such as the topography, vegetation and soil of the fragment predict their persistence. In Xishuangbanna, southwest China, we established 43 transects (200 m×60 m within 20 forest fragments to sample nocturnal birds, both visually and aurally. We used a multimodel inference approach to identify the factors that influence owl species richness, and generalized linear mixed models to predict the occurrence probabilities of each species. We found that fragmentation factors dominated location factors, with larger fragments having more species, and four of eight species were significantly more likely to occur in large fragments. Given the potential importance of these birds on regulating small mammal and other animal populations, and thus indirectly affecting seed dispersal, we suggest further protection of large fragments and programs to increase their connectivity to the remaining smaller fragments.

Aridity influences the recovery of vegetation and shrubland birds after wildfire

OpenAIRE

Puig Gironès, Roger; Brotons, Lluís; Pons Ferran, Pere

2017-01-01

Wildfires play a determining role in the composition and structure of many plant and animal communities. On the other hand, climate change is considered to be a major driver of current and future fire regime changes. Despite increases in drought in many areas of the world, the effects of aridity on post-fire colonization by animals have been rarely addressed. This study aims to analyse how a regional aridity gradient affects post-fire recovery of vegetation, bird species richness and the numb...

The importance of agricultural lands for Himalayan birds in winter.

Science.gov (United States)

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

Behavioral responses of birds of prey to large scale energy development in southcentral Washington

International Nuclear Information System (INIS)

Fitzner, R.E.

1985-02-01

The types of raptorial and semi-raptorial birds that use the Hanford environs are discussed along with the impacts of past operations and the recent WPPSS project on their populations. These findings add to our understanding of the population dynamics of the birds of prey community at the Hanford Site and the expected impacts of the WPPSS energy facilities. The results may have implications toward other large scale energy facilities, and may aid us in management of bird of prey communities throughout the grasslands of the western United States. 110 refs., 5 figs., 4 tabs

Columbia River ESI: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, diving birds, seabirds, passerine birds, gulls, and terns in...

The North Sea Bird Club

International Nuclear Information System (INIS)

Doyle, P.A.T.; Gorman, M.L.; Patterson, I.J.; Howe, S.

1991-01-01

This paper reports that the creation of a club for the purpose of encouraging oil and gas workers to watch birds may not at first seem a viable proposition. To the layperson, birds offshore conjures up an image of hundreds of seagulls following fishing boats, and very little else. Also, the act of birdwatching is not seen as a typical offshore worker's activity. Anyone who has worked on an installation offshore and who has any interest in wildlife will be aware of the occasional presence of land-birds. Two decades ago, prompted by some keen offshore workers, a single oil company set up a monitoring program, which quickly became popular with a number of its employees. Birds seem offshore were recorded on data forms and collected together. At this stage the club was purely another recreation facility; however, when the data were collated it was soon realized that installations offshore were being used as staging posts by birds on migration, and that the information being collected would be of great interest in the study of bird movements. All over Britain, at strategic points on the coastline, there are bird observatories which record the arrival and departure of migrating birds. The presence of several hundred solid structures up and down the North Sea, which are used by birds en route, represents a huge, unique bird observatory, capable of uncovering facts about bird migration which have long eluded land-based scientists. Eleven years ago, the North Sea Bird Club began, composed of eight member companies, a recorder from Aberdeen University and a representative from the Nature Conservancy Council. The club received data from 41 installations, and the recorder collated these on Aberdeen University's computer and produced an annual report of sightings

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...

Characteristics of urban woodlands affecting breeding bird diversity and abundance

Science.gov (United States)

N.G. Tilghman

1987-01-01

Breeding bird communities were studied in 32 forest islands surrounded by urban development. These isolated woodlands in Springfield, Massachusetts, provided breeding habitats for a wider variety of birds (77 species) than previously described for other urban habitats (e.g. four times as many species as found in urban residential areas in the same city in a...

Bird assemblages in natural and urbanized habitats along elevational gradient in Nainital district (western Himalaya of Uttarakhand state, India

Directory of Open Access Journals (Sweden)

Dinesh BHATT, Kamal Kant JOSHI

2011-06-01

Full Text Available The Indian subcontinent is amongst the biologically better known parts of the tropics and its bird fauna has been well documented. However, avian community composition and diversity along elevational gradients and amongst habitat types remains unclear in India. We attempted to estimate bird assemblages in terms of diversity, species composition, status and abundance in urban and forest habitats of Nainital district of Uttarakhand (350–2450 m asl; 29°N, Western Himalayas. We sampled different elevational gradients and to understand the effect of urbanization and season on avian community composition. Field studies were conducted during January 2005 to January 2007. Results indicated that the forest had more complex bird community structure in terms of higher species richness (14.35 vs 8.69, higher species diversity (Shannon’s index 4.00 vs 3.54, higher evenness (0.838 vs 0.811 and more rare species (17 vs 5 as compared to urban habitat. However, the abundance of 11 species was higher in urban habitats. Bird Species Richness (BSR varied considerably among study areas (91 to 113 species, was highest (113 species at mid elevation (1450–1700 m asl and decreased (22 species at high elevation (1900–2450 m asl. It seems that high BSR at mid altitudes is not caused by the presence of a group of mid altitude specialists but rather that there is an overlap in the distribution of low land and high elevation specialists at this altitude. BSR and Bird Species Diversity fluctuated across seasons but not habitat type [Current Zoology 57 (3: 318–329, 2011].

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

Science.gov (United States)

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

Science.gov (United States)

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 influence of fire on the assemblage structure of foraging birds in grasslands of the Serra da Canastra National Park, Brazil

Directory of Open Access Journals (Sweden)

Matheus G. Reis

2016-06-01

Full Text Available Grasslands are the most threatened physiognomies of the Cerrado biome (Brazilian savanna, a biodiversity hotspot with conservation as a priority. The Serra da Canastra National Park protects the most important remnants of the Cerrado's southern grasslands, which are under strong anthropogenic pressure. The present study describes the structure of bird assemblages that directly use food resources in burned areas, comparing areas affected by natural fire to the areas where controlled fires were set (a management strategy to combat arson. The tested null hypothesis was that different bird assemblages are structured in a similar manner, regardless of the post-fire period or assessed area. Between December/2012 and January/2015, 92 species were recorded foraging in the study areas. The results indicate that both types of burnings triggered profound and immediate changes in bird assemblages, increasing the number of species and individuals. Natural fires exhibited a more significant influence on the structure (diversity and dominance than prescribed burnings. Nevertheless, all the differences were no longer noticeable after a relatively short time interval of 2-3 months after prescribed burnings and 3-4 after natural fires. The findings may help the understanding of prescribed burnings as a management strategy for bird conservation in grasslands.

Partitioning of seed dispersal services between birds and bats in a fragment of the Brazilian Atlantic Forest

Directory of Open Access Journals (Sweden)

Raissa Sarmento

2014-06-01

Full Text Available Community-level network studies suggest that seed dispersal networks may share some universal properties with other complex systems. However, most of the datasets used so far in those studies have been strongly biased towards temperate birds, including not only dispersers, but also seed predators. Recent evidence from multi-taxon networks suggests that seed dispersal networks are not all alike and may be more complex than previously thought. Here, we used network theory to evaluate seed dispersal in a strongly impacted Atlantic Forest fragment in northeastern Brazil, where bats and birds are the only extant dispersers. We hypothesized that the seed dispersal network should be more modular then nested, and that the dispersers should segregate their services according to dispersal syndromes. Furthermore, we predicted that bat and bird species that are more specialized in frugivory would be more important for maintaining the network structure. The mixed network contained 56 plant species, 12 bat species, and eight bird species, and its structure was more modular (M = 0.58 then nested (NODF = 0.21 compared with another multi-taxon network and 21 single-taxon networks (with either bats or birds. All dispersed fruits had seeds smaller than 9 mm. Bats dispersed mainly green fruits, whereas birds dispersed fruits of various colors. The network contained eight modules: five with birds only, two with bats only, and one mixed. Most dispersers were peripheral, and only specialized frugivores acted as hubs or connectors. Our results strongly support recent studies, suggesting that seed dispersal networks are complex mosaics, where different taxa form separate modules with different properties, which in turn play complementary roles in the maintenance of the associated ecosystem functions and services.

Bird diversity and dissimilarity show contrasting patterns along heavy metal pollution gradients in the Urals, Russia.

Science.gov (United States)

Belskii, Eugen A; Mikryukov, Vladimir S

2018-05-07

The effects of industrial pollution on bird diversity have been widely studied using traditional diversity measures, which assume all species to be equivalent. We compared species richness and Shannon index with distance-based measures of taxonomic, functional, and phylogenetic diversity (the abundance-weighted mean nearest taxon distances), which describe within-community dissimilarity at terminal branches. Analysis of dissimilarity can shed light on the processes underlying community assembly, i.e., environmental filtering decreases dissimilarity whereas competitive exclusion increases it. In the 2-year study near Karabash and Revda copper smelters in Russia, point counts of nesting birds and habitat descriptions were taken at 10 sites (40 plots) along each pollution gradient. The abundance and diversity of birds showed good repeatability in both regions. The total density of birds, number of species per plot, and Shannon diversity decreased at high toxic load in both regions. The taxonomic, functional, and phylogenetic nearest taxon distances showed the same pattern within regions. Species dissimilarity within communities increased with pollution in Karabash (due to loss of functionally similar species), but did not change in Revda (due to mass replacement of forest species by species of open habitats). Pollution-induced changes in bird communities near Karabash were greater due to the stronger deterioration of the forest ecosystems and less favorable natural conditions (more arid climate, lower diversity and vitality of the tree stand and understorey) compared to Revda. This study emphasizes the need for a multi-level approach to the analysis of bird communities using traditional indices of diversity, functional, taxonomic, or phylogenetic distances between species and environmental variables.

Birds as predators in tropical agroforestry systems.

Science.gov (United States)

Van Bael, Sunshine A; Philpott, Stacy M; Greenberg, Russell; Bichier, Peter; Barber, Nicholas A; Mooney, Kailen A; Gruner, Daniel S

2008-04-01

Insectivorous birds reduce arthropod abundances and their damage to plants in some, but not all, studies where predation by birds has been assessed. The variation in bird effects may be due to characteristics such as plant productivity or quality, habitat complexity, and/or species diversity of predator and prey assemblages. Since agroforestry systems vary in such characteristics, these systems provide a good starting point for understanding when and where we can expect predation by birds to be important. We analyze data from bird exclosure studies in forests and agroforestry systems to ask whether birds consistently reduce their arthropod prey base and whether bird predation differs between forests and agroforestry systems. Further, we focus on agroforestry systems to ask whether the magnitude of bird predation (1) differs between canopy trees and understory plants, (2) differs when migratory birds are present or absent, and (3) correlates with bird abundance and diversity. We found that, across all studies, birds reduce all arthropods, herbivores, carnivores, and plant damage. We observed no difference in the magnitude of bird effects between agroforestry systems and forests despite simplified habitat structure and plant diversity in agroforests. Within agroforestry systems, bird reduction of arthropods was greater in the canopy than the crop layer. Top-down effects of bird predation were especially strong during censuses when migratory birds were present in agroforestry systems. Importantly, the diversity of the predator assemblage correlated with the magnitude of predator effects; where the diversity of birds, especially migratory birds, was greater, birds reduced arthropod densities to a greater extent. We outline potential mechanisms for relationships between bird predator, insect prey, and habitat characteristics, and we suggest future studies using tropical agroforests as a model system to further test these areas of ecological theory.

Richness, diversity, and similarity of arthropod prey consumed by a community of Hawaiian forest birds.

Science.gov (United States)

Banko, Paul C.; Peck, Robert W.; Brinck, Kevin W.; Leonard, David L.

2015-01-01

We evaluated the diet richness, diversity, and similarity of a community of seven endemic and two introduced passerine birds by analyzing the composition of arthropod prey in fecal samples collected during 1994–1998 at Hakalau Forest National Wildlife Refuge, Hawai‘i Island. Most prey fragments were identified to order, but we also distinguished among morpho-species of Lepidoptera based on the shape of larval (caterpillar) mandibles for higher resolution of this important prey type. Diets were compared among feeding specialists, generalists, and “intermediate” species and among introduced and three endangered Hawaiian honeycreeper (Fringillidae) species. Lepidoptera (moths), especially the larval (caterpillar) stage, comprised the greatest proportion of prey in samples of all bird species except for the introduced Japanese white-eye (Zosterops japonicus; JAWE). Araneae (spiders) was the most abundant order in JAWE samples and the second most abundant order for most other species. The two specialist honeycreepers ranked lowest in the richness and diversity of arthropod orders, but only the ‘akiapōlā‘au (Hemignathus munroi, AKIP) was significantly lower than the three generalist or intermediate honeycreeper species. The diversity of arthropod orders was significantly lower for the three endangered honeycreeper species compared to the two introduced species. No significant differences were observed among the five honeycreepers with respect to the arthropod orders they consumed. The use of arthropod orders taken by endangered honeycreepers and introduced species was significantly different in all paired comparisons except for JAWE and ‘ākepa (Loxops coccineus; AKEP). In terms of richness and diversity of caterpillar morpho-species in the diet, only the specialist, AKEP, was significantly lower than all three generalist and intermediate species. Both AKEP and AKIP consumed a significantly different diet of caterpillar morpho-species compared to at least

Cavity-nesting bird abundance in thinned versus unthinned Massachusetts oak stands

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Christopher J.E. Welsh; William M. Healy; Richard M. DeGraaf

1992-01-01

Cavity-nesting birds provide significant benefits to forest communities, but timber management techniques may negatively affect cavity-nesting species by reducing the availability of suitable nest and foraging sites. We surveyed cavity-nesting birds from transects in eight Massachusetts oak stands to examine the effect of thinning with retention of snag and wildlife...

The U.S. Geological Survey Bird Banding Laboratory: an integrated scientific program supporting research and conservation of North American birds

Science.gov (United States)

Smith, Gregory J.

2013-01-01

The U.S. Geological Survey (USGS) Bird Banding Laboratory (BBL) was established in 1920 after ratification of the Migratory Bird Treaty Act with the United Kingdom in 1918. During World War II, the BBL was moved from Washington, D.C., to what is now the USGS Patuxent Wildlife Research Center (PWRC). The BBL issues permits and bands to permittees to band birds, records bird band recoveries or encounters primarily through telephone and Internet reporting, and manages more than 72 million banding records and more than 4.5 million records of encounters using state-of-the-art technologies. Moreover, the BBL also issues bands and manages banding and encounter data for the Canadian Bird Banding Office (BBO). Each year approximately 1 million bands are shipped from the BBL to banders in the United States and Canada, and nearly 100,000 encounter reports are entered into the BBL systems. Banding data are essential for regulatory programs, especially migratory waterfowl harvest regulations. The USGS BBL works closely with the U.S. Fish and Wildlife Service (USFWS) to develop regulations for the capture, handling, banding, and marking of birds. These regulations are published in the Code of Federal Regulations (CFR). In 2006, the BBL and the USFWS Division of Migratory Bird Management (DMBM) began a comprehensive revision of the banding regulations. The bird banding community has three major constituencies: Federal and State agency personnel involved in the management and conservation of bird populations that include the Flyway Councils, ornithological research scientists, and avocational banders. With increased demand for banding activities and relatively constant funding, a Federal Advisory Committee (Committee) was chartered and reviewed the BBL program in 2005. The final report of the Committee included six major goals and 58 specific recommendations, 47 of which have been addressed by the BBL. Specifically, the Committee recommended the BBL continue to support science

Analysis of Bird Diversity for Supporting Ecotourism Development in Rajegwesi, Meru Betiri National Park

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Hafid Zain Muttaqien

2015-09-01

Full Text Available Potential ecotourism attraction in Rajegwesi Village, Meru Betiri National Park is high due to its high biodiversity, especially bird diversity, in the form of bird watching activity. This study was aimed to determine the species, level of abundance, and diversity of birds found in the Rajegwesi area. Further, this basic information is important to develop the bird watching track at Rajegwesi. We used Quantum-GIS to create the land classification and observation mapping. Bird observation used point count method in the morning and evening with three periods of hour and three repetitions. The study confirmed about 76 species of 39 bird families was found in Rajegwesi. The highest abundance was Pygnonotus goiavier (E:Yellow-vented Bulbul, at the meadows, village, and rehabilitation land. The diversity index showed that the highest diversity was found at the heterogeneous forest (H’ index 3.745, followed by homogenous forest (H’ index 3.150, rehabilitation land (H’ index 2.845, village (H’ index 2.693, paddy fields (H’ index 2.529, and savanna (H’ index 1.880. The observation track was divided into 3 lines based on the bird’s distribution, the Village – Rehabilitation Land track (6.5 Km, Village track (2.3 Km, and Village – Rafflessia Park track (7.5 Km. Total of 25 bird species were found at the Village – Rehabilitation Land track, 22 species were found at the Village track, and 29 bird species were found at the Village – Rafflessia Park track. For the future of ecotourism development through birding development program, there are several issues that should be promoted: promoting birds conservation in the community through bird watching and birds observation competition (Bird race, training on conservation and ecotourism for the community, and strengthening the capacity and capability of Rajegwesi Ecotourism Society (RES on the ecotourism program management. Keywords: bird watching, conservation, ecotourism development, RES

Collision effects of wind-power generators and other obstacles on birds.

Science.gov (United States)

Drewitt, Allan L; Langston, Rowena H W

2008-01-01

There is extensive literature on avian mortality due to collision with man-made structures, including wind turbines, communication masts, tall buildings and windows, power lines, and fences. Many studies describe the consequences of bird-strike rather than address the causes, and there is little data based on long-term, standardized, and systematic assessments. Despite these limitations, it is apparent that bird-strike is a significant cause of mortality. It is therefore important to understand the effects of this mortality on bird populations. The factors which determine avian collision risk are described, including location, structural attributes, such as height and the use of lighting, weather conditions, and bird morphology and behavior. The results of incidental and more systematic observations of bird-strike due to a range of structures are presented and the implications of collision mortality for bird populations, particularly those of scarce and threatened species susceptible to collisions, are discussed. Existing measures for reducing collision mortality are described, both generally and specifically for each type of structure. It is concluded that, in some circumstances, collision mortality can adversely affect bird populations, and that greater effort is needed to derive accurate estimates of mortality levels locally, regionally, and nationally to better assess impacts on avian populations. Priority areas for future work are suggested, including further development of remote technology to monitor collisions, research into the causes of bird-strike, and the design of new, effective mitigation measures.

Ecological drivers of community assembly across taxonomic groups and trophic levels

DEFF Research Database (Denmark)

Özkan, Korhan

assembly is a complex phenomenon driven by the interplay between environmental species sorting, ecological interactions between species and dispersal, linking local communities with the surrounding communities as well as with their regional populations. Although the research on community assembly....... Local bird abundance was strongly linked with occupancy across the metacommunity (the bird communities in the Istranca landscape) as well as the species’ regional population and range size across the western Palearctic. Null model analyses showed that bird occupancy was non-randomly related to species...... environmental niche. Furthermore, species abundance and occupancy across both the metacommunity and the whole western Palearctic were significantly related to an independent species specialization index calculated for the French birds. Together these results indicated that forest bird community assembly...

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 ...

How Noniridescent Colors Are Generated by Quasi-ordered Structures of Bird Feathers

Energy Technology Data Exchange (ETDEWEB)

Noh, Heeso; Liew, Seng Fatt; Saranathan, Vinodkumar; Mochrie, Simon G.J.; Prum, Richard O.; Dufresne, Eric R.; Cao, Hui (Yale)

2012-03-26

We investigate the mechanism of structural coloration by quasi-ordered nanostructures in bird feather barbs. Small-angle X-ray scattering (SAXS) data reveal the structures are isotropic and have short-range order on length scales comparable to optical wavelengths. We perform angle-resolved reflection and scattering spectrometry to fully characterize the colors under directional and omni-directional illumination of white light. Under directional lighting, the colors change with the angle between the directions of illumination and observation. The angular dispersion of the primary peaks in the scattering/reflection spectra can be well explained by constructive interference of light that is scattered only once in the quasi-ordered structures. Using the Fourier power spectra of structure from the SAXS data we calculate optical scattering spectra and explain why the light scattering peak is the highest in the backscattering direction. Under omni-directional lighting, colors from the quasi-ordered structures are invariant with the viewing angle. The non-iridescent coloration results from the isotropic nature of structures instead of strong backscattering.

The diversity and biogeography of late Pleistocene birds from the lowland Neotropics

Science.gov (United States)

Steadman, David W.; Oswald, Jessica A.; Rincón, Ascanio D.

2015-05-01

The Neotropical lowlands sustain the world's richest bird communities, yet little that we know about their history is based on paleontology. Fossils afford a way to investigate distributional shifts in individual species, and thus improve our understanding of long-term change in Neotropical bird communities. We report a species-rich avian fossil sample from a late Pleistocene tar seep (Mene de Inciarte) in northwestern Venezuela. A mere 175 identified fossils from Mene de Inciarte represent 73 species of birds, among which six are extinct, and eight others no longer occur within 100 km. These 14 species consist mainly of ducks (Anatidae), snipe (Scolopacidae), vultures/condors (Vulturidae), hawks/eagles (Accipitridae), and blackbirds (Icteridae). Neotropical bird communities were richer in the late Pleistocene than today; their considerable extinction may be related to collapse of the large mammal fauna at that time. The species assemblage at Mene de Inciarte suggests that biogeographic patterns, even at continental scales, have been remarkably labile over short geological time frames. Mene de Inciarte is but one of 300 + tar seeps in Venezuela, only two of which have been explored for fossils. We may be on the cusp of an exciting new era of avian paleontology in the Neotropics.

The Bird.

Science.gov (United States)

Hannon, Jean

2001-01-01

Students use a dead bird to learn about bird life, anatomy, and death. Students examine a bird body and discuss what happened to the bird. Uses outdoor education as a resource for learning about animals. (SAH)

Looking beyond rare species as umbrella species: Northern Bobwhites (Colinus virginianus) and conservation of grassland and shrubland birds

Science.gov (United States)

Crosby, Andrew D.; Elmore, R.D.; Leslie,, David M.; Will, Rodney E.

2015-01-01

Changes in land use and land cover throughout the eastern half of North America have caused substantial declines in populations of birds that rely on grassland and shrubland vegetation types, including socially and economically important game birds such as the Northern Bobwhite (Colinus virginianus; hereafter bobwhites). As much attention is focused on habitat management and restoration for bobwhites, they may act as an umbrella species for other bird species with similar habitat requirements. We quantified the relationship of bobwhites to the overall bird community and evaluated the potential for bobwhites to act as an umbrella species for grassland and shrubland birds. We monitored bobwhite presence and bird community composition within 31 sample units on selected private lands in the south-central United States from 2009 to 2011. Bobwhites were strongly associated with other grassland and shrubland birds and were a significant positive predictor for 9 species. Seven of these, including Bell's Vireo (Vireo bell), Dicksissel (Spiza americana), and Grasshopper Sparrow (Ammodramus savannarum), are listed as species of conservation concern. Species richness and occupancy probability of grassland and shrubland birds were higher relative to the overall bird community in sample units occupied by bobwhites. Our results show that bobwhites can act as an umbrella species for grassland and shrubland birds, although the specific species in any given situation will depend on region and management objectives. These results suggest that efficiency in conservation funding can be increased by using public interest in popular game species to leverage resources to meet multiple conservation objectives.

Bird nesting and droppings control on highway structures.

Science.gov (United States)

2010-10-01

This report provides a comprehensive literature survey of permanent and temporary deterrents to nesting and roosting, a : discussion of risks to human health and safety from exposure to bird nests and droppings and recommended protective measures, : ...

Simple neural substrate predicts complex rhythmic structure in duetting birds

Science.gov (United States)

Amador, Ana; Trevisan, M. A.; Mindlin, G. B.

2005-09-01

Horneros (Furnarius Rufus) are South American birds well known for their oven-looking nests and their ability to sing in couples. Previous work has analyzed the rhythmic organization of the duets, unveiling a mathematical structure behind the songs. In this work we analyze in detail an extended database of duets. The rhythms of the songs are compatible with the dynamics presented by a wide class of dynamical systems: forced excitable systems. Compatible with this nonlinear rule, we build a biologically inspired model for how the neural and the anatomical elements may interact to produce the observed rhythmic patterns. This model allows us to synthesize songs presenting the acoustic and rhythmic features observed in real songs. We also make testable predictions in order to support our hypothesis.

An evolving network model with community structure

International Nuclear Information System (INIS)

Li Chunguang; Maini, Philip K

2005-01-01

Many social and biological networks consist of communities-groups of nodes within which connections are dense, but between which connections are sparser. Recently, there has been considerable interest in designing algorithms for detecting community structures in real-world complex networks. In this paper, we propose an evolving network model which exhibits community structure. The network model is based on the inner-community preferential attachment and inter-community preferential attachment mechanisms. The degree distributions of this network model are analysed based on a mean-field method. Theoretical results and numerical simulations indicate that this network model has community structure and scale-free properties

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.

Coastal Resources Atlas: Long Island: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, seabirds, passerine birds, and gulls and...

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.

Bird nesting on an Athabasca power line structure

International Nuclear Information System (INIS)

Stedwill, R.J.

1989-01-01

SaskPower has recently completed its 400 km Athabasca power line, and is evaluating the predicted environmental impact of the line on the resident population of bald eagles and other raptors. During construction of the line, five major types of impact associated with the line were addressed. Minor route adjustments were made to by-pass nests of bald eagles and osprey to minimize impact of construction on breeding. The proximity of the power line to cliff faces and the north shore of lake Athabasca was maximized, and frequency of stream crossings and proximity to rapids were minimized. Route adjustments were made to ensure that the line was at least 1.6 km from bald eagle nest sites. As structures of the main 115 kV power line allow a minimum separation between conductors and grounded spars of 1.6 m, and between conductors of 4.6 m, electrocution was not considered to be a significant risk. However, on the 25 kV power line in regions of known bald eagle activity and in close proximity to bodies of water, provision was made for special structures to allow birds to perch without danger of electrocution. It was concluded that the resident population of raptors will probably be enhanced, particularly in areas not previously utilized. 8 refs., 5 figs

The overlapping community structure of structural brain network in young healthy individuals.

Directory of Open Access Journals (Sweden)

Kai Wu

2011-05-01

Full Text Available Community structure is a universal and significant feature of many complex networks in biology, society, and economics. Community structure has also been revealed in human brain structural and functional networks in previous studies. However, communities overlap and share many edges and nodes. Uncovering the overlapping community structure of complex networks remains largely unknown in human brain networks. Here, using regional gray matter volume, we investigated the structural brain network among 90 brain regions (according to a predefined anatomical atlas in 462 young, healthy individuals. Overlapped nodes between communities were defined by assuming that nodes (brain regions can belong to more than one community. We demonstrated that 90 brain regions were organized into 5 overlapping communities associated with several well-known brain systems, such as the auditory/language, visuospatial, emotion, decision-making, social, control of action, memory/learning, and visual systems. The overlapped nodes were mostly involved in an inferior-posterior pattern and were primarily related to auditory and visual perception. The overlapped nodes were mainly attributed to brain regions with higher node degrees and nodal efficiency and played a pivotal role in the flow of information through the structural brain network. Our results revealed fuzzy boundaries between communities by identifying overlapped nodes and provided new insights into the understanding of the relationship between the structure and function of the human brain. This study provides the first report of the overlapping community structure of the structural network of the human brain.

Woody structure facilitates invasion of woody plants by providing perches for birds.

Science.gov (United States)

Prather, Chelse M; Huynh, Andrew; Pennings, Steven C

2017-10-01

Woody encroachment threatens prairie ecosystems globally, and thus understanding the mechanisms that facilitate woody encroachment is of critical importance. Coastal tallgrass prairies along the Gulf Coast of the US are currently threatened by the spread of several species of woody plants. We studied a coastal tallgrass prairie in Texas, USA, to determine if existing woody structure increased the supply of seeds from woody plants via dispersal by birds. Specifically, we determined if (i) more seedlings of an invasive tree ( Tridacia sebifera ) are present surrounding a native woody plant ( Myrica cerifera ); (ii) wooden perches increase the quantity of seeds dispersed to a grassland; and (iii) perches alter the composition of the seed rain seasonally in prairie habitats with differing amounts of native and invasive woody vegetation, both underneath and away from artificial wooden perches. More T. sebifera seedlings were found within M. cerifera patches than in graminoid-dominated areas. Although perches did not affect the total number of seeds, perches changed the composition of seed rain to be less dominated by grasses and forbs. Specifically, 20-30 times as many seeds of two invasive species of woody plants were found underneath perches independent of background vegetation, especially during months when seed rain was highest. These results suggest that existing woody structure in a grassland can promote further woody encroachment by enhancing seed dispersal by birds. This finding argues for management to reduce woody plant abundance before exotic plants set seeds and argues against the use of artificial perches as a restoration technique in grasslands threatened by woody species.

Afforestation alters community structure of soil fungi.

Science.gov (United States)

Carson, Jennifer K; Gleeson, Deirdre B; Clipson, Nicholas; Murphy, Daniel V

2010-07-01

Relatively little is known about the effect of afforestation on soil fungal communities. This study demonstrated that afforestation altered fungal community structure and that changes were correlated to pools of soil C. Pasture at three locations on the same soil type was afforested with Eucalyptus globulus or Pinus pinaster. The structure of fungal communities under the three land uses was measured after 13y using automated ribosomal intergenic spacer analysis (ARISA). Afforestation significantly altered the structure of fungal communities. The effect of location on the structure of fungal communities was limited to pasture soils; although these contained the same plant species, the relative composition of each species varied between locations. Differences in the structure of fungal communities between pasture, E. globulus and P. pinaster were significantly correlated with changes in the amount of total organic C and microbial biomass-C in soil. Afforestation of patches of agricultural land may contribute to conserving soil fungi in agricultural landscapes by supporting fungal communities with different composition to agricultural soils. Copyright © 2010 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

The roles of mosquito and bird communities on the prevalence of West Nile virus in urban wetland and residential habitats

Science.gov (United States)

Johnson, Brian J.; Munafo, Kristin; Shappell, Laura; Tsipoura, Nellie; Robson, Mark; Ehrenfeld, Joan; Sukhdeo, Michael V. K.

2014-01-01

This study investigated the impacts of urban wetlands and their adjacent residential environments on the transmission dynamics of West Nile virus (WNV) within the state of New Jersey (USA). A working hypothesis was that urban wetlands decrease the local prevalence of WNV through the dilution effect from increased bird diversity, and through relative reductions in the numbers of competent avian host and mosquito species commonly associated with WNV. Surveys of mosquito and bird communities were undertaken at six urban wetlands and their adjacent residential environments over two seasons (2009, 2010). The community compositions of both avian and mosquito species differed significantly across habitats, and over relatively short geographical distances. Residential areas contained significantly higher proportions of WNV-competent mosquito species (31.25±5.3 %; e.g. Culex pipiens and Culex restuans), and WNV-competent avian host species (62.8±2.3 %, e.g. House Sparrow and American Robin) when compared to adjacent urban wetlands (13.5±2.1 %; 35.4±2.1 % respectively). Correspondingly, WNV infection rates within local Culex spp. populations indicate that WNV was more prevalent within residential areas (28.53/1000) compared to wetlands (16.77/1000). Large urban wetlands (>100 ha) produced significantly lower weekly WNV infection rates in local Culex spp. (6.67±2.84/1000) compared to small (urban wetlands contained significantly more species than small wetland patches. These results confirm that the community compositions of mosquito and avian hosts are important drivers in WNV infections, and that the ecological conditions that favor transmission are more strongly associated with urban residential environments than with adjacent urban wetlands. PMID:25484570

Habitat utilization by wetland birds of Munderikadavu, a proposed bird sanctuary in northern Kerala, India

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R. Roshnath

2015-10-01

Full Text Available Munderikadavu is rich in avifaunal diversity. A total of 82 species of birds from 36 families belonging to 13 orders were recorded in the wetland including wetland dependant species. Lowland vegetation had the highest species richness (46 species followed by upland (41 species, aerial (38 species, emergent vegetation (22 species and paddy fields (21 species.  Open water had the lowest species richness. Upland vegetation had the highest species diversity (H′-3.19 followed by aerial (H′-2.52.  There was more species overlap between emergent and low land vegetations (Cm-0.7.  The threats in Munderikadavu wetland were dumping of waste and conversion of cultivation land into shrimp farming area. Thus land use changes need to be regulated in order to conserve the wetland and bird community.  

Habitat structure and diversity influence the nesting success of an endangered large cavity-nesting bird, the Southern Ground-hornbill

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Leigh Combrink

2017-11-01

Full Text Available Habitat features can have a profound effect on the nesting success of birds. Savannas are often managed with predators and large herbivores as priority species, with little thought to the many bird species that management decisions could affect. Using a data set spanning seven breeding seasons, we examined how nesting success of Southern Ground-hornbills (SGHs Bucorvus leadbeateri in the Kruger National Park varied as a result of various environmental and habitat factors within a radius of 3 km surrounding the nest site. Identifying which factors affect nesting success will allow for targeted management efforts to ensure the long-term survival of SGHs both within and outside of protected areas. Habitat structure and diversity of the vegetation surrounding the nest were the most influential factors on SGH nesting success. SGHs require open grassy areas for foraging and areas with large trees for nesting. Savanna habitat drivers such as elephants and fire should be managed to ensure that sufficient large trees are able to establish in the landscape and to control for bush encroachment. This is especially important in areas earmarked for SGH reintroductions. Nest sites of SGHs should be monitored to mitigate any structural changes in the habitat surrounding the nests. Nests should be modified or artificial nest sites provided, where nests have been damaged or lost, to ensure the continued presence of these birds in African savannas. Conservation implications: Habitat structure and diversity surrounding Southern Groundhornbill nests has a significant impact on their nesting success. This highlights the importance of monitoring vegetation change in savanna habitats where they occur. Management of savanna areas should take factors that influence bush encroachment, such as fire and elephants, into account to ensure the long-term persistence of these birds.

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

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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...

Epidemic spreading on complex networks with community structures

NARCIS (Netherlands)

Stegehuis, C.; van der Hofstad, R.W.; van Leeuwaarden, J.S.H.

2016-01-01

Many real-world networks display a community structure. We study two random graph models that create a network with similar community structure as a given network. One model preserves the exact community structure of the original network, while the other model only preserves the set of communities

Conservation status and recovery strategies for endemic Hawaiian birds

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Banko, Paul C.; David, Reginald E.; Jacobi, James D.; Banko, Winston E.

2001-01-01

of birds initially increase slowly even when habitat conditions are favorable. Consequently, even as habitat conditions begin to improve, small populations may disappear unless they are supplemented directly. Hawaiian bird conservation is also affected by social and legal factors, including hunting alien game species, commercial land use practices, and lawsuits and policies concerning endangered species and critical habitat. Influenced by this mixture of conflicting and competing issues, Hawaiian bird recovery programs range from management of single species and some components of their habitats to limited forms of community or ecosystem management. Although the effectiveness of most programs is difficult to evaluate because of monitoring limitations, several programs exemplify species and community management. Programs primarily intended to recover single species include Hawaiian Goose or Nene (Branta sandvicensis), Hawaiian Crow or ‘Alala (Corvus hawaiiensis), and Palila (Loxioides bailleui). Programs attempting to manage entire communities of forest birds include Hakalau Forest National Wildlife Refuge and Hawai‘i Volcanoes National Park on Hawai‘i, and Waikamoi Preserve, Hanawi Natural Area Reserve, and Haleakala National Park on Maui.

The influence of habitat structure on bird species composition in lowland malaysian rain forests.

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Mansor, Mohammad Saiful; Sah, Shahrul Anuar Mohd

2012-05-01

Bird surveys were conducted in the Bukit Kepala Gajah limestone area in Lenggong, Perak from July 2010 to January 2011. The study area was divided into three zones: forest edge, forest intermediate and forest interior. A point-count distance sampling method was used in the bird surveys. The study recorded 7789 detections, representing 100 bird species belonging to 28 families. Pycnonotidae, Timaliidae and Nectariniidae were the dominant families overall and showed the highest number of observations recorded in the study area whereas Motacillidae showed the fewest observations. The bird species were grouped into three feeding guilds: insectivores, frugivores and others (omnivores, carnivores, nectarivores and granivores). The species richness of insectivorous birds differed significantly among the forest zones sampled (Kruskal-Wallis: α=0.05, H=10.979, d.f.=2, p=0.004), with more insectivorous birds occurring in the forest interior. No significant differences were found among the zones in the species richness of either the frugivore guild or the composite others guild.

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

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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

Evolution of the hippocampus in reptiles and birds.

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Striedter, Georg F

2016-02-15

Although the hippocampus is structurally quite different among reptiles, birds, and mammals, its function in spatial memory is said to be highly conserved. This is surprising, given that structural differences generally reflect functional differences. Here I review this enigma in some detail, identifying several evolutionary changes in hippocampal cytoarchitecture and connectivity. I recognize a lepidosaurid pattern of hippocampal organization (in lizards, snakes, and the tuatara Sphenodon) that differs substantially from the pattern of organization observed in the turtle/archosaur lineage, which includes crocodilians and birds. Although individual subdivisions of the hippocampus are difficult to homologize between these two patterns, both lack a clear homolog of the mammalian dentate gyrus. The strictly trilaminar organization of the ancestral amniote hippocampus was gradually lost in the lineage leading to birds, and birds expanded the system of intrahippocampal axon collaterals, relative to turtles and lizards. These expanded collateral axon branches resemble the extensive collaterals in CA3 of the mammalian hippocampus but probably evolved independently of them. Additional examples of convergent evolution between birds and mammals are the loss of direct inputs to the hippocampus from the primary olfactory cortex and the general expansion of telencephalic regions that communicate reciprocally with the hippocampus. Given this structural convergence, it seems likely that some similarities in the function of the hippocampus between birds and mammals, notably its role in the ability to remember many different locations without extensive training, likewise evolved convergently. The currently available data do not allow for a strong test of this hypothesis, but the hypothesis itself suggests some promising new research directions. © 2015 Wiley Periodicals, Inc.

Effect of incubation on bacterial communities of eggshells in a temperate bird, the Eurasian Magpie (Pica pica.

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Won Young Lee

Full Text Available Inhibitory effect of incubation on microbial growth has extensively been studied in wild bird populations using culture-based methods and conflicting results exist on whether incubation selectively affects the growth of microbes on the egg surface. In this study, we employed culture-independent methods, quantitative PCR and 16S rRNA gene pyrosequencing, to elucidate the effect of incubation on the bacterial abundance and bacterial community composition on the eggshells of the Eurasian Magpie (Pica pica. We found that total bacterial abundance increased and diversity decreased on incubated eggs while there were no changes on non-incubated eggs. Interestingly, Gram-positive Bacillus, which include mostly harmless species, became dominant and genus Pseudomonas, which include opportunistic avian egg pathogens, were significantly reduced after incubation. These results suggest that avian incubation in temperate regions may promote the growth of harmless (or benevolent bacteria and suppress the growth of pathogenic bacterial taxa and consequently reduce the diversity of microbes on the egg surface. We hypothesize that this may occur due to difference in sensitivity to dehydration on the egg surface among microbes, combined with the introduction of Bacillus from bird feathers and due to the presence of antibiotics that certain bacteria produce.

The importance of scaling for detecting community patterns: success and failure in assemblages of introduced species

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Allen, Craig R.; Angeler, David G.; Moulton, Michael P.; Holling, Crawford S.

2015-01-01

Community saturation can help to explain why biological invasions fail. However, previous research has documented inconsistent relationships between failed invasions (i.e., an invasive species colonizes but goes extinct) and the number of species present in the invaded community. We use data from bird communities of the Hawaiian island of Oahu, which supports a community of 38 successfully established introduced birds and where 37 species were introduced but went extinct (failed invasions). We develop a modified approach to evaluate the effects of community saturation on invasion failure. Our method accounts (1) for the number of species present (NSP) when the species goes extinct rather than during its introduction; and (2) scaling patterns in bird body mass distributions that accounts for the hierarchical organization of ecosystems and the fact that interaction strength amongst species varies with scale. We found that when using NSP at the time of extinction, NSP was higher for failed introductions as compared to successful introductions, supporting the idea that increasing species richness and putative community saturation mediate invasion resistance. Accounting for scale-specific patterns in body size distributions further improved the relationship between NSP and introduction failure. Results show that a better understanding of invasion outcomes can be obtained when scale-specific community structure is accounted for in the analysis.

Potential influence of birds on soil testate amoebae in the Arctic

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Mazei, Yuri A.; Lebedeva, Natalia V.; Taskaeva, Anastasia A.; Ivanovsky, Alexander A.; Chernyshov, Viktor A.; Tsyganov, Andrey N.; Payne, Richard J.

2018-06-01

Birds can be an important agent of environmental change in High Arctic ecosystems, particularly due to the role of seabirds as a vector transferring nutrients from the marine to terrestrial realms. The soils of bird nesting sites are known to host distinct plant communities but the consequences of bird modification for microorganisms are much less clear. Our focus here is testate amoebae: a widely-distributed group of protists with significant roles in many aspects of ecosystem functioning. We compared the testate amoeba assemblages of a site on Spitsbergen (Svalbard archipelago) affected by nesting birds, with nearby control sites. We found differences in assemblage between sites, typified by reduced relative abundance of Phryganella acropodia and Centropyxis aerophila in bird-modified soils. These changes may reflect a reduced availability of fungal food sources. We found no evidence for differences in assemblage diversity or test concentration between bird-modified and control soils. Our dataset is small but results provide the first evidence for the potential effect of bird modification of soils on testate amoebae in the Arctic. Results show only limited similarity to experimental studies of nutrient addition, implying that response mechanisms may be more complicated than simply additional nutrient supply.

Structuring evolution: biochemical networks and metabolic diversification in birds.

Science.gov (United States)

Morrison, Erin S; Badyaev, Alexander V

2016-08-25

Recurrence and predictability of evolution are thought to reflect the correspondence between genomic and phenotypic dimensions of organisms, and the connectivity in deterministic networks within these dimensions. Direct examination of the correspondence between opportunities for diversification imbedded in such networks and realized diversity is illuminating, but is empirically challenging because both the deterministic networks and phenotypic diversity are modified in the course of evolution. Here we overcome this problem by directly comparing the structure of a "global" carotenoid network - comprising of all known enzymatic reactions among naturally occurring carotenoids - with the patterns of evolutionary diversification in carotenoid-producing metabolic networks utilized by birds. We found that phenotypic diversification in carotenoid networks across 250 species was closely associated with enzymatic connectivity of the underlying biochemical network - compounds with greater connectivity occurred the most frequently across species and were the hotspots of metabolic pathway diversification. In contrast, we found no evidence for diversification along the metabolic pathways, corroborating findings that the utilization of the global carotenoid network was not strongly influenced by history in avian evolution. The finding that the diversification in species-specific carotenoid networks is qualitatively predictable from the connectivity of the underlying enzymatic network points to significant structural determinism in phenotypic evolution.

Assessing the impact of revegetation and weed control on urban sensitive bird species.

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Archibald, Carla L; McKinney, Matthew; Mustin, Karen; Shanahan, Danielle F; Possingham, Hugh P

2017-06-01

Nature in cities is concentrated in urban green spaces, which are key areas for urban biodiversity and also important areas to connect people with nature. To conserve urban biodiversity within these natural refugia, habitat restoration such as weed control and revegetation is often implemented. These actions are expected to benefit biodiversity, although species known to be affected by urbanization may not be interacting with restoration in the ways we anticipate. In this study, we use a case study to explore how urban restoration activities impact different bird species. Birds were grouped into urban sensitivity categories and species abundance, and richness was then calculated using a hierarchical species community model for individual species responses, with "urban class" used as the hierarchical parameter. We highlight variable responses of birds to revegetation and weed control based on their level of urban sensitivity. Revegetation of open grassy areas delivers significant bird conservation outcomes, but the effects of weed control are neutral or in some cases negative. Specifically, the species most reliant on remnant vegetation in cities seem to remain stable or decline in abundance in areas with weed control, which we suspect is the result of a simplification of the understorey. The literature reports mixed benefits of weed control between taxa and between locations. We recommend, in our case study site, that weed control be implemented in concert with replanting of native vegetation to provide the understory structure preferred by urban sensitive birds. Understanding the impacts of revegetation and weed control on different bird species is important information for practitioners to make restoration decisions about the allocation of funds for conservation action. This new knowledge can be used both for threatened species and invasive species management.

Effects of silviculture on neotropical migratory birds in central and southeastern oak pine forests

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James G. Dickson; Frank R. Thompson; Richard N. Conner; Kathleen E. Franzreb

1993-01-01

Avian communities that are associated with forest habitat attributes are affected by silvicultural and other stand influences. Some species have specific habitat requirements, whereas others occupy a broad range of vegetative conditions. In general, bird species richness and density are positively related to stand foliage volume and diversity. Bird density and...

Avifaunal diversity and bird community responses to man-made habitats in St. Coombs Tea Estate, Sri Lanka

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J. Dananjaya Kottawa-Arachchi

2015-02-01

Full Text Available A survey on birds was conducted at St. Coombs Tea Estate, Talawakelle, Sri Lanka with the objective of assessing the avifaunal diversity of a given tea plantation ecosystem. Bird populations were sampled in man-made habitats such as home garden, wetland, tea plantation, Eucalyptus plantation and small scale reservoir. Hundred-and-twenty counts were made for each habitat and in addition, activities of birds, feeding habits and food recourses were also observed. A total of 87 species, including 11 endemic and 11 migrant species of birds, was recorded, which included one globally threatened species, Kashmir Flycatcher Ficedula subrubra and 16 nationally threatened species. A majority of the bird species were observed in home gardens (75%, followed by reservoirs (57%, wetlands (48%, tea plantations (43% and in Eucalyptus plantations (23%. Home gardens support bird diversity while the species richness of endemic bird species increases thereby enabling these findings to be used as guidelines in long term conservational practices. Several conservation measures such as increasing plant diversity, introduction of shade trees and prevention of fire are recommended to conserve and enhance avifaunal diversity in tea plantations.

Cavity Nesting Birds

Science.gov (United States)

Virgil E. Scott; Keith E. Evans; David R. Patton; Charles P. Stone

1977-01-01

Many species of cavity-nesting birds have declined because of habitat reduction. In the eastern United States, where primeval forests are gone, purple martins depend almost entirely on man-made nesting structures (Allen and Nice 1952). The hole-nesting population of peregrine falcons disappeared with the felling of the giant trees upon which they depended (Hickey and...

Smooth particle hydrodynamic modeling and validation for impact bird substitution

Science.gov (United States)

Babu, Arun; Prasad, Ganesh

2018-04-01

Bird strike events incidentally occur and can at times be fatal for air frame structures. Federal Aviation Regulations (FAR) and such other ones mandates aircrafts to be modeled to withstand various levels of bird hit damages. The subject matter of this paper is numerical modeling of a soft body geometry for realistically substituting an actual bird for carrying out simulations of bird hit on target structures. Evolution of such a numerical code to effect an actual bird behavior through impact is much desired for making use of the state of the art computational facilities in simulating bird strike events. Validity, of simulations depicting bird hits, is largely dependent on the correctness of the bird model. In an impact, a set of complex and coupled dynamic interaction exists between the target and the impactor. To simplify this problem, impactor response needs to be decoupled from that of the target. This can be done by assuming and modeling the target as noncompliant. Bird is assumed as fluidic in a impact. Generated stresses in the bird body are significant than its yield stresses. Hydrodynamic theory is most ideal for describing this problem. Impactor literally flows steadily over the target for most part of this problem. The impact starts with an initial shock and falls into a radial release shock regime. Subsequently a steady flow is established in the bird body and this phase continues till the whole length of the bird body is turned around. Initial shock pressure and steady state pressure are ideal variables for comparing and validating the bird model. Spatial discretization of the bird is done using Smooth Particle Hydrodynamic (SPH) approach. This Discrete Element Model (DEM) offers significant advantages over other contemporary approaches. Thermodynamic state variable relations are established using Polynomial Equation of State (EOS). ANSYS AUTODYN is used to perform the explicit dynamic simulation of the impact event. Validation of the shock and steady

Large extents of intensive land use limit community reorganization during climate warming.

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Oliver, Tom H; Gillings, Simon; Pearce-Higgins, James W; Brereton, Tom; Crick, Humphrey Q P; Duffield, Simon J; Morecroft, Michael D; Roy, David B

2017-06-01

Climate change is increasingly altering the composition of ecological communities, in combination with other environmental pressures such as high-intensity land use. Pressures are expected to interact in their effects, but the extent to which intensive human land use constrains community responses to climate change is currently unclear. A generic indicator of climate change impact, the community temperature index (CTI), has previously been used to suggest that both bird and butterflies are successfully 'tracking' climate change. Here, we assessed community changes at over 600 English bird or butterfly monitoring sites over three decades and tested how the surrounding land has influenced these changes. We partitioned community changes into warm- and cold-associated assemblages and found that English bird communities have not reorganized successfully in response to climate change. CTI increases for birds are primarily attributable to the loss of cold-associated species, whilst for butterflies, warm-associated species have tended to increase. Importantly, the area of intensively managed land use around monitoring sites appears to influence these community changes, with large extents of intensively managed land limiting 'adaptive' community reorganization in response to climate change. Specifically, high-intensity land use appears to exacerbate declines in cold-adapted bird and butterfly species, and prevent increases in warm-associated birds. This has broad implications for managing landscapes to promote climate change adaptation. © 2017 John Wiley & Sons Ltd.

Understory Bird Communities in Amazonian Rainforest Fragments: Species Turnover through 25 Years Post-Isolation in Recovering Landscapes

Science.gov (United States)

Stouffer, Philip C.; Johnson, Erik I.; Bierregaard, Richard O.; Lovejoy, Thomas E.

2011-01-01

Inferences about species loss following habitat conversion are typically drawn from short-term surveys, which cannot reconstruct long-term temporal dynamics of extinction and colonization. A long-term view can be critical, however, to determine the stability of communities within fragments. Likewise, landscape dynamics must be considered, as second growth structure and overall forest cover contribute to processes in fragments. Here we examine bird communities in 11 Amazonian rainforest fragments of 1–100 ha, beginning before the fragments were isolated in the 1980s, and continuing through 2007. Using a method that accounts for imperfect detection, we estimated extinction and colonization based on standardized mist-net surveys within discreet time intervals (1–2 preisolation samples and 4–5 post-isolation samples). Between preisolation and 2007, all fragments lost species in an area-dependent fashion, with loss of as few as <10% of preisolation species from 100-ha fragments, but up to 70% in 1-ha fragments. Analysis of individual time intervals revealed that the 2007 result was not due to gradual species loss beginning at isolation; both extinction and colonization occurred in every time interval. In the last two samples, 2000 and 2007, extinction and colonization were approximately balanced. Further, 97 of 101 species netted before isolation were detected in at least one fragment in 2007. Although a small subset of species is extremely vulnerable to fragmentation, and predictably goes extinct in fragments, developing second growth in the matrix around fragments encourages recolonization in our landscapes. Species richness in these fragments now reflects local turnover, not long-term attrition of species. We expect that similar processes could be operating in other fragmented systems that show unexpectedly low extinction. PMID:21731616

Understory bird communities in Amazonian rainforest fragments: species turnover through 25 years post-isolation in recovering landscapes.

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Philip C Stouffer

Full Text Available Inferences about species loss following habitat conversion are typically drawn from short-term surveys, which cannot reconstruct long-term temporal dynamics of extinction and colonization. A long-term view can be critical, however, to determine the stability of communities within fragments. Likewise, landscape dynamics must be considered, as second growth structure and overall forest cover contribute to processes in fragments. Here we examine bird communities in 11 Amazonian rainforest fragments of 1-100 ha, beginning before the fragments were isolated in the 1980s, and continuing through 2007. Using a method that accounts for imperfect detection, we estimated extinction and colonization based on standardized mist-net surveys within discreet time intervals (1-2 preisolation samples and 4-5 post-isolation samples. Between preisolation and 2007, all fragments lost species in an area-dependent fashion, with loss of as few as <10% of preisolation species from 100-ha fragments, but up to 70% in 1-ha fragments. Analysis of individual time intervals revealed that the 2007 result was not due to gradual species loss beginning at isolation; both extinction and colonization occurred in every time interval. In the last two samples, 2000 and 2007, extinction and colonization were approximately balanced. Further, 97 of 101 species netted before isolation were detected in at least one fragment in 2007. Although a small subset of species is extremely vulnerable to fragmentation, and predictably goes extinct in fragments, developing second growth in the matrix around fragments encourages recolonization in our landscapes. Species richness in these fragments now reflects local turnover, not long-term attrition of species. We expect that similar processes could be operating in other fragmented systems that show unexpectedly low extinction.

Effects of Selective Logging on Birds in the Sierra de Coalcoman, Sierra Madre del Sur, Michoacan, Western Mexico

Science.gov (United States)

Jose Fernando Villaseñor; Neyra Sosa; Laura Villaseñor

2005-01-01

In order to determine the effects of selective logging on pine-oak forest?s bird communities in central-western Mexico, we gathered information through 10-min point counts in plots without wood extraction and sites logged at different times in the past (1, 4, and 8 years). We did not find evidences to argue for effects of logging on bird communities; the study plots...

Research on Community Structure in Bus Transport Networks

International Nuclear Information System (INIS)

Yang Xuhua; Wang Bo; Sun Youxian

2009-01-01

We abstract the bus transport networks (BTNs) to two kinds of complex networks with space L and space P methods respectively. Using improved community detecting algorithm (PKM agglomerative algorithm), we analyze the community property of two kinds of BTNs graphs. The results show that the BTNs graph described with space L method have obvious community property, but the other kind of BTNs graph described with space P method have not. The reason is that the BTNs graph described with space P method have the intense overlapping community property and general community division algorithms can not identify this kind of community structure. To overcome this problem, we propose a novel community structure called N-depth community and present a corresponding community detecting algorithm, which can detect overlapping community. Applying the novel community structure and detecting algorithm to a BTN evolution model described with space P, whose network property agrees well with real BTNs', we get obvious community property. (general)

Epidemics in adaptive networks with community structure

Science.gov (United States)

Shaw, Leah; Tunc, Ilker

2010-03-01

Models for epidemic spread on static social networks do not account for changes in individuals' social interactions. Recent studies of adaptive networks have modeled avoidance behavior, as non-infected individuals try to avoid contact with infectives. Such models have not generally included realistic social structure. Here we study epidemic spread on an adaptive network with community structure. We model the effect of heterogeneous communities on infection levels and epidemic extinction. We also show how an epidemic can alter the community structure.

Hawai`i forest bird monitoring database: Database dictionary

Science.gov (United States)

Camp, Richard J.; Genz, Ayesha

2017-01-01

Between 1976 and 1981, the U.S. Fish and Wildlife Service (now U.S. Geological Survey – Pacific Island Ecosystems Research Center [USGS-PIERC]) conducted systematic surveys of forest birds and plant communities on all the main Hawaiian Islands, except O‘ahu, as part of the Hawai‘i Forest Bird Surveys (HFBS). Results of this monumental effort have guided conservation efforts and provided the basis for many plant and bird recovery plans and land acquisition decisions in Hawai‘i. Unfortunately, these estimates and range maps are now seriously outdated, hindering modern conservation decision-making and recovery planning. HFBIDP staff work closely with land managers and others to identify the location of bird populations in need of protection. In addition, HFBIDP is able to assess field collection methods, census areas, and survey frequency for their effectiveness. Survey and geographical data are refined and released in successive versions, each more inclusive, detailed, and accurate than the previous release. Incrementally releasing data gives land managers and survey coordinators reasonably good data to work with early on rather than waiting for the release of ‘perfect’ data, ‘perfectly’ analyzed. Consequently, summary results are available in a timely manner.

Nest Site Characteristics of Cavity Nesting Birds in Central Missouri

Science.gov (United States)

Jeffery D. Brawn; Bernice Tannenbaum; Keith E. Evans

1984-01-01

Two study sites in central Missouri oak-hickory forests were searched for nest sites of cavity nesting birds. Researchers located and measured 133 nests of 11 species. Cavity nesting bird habitat selection is affected by both snag characteristics and vegetation structure.

Bats and birds increase crop yield in tropical agroforestry landscapes.

Science.gov (United States)

Maas, Bea; Clough, Yann; Tscharntke, Teja

2013-12-01

Human welfare is significantly linked to ecosystem services such as the suppression of pest insects by birds and bats. However, effects of biocontrol services on tropical cash crop yield are still largely unknown. For the first time, we manipulated the access of birds and bats in an exclosure experiment (day, night and full exclosures compared to open controls in Indonesian cacao agroforestry) and quantified the arthropod communities, the fruit development and the final yield over a long time period (15 months). We found that bat and bird exclusion increased insect herbivore abundance, despite the concurrent release of mesopredators such as ants and spiders, and negatively affected fruit development, with final crop yield decreasing by 31% across local (shade cover) and landscape (distance to primary forest) gradients. Our results highlight the tremendous economic impact of common insectivorous birds and bats, which need to become an essential part of sustainable landscape management. © 2013 John Wiley & Sons Ltd/CNRS.

Research and management priorities for Hawai‘i forest birds

Science.gov (United States)

Paxton, Eben H.; Laut, Megan; Vetter, J.P.; Kendall, Steve J.

2018-01-01

Hawai‘i’s forest birds face a number of conservation challenges that, if unaddressed, will likely lead to the extinction of multiple species in the coming decades. Threats include habitat loss, invasive plants, non-native predators, and introduced diseases. Climate change is predicted to increase the geographic extent and intensity of these threats, adding urgency to implementation of tractable conservation strategies. We present a set of actionable research and management approaches, identified by conservation practitioners in Hawai’i, that will be critical for the conservation of Hawaiian forest birds in the coming years. We also summarize recent progress on these conservation priorities. The threats facing Hawai‘i’s forest birds are not unique to Hawai‘i, and successful conservation strategies developed in Hawai‘i can serve as a model for other imperiled communities around the world, especially on islands.

Viñales Taxonomic Characterization and trophic groups of two communities of birds associated to semideciduos forests and vegetation of Pine-oak of the paths «Marvels of Viñales» and «Valley Ancón» in Viñales National Park

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Miguel Cué Rivero

2015-06-01

Full Text Available The present work was carried out in the months of February to April 2009 in the semideciduos forest «Marvels of Viñales» and the formation pine-encino of the «Valley Ancón» of the Viñales National Park and it pursued as main objective to characterize the taxonomic composition and tropic groups tof two communities of birds associated to semideciduos forest and pine oak vegetation from both -. The method of circular parcels of fixed radio was used in 30 points of counts separated to 150 m one of another. There were detected a total of 44 species of birds (in the semideciduo and 42 in pine-oak contained in 9 orders and 18 families. They registered 23 trophic groups with prevalence of Insectivorous. The communities of birds of the formation of semideciduo forest of the path «Marvels of Viñales» and of the forest of pine oak of «Valley Ancón» presented differences in its taxonomic composition The communities of birds of both vegetable formations showed differences as for their trophiccomposition but so much in one as in other majority of birds consumers of insects and grains was observed.

Finding Community Structures In Social Activity Data

KAUST Repository

Peng, Chengbin

2015-01-01

Social activity data sets are increasing in number and volume. Finding community structure in such data is valuable in many applications. For example, understand- ing the community structure of social networks may reduce the spread of epidemics

Potential impacts of wind turbines on birds at North Cape, Prince Edward Island

Energy Technology Data Exchange (ETDEWEB)

Kingsley, A.; Whitman, B.

2001-12-13

As the number of new wind power generating stations in Canada grows, so do concerns regarding the environmental impact of turbines on birds, particularly on raptors and migrating songbirds. These birds are generally at greatest risk of injury or death from turbines, but the impact of these structures on all bird species must be considered on a site-by-site basis. Disturbance to breeding and wintering as a result of turbines must be better researched. This report reviews the literature on the effects of wind turbines on birds, with reference to the North Cape, Prince Edward Island. It recommends ways to reduce potential impacts of turbines on birds in that area, and suggests a program whereby the potential effects of wind turbines on birds can be monitored. The bird groups likely to be seen at North Cape include water birds, raptors, songbirds, and 5 bird species that are considered to be provincially rare. The main causes of bird mortality at wind powered energy facilities are birds flying into rotating turbine blades. Migrating birds are attracted to warning lights on the turbines and collide with the structures and they also collide with the power lines connected to the station. Poor weather conditions, such as fog, increase the occurrence of collisions with towers. Several studies have shown that most migrating and wintering bird species alter their flight paths to avoid turbines. Studies also indicate that bird mortalities at wind energy facilities are not biologically significant and that impacts are not likely to be significant if wind turbines are located in areas of poor habitat and low bird densities. 61 refs., 1 tab., 1 fig.

Guam and the Northern Mariana Islands ESI: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for pelagic birds, shorebirds, wading birds, waterfowl, gulls, terns, and passerine birds in Guam and the...

Status of wetland birds of Chhilchhila Wildlife Sanctuary, Haryana, India

Directory of Open Access Journals (Sweden)

P. Kumar

2013-03-01

Full Text Available The Chhilchhila Wildlife Sanctuary (76036-76046 E and 29052-30000 N, situated in Kurukshetra District of Haryana provides an important wintering ground for a diverse range of wetland birds. This study was carried out from April 2009 to March 2012 to document the diversity of wetland birds. Altogether 57 species of wetland birds belonging to 37 genera and 16 families were recorded from the study area. Family Anatidae dominated the wetland bird community with 13 species. Among recorded species, 33 were winter migrants, two summer migrants and 22 were resident species. The winter migratory birds did not arrive at this wetland in one lot and at one time. Instead, they displayed a definite pattern specific to species for arrival and departure. They appeared at the wetland during mid-October and stayed up to early April. The composition of birds in major feeding guilds in the study area showed that the insectivore guild was the most common with 35.09% species, followed by carnivore (29.82%, omnivore (19.30%, herbivore (10.53% and piscivore (5.26%. Among the birds recorded in this study area, Darter (Anhinga melanogaster and Painted Stork (Mycterialeucocephala were Near Threatened species. Comb Duck (Sarkidiornismelanotos, listed in Appendix II of CITES, was also spotted in the sanctuary. The spotting of these threatened bird species highlights the importance of Chhilchhila Wildlife Sanctuary as a significant wetland bird habitat in Haryana. However, anthropogenic activities like fire wood collection, livestock grazing, cutting of emergent and fringe vegetation and improper management of the wetland are major threats to the ecology of this landscape.

Effects of Tide Stage on the Use of Salt Marshes by Wading Birds in Rhode Island

Science.gov (United States)

To determine how tide stage affects wading bird abundance, behavior, and foraging in three Narragansett Bay salt marshes (RI), we conducted surveys at 10-min intervals—across the full tidal range—during six days at each marsh in July/September of 2006. The wading bird community ...

Native birds and alien insects: spatial density dependence in songbird predation of invading oak gallwasps.

Directory of Open Access Journals (Sweden)

Karsten Schönrogge

Full Text Available Revealing the interactions between alien species and native communities is central to understanding the ecological consequences of range expansion. Much has been learned through study of the communities developing around invading herbivorous insects. Much less, however, is known about the significance of such aliens for native vertebrate predators for which invaders may represent a novel food source. We quantified spatial patterns in native bird predation of invading gall-inducing Andricus wasps associated with introduced Turkey oak (Quercus cerris at eight sites across the UK. These gallwasps are available at high density before the emergence of caterpillars that are the principle spring food of native insectivorous birds. Native birds showed positive spatial density dependence in gall attack rates at two sites in southern England, foraging most extensively on trees with highest gall densities. In a subsequent study at one of these sites, positive spatial density dependence persisted through four of five sequential week-long periods of data collection. Both patterns imply that invading galls are a significant resource for at least some native bird populations. Density dependence was strongest in southern UK bird populations that have had longest exposure to the invading gallwasps. We hypothesise that this pattern results from the time taken for native bird populations to learn how to exploit this novel resource.

Rhode Island, Connecticut, New York, and New Jersey ESI: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, pelagic birds, passerine birds, gulls and...

Drug metabolism in birds

Science.gov (United States)

Pan, Huo Ping; Fouts, James R.

1979-01-01

Papers published over 100 years since the beginning of the scientific study of drug metabolism in birds were reviewed. Birds were found to be able to accomplish more than 20 general biotransformation reactions in both functionalization and conjugation. Chickens were the primary subject of study but over 30 species of birds were used. Large species differences in drug metabolism exist between birds and mammals as well as between various birds, these differences were mostly quantitative. Qualitative differences were rare. On the whole, drug metabolism studies in birds have been neglected as compared with similar studies on insects and mammals. The uniqueness of birds and the advantages of using birds in drug metabolism studies are discussed. Possible future studies of drug metabolism in birds are recommended.

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

Directory of Open Access Journals (Sweden)

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.

Unraveling the drivers of community dissimilarity and species extinction in fragmented landscapes.

Science.gov (United States)

Banks-Leite, Cristina; Ewers, Robert M; Metzger, Jean Paul

2012-12-01

Communities in fragmented landscapes are often assumed to be structured by species extinction due to habitat loss, which has led to extensive use of the species-area relationship (SAR) in fragmentation studies. However, the use of the SAR presupposes that habitat loss leads species to extinction but does not allow for extinction to be offset by colonization of disturbed-habitat specialists. Moreover, the use of SAR assumes that species richness is a good proxy of community changes in fragmented landscapes. Here, we assessed how communities dwelling in fragmented landscapes are influenced by habitat loss at multiple scales; then we estimated the ability of models ruled by SAR and by species turnover in successfully predicting changes in community composition, and asked whether species richness is indeed an informative community metric. To address these issues, we used a data set consisting of 140 bird species sampled in 65 patches, from six landscapes with different proportions of forest cover in the Atlantic Forest of Brazil. We compared empirical patterns against simulations of over 8 million communities structured by different magnitudes of the power-law SAR and with species-specific rules to assign species to sites. Empirical results showed that, while bird community composition was strongly influenced by habitat loss at the patch and landscape scale, species richness remained largely unaffected. Modeling results revealed that the compositional changes observed in the Atlantic Forest bird metacommunity were only matched by models with either unrealistic magnitudes of the SAR or by models ruled by species turnover, akin to what would be observed along natural gradients. We show that, in the presence of such compositional turnover, species richness is poorly correlated with species extinction, and z values of the SAR strongly underestimate the effects of habitat loss. We suggest that the observed compositional changes are driven by each species reaching its

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...

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

Science.gov (United States)

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

2014-02-01

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

Birds of Puerto Interior Turístico Jocotepec in Lake Chapala, Jalisco, México

Directory of Open Access Journals (Sweden)

J. Carlo Cuevas

2017-10-01

Full Text Available Lake Chapala is the largest lake in Mexico. It is an area of interest for biological conservation, designated as a Ramsar site and recognized as an Important Bird Conservation Area for Mexico (aica 58. The wetlands of Jalisco are of high importance for bird conservation; however, there are few studies about the birds of Lake Chapala. We studied bird community in the Puerto Interior Turistico Jocotepec, an urban park of Lake Chapala. We conducted our study from April 2015 to March 2016. We registered 100 bird species of 14 orders and 34 families. Sixty-nine percent of birds are residents, 30% are winter visitors, and 1% are transient. Also, we compared species richness and composition between our results and other studies from the state of Jalisco. We highlight the presence of Rallus longirostris, a resident and endemic species to central-western Mexico, which has the highest vulnerability value. We highlight the biological importance of the urban park and we suggest increasing the number of bird research in Lake Chapala.

Similarity between community structures of different online social networks and its impact on underlying community detection

Science.gov (United States)

Fan, W.; Yeung, K. H.

2015-03-01

As social networking services are popular, many people may register in more than one online social network. In this paper we study a set of users who have accounts of three online social networks: namely Foursquare, Facebook and Twitter. Community structure of this set of users may be reflected in these three online social networks. Therefore, high correlation between these reflections and the underlying community structure may be observed. In this work, community structures are detected in all three online social networks. Also, we investigate the similarity level of community structures across different networks. It is found that they show strong correlation with each other. The similarity between different networks may be helpful to find a community structure close to the underlying one. To verify this, we propose a method to increase the weights of some connections in networks. With this method, new networks are generated to assist community detection. By doing this, value of modularity can be improved and the new community structure match network's natural structure better. In this paper we also show that the detected community structures of online social networks are correlated with users' locations which are identified on Foursquare. This information may also be useful for underlying community detection.

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.

Tritrophic effects of birds and ants on a canopy food web, tree growth, and phytochemistry

Science.gov (United States)

Kailen A. Mooney

2007-01-01

Insectivorous birds and ants co-occur in most terrestrial communities, and theory predicts that emergent properties (i.e., nonadditive effects) can determine their combined influence on arthropods and plants. In a three-year factorial experiment, I investigated whether the effects of birds on pine and its arthropods differed based on the presence of ants that were...

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.

Breeding bird populations and habitat associations within the Savannah River Site (SRS).

Energy Technology Data Exchange (ETDEWEB)

Gauthreaux, Sidney, A.; Steven J. Wagner.

2005-06-29

Gauthreaux, Sidney, A., and Steven J. Wagner. 2005. Breeding bird populations and habitat associations within the Savannah River Site (SRS). Final Report. USDA Forest Service, Savannah River, Aiken, SC. 48 pp. Abstract: During the 1970's and 1980's a dramatic decline occurred in the populations of Neotropical migratory birds, species that breed in North America and winter south of the border in Central and South America and in the Caribbean. In 1991 an international initiative was mounted by U. S. governmental land management agencies, nongovernmental conservation agencies, and the academic and lay ornithological communities to understand the decline of Neotropical migratory birds in the Americas. In cooperation with the USDA Forest Service - Savannah River (FS - SR) we began 1992 a project directed to monitoring population densities of breeding birds using the Breeding Bird Census (BBC) methodology in selected habitats within the Savannah River Site SRS. In addition we related point count data on the occurrence of breeding Neotropical migrants and other bird species to the habitat data gathered by the Forest Inventory and Analysis (FIA) program of the USDA Forest Service and data on habitat treatments within forest stands.

Large-scale wind energy and birds in Friesland: A survey of the possible hindrance for birds of the project Windstreek: Environmental Effect Report Windstreek, Base report A

International Nuclear Information System (INIS)

Van den Bergh, L.M.J.; Spaans, A.L.

1994-01-01

For several alternative sites in the Dutch province Friesland, where it is planned to install 500 kW and 1 MW wind turbines on a large scale (the Windstreek project), the possible hindrance for breeding birds, stopping birds and migratory birds has been investigated. First an overview is given of basic data from the literature and experts in the field with regard to the possible hindrances for birds and the situation of the birds in the areas considered. Next, several criteria are used to determine which locations are the most suitable sites for placing the wind turbines. For the 500 kW wind turbines (worst case) the suitability differs strongly per site. The variation is the largest for the option of decentralized sites. Realization of 200 MW large-scale generated wind power is the least unfavourable option, regarding the effects on birds, by means of decentralized sites. The super-structure option Afsluitdijk-Waddenkust and the Project Memorandum alternative are for that matter the least favourable options. The combined alternative and the super-structure Middelzeetrechter take the in-between position. The 1MW variants of the alternatives score better than the similar 500 kW options. The hindrance for birds can be reduced further by applying two-bladed rotors instead of three-bladed rotors and to adjust the site. 20 figs., 9 tabs., 2 appendices, 42 refs

Enhancing community detection by using local structural information

International Nuclear Information System (INIS)

Xiang, Ju; Bao, Mei-Hua; Tang, Liang; Li, Jian-Ming; Hu, Ke; Chen, Benyan; Hu, Jing-Bo; Zhang, Yan; Tang, Yan-Ni; Gao, Yuan-Yuan

2016-01-01

Many real-world networks, such as gene networks, protein–protein interaction networks and metabolic networks, exhibit community structures, meaning the existence of groups of densely connected vertices in the networks. Many local similarity measures in the networks are closely related to the concept of the community structures, and may have a positive effect on community detection in the networks. Here, various local similarity measures are used to extract local structural information, which is then applied to community detection in the networks by using the edge-reweighting strategy. The effect of the local similarity measures on community detection is carefully investigated and compared in various networks. The experimental results show that the local similarity measures are crucial for the improvement of community detection methods, while the positive effect of the local similarity measures is closely related to the networks under study and applied community detection methods. (paper: interdisciplinary statistical mechanics)

Birds of Sabaki Birds of Sabaki

African Journals Online (AJOL)

CJ

2005-02-25

Feb 25, 2005 ... covers approximately 250ha.The area encompassed by this study extends from Mambrui to the north, the sea to the east, the opposite bank of the estuary to the south and the Sabaki bridge and Malindi-Garsen road to the west. The area is defined as an Important Bird Area(IBA) by BirdLife International in ...

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.

Fossilized skin reveals coevolution with feathers and metabolism in feathered dinosaurs and early birds.

Science.gov (United States)

McNamara, Maria E; Zhang, Fucheng; Kearns, Stuart L; Orr, Patrick J; Toulouse, André; Foley, Tara; Hone, David W E; Rogers, Chris S; Benton, Michael J; Johnson, Diane; Xu, Xing; Zhou, Zhonghe

2018-05-25

Feathers are remarkable evolutionary innovations that are associated with complex adaptations of the skin in modern birds. Fossilised feathers in non-avian dinosaurs and basal birds provide insights into feather evolution, but how associated integumentary adaptations evolved is unclear. Here we report the discovery of fossil skin, preserved with remarkable nanoscale fidelity, in three non-avian maniraptoran dinosaurs and a basal bird from the Cretaceous Jehol biota (China). The skin comprises patches of desquamating epidermal corneocytes that preserve a cytoskeletal array of helically coiled α-keratin tonofibrils. This structure confirms that basal birds and non-avian dinosaurs shed small epidermal flakes as in modern mammals and birds, but structural differences imply that these Cretaceous taxa had lower body heat production than modern birds. Feathered epidermis acquired many, but not all, anatomically modern attributes close to the base of the Maniraptora by the Middle Jurassic.

Global Avian Influenza Surveillance in Wild Birds: A Strategy to Capture Viral Diversity

Science.gov (United States)

Machalaba, Catherine C.; Elwood, Sarah E.; Forcella, Simona; Smith, Kristine M.; Hamilton, Keith; Jebara, Karim B.; Swayne, David E.; Webby, Richard J.; Mumford, Elizabeth; Mazet, Jonna A.K.; Gaidet, Nicolas; Daszak, Peter

2015-01-01

Wild birds play a major role in the evolution, maintenance, and spread of avian influenza viruses. However, surveillance for these viruses in wild birds is sporadic, geographically biased, and often limited to the last outbreak virus. To identify opportunities to optimize wild bird surveillance for understanding viral diversity, we reviewed responses to a World Organisation for Animal Health–administered survey, government reports to this organization, articles on Web of Knowledge, and the Influenza Research Database. At least 119 countries conducted avian influenza virus surveillance in wild birds during 2008–2013, but coordination and standardization was lacking among surveillance efforts, and most focused on limited subsets of influenza viruses. Given high financial and public health burdens of recent avian influenza outbreaks, we call for sustained, cost-effective investments in locations with high avian influenza diversity in wild birds and efforts to promote standardized sampling, testing, and reporting methods, including full-genome sequencing and sharing of isolates with the scientific community. PMID:25811221

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.

Bird Integumentary Melanins: Biosynthesis, Forms, Function and Evolution

Science.gov (United States)

Galván, Ismael; Solano, Francisco

2016-01-01

Melanins are the ubiquitous pigments distributed in nature. They are one of the main pigments responsible for colors in living cells. Birds are among the most diverse animals regarding melanin-based coloration, especially in the plumage, although they also pigment bare parts of the integument. This review is devoted to the main characteristics of bird melanins, including updated views of the formation and nature of melanin granules, whose interest has been raised in the last years for inferring the color of extinct birds and non-avian theropod dinosaurs using resistant fossil feathers. The molecular structure of the two main types of melanin, eumelanin and pheomelanin, and the environmental and genetic factors that regulate avian melanogenesis are also presented, establishing the main relationship between them. Finally, the special functions of melanin in bird feathers are also discussed, emphasizing the aspects more closely related to these animals, such as honest signaling, and the factors that may drive the evolution of pheomelanin and pheomelanin-based color traits, an issue for which birds have been pioneer study models. PMID:27070583

Bird Integumentary Melanins: Biosynthesis, Forms, Function and Evolution

Directory of Open Access Journals (Sweden)

Ismael Galván

2016-04-01

Full Text Available Melanins are the ubiquitous pigments distributed in nature. They are one of the main pigments responsible for colors in living cells. Birds are among the most diverse animals regarding melanin-based coloration, especially in the plumage, although they also pigment bare parts of the integument. This review is devoted to the main characteristics of bird melanins, including updated views of the formation and nature of melanin granules, whose interest has been raised in the last years for inferring the color of extinct birds and non-avian theropod dinosaurs using resistant fossil feathers. The molecular structure of the two main types of melanin, eumelanin and pheomelanin, and the environmental and genetic factors that regulate avian melanogenesis are also presented, establishing the main relationship between them. Finally, the special functions of melanin in bird feathers are also discussed, emphasizing the aspects more closely related to these animals, such as honest signaling, and the factors that may drive the evolution of pheomelanin and pheomelanin-based color traits, an issue for which birds have been pioneer study models.

Birds in Anthropogenic Landscapes: The Responses of Ecological Groups to Forest Loss in the Brazilian Atlantic Forest.

Directory of Open Access Journals (Sweden)

José Carlos Morante-Filho

Full Text Available Habitat loss is the dominant threat to biodiversity and ecosystem functioning in terrestrial environments. In this study, we used an a priori classification of bird species based on their dependence on native forest habitats (forest-specialist and habitat generalists and specific food resources (frugivores and insectivores to evaluate their responses to forest cover reduction in landscapes in the Brazilian Atlantic Forest. From the patch-landscapes approach, we delimited 40 forest sites, and quantified the percentage of native forest within a 2 km radius around the center of each site (from 6 - 85%. At each site, we sampled birds using the point-count method. We used a null model, a generalized linear model and a four-parameter logistic model to evaluate the relationship between richness and abundance of the bird groups and the native forest amount. A piecewise model was then used to determine the threshold value for bird groups that showed nonlinear responses. The richness and abundance of the bird community as a whole were not affected by changes in forest cover in this region. However, a decrease in forest cover had a negative effect on diversity of forest-specialist, frugivorous and insectivorous birds, and a positive effect on generalist birds. The species richness and abundance of all ecological groups were nonlinearly related to forest reduction and showed similar threshold values, i.e., there were abrupt changes in individuals and species numbers when forest amount was less than approximately 50%. Forest sites within landscapes with forest cover that was less than 50% contained a different bird species composition than more extensively forested sites and had fewer forest-specialist species and higher beta-diversity. Our study demonstrated the pervasive effect of forest reduction on bird communities in one of the most important hotspots for bird conservation and shows that many vulnerable species require extensive forest cover to persist.

Birds in Anthropogenic Landscapes: The Responses of Ecological Groups to Forest Loss in the Brazilian Atlantic Forest.

Science.gov (United States)

Morante-Filho, José Carlos; Faria, Deborah; Mariano-Neto, Eduardo; Rhodes, Jonathan

2015-01-01

Habitat loss is the dominant threat to biodiversity and ecosystem functioning in terrestrial environments. In this study, we used an a priori classification of bird species based on their dependence on native forest habitats (forest-specialist and habitat generalists) and specific food resources (frugivores and insectivores) to evaluate their responses to forest cover reduction in landscapes in the Brazilian Atlantic Forest. From the patch-landscapes approach, we delimited 40 forest sites, and quantified the percentage of native forest within a 2 km radius around the center of each site (from 6 - 85%). At each site, we sampled birds using the point-count method. We used a null model, a generalized linear model and a four-parameter logistic model to evaluate the relationship between richness and abundance of the bird groups and the native forest amount. A piecewise model was then used to determine the threshold value for bird groups that showed nonlinear responses. The richness and abundance of the bird community as a whole were not affected by changes in forest cover in this region. However, a decrease in forest cover had a negative effect on diversity of forest-specialist, frugivorous and insectivorous birds, and a positive effect on generalist birds. The species richness and abundance of all ecological groups were nonlinearly related to forest reduction and showed similar threshold values, i.e., there were abrupt changes in individuals and species numbers when forest amount was less than approximately 50%. Forest sites within landscapes with forest cover that was less than 50% contained a different bird species composition than more extensively forested sites and had fewer forest-specialist species and higher beta-diversity. Our study demonstrated the pervasive effect of forest reduction on bird communities in one of the most important hotspots for bird conservation and shows that many vulnerable species require extensive forest cover to persist.

Contribution of double scattering to structural coloration in quasiordered nanostructures of bird feathers

Science.gov (United States)

Noh, Heeso; Liew, Seng Fatt; Saranathan, Vinodkumar; Prum, Richard O.; Mochrie, Simon G. J.; Dufresne, Eric R.; Cao, Hui

2010-05-01

We measured the polarization- and angle-resolved optical scattering and reflection spectra of the quasiordered nanostructures in the bird feather barbs. In addition to the primary peak that originates from single scattering, we observed a secondary peak which exhibits depolarization and distinct angular dispersion. We explained the secondary peak in terms of double scattering, i.e., light is scattered successively twice by the structure. The two sequential single-scattering events are considered uncorrelated. Using the Fourier power spectra of the nanostructures obtained from the small-angle x-ray scattering experiment, we calculated the double scattering of light in various directions. The double-scattering spectrum is broader than the single-scattering spectrum, and it splits into two subpeaks at larger scattering angle. The good agreement between the simulation results and the experimental data confirms that double scattering of light makes a significant contribution to the structural color.

Contribution of double scattering to structural coloration in quasiordered nanostructures of bird feathers

Energy Technology Data Exchange (ETDEWEB)

Noh, Heeso; Liew, Seng Fatt; Saranathan, Vinodkumar; Prum, Richard O.; Mochrie, Simon G.J.; Dufresne, Eric R.; Cao, Hui (Yale)

2010-07-28

We measured the polarization- and angle-resolved optical scattering and reflection spectra of the quasiordered nanostructures in the bird feather barbs. In addition to the primary peak that originates from single scattering, we observed a secondary peak which exhibits depolarization and distinct angular dispersion. We explained the secondary peak in terms of double scattering, i.e., light is scattered successively twice by the structure. The two sequential single-scattering events are considered uncorrelated. Using the Fourier power spectra of the nanostructures obtained from the small-angle x-ray scattering experiment, we calculated the double scattering of light in various directions. The double-scattering spectrum is broader than the single-scattering spectrum, and it splits into two subpeaks at larger scattering angle. The good agreement between the simulation results and the experimental data confirms that double scattering of light makes a significant contribution to the structural color.

Trophic structure and avian communities across a salinity gradient in evaporation ponds of the San Francisco Bay estuary

Science.gov (United States)

Takekawa, John Y.; Miles, A.K.; Schoellhamer, D.H.; Athearn, N.D.; Saiki, M.K.; Duffy, W.D.; Kleinschmidt, S.; Shellenbarger, G.G.; Jannusch, C.A.

2006-01-01

Commercial salt evaporation ponds comprise a large proportion of baylands adjacent to the San Francisco Bay, a highly urbanized estuary. In the past two centuries, more than 79% of the historic tidal wetlands in this estuary have been lost. Resource management agencies have acquired more than 10 000 ha of commercial salt ponds with plans to undertake one of the largest wetland restoration projects in North America. However, these plans have created debate about the ecological importance of salt ponds for migratory bird communities in western North America. Salt ponds are unique mesohaline (5–18 g l−1) to hyperhaline (> 40 g l−1) wetlands, but little is known of their ecological structure or value. Thus, we studied decommissioned salt ponds in the North Bay of the San Francisco Bay estuary from January 1999 through November 2001. We measured water quality parameters (salinity, DO, pH, temperature), nutrient concentrations, primary productivity, zooplankton, macroinvertebrates, fish, and birds across a range of salinities from 24 to 264 g l−1. Our studies documented how unique limnological characteristics of salt ponds were related to nutrient levels, primary productivity rates, invertebrate biomass and taxa richness, prey fish, and avian predator numbers. Salt ponds were shown to have unique trophic and physical attributes that supported large numbers of migratory birds. Therefore, managers should carefully weigh the benefits of increasing habitat for native tidal marsh species with the costs of losing these unique hypersaline systems.

Comparing the response of birds and butterflies to vegetation-based mountain ecotones using boundary detection approaches.

Science.gov (United States)

Kent, Rafi; Levanoni, Oded; Banker, Eran; Pe'er, Guy; Kark, Salit

2013-01-01

Mountains provide an opportunity to examine changes in biodiversity across environmental gradients and areas of transition (ecotones). Mountain ecotones separate vegetation belts. Here, we aimed to examine whether transition areas for birds and butterflies spatially correspond with ecotones between three previously described altitudinal vegetation belts on Mt. Hermon, northern Israel. These include the Mediterranean Maquis, xero-montane open forest and Tragacanthic mountain steppe vegetation belts. We sampled the abundance of bird and butterfly species in 34 sampling locations along an elevational gradient between 500 and 2200 m. We applied wombling, a boundary-detection technique, which detects rapid changes in a continuous variable, in order to locate the transition areas for bird and butterfly communities and compare the location of these areas with the location of vegetation belts as described in earlier studies of Mt. Hermon. We found some correspondence between the areas of transition of both bird and butterfly communities and the ecotones between vegetation belts. For birds and butterflies, important transitions occurred at the lower vegetation ecotone between Mediterranean maquis and the xero-montane open forest vegetation belts, and between the xero-montane open forest and the mountain steppe Tragacanthic belts. While patterns of species turnover with elevation were similar for birds and butterflies, the change in species richness and diversity with elevation differed substantially between the two taxa. Birds and butterflies responded quite similarly to the elevational gradient and to the shift between vegetation belts in terms of species turnover rates. While the mechanisms generating these patterns may differ, the resulting areas of peak turnover in species show correspondence among three different taxa (plants, birds and butterflies).

Birds and music

Directory of Open Access Journals (Sweden)

L Amini

2009-03-01

Through research in old mythological narrations, and literary texts, one could assume an intrinsic relationship between music and such sweet-singing mythological birds as phoenix, sphinx, Song-song, holy birds like Kership-tah, and other birds including swan and ring dove.

Home Page: Division of Birds: Department of Vertebrate Zoology: National

Science.gov (United States)

Division Hall of Fame How do you identify a bird from a feather? Zoologist Carla Dove explains in this Ask Smithsonian video how the microscopic structure of a bird's feather can help identify the species and at the same time, make air travel safer for humans. Honeycreeper Family Tree Phylogeny of the Hawaiian

Epizootiology of Newcastle disease in two live bird markets in ...

African Journals Online (AJOL)

Newcastle disease (ND) is a devastating viral disease of poultry worldwide. This study was therefore undertaken to understand the role of live bird markets (LBMs) in the epizootiology of ND in Nigeria. A structured questionnaire was administered to poultry dealers and cloacal swab sampling of live birds in two LBMs in ...

Can a bird brain do phonology?

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Bridget D. Samuels

2015-07-01

Full Text Available A number of recent studies have revealed correspondences between song- and language-related neural structures, pathways, and gene expression in humans and songbirds. Analyses of vocal learning, song structure, and the distribution of song elements have similarly revealed a remarkable number of shared characteristics with human speech. This article reviews recent developments in the understanding of these issues with reference to the phonological phenomena observed in human language. This investigation suggests that birds possess a host of abilities necessary for human phonological computation, as evidenced by behavioral, neuroanatomical, and molecular genetic studies. Vocal-learning birds therefore present an excellent model for studying some areas of human phonology, though differences in the primitives of song and language as well as the absence of a human-like morphosyntax make human phonology differ from birdsong phonology in crucial ways.

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

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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

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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

Emergence of structured communities through evolutionary dynamics.

Science.gov (United States)

Shtilerman, Elad; Kessler, David A; Shnerb, Nadav M

2015-10-21

Species-rich communities, in which many competing species coexist in a single trophic level, are quite frequent in nature, but pose a formidable theoretical challenge. In particular, it is known that complex competitive systems become unstable and unfeasible when the number of species is large. Recently, many studies have attributed the stability of natural communities to the structure of the interspecific interaction network, yet the nature of such structures and the underlying mechanisms responsible for them remain open questions. Here we introduce an evolutionary model, based on the generic Lotka-Volterra competitive framework, from which a stable, structured, diverse community emerges spontaneously. The modular structure of the competition matrix reflects the phylogeny of the community, in agreement with the hierarchial taxonomic classification. Closely related species tend to have stronger niche overlap and weaker fitness differences, as opposed to pairs of species from different modules. The competitive-relatedness hypothesis and the idea of emergent neutrality are discussed in the context of this evolutionary model. Copyright © 2015 Elsevier Ltd. All rights reserved.

Birds and fish as bioindicators of tourist disturbance in springs in semi-arid regions in Mexico: a basis for management

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Palacio-Núñez, J.

2007-06-01

Full Text Available Tourist disturbance in semi–arid springs was analysed; birds and fish were selected as bioindicators. Media Luna spring is the biggest and most spatially complex system in the region, with the highest biodiversity levels and tourist use. Areas with the highest bird species richness and abundances showed highest structural heterogeneity and least direct human impact. No differences in species richness of fish were observed between sectors and the most abundant species were found in the sectors least perturbed by human activity. Factors that explained the bird distribution were the species´ tolerance to the effects of direct tourism (noise and direct presence of people and habitat quality, mainly riparian vegetation. Aquatic vegetation condition was very important for fish. Six bird species and two fish species were relevant as indicators of the habitat quality related to human impact. Anthropic disturbance such as tree plantation favoured some bird species, whereas aquatic vegetation removal was favourable for some fish species, such as the endemic Cichlasoma bartoni, however, both types of disturbance were unfavourable for other species; riparian vegetation removal was negative for both groups. Controlled tourism promotes good conditions for C. bartoni establishment. Efficient conservation measures such as limiting touristic distribution are necessary for all species, especially for the fish community, in order to conserve biodiversity in general.

Differences in knowledge about birds and their conservation between rural and urban residents of Puerto Rico

Science.gov (United States)

Edgar O. Vazquez-Plass; Joseph M. Wunderle

2010-01-01

People’s knowledge of birds and the opinions and perceptions about specific issues related to the conservation of birds were quantified in rural and urban communities in northeastern Puerto Rico. Data were collected using questionnaires in interviews with 131 citizens haphazardly selected within the study site. Our results indicate that urban residents had a...

Phase synchronization on small-world networks with community structure

International Nuclear Information System (INIS)

Xiao-Hua, Wang; Li-Cheng, Jiao; Jian-She, Wu

2010-01-01

In this paper, we propose a simple model that can generate small-world network with community structure. The network is introduced as a tunable community organization with parameter r, which is directly measured by the ratio of inter- to intra-community connectivity, and a smaller r corresponds to a stronger community structure. The structure properties, including the degree distribution, clustering, the communication efficiency and modularity are also analysed for the network. In addition, by using the Kuramoto model, we investigated the phase synchronization on this network, and found that increasing the fuzziness of community structure will markedly enhance the network synchronizability; however, in an abnormal region (r ≤ 0.001), the network has even worse synchronizability than the case of isolated communities (r = 0). Furthermore, this network exhibits a remarkable synchronization behaviour in topological scales: the oscillators of high densely interconnected communities synchronize more easily, and more rapidly than the whole network. (general)

Effects of drainage-basin geomorphology on insectivorous bird abundance in temperate forests.

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Iwata, Tomoya; Urabe, Jotaro; Mitsuhashi, Hiromune

2010-10-01

Interfaces between terrestrial and stream ecosystems often enhance species diversity and population abundance of ecological communities beyond levels that would be expected separately from both the ecosystems. Nevertheless, no study has examined how stream configuration within a watershed influences the population of terrestrial predators at the drainage-basin scale. We examined the habitat and abundance relationships of forest insectivorous birds in eight drainage basins in a cool temperate forest of Japan during spring and summer. Each basin has different drainage-basin geomorphology, such as the density and frequency of stream channels. In spring, when terrestrial arthropod prey biomass is limited, insectivorous birds aggregated in habitats closer to streams, where emerging aquatic prey was abundant. Nevertheless, birds ceased to aggregate around streams in summer because terrestrial prey became plentiful. Watershed-scale analyses showed that drainage basins with longer stream channels per unit area sustained higher densities of insectivorous birds. Moreover, such effects of streams on birds continued from spring through summer, even though birds dispersed out of riparian areas in the summer. Although our data are from only a single year, our findings imply that physical modifications of stream channels may reduce populations of forest birds; thus, they emphasize the importance of landscape-based management approaches that consider both stream and forest ecosystems for watershed biodiversity conservation. © 2010 Society for Conservation Biology.

Bird use of organic apple orchards: Frugivory, pest control and implications for production.

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Anna M Mangan

Full Text Available As the largest terrestrial biomes, crop and pasturelands can have very large positive or negative impacts on biodiversity and human well-being. Understanding how animals use and impact agroecosystems is important for making informed decisions that achieve conservation and production outcomes. Yet, few studies examine the tradeoffs associated with wildlife in agricultural systems. We examined bird use of organic apple orchards as well as how birds influence fruit production positively through control of an economically important insect pest (codling moth (Cydia pomonella and negatively through fruit damage. We conducted transect surveys, observed bird frugivory and assessed bird and insect damage with an exclosure experiment in small organic farms in western Colorado. We found that organic apple orchards in this region provide habitat for a large number of both human-adapted and human-sensitive species and that the species in orchards were relatively similar to adjacent hedgerow habitats. Habitat use did not vary as a function of orchard characteristics, and apple damage by both birds and C. pomonella was consistent within and across apple blocks that varied in size. A small subset of bird species was observed foraging on apples yet the effect of birds as agents of fruit damage appeared rather minor and birds did not reduce C. pomonella damage. Our results demonstrate that organic apple orchards have the potential to provide habitat for diverse bird communities, including species typically sensitive to human activities, with little apparent effect on production.

Spatial and Time Pattern Distribution of Water Birds Community at Mangrove Ecosystem of Bengawan Solo Estuary - Gresik Regency

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Sutopo .

2018-01-01

Full Text Available Mangrove ecosystem in Bengawan Solo estuary is a part of the essential ecosystem and also as important and endemic birds’ areas. Aim of this study is to analysis the parameter of habitat condition, analysis the different of time and spatial pattern and provide the management strategy for water birds and habitat. Reseach was carry out at January – May, 2017 (two period observation. Methods are used i.e. concentration count, single and unit plot, point count, interview and field observation. Data analyze using chi-square, grid-line point and mark point, beak-type and vegetation analysis. There are 41 (forty one species of water birds (23 migrant species and 17 native species. Chi-square analysis have significance difference both the time and spatial and also type of feed with chi-square values (χ2 hit.(2;0,95 > χ2 tab.(2;0,95. Migrant birds’ occupy the mudflat for feeding and resting ground, while the native birds use pond areas. Common the invertebrate species as feed for migrant like crustace and native birds are tend to feed fish and shrimp. Feeding and resting activities by migrant birds was influence by water-tidal condition. Total of water birds population are 112.100+ individual. Total of mangrove species was identified are 15 (fifteen species, and dominant at three habitus by Avicennia alba.Keywords: Bengawan Solo Estuary, mangrove ecosystem, spatial and time, water birds

Isotopic and anatomical evidence of an herbivorous diet in the Early Tertiary giant bird Gastornis. Implications for the structure of Paleocene terrestrial ecosystems

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Angst, D.; Lécuyer, C.; Amiot, R.; Buffetaut, E.; Fourel, F.; Martineau, F.; Legendre, S.; Abourachid, A.; Herrel, A.

2014-04-01

The mode of life of the early Tertiary giant bird Gastornis has long been a matter of controversy. Although it has often been reconstructed as an apex predator feeding on small mammals, according to other interpretations, it was in fact a large herbivore. To determine the diet of this bird, we analyze here the carbon isotope composition of the bone apatite from Gastornis and contemporaneous herbivorous mammals. Based on 13C-enrichment measured between carbonate and diet of carnivorous and herbivorous modern birds, the carbonate δ13C values of Gastornis bone remains, recovered from four Paleocene and Eocene French localities, indicate that this bird fed on plants. This is confirmed by a morphofunctional study showing that the reconstructed jaw musculature of Gastornis was similar to that of living herbivorous birds and unlike that of carnivorous forms. The herbivorous Gastornis was the largest terrestrial tetrapod in the Paleocene biota of Europe, unlike the situation in North America and Asia, where Gastornis is first recorded in the early Eocene, and the largest Paleocene animals were herbivorous mammals. The structure of the Paleocene terrestrial ecosystems of Europe may have been similar to that of some large islands, notably Madagascar, prior to the arrival of humans.

76 FR 32224 - Migratory Birds; Take of Migratory Birds by the Armed Forces

Science.gov (United States)

2011-06-03

... DEPARTMENT OF THE INTERIOR Fish and Wildlife Service Migratory Birds; Take of Migratory Birds by... Forces to incidentally take migratory birds during approved military readiness activities without violating the Migratory Bird Treaty Act (MBTA). The Authorization Act provided this interim authority to...

Bird communities in three forest types in the Pernambuco Centre of Endemism, Alagoas, Brazil

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Lahert W. Lobo-Araújo

2013-06-01

Full Text Available The Pernambuco Center of Endemism (PCE in northeastern Brazil is highly fragmented and degraded. Despite its potential conservation importance the bird fauna in this area is still relatively unknown and there are many remnant fragments that have not been systematically surveyed. Here, we report the results of bird surveys in five forest fragments (one pioneer, two ombrophilous and two seasonal. In total, 162 taxa were recorded, 12 of which are endemic to the PCE. The frequency of endangered species was lower than what has been reported in studies from the same area and most of the taxa considered to be at risk of extinction were sub-species of uncertain taxonomic validity. The comparatively low number of endemic/threatened species may be due to the small size of the fragments in the present study - a consequence of the high levels of habitat loss in this region. Analysis of species richness patterns indicates that ombrophilous forest fragments are acting as refuges for those bird species that are most sensitive to environmental degradation.

Global associations between birds and vane-dwelling feather mites.

Science.gov (United States)

Doña, Jorge; Proctor, Heather; Mironov, Sergey; Serrano, David; Jovani, Roger

2016-11-01

Understanding host-symbiont networks is a major question in evolutionary ecology. Birds host a great diversity of endo- and ectosymbiotic organisms, with feather mites (Arachnida: Acariformes: Analgoidea, Pterolichoidea) being among the most diverse of avian symbionts. A global approach to the ecology and evolution of bird-feather-mite associations has been hampered because of the absence of a centralized data repository. Here we present the most extensive data set of associations between feather mites and birds. Data include 12 036 records of 1887 feather mite species located on the flight feathers of 2234 bird species from 147 countries. Feather mites typically located inside quills, on the skin, or on downy body feathers are not included. Data were extracted from 493 published sources dating from 1882 to 2015. Data exploration shows that although most continents and bird families are represented, most bird species remain unexplored for feather mites. Nevertheless, this is the most comprehensive data set available for enabling global macroecological analyses of feather mites and their hosts, such as ecological network analyses. This metadata file outlines the structure of these data and provides primary references for all records used. © 2016 by the Ecological Society of America.

Quantification of bird-to-bird and bird-to-human infections during 2013 novel H7N9 avian influenza outbreak in China.

Science.gov (United States)

Hsieh, Ying-Hen; Wu, Jianhong; Fang, Jian; Yang, Yong; Lou, Jie

2014-01-01

From February to May, 2013, 132 human avian influenza H7N9 cases were identified in China resulting in 37 deaths. We developed a novel, simple and effective compartmental modeling framework for transmissions among (wild and domestic) birds as well as from birds to human, to infer important epidemiological quantifiers, such as basic reproduction number for bird epidemic, bird-to-human infection rate and turning points of the epidemics, for the epidemic via human H7N9 case onset data and to acquire useful information regarding the bird-to-human transmission dynamics. Estimated basic reproduction number for infections among birds is 4.10 and the mean daily number of human infections per infected bird is 3.16*10-5 [3.08*10-5, 3.23*10-5]. The turning point of 2013 H7N9 epidemic is pinpointed at April 16 for bird infections and at April 9 for bird-to-human transmissions. Our result reveals very low level of bird-to-human infections, thus indicating minimal risk of widespread bird-to-human infections of H7N9 virus during the outbreak. Moreover, the turning point of the human epidemic, pinpointed at shortly after the implementation of full-scale control and intervention measures initiated in early April, further highlights the impact of timely actions on ending the outbreak. This is the first study where both the bird and human components of an avian influenza epidemic can be quantified using only the human case data.

The design and function of birds' nests

Science.gov (United States)

Mainwaring, Mark C; Hartley, Ian R; Lambrechts, Marcel M; Deeming, D Charles

2014-01-01

All birds construct nests in which to lay eggs and/or raise offspring. Traditionally, it was thought that natural selection and the requirement to minimize the risk of predation determined the design of completed nests. However, it is becoming increasingly apparent that sexual selection also influences nest design. This is an important development as while species such as bowerbirds build structures that are extended phenotypic signals whose sole purpose is to attract a mate, nests contain eggs and/or offspring, thereby suggesting a direct trade-off between the conflicting requirements of natural and sexual selection. Nest design also varies adaptively in order to both minimize the detrimental effects of parasites and to create a suitable microclimate for parents and developing offspring in relation to predictable variation in environmental conditions. Our understanding of the design and function of birds' nests has increased considerably in recent years, and the evidence suggests that nests have four nonmutually exclusive functions. Consequently, we conclude that the design of birds' nests is far more sophisticated than previously realized and that nests are multifunctional structures that have important fitness consequences for the builder/s. PMID:25505520

The design and function of birds' nests.

Science.gov (United States)

Mainwaring, Mark C; Hartley, Ian R; Lambrechts, Marcel M; Deeming, D Charles

2014-10-01

All birds construct nests in which to lay eggs and/or raise offspring. Traditionally, it was thought that natural selection and the requirement to minimize the risk of predation determined the design of completed nests. However, it is becoming increasingly apparent that sexual selection also influences nest design. This is an important development as while species such as bowerbirds build structures that are extended phenotypic signals whose sole purpose is to attract a mate, nests contain eggs and/or offspring, thereby suggesting a direct trade-off between the conflicting requirements of natural and sexual selection. Nest design also varies adaptively in order to both minimize the detrimental effects of parasites and to create a suitable microclimate for parents and developing offspring in relation to predictable variation in environmental conditions. Our understanding of the design and function of birds' nests has increased considerably in recent years, and the evidence suggests that nests have four nonmutually exclusive functions. Consequently, we conclude that the design of birds' nests is far more sophisticated than previously realized and that nests are multifunctional structures that have important fitness consequences for the builder/s.

Rapid colonization of a Hawaiian restoration forest by a diverse avian community

Science.gov (United States)

Paxton, Eben H.; Yelenik, Stephanie G.; Borneman, Tracy E.; Rose, Eli; Camp, Richard J.; Kendall, Steve J.

2018-01-01

Deforestation of tropical forests has led to widespread loss and extirpation of forest bird species around the world, including the Hawaiian Islands which have experienced a dramatic loss of forests over the last 200–800 years. Given the important role birds play in forest ecosystem functions via seed dispersal and pollination, a bird community's response to forest restoration is an important measure of the success of such conservation actions. We evaluated the bird response to reforestation at an important bird sanctuary, Hakalau Forest National Wildlife Refuge, Hawai′i Island, using 26 years of bird count data. We show that most species from within the diverse avian community increased significantly, but species colonized the restoration forest at different rates. Distance from intact forest and time since restoration were both important predictors of colonization rate, interacting such that for most species it took more time to colonize areas farther from the intact forest. In addition, both forest cover and understory diversity helped to explain bird densities, but the effect varied among species, suggesting that different habitat requirements may help drive variation in colonization rates. This article provides the first detailed evaluation of how a diverse community of birds has responded to one of the largest, ongoing reforestation projects in Hawai′i.

Using landscape ecology to test hypotheses about large-scale abundance patterns in migratory birds

Science.gov (United States)

Flather, C.H.; Sauer, J.R.

1996-01-01

The hypothesis that Neotropical migrant birds may be undergoing widespread declines due to land use activities on the breeding grounds has been examined primarily by synthesizing results from local studies. Growing concern for the cumulative influence of land use activities on ecological systems has heightened the need for large-scale studies to complement what has been observed at local scales. We investigated possible landscape effects on Neotropical migrant bird populations for the eastern United States by linking two large-scale inventories designed to monitor breeding-bird abundances and land use patterns. The null hypothesis of no relation between landscape structure and Neotropical migrant abundance was tested by correlating measures of landscape structure with bird abundance, while controlling for the geographic distance among samples. Neotropical migrants as a group were more 'sensitive' to landscape structure than either temperate migrants or permanent residents. Neotropical migrants tended to be more abundant in landscapes with a greater proportion of forest and wetland habitats, fewer edge habitats, large forest patches, and with forest habitats well dispersed throughout the scene. Permanent residents showed few correlations with landscape structure and temperate migrants were associated with habitat diversity and edge attributes rather than with the amount, size, and dispersion of forest habitats. The association between Neotropical migrant abundance and forest fragmentation differed among physiographic strata, suggesting that land-scape context affects observed relations between bird abundance and landscape structure. Finally, associations between landscape structure and temporal trends in Neotropical migrant abundance were negatively correlated with forest habitats. These results suggest that extrapolation of patterns observed in some landscapes is not likely to hold regionally, and that conservation policies must consider the variation in landscape

Sensitivity of Coastal Environments and Wildlife to Spilled Oil: South Florida: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for diving birds, gulls, terns, passerine birds, pelagic birds, raptors, shorebirds, wading birds, and...

Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Central California: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for alcids, diving birds, gulls, terns, passerine birds, pelagic birds, raptors, shorebirds, wading birds,...

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...

High-Speed Surface Reconstruction of Flying Birds Using Structured Light

Science.gov (United States)

Deetjen, Marc; Lentink, David

2017-11-01

Birds fly effectively through complex environments, and in order to understand the strategies that enable them to do so, we need to determine the shape and movement of their wings. Previous studies show that even small perturbations in wing shape have dramatic aerodynamic effects, but these shape changes have not been quantified automatically at high temporal and spatial resolutions. Hence, we developed a custom 3D surface mapping method which uses a high-speed camera to view a grid of stripes projected onto a flying bird. Because the light is binary rather than grayscale, and each frame is separately analyzed, this method can function at any frame rate with sufficient light. The method is automated, non-invasive, and able to measure a volume by simultaneously reconstructing from multiple views. We use this technique to reconstruct the 3D shape of the surface of a parrotlet during flapping flight at 3200 fps. We then analyze key dynamic parameters such as wing twist and angle of attack, and compute aerodynamic parameters such as lift and drag. While this novel system is designed to quantify bird wing shape and motion, it is adaptable for tracking other objects such as quickly deforming fish, especially those which are difficult to reconstruct using other 3D tracking methods. The presenter needs to leave by 3 pm on the final day of the conference (11/21) in order to make his flight. Please account for this in the scheduling if possible by scheduling the presentation earlier in the day or a different day.

Screamy Bird

DEFF Research Database (Denmark)

Tarby, Sara; Cermak, Daniel

2016-01-01

Sara Tarby, Daniel Cermak-Sassenrath. Screamy Bird. Digital game. Kulturnatten 2016, Danish Science Ministry, Copenhagen, DK, Oct 14, 2016.......Sara Tarby, Daniel Cermak-Sassenrath. Screamy Bird. Digital game. Kulturnatten 2016, Danish Science Ministry, Copenhagen, DK, Oct 14, 2016....

Community structure informs species geographic distributions

KAUST Repository

Montesinos-Navarro, Alicia

2018-05-23

Understanding what determines species\\' geographic distributions is crucial for assessing global change threats to biodiversity. Measuring limits on distributions is usually, and necessarily, done with data at large geographic extents and coarse spatial resolution. However, survival of individuals is determined by processes that happen at small spatial scales. The relative abundance of coexisting species (i.e. \\'community structure\\') reflects assembly processes occurring at small scales, and are often available for relatively extensive areas, so could be useful for explaining species distributions. We demonstrate that Bayesian Network Inference (BNI) can overcome several challenges to including community structure into studies of species distributions, despite having been little used to date. We hypothesized that the relative abundance of coexisting species can improve predictions of species distributions. In 1570 assemblages of 68 Mediterranean woody plant species we used BNI to incorporate community structure into Species Distribution Models (SDMs), alongside environmental information. Information on species associations improved SDM predictions of community structure and species distributions moderately, though for some habitat specialists the deviance explained increased by up to 15%. We demonstrate that most species associations (95%) were positive and occurred between species with ecologically similar traits. This suggests that SDM improvement could be because species co-occurrences are a proxy for local ecological processes. Our study shows that Bayesian Networks, when interpreted carefully, can be used to include local conditions into measurements of species\\' large-scale distributions, and this information can improve the predictions of species distributions.

Non-sequential fruit tracking by birds along an altitudinal gradient

Science.gov (United States)

Hasui, Erica; Ramos, Flavio Nunes; Tamashiro, Jorge Yoshio; Silva, Wesley Rodrigues

2012-11-01

Despite landscape-level changes in fruit quantity, food resources may be constantly available to frugivorous animals if they track asynchronous fruit peaks. To investigate fruit availability patterns and their consequences on bird abundance, we tested for the occurrence of seasonal patterns in fruit production at three elevations (range 500-1000 m asl) in the Brazilian Atlantic Forest over three years and compared these patterns among the elevations and years. Fruit production occurred throughout the year and showed only slight seasonality, and only at the two higher elevation sites. Contrary to expectation, fruiting peaks were neither predictable nor complementary. A few plant species (about 5%) contributed disproportionately to the high annual variation of fruit production in plant communities. We found no relationship between fruit production and bird capture rates of both generalist and specialist fruit eating species, suggesting that birds do not track fruit resources along the gradient, at least in some parts of the Atlantic Forest, or in some years. The apparent constancy of fruit availability probably does not stimulate birds to track to other elevations. In addition, plants with high annual variation in fruit production could be influencing and biasing our assessment of this relationship.

Birds and Bird Habitat: What Are the Risks from Industrial Wind Turbine Exposure?

Science.gov (United States)

Sprague, Terry; Harrington, M. Elizabeth; Krogh, Carmen M. E.

2011-01-01

Bird kill rate and disruption of habitat has been reported when industrial wind turbines are introduced into migratory bird paths or other environments. While the literature could be more complete regarding the documentation of negative effects on birds and bird habitats during the planning, construction, and operation of wind power projects,…

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.

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).

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.

Ecological and evolutionary effects of stickleback on community structure.

Directory of Open Access Journals (Sweden)

Simone Des Roches

Full Text Available Species' ecology and evolution can have strong effects on communities. Both may change concurrently when species colonize a new ecosystem. We know little, however, about the combined effects of ecological and evolutionary change on community structure. We simultaneously examined the effects of top-predator ecology and evolution on freshwater community parameters using recently evolved generalist and specialist ecotypes of three-spine stickleback (Gasterosteus aculeatus. We used a mesocosm experiment to directly examine the effects of ecological (fish presence and density and evolutionary (phenotypic diversity and specialization factors on community structure at lower trophic levels. We evaluated zooplankton biomass and composition, periphyton and phytoplankton chlorophyll-a concentration, and net primary production among treatments containing different densities and diversities of stickleback. Our results showed that both ecological and evolutionary differences in the top-predator affect different aspects of community structure and composition. Community structure, specifically the abundance of organisms at each trophic level, was affected by stickleback presence and density, whereas composition of zooplankton was influenced by stickleback diversity and specialization. Primary productivity, in terms of chlorophyll-a concentration and net primary production was affected by ecological but not evolutionary factors. Our results stress the importance of concurrently evaluating both changes in density and phenotypic diversity on the structure and composition of communities.

Regionalizing land use impacts on farmland birds.

Science.gov (United States)

Glemnitz, Michael; Zander, Peter; Stachow, Ulrich

2015-06-01

The environmental impacts of land use vary regionally. Differences in geomorphology, climate, landscape structure, and biotope inventories are regarded as the main causes of this variation. We present a methodological approach for identifying regional responses in land use type to large-scale changes and the implications for the provision of habitat for farmland birds. The methodological innovations of this approach are (i) the coupling of impact assessments with economic models, (ii) the linking of cropping techniques at the plot scale with the regional distribution of land use, and (iii) the integration of statistical or monitoring data on recent states. This approach allows for the regional differentiation of farmers' responses to changing external conditions and for matching the ecological impacts of land use changes with regional environmental sensitivities. An exemplary scenario analysis was applied for a case study of an area in Germany, assessing the impacts of increased irrigation and the promotion of energy cropping on farmland birds, evaluated as a core indicator for farmland biodiversity. The potential effects on farmland birds were analyzed based on the intrinsic habitat values of the crops and cropping techniques. The results revealed that the strongest decrease in habitat availability for farmland birds occurred in regions with medium-to-low agricultural yields. As a result of the limited cropping alternatives, the increase in maize production was highest in marginal regions for both examined scenarios. Maize production replaced many crops with good-to-medium habitat suitability for birds. The declines in habitat quality were strongest in regions that are not in focus for conservation efforts for farmland birds.

Sparkling feather reflections of a bird-of-paradise explained by finite-difference time-domain modeling

NARCIS (Netherlands)

Wilts, Bodo D; Michielsen, Kristel; De Raedt, Hans; Stavenga, Doekele G

2014-01-01

Birds-of-paradise are nature's prime examples of the evolution of color by sexual selection. Their brilliant, structurally colored feathers play a principal role in mating displays. The structural coloration of both the occipital and breast feathers of the bird-of-paradise Lawes' parotia is produced

Climate extremes drive changes in functional community structure.

Science.gov (United States)

Boucek, Ross E; Rehage, Jennifer S

2014-06-01

The response of communities to climate extremes can be quite variable. Much of this variation has been attributed to differences in community-specific functional trait diversity, as well as community composition. Yet, few if any studies have explicitly tested the response of the functional trait structure of communities following climate extremes (CEs). Recently in South Florida, two independent, but sequential potential CEs took place, a 2010 cold front, followed by a 2011 drought, both of which had profound impacts on a subtropical estuarine fish community. These CEs provided an opportunity to test whether the structure of South Florida fish communities following each extreme was a result of species-specific differences in functional traits. From historical temperature (1927-2012) and freshwater inflows records into the estuary (1955-2012), we determined that the cold front was a statistically extreme disturbance, while the drought was not, but rather a decadal rare disturbance. The two disturbances predictably affected different parts of functional community structure and thus different component species. The cold front virtually eliminated tropical species, including large-bodied snook, mojarra species, nonnative cichlids, and striped mullet, while having little affect on temperate fishes. Likewise, the drought severely impacted freshwater fishes including Florida gar, bowfin, and two centrarchids, with little effect on euryhaline species. Our findings illustrate the ability of this approach to predict and detect both the filtering effects of different types of disturbances and the implications of the resulting changes in community structure. Further, we highlight the value of this approach to developing predictive frameworks for better understanding community responses to global change. © 2014 John Wiley & Sons Ltd.

Wind power and bird kills

International Nuclear Information System (INIS)

Raynolds, M.

1998-01-01

The accidental killing of birds by wind generators, and design improvements in the towers that support the turbines that might cut down on the bird killings were discussed. The first problem for the industry began in the late 1980s when the California Energy Commission reported as many as 160 birds (the majority being raptors, including the protected golden eagle) killed in one year in the vicinity of wind power plants. The key factor identified was the design of the towers as birds of prey are attracted to lattice towers as a place to hunt from. Tubular towers do not provide a place for the birds to perch, therefore they reduce the potential for bird strikes. Bird strikes also have been reported in Spain and the siting of the towers have been considered as the principal cause of the bird strikes. In view of these incidents, the wind power industry is developing standards for studying the potential of bird strikes and is continuing to study bird behaviour leading to collisions, the impact of topography, cumulative impacts and new techniques to reduce bird strikes. Despite the reported incidents, the risk of bird strikes by wind turbines, compared to other threats to birds such as pollution, oil spills, and other threats from fossil and nuclear fuels, is considered to be negligible. With continuing efforts to minimize incidents by proper design and siting, wind power can continue to grow as an environmentally sound and efficient source of energy

Wind power and bird kills

Energy Technology Data Exchange (ETDEWEB)

Raynolds, M.

1998-12-01

The accidental killing of birds by wind generators, and design improvements in the towers that support the turbines that might cut down on the bird killings were discussed. The first problem for the industry began in the late 1980s when the California Energy Commission reported as many as 160 birds (the majority being raptors, including the protected golden eagle) killed in one year in the vicinity of wind power plants. The key factor identified was the design of the towers as birds of prey are attracted to lattice towers as a place to hunt from. Tubular towers do not provide a place for the birds to perch, therefore they reduce the potential for bird strikes. Bird strikes also have been reported in Spain and the siting of the towers have been considered as the principal cause of the bird strikes. In view of these incidents, the wind power industry is developing standards for studying the potential of bird strikes and is continuing to study bird behaviour leading to collisions, the impact of topography, cumulative impacts and new techniques to reduce bird strikes. Despite the reported incidents, the risk of bird strikes by wind turbines, compared to other threats to birds such as pollution, oil spills, and other threats from fossil and nuclear fuels, is considered to be negligible. With continuing efforts to minimize incidents by proper design and siting, wind power can continue to grow as an environmentally sound and efficient source of energy.

SUBMONTANE FOREST AT BANTIMURUNG BULUSARAUNG NATIONAL PARK: HOTSPOT OF BIRD DIVERSITY AND ITS MANAGEMENT CONSERVATION

Directory of Open Access Journals (Sweden)

Indra A.S.L.P. Putri

2015-09-01

Full Text Available Submontane forest is considered as one of the biodiversity hotspot.  Scientific information on bird diversity in this forest, however are lacking.  The aim of this research was to find out submontane forest bird diversity and its conservation management.  The research was carried out in three forests areas at Bantimurung Bulusaraung National Park submontane forest.  Point Count method was used to observe bird population. Data were analyzed using Shannon-Weiner diversity index, Pielou Evenness index, Simpson dominance index, Margalef species richness index, and Sorensen Similarity index. The significance different between the number of individual bird was tested using Kolmogorov-Smirnov test.  The result showed that submontane forest at Bantimurung Bulusaraung National Park is rich in bird diversity, bird endemic species and protected bird species.  There was a significant different on the number of individual bird at several human disturbance levels.  Based on these conditions, it is important to enhance understanding of the local people regarding zonation and develop cooperation with many stakeholders to increase the local community awareness concerning forest conservation. It is also necessary to ensure the sustainability of the National Park’s conservation program to maintain the submontane forest conservation.

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.

76 FR 19875 - Migratory Bird Hunting; Proposed 2011-12 Migratory Game Bird Hunting Regulations (Preliminary...

Science.gov (United States)

2011-04-08

..., carriage, or export of any * * * bird, or any part, nest, or egg'' of migratory game birds can take place... 50 CFR Part 20 Migratory Bird Hunting; Proposed 2011-12 Migratory Game Bird Hunting Regulations (Preliminary) With Requests for Indian Tribal Proposals and Requests for 2013 Spring and Summer Migratory Bird...

Influence of restored koa in supporting bird communities

Science.gov (United States)

Camp, Richard J.; Paxton, Eben H.; Yelenik, Stephanie G.

2017-01-01

Deforestation of Hawaiian forests has adversely impacted native wildlife, including forest birds, bats and arthropods. Restoration activities have included reforestation with the native koa (Acacia koa), a dominant canopy tree species that is easy to propagate, has high survivorship, and has fast growth rates. We review recent research describing the ecological benefits of koa restoration on wildlife colonization/use, plant dispersal, and native plant recruitment. In general, planting monotypic koa stands can provide forest habitats for species that need them but does not automatically lead to natural regeneration of a diverse forest species assemblage and may require additional restoration activities such as outplanting of other native plants and alien grass control to achieve more natural forest systems. Although early signs of forest and wildlife recovery have been encouraging, the goals of restoration for wildlife conservation versus commercial grade harvesting require different restoration methods.

The influence of small urban parks characteristics on bird diversity

DEFF Research Database (Denmark)

Jasmani, Zanariah; Ravn, Hans Peter; van den Bosch, Cecil C.Konijnendijk

2017-01-01

using the combined field survey method of structured observation and field measurements. The measured variables were divided into three broad categories of physical characteristics, species richness and human factors. Bird species richness and abundance were used as the indicators for assessing...... biodiversity. Pearson correlations and multiple regressions were conducted to analyse the relationships between variables and to identify which variables had a significant effect on bird species richness and abundance. The results demonstrated that park area and vegetation variables (e.g. the percentage...... of tree canopy cover, open grass/ground, native-exotic plants) are the important predictors of bird species richness and abundance. The percentage of canopy covers (negative relation) and park area (positive relation) are the best predictors of bird species richness in small urban parks. Meanwhile...

Annotated Bibliography of Bird Hazards to Aircraft: Bird Strike Committee Citations 1967-1997

National Research Council Canada - National Science Library

Short, Jeffrey

1998-01-01

.... This annotated bibliography of bird hazards to aircraft, termed ABBHA, is a compilation of citations with abstracts on a wide range of related topics such as bird strike tolerance engineering, bird...

78 FR 53217 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

Science.gov (United States)

2013-08-28

..., and by what means such birds or any part, nest, or egg thereof may be taken, hunted, captured, killed... Service 50 CFR Part 20 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal...-FXMB1231099BPP0] RIN 1018-AY87 Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal...

Functional traits determine heterospecific use of risk-related social information in forest birds of tropical South-East Asia.

Science.gov (United States)

Hua, Fangyuan; Yong, Ding Li; Janra, Muhammad Nazri; Fitri, Liza M; Prawiradilaga, Dewi; Sieving, Kathryn E

2016-12-01

In birds and mammals, mobbing calls constitute an important form of social information that can attract numerous sympatric species to localized mobbing aggregations. While such a response is thought to reduce the future predation risk for responding species, there is surprisingly little empirical evidence to support this hypothesis. One way to test the link between predation risk reduction and mobbing attraction involves testing the relationship between species' attraction to mobbing calls and the functional traits that define their vulnerability to predation risk. Two important traits known to influence prey vulnerability include relative prey-to-predator body size ratio and the overlap in space use between predator and prey; in combination, these measures strongly influence prey accessibility, and therefore their vulnerability, to predators. Here, we combine community surveys with behavioral experiments of a diverse bird assemblage in the lowland rainforest of Sumatra to test whether the functional traits of body mass (representing body size) and foraging height (representing space use) can predict species' attraction to heterospecific mobbing calls. At four forest sites along a gradient of forest degradation, we characterized the resident bird communities using point count and mist-netting surveys, and determined the species groups attracted to standardized playbacks of mobbing calls produced by five resident bird species of roughly similar body size and foraging height. We found that (1) a large, diverse subcommunity of bird species was attracted to the mobbing calls and (2) responding species (especially the most vigorous respondents) tended to be (a) small (b) mid-storey foragers (c) with similar trait values as the species producing the mobbing calls. Our findings from the relatively lesser known bird assemblages of tropical Asia add to the growing evidence for the ubiquity of heterospecific information networks in animal communities, and provide empirical

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.

Fish Community Structure and Diet Responses to Newbury Weirs in a Low-Gradient River

Science.gov (United States)

Bonjour, Sophia M.; Rantala, Heidi M.; Bennett, Micah G.; Whiles, Matt R.

2018-06-01

Restoration projects are often implemented to address specific issues in the environment. Consequences of a restoration project, if any are measured, typically focus on direct changes to the projects focus. However, changing habitat structure likely results in changes to the environment that affect the communities living there. Rock weirs have been used for channel stabilization in many midwestern rivers. Previous research in a southern Illinois river found that weirs benefitted aquatic macroinvertebrate and riparian bird communities by enhancing habitat heterogeneity and insect emergence production. We hypothesized that fishes would also benefit from weirs through enhanced habitat and food availability. We collected fishes in the Cache River in southern Illinois using hand nets, seines, and electroshocking at sites where weirs had been installed and at non-weir sites. Gut contents were identified and individual food items measured. Fish species richness, but not diversity, was higher at weir sites. Fish communities also differed between site types, with benthic feeders characterizing weir sites. Gut content biomass and abundance differed among fish guilds but not between weir and non-weir sites. Fishes from both site types selected for prey taxa predominately found at weirs. Differences between site types were not always captured by univariate metrics, but connecting fish prey to habitat suggests a reach-scale benefit for fishes through increased abundance of favored prey and enhanced prey diversity. Additionally, given the paucity of rocky substrata in the river as a whole, rock weirs enhance fish species richness by providing habitat for less common benthic species.

Cook Inlet and Kenai Peninsula, Alaska ESI: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains biological resource data for alcids, shorebirds, waterfowl, diving birds, pelagic birds, gulls and terns in Cook Inlet and Kenai Peninsula,...

Forest fire impact on bird habitat in a mixed oak-pine forest in Puebla, Mexico

Science.gov (United States)

Laura P. Ponce-Calderón Ponce-Calderón; Dante A. Rodríguez-Trejo; Beatriz C. Aguilar-Váldez; Elvia. López-Pérez

2013-01-01

To assess the impact of different-severity wildfires on bird habitat, habitat quality was determined by analyzing the degree of richness association, abundance and diversity of bird species and vegetation structure (richness, abundance, diversity and coverage). These attributes were quantified with four sampling sites for birds and five for quadrant-centered points...

Mapping migratory bird prevalence using remote sensing data fusion.

Science.gov (United States)

Swatantran, Anu; Dubayah, Ralph; Goetz, Scott; Hofton, Michelle; Betts, Matthew G; Sun, Mindy; Simard, Marc; Holmes, Richard

2012-01-01

Improved maps of species distributions are important for effective management of wildlife under increasing anthropogenic pressures. Recent advances in lidar and radar remote sensing have shown considerable potential for mapping forest structure and habitat characteristics across landscapes. However, their relative efficacies and integrated use in habitat mapping remain largely unexplored. We evaluated the use of lidar, radar and multispectral remote sensing data in predicting multi-year bird detections or prevalence for 8 migratory songbird species in the unfragmented temperate deciduous forests of New Hampshire, USA. A set of 104 predictor variables describing vegetation vertical structure and variability from lidar, phenology from multispectral data and backscatter properties from radar data were derived. We tested the accuracies of these variables in predicting prevalence using Random Forests regression models. All data sets showed more than 30% predictive power with radar models having the lowest and multi-sensor synergy ("fusion") models having highest accuracies. Fusion explained between 54% and 75% variance in prevalence for all the birds considered. Stem density from discrete return lidar and phenology from multispectral data were among the best predictors. Further analysis revealed different relationships between the remote sensing metrics and bird prevalence. Spatial maps of prevalence were consistent with known habitat preferences for the bird species. Our results highlight the potential of integrating multiple remote sensing data sets using machine-learning methods to improve habitat mapping. Multi-dimensional habitat structure maps such as those generated from this study can significantly advance forest management and ecological research by facilitating fine-scale studies at both stand and landscape level.

Cecal bacterial communities in wild Japanese rock ptarmigans and captive Svalbard rock ptarmigans.

Science.gov (United States)

Ushida, Kazunari; Segawa, Takahiro; Tsuchida, Sayaka; Murata, Koichi

2016-02-01

Preservation of indigenous gastrointestinal microbiota is deemed to be critical for successful captive breeding of endangered wild animals, yet its biology is poorly understood. Here, we investigated cecal bacterial communities in wild Japanese rock ptarmigans (Lagopus muta japonica) and compared them with those in Svalbard rock ptarmigans (L. m. hyperborea) in captivity. Ultra-deep sequencing of 16S rRNA gene indicated that the community structure of cecal microbiota in wild rock ptarmigans was remarkably different from that in captive Svalbard rock ptarmigans. Fundamental differences between bacterial communities in the two groups of birds were detected at the phylum level. Firmicutes, Actinobacteria, Bacteroidetes and Synergistetes were the major phyla detected in wild Japanese rock ptarmigans, whereas Firmicutes alone occupied more than 80% of abundance in captive Svalbard rock ptarmigans. Furthermore, unclassified genera of Coriobacteriaceae, Synergistaceae, Bacteroidaceae, Actinomycetaceae, Veillonellaceae and Clostridiales were the major taxa detected in wild individuals, whereas in zoo-reared birds, major genera were Ruminococcus, Blautia, Faecalibacterium and Akkermansia. Zoo-reared birds seemed to lack almost all rock ptarmigan-specific bacteria in their intestine, which may explain the relatively high rate of pathogenic infections affecting them. We show evidence that preservation and reconstitution of indigenous cecal microflora are critical for successful ex situ conservation and future re-introduction plan for the Japanese rock ptarmigan.

Information transfer in community structured multiplex networks

Science.gov (United States)

Solé Ribalta, Albert; Granell, Clara; Gómez, Sergio; Arenas, Alex

2015-08-01

The study of complex networks that account for different types of interactions has become a subject of interest in the last few years, specially because its representational power in the description of users interactions in diverse online social platforms (Facebook, Twitter, Instagram, etc.). The mathematical description of these interacting networks has been coined under the name of multilayer networks, where each layer accounts for a type of interaction. It has been shown that diffusive processes on top of these networks present a phenomenology that cannot be explained by the naive superposition of single layer diffusive phenomena but require the whole structure of interconnected layers. Nevertheless, the description of diffusive phenomena on multilayer networks has obviated the fact that social networks have strong mesoscopic structure represented by different communities of individuals driven by common interests, or any other social aspect. In this work, we study the transfer of information in multilayer networks with community structure. The final goal is to understand and quantify, if the existence of well-defined community structure at the level of individual layers, together with the multilayer structure of the whole network, enhances or deteriorates the diffusion of packets of information.

Information transfer in community structured multiplex networks

Directory of Open Access Journals (Sweden)

Albert eSolé Ribalta

2015-08-01

Full Text Available The study of complex networks that account for different types of interactions has become a subject of interest in the last few years, specially because its representational power in the description of users interactions in diverse online social platforms (Facebook, Twitter, Instagram, etc.. The mathematical description of these interacting networks has been coined under the name of multilayer networks, where each layer accounts for a type of interaction. It has been shown that diffusive processes on top of these networks present a phenomenology that cannot be explained by the naive superposition of single layer diffusive phenomena but require the whole structure of interconnected layers. Nevertheless, the description of diffusive phenomena on multilayer networks has obviated the fact that social networks have strong mesoscopic structure represented by different communities of individuals driven by common interests, or any other social aspect. In this work, we study the transfer of information in multilayer networks with community structure. The final goal is to understand and quantify, if the existence of well-defined community structure at the level of individual layers, together with the multilayer structure of the whole network, enhances or deteriorates the diffusion of packets of information.

Evidence for the functional significance of diazotroph community structure in soil.

Science.gov (United States)

Hsu, Shi-Fang; Buckley, Daniel H

2009-01-01

Microbial ecologists continue to seek a greater understanding of the factors that govern the ecological significance of microbial community structure. Changes in community structure have been shown to have functional significance for processes that are mediated by a narrow spectrum of organisms, such as nitrification and denitrification, but in some cases, functional redundancy in the community seems to buffer microbial ecosystem processes. The functional significance of microbial community structure is frequently obscured by environmental variation and is hard to detect in short-term experiments. We examine the functional significance of free-living diazotrophs in a replicated long-term tillage experiment in which extraneous variation is minimized and N-fixation rates can be related to soil characteristics and diazotroph community structure. Soil characteristics were found to be primarily impacted by tillage management, whereas N-fixation rates and diazotroph community structure were impacted by both biomass management practices and interactions between tillage and biomass management. The data suggest that the variation in diazotroph community structure has a greater impact on N-fixation rates than do soil characteristics at the site. N-fixation rates displayed a saturating response to increases in diazotroph community diversity. These results show that the changes in the community structure of free-living diazotrophs in soils can have ecological significance and suggest that this response is related to a change in community diversity.

14 CFR 33.76 - Bird ingestion.

Science.gov (United States)

2010-01-01

... single bird, the single largest medium bird which can enter the inlet, and the large flocking bird must...) (d) Large flocking bird. An engine test will be performed as follows: (1) Large flocking bird engine.... (4) Ingestion of a large flocking bird under the conditions prescribed in this paragraph must not...

The Effects of Urban Sprawl on Birds at Multiple Levels of Biological Organization

Directory of Open Access Journals (Sweden)

Robert Blair

2004-12-01

Full Text Available Urban sprawl affects the environment in myriad ways and at multiple levels of biological organization. In this paper I explore the effects of sprawl on native bird communities by comparing the occurrence of birds along gradients of urban land use in southwestern Ohio and northern California and by examining patterns at the individual, species, community, landscape, and continental levels. I do this by assessing the distribution and abundance of all bird species occupying sites of differing land-use intensity in Ohio and California. Additionally, I conducted predation experiments using artificial nests, tracked the nest fate of American Robins and Northern Cardinals, and assessed land cover in these sites. At the individual level, predation on artificial nests decreased with urbanization; however, this trend was not reflected in the nesting success of robins and cardinals, which did not increase with urbanization. At the species level, sprawl affected local patterns of extinction and invasion; the density of different species peaked at different levels of urbanization. At the community level, species richness and diversity peaked at moderate levels of urbanization, and the number of low-nesting species and of species with multiple broods increased with urbanization. The community-level results may reflect both the species-level patterns of local extinction and invasion as well as broader landscape-level patterns. At the landscape level, a linear combination of spatial heterogeneity and density of woody patches accurately predicted both species richness and Shannon Diversity. At the continental level, local extinction of endemic species, followed by the invasion of ubiquitous weedy species, leads to faunal homogenization between ecoregions.

Detailed description of the Ócsa Bird Ringing Station, Hungary

Directory of Open Access Journals (Sweden)

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.

Finding Community Structures In Social Activity Data

KAUST Repository

Peng, Chengbin

2015-05-19

Social activity data sets are increasing in number and volume. Finding community structure in such data is valuable in many applications. For example, understand- ing the community structure of social networks may reduce the spread of epidemics or boost advertising revenue; discovering partitions in tra c networks can help to optimize routing and to reduce congestion; finding a group of users with common interests can allow a system to recommend useful items. Among many aspects, qual- ity of inference and e ciency in finding community structures in such data sets are of paramount concern. In this thesis, we propose several approaches to improve com- munity detection in these aspects. The first approach utilizes the concept of K-cores to reduce the size of the problem. The K-core of a graph is the largest subgraph within which each node has at least K connections. We propose a framework that accelerates community detection. It first applies a traditional algorithm that is relatively slow to the K-core, and then uses a fast heuristic to infer community labels for the remaining nodes. The second approach is to scale the algorithm to multi-processor systems. We de- vise a scalable community detection algorithm for large networks based on stochastic block models. It is an alternating iterative algorithm using a maximum likelihood ap- proach. Compared with traditional inference algorithms for stochastic block models, our algorithm can scale to large networks and run on multi-processor systems. The time complexity is linear in the number of edges of the input network. The third approach is to improve the quality. We propose a framework for non- negative matrix factorization that allows the imposition of linear or approximately linear constraints on each factor. An example of the applications is to find community structures in bipartite networks, which is useful in recommender systems. Our algorithms are compared with the results in recent papers and their quality and e

Detecting the overlapping and hierarchical community structure in complex networks

International Nuclear Information System (INIS)

Lancichinetti, Andrea; Fortunato, Santo; Kertesz, Janos

2009-01-01

Many networks in nature, society and technology are characterized by a mesoscopic level of organization, with groups of nodes forming tightly connected units, called communities or modules, that are only weakly linked to each other. Uncovering this community structure is one of the most important problems in the field of complex networks. Networks often show a hierarchical organization, with communities embedded within other communities; moreover, nodes can be shared between different communities. Here, we present the first algorithm that finds both overlapping communities and the hierarchical structure. The method is based on the local optimization of a fitness function. Community structure is revealed by peaks in the fitness histogram. The resolution can be tuned by a parameter enabling different hierarchical levels of organization to be investigated. Tests on real and artificial networks give excellent results.

Virality Prediction and Community Structure in Social Networks

Science.gov (United States)

Weng, Lilian; Menczer, Filippo; Ahn, Yong-Yeol

2013-08-01

How does network structure affect diffusion? Recent studies suggest that the answer depends on the type of contagion. Complex contagions, unlike infectious diseases (simple contagions), are affected by social reinforcement and homophily. Hence, the spread within highly clustered communities is enhanced, while diffusion across communities is hampered. A common hypothesis is that memes and behaviors are complex contagions. We show that, while most memes indeed spread like complex contagions, a few viral memes spread across many communities, like diseases. We demonstrate that the future popularity of a meme can be predicted by quantifying its early spreading pattern in terms of community concentration. The more communities a meme permeates, the more viral it is. We present a practical method to translate data about community structure into predictive knowledge about what information will spread widely. This connection contributes to our understanding in computational social science, social media analytics, and marketing applications.

Dynamical community structure of populations evolving on genotype networks

International Nuclear Information System (INIS)

Capitán, José A.; Aguirre, Jacobo; Manrubia, Susanna

2015-01-01

Neutral evolutionary dynamics of replicators occurs on large and heterogeneous networks of genotypes. These networks, formed by all genotypes that yield the same phenotype, have a complex architecture that conditions the molecular composition of populations and their movements on genome spaces. Here we consider as an example the case of populations evolving on RNA secondary structure neutral networks and study the community structure of the network revealed through dynamical properties of the population at equilibrium and during adaptive transients. We unveil a rich hierarchical community structure that, eventually, can be traced back to the non-trivial relationship between RNA secondary structure and sequence composition. We demonstrate that usual measures of modularity that only take into account the static, topological structure of networks, cannot identify the community structure disclosed by population dynamics

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

Birds Kept as Pets

Science.gov (United States)

... your pet’s health Visit a veterinarian who has experience with pet birds for routine check-ups to keep your bird healthy and prevent infectious diseases. If your bird becomes sick or dies within a month after purchase or adoption: Contact your veterinarian. Inform the pet ...

Comparing aerodynamic efficiency in birds and bats suggests better flight performance in birds.

Directory of Open Access Journals (Sweden)

Florian T Muijres

Full Text Available Flight is one of the energetically most costly activities in the animal kingdom, suggesting that natural selection should work to optimize flight performance. The similar size and flight speed of birds and bats may therefore suggest convergent aerodynamic performance; alternatively, flight performance could be restricted by phylogenetic constraints. We test which of these scenarios fit to two measures of aerodynamic flight efficiency in two passerine bird species and two New World leaf-nosed bat species. Using time-resolved particle image velocimetry measurements of the wake of the animals flying in a wind tunnel, we derived the span efficiency, a metric for the efficiency of generating lift, and the lift-to-drag ratio, a metric for mechanical energetic flight efficiency. We show that the birds significantly outperform the bats in both metrics, which we ascribe to variation in aerodynamic function of body and wing upstroke: Bird bodies generated relatively more lift than bat bodies, resulting in a more uniform spanwise lift distribution and higher span efficiency. A likely explanation would be that the bat ears and nose leaf, associated with echolocation, disturb the flow over the body. During the upstroke, the birds retract their wings to make them aerodynamically inactive, while the membranous bat wings generate thrust and negative lift. Despite the differences in performance, the wake morphology of both birds and bats resemble the optimal wake for their respective lift-to-drag ratio regimes. This suggests that evolution has optimized performance relative to the respective conditions of birds and bats, but that maximum performance is possibly limited by phylogenetic constraints. Although ecological differences between birds and bats are subjected to many conspiring variables, the different aerodynamic flight efficiency for the bird and bat species studied here may help explain why birds typically fly faster, migrate more frequently and migrate

Comparing aerodynamic efficiency in birds and bats suggests better flight performance in birds.

Science.gov (United States)

Muijres, Florian T; Johansson, L Christoffer; Bowlin, Melissa S; Winter, York; Hedenström, Anders

2012-01-01

Flight is one of the energetically most costly activities in the animal kingdom, suggesting that natural selection should work to optimize flight performance. The similar size and flight speed of birds and bats may therefore suggest convergent aerodynamic performance; alternatively, flight performance could be restricted by phylogenetic constraints. We test which of these scenarios fit to two measures of aerodynamic flight efficiency in two passerine bird species and two New World leaf-nosed bat species. Using time-resolved particle image velocimetry measurements of the wake of the animals flying in a wind tunnel, we derived the span efficiency, a metric for the efficiency of generating lift, and the lift-to-drag ratio, a metric for mechanical energetic flight efficiency. We show that the birds significantly outperform the bats in both metrics, which we ascribe to variation in aerodynamic function of body and wing upstroke: Bird bodies generated relatively more lift than bat bodies, resulting in a more uniform spanwise lift distribution and higher span efficiency. A likely explanation would be that the bat ears and nose leaf, associated with echolocation, disturb the flow over the body. During the upstroke, the birds retract their wings to make them aerodynamically inactive, while the membranous bat wings generate thrust and negative lift. Despite the differences in performance, the wake morphology of both birds and bats resemble the optimal wake for their respective lift-to-drag ratio regimes. This suggests that evolution has optimized performance relative to the respective conditions of birds and bats, but that maximum performance is possibly limited by phylogenetic constraints. Although ecological differences between birds and bats are subjected to many conspiring variables, the different aerodynamic flight efficiency for the bird and bat species studied here may help explain why birds typically fly faster, migrate more frequently and migrate longer distances

Herpesvirus infections in psittacine birds in Japan.

Science.gov (United States)

Tsai, S S; Park, J H; Hirai, K; Itakura, C

1993-03-01

Herpesvirus infection was diagnosed histologically and electron microscopically in 21 out of 241 pet birds examined. The infected birds included 14 parakeets (Psittacula krameri manillensis) with respiratory infection and three parrots (Ama-zona aestiva aestiva), two cockatiels (Nymphicus hollandicus) and two rosellas (Platycercus emimius) with Pacheco's disease. The consistent lesions of respiratory herpesvirus infection were the formation of syncytial cells associated with the presence of intranuclear inclusion bodies, mainly in the lung and air sac. There was lack of an apparent cellular reaction in situ. The agent induced tubular structures containing a clear core in the nuclei of the affected cells. The present study indicated that it was a distinct entity from infectious laryngotracheitis based on tissue tropism, host reaction and morphology of the tubular structures. The striking lesions of Pacheco's disease consisted of syncytial cell formation with intranuclear inclusion bodies in various organs, especially the liver, parathyroid, ovary, bone marrow and intestine. This agent showed similar morphology to that of the respiratory herpesvirus infection, but was larger in size and had no tubular structure formation in the nuclei of affected cells.

Structural analysis of raw and commercial farm edible bird nests.

Science.gov (United States)

Kew, P E; Wong, S F; Lim, P K; Mak, J W

2014-03-01

Edible bird nests (EBNs) are consumed worldwide for various health benefits. EBNs are nests built from the saliva of swiftlets of Aerodramus species. The global market for EBNs is on the rise, especially from Hong Kong and mainland China. In the past, EBNs were harvested mainly from natural caves; however in the recent years, there has been a rapid growth of swiftlet farming. Little is known about the actual composition of EBNs except for protein, carbohydrate, ash and lipid contents, amino acids, vitamins and macro/ micronutrients. Besides the biochemical components of EBNs, are there any other structures that are associated with EBNs? This paper reports on the structural analysis of raw unprocessed farm and processed commercial EBNs. The raw EBNs were purchased from swiftlet farms in five locations in Peninsula Malaysia: Kuala Sanglang (Perlis; 6° 16' 0"N, 100° 12' 0"E), Pantai Remis (Perak; 4º 27' 0" N, 100º 38' 0" E), Kluang (Johor; 02º 012 303N 103º 192 583E), Kajang (Selangor; 2º 59' 0"N, 101º 47' 0"E) and Kota Bharu (Kelantan; 6º 8' 0"N, 102º 15' 0"E). The commercial nests were purchased from five different Chinese traditional medicinal shops (Companies A-E). A portion of each EBN was randomly broken into small fragments, attached to carbon tape and coated with gold and palladium particles for examination and photography under a scanning electron microscope. Structural analysis revealed the presence of mites, fungi, bacteria and feather strands on both the raw and commercial nests. Mite eggshells and faecal pellets, and body parts of other arthropods were seen only in the raw nests. The commercial nests had a variety of unidentified structures and substances coated on the nests' surfaces that were not found on the raw nests. The presence of these contaminants may jeopardise the quality of EBNs and pose health risks to consumers. Further identification of the mites and their allergens, fungi and bacteria are on-going and will be reported separately.

Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Upper Coast of Texas: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for diving birds, gulls, terns, passerine birds, pelagic birds, raptors, shorebirds, wading birds,...

Reduced spread of Campylobacter jejuni in broiler chickens by stimulating the bird's natural barriers.

Science.gov (United States)

Moen, B; Rudi, K; Svihus, B; Skånseng, B

2012-11-01

We have tested the effect of feed structure and feeding regime to prevent the spread of the zoonotic pathogen Campylobacter jejuni in broiler chicken flocks. Birds were offered two types of feed, control diet and a diet supplemented with 15% oat/barley hulls for structure. In addition, the birds were either fed ad libitum or intermittent. One bird in each treatment group was infected with a three-strain-mix of Camp. jejuni, and the spread of Camp. jejuni within the group was investigated. Feed structure increased the gizzard weight, delayed the spread of Camp. jejuni within the group and reduced the relative amount of Camp. jejuni in the caecum compared with the control diet. Our results show that stimulating the bird's natural barriers is a novel and promising intervention strategy to reduce the spread of Camp. jejuni in chicken flocks. Preventing Camp. jejuni in broiler chicken flocks is essential to ensure food safety because this bacterium is transferred to chicken carcasses during the slaughter process and readily survive in unprocessed poultry products. We have evaluated a novel approach for stimulation of the bird's natural barriers in the upper digestive tract with promising results. © 2012 The Authors Journal of Applied Microbiology © 2012 The Society for Applied Microbiology.

Fossilized melanosomes and the colour of Cretaceous dinosaurs and birds.

Science.gov (United States)

Zhang, Fucheng; Kearns, Stuart L; Orr, Patrick J; Benton, Michael J; Zhou, Zhonghe; Johnson, Diane; Xu, Xing; Wang, Xiaolin

2010-02-25

Spectacular fossils from the Early Cretaceous Jehol Group of northeastern China have greatly expanded our knowledge of the diversity and palaeobiology of dinosaurs and early birds, and contributed to our understanding of the origin of birds, of flight, and of feathers. Pennaceous (vaned) feathers and integumentary filaments are preserved in birds and non-avian theropod dinosaurs, but little is known of their microstructure. Here we report that melanosomes (colour-bearing organelles) are not only preserved in the pennaceous feathers of early birds, but also in an identical manner in integumentary filaments of non-avian dinosaurs, thus refuting recent claims that the filaments are partially decayed dermal collagen fibres. Examples of both eumelanosomes and phaeomelanosomes have been identified, and they are often preserved in life position within the structure of partially degraded feathers and filaments. Furthermore, the data here provide empirical evidence for reconstructing the colours and colour patterning of these extinct birds and theropod dinosaurs: for example, the dark-coloured stripes on the tail of the theropod dinosaur Sinosauropteryx can reasonably be inferred to have exhibited chestnut to reddish-brown tones.

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.

Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Northern California: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for alcids, diving birds, gulls, terns, passerines, pelagic birds, raptors, shorebirds, wading birds, and...

Phylogenetic structure in tropical hummingbird communities

DEFF Research Database (Denmark)

Graham, Catherine H; Parra, Juan L; Rahbek, Carsten

2009-01-01

How biotic interactions, current and historical environment, and biogeographic barriers determine community structure is a fundamental question in ecology and evolution, especially in diverse tropical regions. To evaluate patterns of local and regional diversity, we quantified the phylogenetic...... composition of 189 hummingbird communities in Ecuador. We assessed how species and phylogenetic composition changed along environmental gradients and across biogeographic barriers. We show that humid, low-elevation communities are phylogenetically overdispersed (coexistence of distant relatives), a pattern...... that is consistent with the idea that competition influences the local composition of hummingbirds. At higher elevations communities are phylogenetically clustered (coexistence of close relatives), consistent with the expectation of environmental filtering, which may result from the challenge of sustaining...

Bird guard

Science.gov (United States)

Fairchild, Dana M [Armour, SD

2010-03-02

The bird guard provides a device to protect electrical insulators comprising a central shaft; a clamp attached to an end of the shaft to secure the device to a transmission tower; a top and bottom cover to shield transmission tower insulators; and bearings to allow the guard to rotate in order to frighten birds away from the insulators.

A new hierarchical method to find community structure in networks

Science.gov (United States)

Saoud, Bilal; Moussaoui, Abdelouahab

2018-04-01

Community structure is very important to understand a network which represents a context. Many community detection methods have been proposed like hierarchical methods. In our study, we propose a new hierarchical method for community detection in networks based on genetic algorithm. In this method we use genetic algorithm to split a network into two networks which maximize the modularity. Each new network represents a cluster (community). Then we repeat the splitting process until we get one node at each cluster. We use the modularity function to measure the strength of the community structure found by our method, which gives us an objective metric for choosing the number of communities into which a network should be divided. We demonstrate that our method are highly effective at discovering community structure in both computer-generated and real-world network data.

Uncovering the community structure associated with the diffusion dynamics on networks

International Nuclear Information System (INIS)

Cheng, Xue-Qi; Shen, Hua-Wei

2010-01-01

As two main focuses of the study of complex networks, the community structure and the dynamics on networks have both attracted much attention in various scientific fields. However, it is still an open question how the community structure is associated with the dynamics on complex networks. In this paper, through investigating the diffusion process taking place on networks, we demonstrate that the intrinsic community structure of networks can be revealed by the stable local equilibrium states of the diffusion process. Furthermore, we show that such community structure can be directly identified through the optimization of the conductance of the network, which measures how easily the diffusion among different communities occurs. Tests on benchmark networks indicate that the conductance optimization method significantly outperforms the modularity optimization methods in identifying the community structure of networks. Applications to real world networks also demonstrate the effectiveness of the conductance optimization method. This work provides insights into the multiple topological scales of complex networks, and the community structure obtained can naturally reflect the diffusion capability of the underlying network

Comparative analysis of vestibular ecomorphology in birds.

Science.gov (United States)

Benson, Roger B J; Starmer-Jones, Ethan; Close, Roger A; Walsh, Stig A

2017-12-01

The bony labyrinth of vertebrates houses the semicircular canals. These sense rotational accelerations of the head and play an essential role in gaze stabilisation during locomotion. The sizes and shapes of the semicircular canals have hypothesised relationships to agility and locomotory modes in many groups, including birds, and a burgeoning palaeontological literature seeks to make ecological interpretations from the morphology of the labyrinth in extinct species. Rigorous tests of form-function relationships for the vestibular system are required to support these interpretations. We test the hypothesis that the lengths, streamlines and angles between the semicircular canals are related to body size, wing kinematics and flying style in birds. To do this, we applied geometric morphometrics and multivariate phylogenetic comparative methods to a dataset of 64 three-dimensional reconstructions of the endosseous labyrinth obtained using micro-computed tomography scanning of bird crania. A strong relationship between centroid size of the semicircular canals and body size indicates that larger birds have longer semicircular canals compared with their evolutionary relatives. Wing kinematics related to manoeuvrability (and quantified using the brachial index) explain a small additional portion of the variance in labyrinth size. We also find strong evidence for allometric shape change in the semicircular canals of birds, indicating that major aspects of the shape of the avian labyrinth are determined by spatial constraints. The avian braincase accommodates a large brain, a large eye and large semicircular canals compared with other tetrapods. Negative allometry of these structures means that the restriction of space within the braincase is intense in small birds. This may explain our observation that the angles between planes of the semicircular canals of birds deviate more strongly from orthogonality than those of mammals, and especially from agile, gliding and flying

Effects of Patagonian pine forestry on native breeding birds

Directory of Open Access Journals (Sweden)

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.

Optimal community structure for social contagions

Science.gov (United States)

Su, Zhen; Wang, Wei; Li, Lixiang; Stanley, H. Eugene; Braunstein, Lidia A.

2018-05-01

Community structure is an important factor in the behavior of real-world networks because it strongly affects the stability and thus the phase transition order of the spreading dynamics. We here propose a reversible social contagion model of community networks that includes the factor of social reinforcement. In our model an individual adopts a social contagion when the number of received units of information exceeds its adoption threshold. We use mean-field approximation to describe our proposed model, and the results agree with numerical simulations. The numerical simulations and theoretical analyses both indicate that there is a first-order phase transition in the spreading dynamics, and that a hysteresis loop emerges in the system when there is a variety of initially adopted seeds. We find an optimal community structure that maximizes spreading dynamics. We also find a rich phase diagram with a triple point that separates the no-diffusion phase from the two diffusion phases.

Unsteady Aerodynamics of Flapping Wing of a Bird

Directory of Open Access Journals (Sweden)

M. Agoes Moelyadi

2013-04-01

Full Text Available The unsteady flow behavior and time-dependent aerodynamic characteristics of the flapping motion of a bird’s wing were investigated using a computational method. During flapping, aerodynamic interactions between bird wing surfaces and surrounding flow may occur, generating local time-dependent flow changes in the flow field and aerodynamic load of birds. To study the effect of flapping speed on unsteady aerodynamic load, two kinds of computational simulations were carried out, namely a quasi-steady and an unsteady simulation. To mimic the movement of the down-stroke and the upstroke of a bird, the flapping path accorded to a sinus function, with the wing attitude changing in dihedral angle and time. The computations of time-dependent viscous flow were based on the solution of the Reynolds Averaged Navier-Stokes equations by applying the k-e turbulence model. In addition, the discretization for the computational domain around the model used multi-block structured grid to provide more accuracy in capturing viscous flow, especially in the vicinity of the wing and body surfaces, to obtain a proper wing-body geometry model. For this research, the seagull bird was chosen, which has high aspect ratio wings with pointed wing-tips and a high camber wing section. The results include mesh movement, velocity contours as well as aerodynamic coefficients of the flapping motion of the bird at various flapping frequencies.

76 FR 59298 - Migratory Bird Hunting; Migratory Bird Hunting Regulations on Certain Federal Indian Reservations...

Science.gov (United States)

2011-09-26

... such birds or any part, nest, or egg thereof may be taken, hunted, captured, killed, possessed, sold...-0014; 91200-1231-9BPP-L2] RIN 1018-AX34 Migratory Bird Hunting; Migratory Bird Hunting Regulations on... Service, Interior. ACTION: Final rule. SUMMARY: This rule prescribes special late-season migratory bird...

The first 50 years of the North American Breeding Bird Survey

Science.gov (United States)

Sauer, John; Ziolkowski, David; Pardieck, Keith L.; Smith, Adam C.; Hudson, Marie-Anne R.; Rodriguez, Vicente; Berlanga, Humberto; Niven, Daniel; Link, William

2017-01-01

The vision of Chandler (Chan) S. Robbins for a continental-scale omnibus survey of breeding birds led to the development of the North American Breeding Bird Survey (BBS). Chan was uniquely suited to develop the BBS. His position as a government scientist had given him experience with designing and implementing continental-scale surveys, his research background made him an effective advocate of the need for a survey to monitor pesticide effects on birds, and his prominence in the birding community gave him connections to infrastructure—a network of qualified volunteer birders who could conduct roadside surveys with standardized point counts. Having started in the eastern United States and the Atlantic provinces of Canada in 1966, the BBS now provides population change information for ∼546 species in the continental United States and Canada, and recently initiated routes in Mexico promise to greatly expand the areas and species covered by the survey. Although survey protocols have remained unchanged for 50 years, the BBS remains relevant in a changing world. Several papers that follow in this Special Section of The Condor: Ornithological Advances review how the BBS has been applied to conservation assessments, especially in combination with other large-scale survey data. A critical feature of the BBS program is an active research program into field and analytical methods to enhance the quality of the count data and to control for factors that influence detectability. Papers in the Special Section also present advances in BBS analyses that improve the utility of this expanding and sometimes controversial survey. In this Perspective, we introduce the Special Section by reviewing the history of the BBS, describing current analyses, and providing summary trend results for all species, highlighting 3 groups of conservation concern: grassland-breeding birds, aridland-breeding birds, and aerial insectivorous birds.

Conceptual ecological model for management of breeding shrubland birds in the Mid-Atlantic Region

Science.gov (United States)

Peterjohn, Bruce G.

2006-01-01

While grassland birds have become the focus of increased conservation activities, the status of birds occupying shrubland habitats has received relatively little attention (Hunter et al. 2001). Yet, in eastern North America, shrubland birds exhibited consistent population declines during the past 40 years, based on data from the North American Breeding Bird Survey (Pardieck and Sauer 2001). These population declines primarily reflect large-scale changes in land use patterns during the previous century (Lorimer 2001). Large areas of marginal farmland were abandoned and underwent secondary succession during the first half of the twentieth century, producing abundant successional habitats favored by shrubland birds. As these habitats matured, combined with strict fire-suppression policies (Hunter et al. 2001), shrublands succeeded into mature forests, and shrubland bird communities were replaced by woodland birds (Irland 1982; Askins 1993). For example, while nearly 29% of New England forests were classified as sapling stage in 1950, only 8% remained at that stage in the 1980s (Askins 1993). The trend towards forest maturation and loss of shrubland habitats continues, yet concerted conservation activities have not been directed to benefit declining shrubland bird populations. The National Park Service (NPS) could contribute to shrubland bird conservation in the Mid- Atlantic Region. The NPS maintains a number of historic sites and former battlefields managed for their cultural significance but also support wildlife populations. Many of these “cultural parks” maintain open landscapes, recreating land use patterns existing at the times of the historical events. While these open landscapes are frequently managed grasslands, some parks also support successional habitats that could be managed to benefit shrubland birds. In 2005, the NPS initiated a project exploring the potential of “cultural parks” to support significant breeding grassland and shrubland bird

50 CFR 92.12 - Relationship to the process for developing national hunting regulations for migratory game birds.

Science.gov (United States)

2010-10-01

... national hunting regulations for migratory game birds. 92.12 Section 92.12 Wildlife and Fisheries UNITED... MIGRATORY BIRD SUBSISTENCE HARVEST IN ALASKA Program Structure § 92.12 Relationship to the process for developing national hunting regulations for migratory game birds. (a) Flyway councils. (1) Proposed annual...

Blood parasites in passerine birds from the Brazilian Atlantic Forest Hemoparasitos em passeriformes da Mata Atlântica Brasileira

Directory of Open Access Journals (Sweden)

Fabiane Sebaio

2012-03-01

Full Text Available Parasites may lead bird species to extinction, affect host temporal and spatial population dynamics, alter community structure and alter individuals’ social status. We evaluated blood parasite prevalence and intensity according to bird families and species, among 925 birds that were caught in 2000 and 2001, in the Atlantic Forest in the State of Minas Gerais, Brazil. We applied Giemsa staining to thin blood smears, to detect blood parasites. The birds (n = 15.8% in 11 families, were infected by at least one parasite genus, especially Muscicapidae (28.3% and Conopophagidae (25%. Among the 146 infected birds, Plasmodium was detected in all bird families and had the highest prevalence (54.8%. Trypanosoma, Haemoproteus and microfilaria had lower prevalence rates (23.3, 23.3 and 2.1%, respectively. Birds caught during the rainy season were more infected than birds caught during the dry season. The overall low prevalence of blood parasites in birds is similar to the patterns found elsewhere in the Neotropical region.Parasitos podem levar espécies de aves à extinção, afetar as dinâmicas temporais e espaciais dos hospedeiros, alterar a estrutura de comunidades e o status social de indivíduos. Avaliou-se a prevalência e a intensidade de parasitos em famílias e espécies de 925 aves capturadas, entre 2000 e 2001, na Mata Atlântica de Minas Gerais. Foram coradas com Giemsa extensões de sangue para detectar parasitos hematozoários. As aves (n= 15,8% 11 famílias estavam infectadas por pelo menos um gênero de parasito, especialmente Muscicapidae (28,3% e Conopophagidae (25%. Entre as 146 aves infectadas, Plasmodium foi detectado em todas as famílias e possuiu a maior prevalência (54,8%. Trypanosoma,Haemoproteus e microfilaria possuíram baixas prevalências (23,3, 23,3 e 2,1%, respectivamente. Aves capturadasdurante a estação chuvosa estavam mais infectadas do que aves capturadas durante a estação seca. A baixa prevalência geral de

Hawaii ESI: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for endangered waterbirds and passerine birds, migratory shorebirds and waterfowl, gulls and terns,...

Soil shapes community structure through fire.

Science.gov (United States)

Ojeda, Fernando; Pausas, Juli G; Verdú, Miguel

2010-07-01

Recurrent wildfires constitute a major selecting force in shaping the structure of plant communities. At the regional scale, fire favours phenotypic and phylogenetic clustering in Mediterranean woody plant communities. Nevertheless, the incidence of fire within a fire-prone region may present strong variations at the local, landscape scale. This study tests the prediction that woody communities on acid, nutrient-poor soils should exhibit more pronounced phenotypic and phylogenetic clustering patterns than woody communities on fertile soils, as a consequence of their higher flammability and, hence, presumably higher propensity to recurrent fire. Results confirm the predictions and show that habitat filtering driven by fire may be detected even in local communities from an already fire-filtered regional flora. They also provide a new perspective from which to consider a preponderant role of fire as a key evolutionary force in acid, infertile Mediterranean heathlands.

78 FR 65578 - Migratory Bird Permits; Depredation Order for Migratory Birds in California

Science.gov (United States)

2013-11-01

...-0037; FF09M21200-134-FXMB1231099BPP0] RIN 1018-AY65 Migratory Bird Permits; Depredation Order for Migratory Birds in California AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule. SUMMARY: We revise the regulations that allow control of depredating birds in California. We specify the counties in...

Modeling birds on wires.

Science.gov (United States)

Aydoğdu, A; Frasca, P; D'Apice, C; Manzo, R; Thornton, J M; Gachomo, B; Wilson, T; Cheung, B; Tariq, U; Saidel, W; Piccoli, B

2017-02-21

In this paper we introduce a mathematical model to study the group dynamics of birds resting on wires. The model is agent-based and postulates attraction-repulsion forces between the interacting birds: the interactions are "topological", in the sense that they involve a given number of neighbors irrespective of their distance. The model is first mathematically analyzed and then simulated to study its main properties: we observe that the model predicts birds to be more widely spaced near the borders of each group. We compare the results from the model with experimental data, derived from the analysis of pictures of pigeons and starlings taken in New Jersey: two different image elaboration protocols allow us to establish a good agreement with the model and to quantify its main parameters. We also discuss the potential handedness of the birds, by analyzing the group organization features and the group dynamics at the arrival of new birds. Finally, we propose a more refined mathematical model that describes landing and departing birds by suitable stochastic processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Change in fish community structure in the Barents Sea.

Directory of Open Access Journals (Sweden)

Michaela Aschan

Full Text Available Change in oceanographic conditions causes structural alterations in marine fish communities, but this effect may go undetected as most monitoring programs until recently mainly have focused on oceanography and commercial species rather than on whole ecosystems. In this paper, the objective is to describe the spatial and temporal changes in the Barents Sea fish community in the period 1992-2004 while taking into consideration the observed abundance and biodiversity patterns for all 82 observed fish species. We found that the spatial structure of the Barents Sea fish community was determined by abiotic factors such as temperature and depth. The observed species clustered into a deep assemblage, a warm water southern assemblage, both associated with Atlantic water, and a cold water north-eastern assemblage associated with mixed water. The latitude of the cold water NE and warm water S assemblages varied from year to year, but no obvious northward migration was observed over time. In the period 1996-1999 we observed a significant reduction in total fish biomass, abundance, mean fish weight, and a change in community structure including an increase in the pelagic/demersal ratio. This change in community structure is probably due to extremely cold conditions in 1996 impacting on a fish community exposed to historically high fishing rates. After 1999 the fish community variables such as biomass, abundance, mean weight, P/D ratio as well as community composition did not return to levels of the early 90s, although fishing pressure and climatic conditions returned to earlier levels.

Birds of a high-altitude cloud forest in Alta Verapaz, Guatemala

Directory of Open Access Journals (Sweden)

Knut Eisermann

2005-09-01

Full Text Available The Northern Central American Highlands have been recognized as endemic bird area, but little is known about bird communities in Guatemalan cloud forests. From 1997 to 2001 a total of 142 bird species were recorded between 2 000 and 2 400 masl in cloud forest and agricultural clearings on Montaña Caquipec (Alta Verapaz, Guatemala. The bird community is described based on line transect counts within the forest. Pooling census data from undisturbed and disturbed forest, the Gray-breasted Wood-Wren (Henicorhina leucophrys was found to be the most abundant species, followed in descending order by the Common Bush-Tanager (Chlorospingus ophthalmicus, the Paltry Tyrannulet (Zimmerius vilissimus, the Yellowish Flycatcher (Empidonax flavescens, the Ruddy-capped Nightingale-Thrush (Catharus frantzii, and the Amethyst-throated Hummingbird (Lampornis amethystinus. Bird communities in undisturbed and disturbed forest were found to be similar (Sørensen similarity index 0.85, indicating low human impact. Of all recorded species, ~27% were Nearctic-Neotropical migratory birds. The most abundant one was the Wilson’s Warbler (Wilsonia pusilla. The Montaña Caquipec is an important area for bird conservation, which is indicated by the presence of four species listed in the IUCN Red List (Highland Guan Penelopina nigra, Resplendent Quetzal Pharomachrus mocinno, Pink-headed Warbler Ergaticus versicolor, Golden-cheeked Warbler Dendroica chrysoparia, and 42 Mesoamerican endemics, of which 14 species are endemic to the Central American Highlands. The results presented here will be useful as baseline data for a long-term monitoring. Rev. Biol. Trop. 53(3-4: 577-594. Epub 2005 Oct 3.Las alturas del norte de Centroamérica han sido reconocidas como región de aves endémicas, pero se conoce poco sobre las comunidades de aves en bosques nubosos de Guatemala. De 1997 a 2001 se han detectado 142 especies de aves entre 2 000 y 2 400 msnm en el bosque nuboso y áreas agr

Epidemic pox and malaria in native forest birds

Science.gov (United States)

Atkinson, C. T.; Dusek, R. J.; Iko, W. M.

1993-01-01

Studies by Warner in the 1950’s and van Riper in the 1970’s identified disease as a potential limiting factor in the distribution and abundance of Hawaii’s native forest birds. Mosquito-transmitted protozoan and viral infections caused by malarial parasites and pox virus were especially significant. Both organisms were introduced to the islands after the arrival of Europeans and are thought to have affected avian communities the same way that measles devastated native Hawaiian peoples.

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�

Active farmsteads are year-round strongholds for farmland birds

Czech Academy of Sciences Publication Activity Database

Šálek, Martin; Bažant, M.; Żmihorski, M.

(2018) ISSN 0021-8901 Institutional support: RVO:68081766 Keywords : biodiversity * birds * conservation * farmland * farmsteads * hotspots * landscape structure * red-listed species * species richness Subject RIV: EG - Zoology Impact factor: 5.301, year: 2016

Audubon Bird Study Program.

Science.gov (United States)

National Audubon Society, New York, NY.

Included are a student reader, "The Story of Birds," a leaders' guide, a large colored Audubon bird chart, and a separate guide for the chart. The student reader is divided into eleven sections which relate to the various physical and behavioral features of birds such as feathers, feeding habits as related to the shape of bills and feet, nests,…

Will a warmer and wetter future cause extinction of native Hawaiian forest birds?

Science.gov (United States)

Liao, Wei; Timm, Oliver Elison; Zhang, Chunxi; Atkinson, Carter T.; LaPointe, Dennis; Samuel, Michael D.

2015-01-01

Isolation of the Hawaiian archipelago produced a highly endemic and unique avifauna. Avian malaria (Plasmodium relictum), an introduced mosquito-borne pathogen, is a primary cause of extinctions and declines of these endemic honeycreepers. Our research assesses how global climate change will affect future malaria risk and native bird populations. We used an epidemiological model to evaluate future bird-mosquito-malaria dynamics in response to alternative climate projections from the Coupled Model Intercomparison Project (CMIP). Climate changes during the second half of the century accelerate malaria transmission and cause a dramatic decline in bird abundance. Different temperature and precipitation patterns produce divergent trajectories where native birds persist with low malaria infection under a warmer and dryer projection (RCP4.5), but suffer high malaria infection and severe reductions under hot and dry (RCP8.5) or warm and wet (A1B) futures. We conclude that future global climate change will cause significant decreases in the abundance and diversity of remaining Hawaiian bird communities. Because these effects appear unlikely before mid-century, natural resource managers have time to implement conservation strategies to protect this unique avifauna from further decimation. Similar climatic drivers for avian and human malaria suggest that mitigation strategies for Hawai'i have broad application to human health.

Covariance, correlation matrix, and the multiscale community structure of networks.

Science.gov (United States)

Shen, Hua-Wei; Cheng, Xue-Qi; Fang, Bin-Xing

2010-07-01

Empirical studies show that real world networks often exhibit multiple scales of topological descriptions. However, it is still an open problem how to identify the intrinsic multiple scales of networks. In this paper, we consider detecting the multiscale community structure of network from the perspective of dimension reduction. According to this perspective, a covariance matrix of network is defined to uncover the multiscale community structure through the translation and rotation transformations. It is proved that the covariance matrix is the unbiased version of the well-known modularity matrix. We then point out that the translation and rotation transformations fail to deal with the heterogeneous network, which is very common in nature and society. To address this problem, a correlation matrix is proposed through introducing the rescaling transformation into the covariance matrix. Extensive tests on real world and artificial networks demonstrate that the correlation matrix significantly outperforms the covariance matrix, identically the modularity matrix, as regards identifying the multiscale community structure of network. This work provides a novel perspective to the identification of community structure and thus various dimension reduction methods might be used for the identification of community structure. Through introducing the correlation matrix, we further conclude that the rescaling transformation is crucial to identify the multiscale community structure of network, as well as the translation and rotation transformations.

Community structures and role detection in music networks

Science.gov (United States)

Teitelbaum, T.; Balenzuela, P.; Cano, P.; Buldú, Javier M.

2008-12-01

We analyze the existence of community structures in two different social networks using data obtained from similarity and collaborative features between musical artists. Our analysis reveals some characteristic organizational patterns and provides information about the driving forces behind the growth of the networks. In the similarity network, we find a strong correlation between clusters of artists and musical genres. On the other hand, the collaboration network shows two different kinds of communities: rather small structures related to music bands and geographic zones, and much bigger communities built upon collaborative clusters with a high number of participants related through the period the artists were active. Finally, we detect the leading artists inside their corresponding communities and analyze their roles in the network by looking at a few topological properties of the nodes.

Local temperatures predict breeding phenology but do not result in breeding synchrony among a community of resident cavity-nesting birds.

Science.gov (United States)

Drake, Anna; Martin, Kathy

2018-02-09

Weather and ecological factors are known to influence breeding phenology and thus individual fitness. We predicted concordance between weather conditions and annual variation in phenology within a community of eight resident, cavity-nesting bird species over a 17-year period. We show that, although clutch initiation dates for six of our eight species are correlated with local daily maximum temperatures, this common driver does not produce a high degree of breeding synchrony due to species-specific responses to conditions during different periods of the preceding winter or spring. These "critical temperature periods" were positively associated with average lay date for each species, although the interval between critical periods and clutch initiation varied from 4-78 days. The ecological factors we examined (cavity availability and a food pulse) had an additional influence on timing in only one of our eight focal species. Our results have strong implications for understanding heterogeneous wildlife responses to climate change: divergent responses would be expected within communities where species respond to local conditions within different temporal windows, due to differing warming trends between winter and spring. Our system therefore indicates that climate change could alter relative breeding phenology among sympatric species in temperate ecosystems.

Investigating Effects of Invasive Species on Plant Community Structure

Science.gov (United States)

Franklin, Wilfred

2008-01-01

In this article, the author presents a field study project that explores factors influencing forest community structure and lifts the veil off of "plant blindness." This ecological study consists of three laboratories: (1) preliminary field trip to the study site; (2) plant survey; and (3) analyzing plant community structure with descriptive…

Community Structural Instability, Anomie, Imitation and Adolescent Suicidal Behavior

Science.gov (United States)

Thorlindsson, Thorolfur; Bernburg, Jon Gunnar

2009-01-01

The current study examines the contextual effects of community structural characteristics, as well as the mediating role of key social mechanisms, on youth suicidal behavior in Iceland. We argue that the contextual influence of community structural instability on youth suicidal behavior should be mediated by weak attachment to social norms and…

Semi-arid grassland bird responses to patch-burn grazing and drought

Science.gov (United States)

Skagen, Susan K.; Augustine, David J.; Derner, Justin D.

2018-01-01

As grassland birds of central North America experience steep population declines with changes in land use, management of remaining tracts becomes increasingly important for population viability. The integrated use of fire and grazing may enhance vegetation heterogeneity and diversity in breeding birds, but the subsequent effects on reproduction are unknown. We examined the influence of patch-burn grazing management in shortgrass steppe in eastern Colorado on habitat use and reproductive success of 3 grassland bird species, horned lark (Eremophila alpestris), lark bunting (Calamospiza melanocorys), and McCown’s longspur (Rhynchophanes mccownii), at several spatial scales during 2011 and 2012. Although no simple direct relationship to patch-burn grazing treatment existed, habitat selection depended on precipitation- and management-induced vegetation conditions and spatial scale. All species selected taller-than-expected vegetation at the nest site, whereas at the territory scale, horned larks and McCown’s longspurs selected areas with low vegetation height and sparse cover of tall plants (taller than the dominant shortgrasses). Buntings nested primarily in unburned grassland under average rainfall. Larks and longspurs shifted activity from patch burns during average precipitation (2011) to unburned pastures during drought (2012). Daily survival rate (DSR) of nests varied with time in season, species, weather, and vegetation structure. Daily survival rate of McCown’s longspur nests did not vary with foliar cover of relatively tall vegetation at the nest under average precipitation but declined with increasing cover during drought. At the 200-m scale, increasing cover of shortgrasses, rather than taller plant species, improved DSR of larks and longspurs. These birds experience tradeoffs in the selection of habitat at different spatial scales: tall structure at nests may reduce visual detection by predators and provide protection from sun, wind, and rain, yet

Partners in flight bird conservation plan for the Upper Great Lakes Plain (Physiographic Area 16)

Science.gov (United States)

Knutson, M.G.; Butcher, G.; Fitzgerald, J.; Shieldcastle, J.

2001-01-01

1 November 2001. Conservation of bird habitats is a major focus of effort by Partners in Flight, an international coalition of agencies, citizens, and other groups dedicated to 'keeping common birds common'. USGS worked on a planning team to publish a bird conservation plan for the Upper Great Lakes Plain ecoregion (PIF 16), which includes large portions of southern Wisconsin, southern Michigan and parts of Minnesota, Iowa, Illinois, Indiana, and Ohio. The conservation plan outlines specific habitat restoration and bird population objectives for the ecoregion over the next decade. The plan provides a context for on-the-ground conservation implementation by the US Fish and Wildlife Service, the USDA Natural Resources Conservation Service, the US Forest Service, states, and conservation groups. Citation: Knutson, M. G., G. Butcher, J. Fitzgerald, and J. Shieldcastle. 2001. Partners in Flight Bird Conservation Plan for The Upper Great Lakes Plain (Physiographic Area 16). USGS Upper Midwest Environmental Sciences Center in cooperation with Partners in Flight, La Crosse, Wisconsin. Download from website: http://www.blm.gov/wildlife/pifplans.htm. The Upper Great Lakes Plain covers the southern half of Michigan, northwest Ohio, northern Indiana, northern Illinois, southern Wisconsin, and small portions of southwest Minnesota and northwest Iowa. Glacial moraines and dissected plateaus are characteristic of the topography. Broadleaf forests, oak savannahs, and a variety of prairie communities are the natural vegetation types. A oDriftless Areao was not glaciated during the late Pleistocene and emerged as a unique area of great biological diversity. Priority bird species for the area include the Henslow's Sparrow, Sedge Wren, Bobolink, Golden-winged Warbler, Cerulean Warbler, Black-billed Cuckoo, and Red-headed Woodpecker. There are many large urban centers in this area whose growth and sprawl will continue to consume land. The vast majority of the presettlement forest and

Sensitivity of Coastal Environments and Wildlife to Spilled Oil: Northwest Arctic, Alaska: BIRDS (Bird Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for wading birds, shorebirds, waterfowl, raptors, diving birds, pelagic birds, and gulls/terns in Northwest...

Parasite communities: patterns and processes

National Research Council Canada - National Science Library

Esch, Gerald W; Bush, Albert O; Aho, John M

1990-01-01

.... Taking examples from many hosts including molluscs, marine and freshwater fish, amphibians, reptiles, birds and mammals, this book shows how parasitic communities are influenced by a multitude...

Thermal Analysis of Concrete Storage Cask with Bird Screen Meshes

Energy Technology Data Exchange (ETDEWEB)

Lee, Ju-Chan; Bang, K.S.; Yu, S.H.; Cho, S.S.; Choi, W.S. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

In this study, a thermal analysis of the cask with bird screen meshes has been performed using a porous media model. The overpack consists of a structural material, a concrete shielding, and a ventilation system. Heat is removed from the cask to the environment by a passive means only. Air inlet and outlet ducts are installed at the bottom and top of the cask for a ventilation system. Bird screen meshes are installed at the air inlet and outlet ducts to inhibit intrusion of debris from the external environment. The presence of this screens introduce an additional resistance to air flow through the ducts. Five types of meshes for bird screen were considered in this study. The bird screen meshes at the inlet and outlet vents reduce the open area for flow by about 44 - 79 %. Flow resistance coefficients for porous media model were deduced from the fluid flow analysis of bird screen meshes. Thermal analyses for the concrete cask have been carried out using a porous media model. The analysis results agreed well with the test results. Therefore, it was shown that the porous media model for the screen mesh was established to estimate the cask temperatures.

Thermal Analysis of Concrete Storage Cask with Bird Screen Meshes

International Nuclear Information System (INIS)

Lee, Ju-Chan; Bang, K.S.; Yu, S.H.; Cho, S.S.; Choi, W.S.

2016-01-01

In this study, a thermal analysis of the cask with bird screen meshes has been performed using a porous media model. The overpack consists of a structural material, a concrete shielding, and a ventilation system. Heat is removed from the cask to the environment by a passive means only. Air inlet and outlet ducts are installed at the bottom and top of the cask for a ventilation system. Bird screen meshes are installed at the air inlet and outlet ducts to inhibit intrusion of debris from the external environment. The presence of this screens introduce an additional resistance to air flow through the ducts. Five types of meshes for bird screen were considered in this study. The bird screen meshes at the inlet and outlet vents reduce the open area for flow by about 44 - 79 %. Flow resistance coefficients for porous media model were deduced from the fluid flow analysis of bird screen meshes. Thermal analyses for the concrete cask have been carried out using a porous media model. The analysis results agreed well with the test results. Therefore, it was shown that the porous media model for the screen mesh was established to estimate the cask temperatures

Epidemic spreading in weighted scale-free networks with community structure