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The study offers a comprehensive avifaunal diversity assessment within the Therthanagal Bird Sanctuary (TBS) in the Ramanathapuram district of Tamil Nadu, India, conducted from April 2021 to March 2023, covering two breeding seasons. A total of 96 bird species from 18 orders and 44 families were recorded. The family representations by species included: Ardeidae with 10 species, Accipitridae and Rallidae with six species each, Anatidae with five species, Alcedinidae, Cuculidae, Columbidae, Threskiornithidae and Cisticolidae with four species each. Four globally "Near Threatened" species (IUCN Red List) were reported: Oriental Darter Anhinga melanogaster, Black-headed Ibis Threskiornis melanocephalus, Asian Woolly-necked Stork Ciconia episcopus, and Spot-billed Pelican Pelecanus philippensis. The observed frequencies of species classes were: common (n=58, 60%), uncommon (n=28, 29%), and rare (n=10, 10%). The majority of species were residents (n=83, 86%), followed by winter visitors (n=12, 12%), and a single passage migrant, (Rosy Starling Pastor roseus). Of conservation significance was the finding that 23 of 40 waterbird species recorded in the sanctuary were breeding on-site. Maximum numbers of birds and nests were recorded in the second year, which was presumed to be due to improved rainfall and water availability. The findings underscored the importance of the sanctuary in providing bird habitat, and emphasised the need for its conservation, particularly in safeguarding breeding waterbird habitat. This study provided essential baseline data for any management plan that the forest department may develop for the sanctuary. [ABSTRACT FROM AUTHOR]

Examining beta diversity of animal assemblages in fragmented habitats, which measures variation in species composition among different fragments, is important for understanding the impact of habitat fragmentation on biodiversity. However, relying solely on taxonomic composition may not provide a comprehensive understanding. Incorporating measures of functional and phylogenetic diversities is essential for elucidating the ecological mechanisms underlying changes in community composition. In addition, prevailing studies often prioritize the evaluation of landscape characteristics within fragments as determinants of beta diversity, neglecting differences in habitat type and plant community composition. In this study, we surveyed birds in 26 remnant woodlot patches (ranging from 0.3 to 290.4 ha) in an urban landscape, southwest China, during the breeding season from 2017 to 2022. We recorded 70 bird species (excluding those recorded only once and high‐flying birds, including raptors, swallows, and swifts), with the number of species per patch varying from 14 to 56. The overall bird taxonomic and phylogenetic beta diversities were primarily contributed by the turnover component, while functional beta diversity was dominated by the nestedness‐resultant component. Patch area and perimeter area ratio significantly influenced the taxonomic, functional, and phylogenetic beta diversities, primarily mediated through the nestedness‐resultant component, while inter‐patch distance had a significant effect via the turnover component. In addition, there was a considerable correlation of bird taxonomic, functional, and phylogenetic beta diversities with habitat type and woody plant beta diversities, including their respective partitioned turnover and nestedness‐resultant components. Our results suggest that bird assemblages in these patches may be regulated by selective extinction, interspecific competition, and environmental filtering. The findings have significant implications for sustainable landscape planning and habitat restoration. Conserving habitat patches of different sizes and maintaining or enhancing habitat heterogeneity between patches can facilitate the persistence of metacommunities. [ABSTRACT FROM AUTHOR]

Indian Skimmer Rynchops albicollis Swainson, 1838 is a riverine habitat specialist bird and a species of significant conservation concern. In 2020 it was up-listed to the 'Endangered' category of the IUCN Red List. Breeding grounds of the species are known from the major rivers of India like Ganga, Chambal, Son, and Mahanadi. We monitored breeding colonies of the species in two breeding seasons (2017 and 2018) in the middle Ganges stretch. We identified nine nesting islands and monitored a total of 111 active nests during the study period. A total of 302 eggs were counted with clutch sizes ranging 1-5 and the mean clutch size of 2.7 (±1.18 SD). We observed a 10% & 7% of hatching and fledgling success rate in 2017 and 10% & 17% in 2018, respectively. Low breeding success was probably due to the severe anthropogenic factors such as egg collection, cattle trampling, and stochastic weather events such as flooding and sand inundation by sand storms in nests. We also recorded instances of nest abandoning because of unknown reasons. This article recommends more surveys to identify new breeding colonies of Indian Skimmer in the middle Ganges and subsequently provide adequate protection to the colonies. We also recommend sensitization programs for different stakeholders to create more awareness for the conservation of this threatened species in the middle Ganges stretch. [ABSTRACT FROM AUTHOR]

The use of species distribution models (SDMs) to predict local abundance has been often proposed and contested. We tested whether SDMs at different spatiotemporal resolutions may predict the local density of 14 bird species of open/semi‐open habitats. SDMs were built at 1 ha and 1 km, and with long‐term versus a mix of current and long‐term climatic variables. The estimated environmental suitability was used to predict local abundance obtained by means of 275 linear transects. We tested SDM ability to predict abundance for all sampled sites versus occurrence sites, using N‐mixture models to account for imperfect detection. Then, we related the R2 of N‐mixture models to SDM traits. Fine‐grain SDMs appeared generally more robust than large‐grain ones. Considering the all‐transects models, for all species environmental suitability displayed a positive and highly significant effect at all the four combinations of spatial and temporal grains. When focusing only on occurrence transects, at the 1 km grain only one species showed a significant and positive effect. At the 1 ha grain, 62% of species models showed (over both climatic sets) a significant or nearly significant positive effect of environmental suitability on abundance. Grain was the only factor significantly affecting the model's explanatory power: 1 km grain led to lower amounts of variation explained by models. Our work re‐opens the debate about predicting abundance using SDM‐derived suitability, emphasizing the importance of grains and of spatiotemporal resolution more in general. The incorporation of local variables into SDMs at fine grains is key to predict local abundance. SDMs worked out at really fine grains, approaching the average size of territory or home range of target species, are needed to predict local abundance effectively. This may result from the fact that each single cell may represent a potential territory/home range, and hence a higher suitability over a given area means that more potential territories occur there. [ABSTRACT FROM AUTHOR]

Abstract Examining beta diversity of animal assemblages in fragmented habitats, which measures variation in species composition among different fragments, is important for understanding the impact of habitat fragmentation on biodiversity. However, relying solely on taxonomic composition may not provide a comprehensive understanding. Incorporating measures of functional and phylogenetic diversities is essential for elucidating the ecological mechanisms underlying changes in community composition. In addition, prevailing studies often prioritize the evaluation of landscape characteristics within fragments as determinants of beta diversity, neglecting differences in habitat type and plant community composition. In this study, we surveyed birds in 26 remnant woodlot patches (ranging from 0.3 to 290.4 ha) in an urban landscape, southwest China, during the breeding season from 2017 to 2022. We recorded 70 bird species (excluding those recorded only once and high‐flying birds, including raptors, swallows, and swifts), with the number of species per patch varying from 14 to 56. The overall bird taxonomic and phylogenetic beta diversities were primarily contributed by the turnover component, while functional beta diversity was dominated by the nestedness‐resultant component. Patch area and perimeter area ratio significantly influenced the taxonomic, functional, and phylogenetic beta diversities, primarily mediated through the nestedness‐resultant component, while inter‐patch distance had a significant effect via the turnover component. In addition, there was a considerable correlation of bird taxonomic, functional, and phylogenetic beta diversities with habitat type and woody plant beta diversities, including their respective partitioned turnover and nestedness‐resultant components. Our results suggest that bird assemblages in these patches may be regulated by selective extinction, interspecific competition, and environmental filtering. The findings have significant implications for sustainable landscape planning and habitat restoration. Conserving habitat patches of different sizes and maintaining or enhancing habitat heterogeneity between patches can facilitate the persistence of metacommunities.

Geographical background and dispersal ability may strongly influence assemblage dissimilarity; however, these aspects have generally been overlooked in previous large-scale beta diversity studies. Here, we examined whether the patterns and drivers of taxonomic beta diversity (TBD) and phylogenetic beta diversity (PBD) of breeding birds in China vary across (1) regions on both sides of the Hu Line, which demarcates China’s topographical, climatic, economic, and social patterns, and (2) species with different dispersal ability. TBD and PBD were calculated and partitioned into turnover and nestedness components using a moving window approach. Variables representing climate, habitat heterogeneity, and habitat quality were employed to evaluate the effects of environmental filtering. Spatial distance was considered to assess the impact of dispersal limitation. Variance partitioning analysis was applied to assess the relative roles of these variables. In general, the values of TBD and PBD were high in mountainous areas and were largely determined by environmental filtering. However, different dominant environmental filters on either side of the Hu Line led to divergent beta diversity patterns. Specifically, climate-driven species turnover and habitat heterogeneity-related species nestedness dominated the regions east and west of the line, respectively. Additionally, bird species with stronger dispersal ability were more susceptible to environmental filtering, resulting in more homogeneous assemblages. Our results indicated that regions with distinctive geographical backgrounds may present different ecological factors that lead to divergent assemblage dissimilarity patterns, and dispersal ability determines the response of assemblages to these ecological factors. Identifying a single universal explanation for the observed pattern without considering these aspects may lead to simplistic or incomplete conclusions. Consequently, a comprehensive understanding of large-scale beta diversity patterns and effective planning of conservation strategies necessitate the consideration of both geographical background and species dispersal ability. [ABSTRACT FROM AUTHOR]

The aim of this study was to contribute to the knowledge of avian diversity and breeding species in Türkiye. Observations were carried out in Iğdır Province within a total of 40 days spread throughout the migration and breeding periods of 2017-2018. Regional status and breeding codes were determined for each species. Some winter visitors have also been observed during the early stages of the spring migration. In the study, 192 species were identified belonging to 50 families from 20 orders and 58 residents, 83 summer visitors, 11 winter visitors, and 40 transit migratory birds. According to the result of the recording breeding behavior, 52 bird species were classified as confirmed breeders, 36 as probable breeders, and 70 as possible breeders. According to IUCN Red List, 10 globally threatened species (Haematopus ostralegus, Vanellus vanellus, Numenius arquata, Gallinago media, Gypaetus barbatus, Aegypius monachus, Circus macrourus, Aythya ferina, Streptopelia turtur, Neophron percnopterus) were observed. Aras Valley and Aralık-Karasu Wetlands are the most important areas for birds. The conservation of these areas is of high importance in the region for migratory birds. [ABSTRACT FROM AUTHOR]

The associations of habitat area and fragmentation with species richness long have been major topics within community ecology. Recent discussion has focused on properly assessing fragmentation independent of habitat area (fragmentation per se), and on whether fragmentation has significant negative or positive associations with species richness. We created a novel, multiple‐region, N‐mixture community model (MNCM) to examine the relations of riparian area and fragmentation with species richness of breeding birds in mountain ranges within the Great Basin, Nevada, USA. Our MNCM accounts for imperfect detection in count data at the survey‐point level while allowing comparisons of species richness among regions in which those points are embedded. We used individual canyons within mountain ranges as regions in our model and measured riparian area and the Normalized Landscape Shape Index, a metric of fragmentation that is independent of total riparian area. We found that riparian area, but not its fragmentation, was a primary predictor of canyon‐level species richness of both riparian obligates and all species. The relationship between riparian area and riparian obligate species richness was nonlinear: canyons with ≥25 ha woody riparian vegetation had relatively high species richness, whereas species richness was considerably lower in canyons with <25 ha. Our MNCM can be used to calculate other metrics of diversity that require abundance estimates. For example, Simpson's evenness of riparian obligate species had a weak negative association with riparian area and was not associated with fragmentation. Projections of future riparian contraction suggested that decreases in species richness are likely to be greatest in canyons that currently have moderate (~10–25 ha) amounts of riparian vegetation. Our results suggest that if a goal of management is to maximize the species richness of breeding birds in montane riparian areas in the Great Basin, it may be more effective to focus on total habitat area than on fragmentation of patches within canyons, and that canyons with at least moderate amounts of riparian vegetation should be prioritized. [ABSTRACT FROM AUTHOR]

River regulation can alter the magnitude, frequency, duration, and timing of flows, which influences the function of downstream ecosystems. Bird communities can be useful indicators of ecosystem function as individual species respond to varied changes in habitat structure and food availability. We examined the relative importance of different aspects of a regulated flow regime (average daily flow, the number of days flows fell below the 25th percentile, the timing and magnitude of maximum flows, and the inter‐annual duration of flows below the historical median) on predicted bird abundance and diversity using 11 years of data collected within a floodplain meadow system located downstream of Hetch Hetchy Reservoir in Yosemite National Park, California. We found that prolonged periods of low flows were negatively associated with the number of breeding birds detected, as well as the species richness of the breeding bird community. Species richness was also negatively correlated with delays in spring runoff delivery. We opportunistically looked at the same hydrologic variables in a parallel unregulated system, the Merced River through Yosemite Valley, and did not find the same strong relationship with bird community data. This suggests that the dam may be exacerbating the effects of drought. [ABSTRACT FROM AUTHOR]

Measuring success or failure in the conservation of seabirds depends on reliable long-term monitoring. Traditionally, this monitoring has been based on line transects and total or point counts, all of which are sensitive to subjective interpretation. Such methods have proven to consistently record fewer individuals than intensive efforts, while requiring many hours of fieldwork and resulting in high disturbance. New technologies, such as drones, are potentially useful monitoring tools, as they can cover large areas in a short time, while providing high-resolution data about bird numbers and status. This study conducted two types of Uncrewed Aerial Vehicle (UAV) surveys in a big colony of multispecies breeding gulls. From a 25 m height, we photographed 30 circle plots where nests were also counted on the ground, showing that the number of occupied nests/breeding pairs could be estimated accurately by multiplying the number of counted individuals with a 0.7 conversion factor. A fixed-wing UAV was used to photograph the entire island to compare drone counts with counts conducted by traditional methods, were we counted a higher number of breeding pairs than the traditional count (1.7–2.2 times more individuals). It was concluded that UAVs provided improved estimates of colony size with much reduced monitoring effort. [ABSTRACT FROM AUTHOR]

Despite the assessment of long-term niche dynamics could provide crucial information for investigating species responses to environmental changes, it is a poorly investigated topic in ecology. Here, we present a case study of multi-species niche analysis for 71 common breeding birds in Northern Italy, exploring long-term niche changes from 1992 to 2017 and their relationship with both population trends and species traits. We (i) quantified the realized Grinnellian niche in the environmental space, (ii) compared variations in niche breadth and centroid, (iii) tested niche divergence and conservatism through equivalency and similarity tests, (iv) calculated niche temporal overlap, expansion and unfilling indices, and (v) investigated their association with both population changes and species traits. Results supported niche divergence (equivalency test) for 32% of species, although two-thirds were not supported by the similarity test. We detected a general tendency to adjust the niche centroids towards warmer thermal conditions. Increasing populations were positively correlated with niche expansion, while negatively correlated with niche overlap, albeit at the limit of the significance threshold. We found moderate evidence for a non-random association between niche changes and species traits, especially for body size, clutch size, number of broods per year, inhabited landscape type, and migration strategy. We encourage studies correlating long-term population trends and niche changes with species traits’ information and a specific focus on cause-effect relationship at both the single and multiple-species level.

Modern agricultural landscapes suffer heavily from biodiversity loss. To counter this loss, it is important to understand the key factors that affect biodiversity in these landscapes. We studied the relationships between breeding birds and the habitat characteristics of the small-scale hedgerow landscapes of East-Fryslân, The Netherlands, a typical agricultural landscape that is under pressure from upscaling and habitat degradation. We questioned whether our findings collaborate the results of hedgerow studies from other countries. We also analysed whether agri-environmental schemes were effective for breeding birds. In this study, breeding birds and fifteen habitat factors were surveyed along 170 transects in two different regions in East-Fryslân in 2018. 37 bird species were identified, of which 19 were woodland species, 18 shrub species and 7 hedgerow specialists. We found five habitat characteristics to be key factors for breeding bird numbers. Four of these factors were intrinsic factors of the hedges (i.e. shrub cover, cover of brambles and nettles, crown width, hedge width at the base) and one spatial factor (i.e. number of hedge corners within a 150-m radius, corresponding to hedge intersections). Four key factors were the same for the two regions, but effect sizes differed between factors and species groups. As proxies for habitat volume (amount of habitat), the intrinsic key factors for hedgerow breeding birds in East-Fryslân correspond to those found in Britain and Eastern Europe, despite considerable differences in botanical composition, structure and management of the hedges. In contrast to studies on British hedges, we found mainly quantitative key factors and only one qualitative factor (cover of brambles and nettles). We found one spatial key factor (hedge intersections) and no correlation of bird numbers with density of hedges in the vicinity. We discuss the ecology of the key factors with respect to food provisioning and breeding. We also conclude that agri-environmental schemes favour key habitat factors and through this shrub birds. Implications of our findings are that traditional management favours breeding birds, but also that management should partly be extensified. [ABSTRACT FROM AUTHOR]

Widespread afforestation is a crucial component of climate mitigation strategies worldwide. This presents a significant opportunity for biodiversity conservation if forests are appropriately managed. Within forests, structural and habitat diversity are known to be critical for biodiversity but pragmatic management recommendations are lacking. We make a comprehensive assessment of the effects of habitat variables on bird populations using data from over 4000 ha of forested landscape. We combine high‐resolution remote sensing data with comprehensive management databases to classify habitat attributes and measure the response of six taxonomic and functional diversity metrics: species richness, Shannon diversity, functional richness, functional evenness, functional divergence, and functional dispersion. We use a novel approach that combines hierarchical partitioning analysis with linear models to determine the relative importance of different habitat variables for each bird diversity metric. The age class of forest stands was consistently the most important variable across all bird diversity metrics, outperforming other structural measures such as horizontal and vertical heterogeneity and canopy density. Shrub density and gap fraction were each significantly associated with one bird diversity metric. In contrast, variables describing within‐stand structural heterogeneity (vertical and horizontal) were generally less important while tree species identity (e.g., conifer or broadleaved) was not significant for any bird diversity metric. Each of the six bird diversity metrics had different patterns of independent variable importance and significance, emphasizing the need to consider multiple diversity metrics in biodiversity assessments. Similarly, the optimal resolution for remote sensing metrics varied between structural variables and bird diversity metrics, suggesting that the use of remote sensing data in biodiversity studies could be greatly improved by first exploring different resolutions and data aggregations. Based on the results from this comprehensive study, we recommend that managers focus on creating habitat diversity at the between‐, rather than exclusively within‐stand scale, such as by creating a matrix of different age classes, to maximize bird diversity. This recommendation for forest managers is powerful yet pragmatic in its simplicity. [ABSTRACT FROM AUTHOR]

A census of the territorial males of the Bluethroat (Cyanecula svecica) was conducted in the year 2014 on the Great Bačka Canal and surrounding wetlands. A total of 32 territorial males were recorded on the total transect length of 67.9 km. Bluethroat population in the study area presents 12-20% of the total estimated population of this species in Serbia. A significant short-term threat recorded was surface water regime maintenance since the removal of vegetation during this activity led to the destruction of habitat in several potential Bluethroat territories. [ABSTRACT FROM AUTHOR]

Globally, grasslands have been heavily degraded, more so than any other biome. Grasslands of the eastern U.S. are no exception to this trend and, consequently, native biota associated with the region's >20 million ha of agricultural grasslands are under considerable stress. For example, grassland associated breeding bird populations have declined precipitously in recent decades as have numerous species of pollinators. Although there is increasing awareness of the role grasslands can play in global carbon cycles and in providing high quality dietary proteins needed by an increasing global population, there is a lack of awareness of the alarming trends in the sustainability of the native biota of these ecosystems. Here, we present the status of this conservation challenge and offer prospective solutions through a working lands conservation approach. Such a strategy entails maintaining appropriate disturbances (i.e., grazing, fire, and their combination), improved grazing management, an increased reliance on native grasses and forbs, and improved plant diversity within pastures. Furthermore, we note some examples of opportunities to achieve these goals, offer suggestions for agricultural and conservation policy, and provide a framework for evaluating tradeoffs that are inevitably required when pursuing a multi-purpose grassland management framework. [ABSTRACT FROM AUTHOR]

A commonly promoted view is that in the absence of driven grouse moor management in the UK uplands, land use on moorland would default to agriculture or afforestation. This forum article questions the orthodoxy of this thinking, discusses alternative scenarios for land use in the uplands and considers the potential effects of these on moorland‐breeding birds. [ABSTRACT FROM AUTHOR]

Simple Summary: Temporal changes of ecological niches in relation to both population trends and species traits (life-history and ecological characteristics) are a poorly investigated topic in animal ecology even though they can provide crucial information for investigating how species respond to ongoing environmental changes. To fill this gap, we assessed niche changes from 1992 to 2017 for 71 common breeding birds in Northern Italy, using several niche metrics and relating them with both population trends and species traits. Our results showed that 32% of the species tended to change their niche in relation to the accessible environmental conditions. We found a tendency to adjust the niche towards warmer thermal conditions. This process may depend on several drivers, which act differently across species. Species undergoing a niche expansion showed increasing populations, while species tending to retain their niche showed a tendency to be associated with decreasing populations. We also found evidence for a non-random association between niche temporal changes and species traits. Investigating these relationships is a pivotal point to implement effective conservation strategies for wildlife. Despite the assessment of long-term niche dynamics could provide crucial information for investigating species responses to environmental changes, it is a poorly investigated topic in ecology. Here, we present a case study of multi-species niche analysis for 71 common breeding birds in Northern Italy, exploring long-term niche changes from 1992 to 2017 and their relationship with both population trends and species traits. We (i) quantified the realized Grinnellian niche in the environmental space, (ii) compared variations in niche breadth and centroid, (iii) tested niche divergence and conservatism through equivalency and similarity tests, (iv) calculated niche temporal overlap, expansion and unfilling indices, and (v) investigated their association with both population changes and species traits. Results supported niche divergence (equivalency test) for 32% of species, although two-thirds were not supported by the similarity test. We detected a general tendency to adjust the niche centroids towards warmer thermal conditions. Increasing populations were positively correlated with niche expansion, while negatively correlated with niche overlap, albeit at the limit of the significance threshold. We found moderate evidence for a non-random association between niche changes and species traits, especially for body size, clutch size, number of broods per year, inhabited landscape type, and migration strategy. We encourage studies correlating long-term population trends and niche changes with species traits' information and a specific focus on cause-effect relationship at both the single and multiple-species level. [ABSTRACT FROM AUTHOR]

Multi-year monitoring of species distribution is important for conservation planners to understand population trajectories. In New York, USA, the Eastern Whip-poor-will (Antrostomus vociferus) is among several bird species that have been documented to be declining and has been monitored for several years through large-scale surveys such as the Breeding Bird Atlas and Breeding Bird Survey. We implemented a study to assess trends in site occupancy at 19 survey routes during 2014–2018 breeding seasons. We surveyed for Eastern Whip-poor-wills following the Center of Conservation Biology Nightjar Survey Network methodology and used these data to estimate yearly relative abundance, factors that may influence the probability of detection, probability of a site being occupied and potentially important landscape features, and dynamic processes of site colonization and extinction. The mean relative abundance ranged from 0.54 in 2016 to 0.89 in 2014, with all yearly estimates having 95% confidence intervals that overlapped. The probability of detection was negatively affected by the greatest wind speeds recorded (12.87–28.97 kph, [8–18 mph]). Site occupancy was relatively low each year ranging from 26% to 32% across all years. We observed a negative effect on site occupancy with survey sites located in the Adirondack ecozone of New York. We additionally found support for a negative effect of median elevation and a positive effect of area of hay and pasture on site occupancy within 675 m of survey sites. The probability of a site becoming colonized ranged from 0.05 to 0.14 and the probability of a site going extinct ranged from 0.14 to 0.42. Overall, we did not find support for a decreasing trend in site occupancy. The yearly relative abundance estimates and site occupancy estimates were small but did not decrease over time and the dynamic processes did not suggest increasing extinction or decreasing colonization rates. Occupied survey locations may represent some of the most suitable and stable habitat for these birds within the state. Important landscape characteristics of lower elevation and area of hay and pasture may be representative of forest mosaics that include open areas with forest edges at lower elevation, which has been documented in other studies. [ABSTRACT FROM AUTHOR]

Kars has an important location in Turkey due to its location on the African-Eurasian bird migration routes and suitable breeding and stopover sites through the province. In this study, the results of observations carried out in Kars Province during 50 days in migration and breeding periods of 2017-2018 were evaluated. According to the results of the study, 193 bird species belonging to 51 families and 8 orders were recorded in Kars Province. 11 of these species listed as globally threatened according to the IUCN criteria. It has been found that 51 species are confirmed breeders, 33 are probable breeders, and 84 are possibly breeding within the borders of province. With the presence of suitable stopover areas, it also hosts a significant number of migratory birds during migration seasons. Also, some of the globally endangered species breed in the province. In Kars and surroundings, important areas that are vital for birds, especially Kuyucuk Lake, need to be protected.

Altitudinal bird migration involves seasonal shifts up and down the altitude gradient annually. Asia as the place with the largest number of altitudinal migrants, has quite few related studies, especially for montane and temperate avifaunas. To explore the potential drivers of seasonal altitudinal migration for birds in the middle of Hengduan Mountains, we conducted a three-year investigation on breeding and non-breeding season bird communities at eight elevational bands (1200–4200 ​m) in the Gongga Mountains. We examined the altitudinal migration patterns and relationships between seasonal distribution shifts and species' traits of 50 species with sufficient data recorded in both seasons. We found that a large proportion of breeding birds underwent altitudinal migration and showed three migration patterns (downslope shift, upslope shift, no shift). Seasonal distribution shifts were mainly correlated with certain ecological traits. Species breeding at high and mid-elevations, nesting in scrub and being omnivorous are more likely to show downslope movements during the non-breeding season. In addition, territorially weaker species exhibited more diverse migration patterns. Notably, we found the hand-wing index (HWI) was actually more convincing than body mass in explaining altitudinal migration. These results consolidate the studies of seasonal altitudinal migration in montane birds. Our study could be used to bridge existing knowledge gaps that currently impeding effective conservation for montane avifaunas in the Hengduan Mountains.

Wood-pastures are socio-ecological systems covering vast areas in Europe. Although used for grazing and production of various forest goods, wood-pastures harbour a rich biodiversity and are usually considered as High Nature Value Farmlands. However, socio-economic pressures are driving the transformation of these valuable landscapes from multi-functional, heterogeneous habitats to homogeneous areas through either intensification or land abandonment. We investigated how changes in management intensity influence the taxonomic diversity, functional diversity and functional composition of birds in these landscapes using generalized linear models. In contrast to taxonomic diversity, functional diversity decreased significantly towards shrub-dominated and less heterogeneous areas related to the abandonment of grazing and/or understory management practices. Grassland and generalist species, and associated guilds such as granivores, ground-nesters and ground-foragers are almost absent less managed areas. On the other hand, shrub-dominated areas favour forest species, particularly understory/canopy foragers and arboreal nesters, although the forest guild is still well-represented in actively managed, heterogeneous areas. Our results indicate the abandonment of wood-pasture management affects the prevalence of grassland and generalist species, leading to functional diversity loss and potentially reduced ecosystem functioning. We suggest non-intensive, active management is needed to maintain habitat heterogeneity and canopy openness, enhancing trait diversity in wood-pastures. [ABSTRACT FROM AUTHOR]

The species-area relationship (SAR) is one of the most investigated patterns in ecology and conservation biology, yet there is no study testing how different levels of urbanization influence its shape. Here we tested the impact of urbanization on avian SARs along a rural-urban gradient using the breeding birds of Rome (Central Italy). We divided the city into 360 cells of 1 km2. Each cell was classified as rural, suburban or urban using the proportion of impervious surface calculated from remote sensing data. For each of these three landscape categories, we constructed a SAR as a species accumulation curve (Gleason function) using bird species distribution data. SAR intercepts (i.e. the number of species per unit area) decreased from rural to urban areas, which indicates that urbanization depressed the number of species, reflecting the loss of specialized species strictly associated with natural habitats. The slope was highest for the rural curve, indicating that natural landscapes have the highest turnover due to their higher habitat heterogeneity. A higher slope for the urban cells, compared to the suburban ones, can be explained by the presence of green spaces embedded in the built-up matrix which host different avian communities. Previous studies that compared whole cities with natural areas failed to find differences in the respective SARs. Our study, which constructed SARs for different levels of urbanization, indicated significant changes in the SARs along the rural-urban gradient. Further analyses in other cities and taxa will be useful to test how general are our findings. [ABSTRACT FROM AUTHOR]

Measuring success or failure in the conservation of seabirds depends on reliable long-term monitoring. Traditionally, this monitoring has been based on line transects and total or point counts, all of which are sensitive to subjective interpretation. Such methods have proven to consistently record fewer individuals than intensive efforts, while requiring many hours of fieldwork and resulting in high disturbance. New technologies, such as drones, are potentially useful monitoring tools, as they can cover large areas in a short time, while providing high-resolution data about bird numbers and status. This study conducted two types of Uncrewed Aerial Vehicle (UAV) surveys in a big colony of multispecies breeding gulls. From a 25 m height, we photographed 30 circle plots where nests were also counted on the ground, showing that the number of occupied nests/breeding pairs could be estimated accurately by multiplying the number of counted individuals with a 0.7 conversion factor. A fixed-wing UAV was used to photograph the entire island to compare drone counts with counts conducted by traditional methods, were we counted a higher number of breeding pairs than the traditional count (1.7–2.2 times more individuals). It was concluded that UAVs provided improved estimates of colony size with much reduced monitoring effort.

Globally, grasslands have been heavily degraded, more so than any other biome. Grasslands of the eastern U.S. are no exception to this trend and, consequently, native biota associated with the region’s >20 million ha of agricultural grasslands are under considerable stress. For example, grassland associated breeding bird populations have declined precipitously in recent decades as have numerous species of pollinators. Although there is increasing awareness of the role grasslands can play in global carbon cycles and in providing high quality dietary proteins needed by an increasing global population, there is a lack of awareness of the alarming trends in the sustainability of the native biota of these ecosystems. Here, we present the status of this conservation challenge and offer prospective solutions through a working lands conservation approach. Such a strategy entails maintaining appropriate disturbances (i.e., grazing, fire, and their combination), improved grazing management, an increased reliance on native grasses and forbs, and improved plant diversity within pastures. Furthermore, we note some examples of opportunities to achieve these goals, offer suggestions for agricultural and conservation policy, and provide a framework for evaluating tradeoffs that are inevitably required when pursuing a multi-purpose grassland management framework.

Conspecific presence can indicate the location or quality of resources, and animals settling near conspecifics often gain fitness benefits. This can result in adaptive conspecific attraction during breeding habitat selection as demonstrated in numerous terrestrial, territorial birds. There is growing interest in using simulated conspecific social cues (e.g., decoys, broadcasted vocalizations) to manage bird distributions, yet it remains unclear when this approach is likely to succeed. We reviewed published studies to evaluate whether the strength of conspecific attraction in terrestrial birds is mediated by characteristics of species (life history traits), simulated cues (e.g., timing and duration), sites (e.g., quality), and how conspecific attraction was measured. We identified 31 experiments that simulated social cues and compared conspecific settlement between treatment and control sites. We then used phylogenetically controlled meta-regression to assess the impacts of 19 moderators on settlement. Nearly all species included in these experiments were migratory passerines, and social cues generally had a strong, positive influence on their settlement decisions, as the odds of site occupancy were 3.12× (95% CI: 0.81-11.69) greater in treatment sites relative to control sites. Within this group, conspecific attraction was evolutionarily conserved with =25.5% (95% CI: 5.1%-65.4%) of the variance in treatment effects explained by phylogenetic relatedness. However, we found no evidence that any covariates influenced the response to social cues, and we posit this stems from limited research specifically designed to identify the mechanisms mediating conspecific attraction. We therefore developed a research agenda that provides a framework for testing mechanistic hypotheses regarding how cue characteristics, species traits, and spatial contexts may mediate attraction to conspecifics. Evaluating these hypotheses will greatly advance the field by helping managers understand when, where, and why simulating social cues can be used to enhance populations of species that are of conservation concern. [ABSTRACT FROM AUTHOR]

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Abstract Aim To document the species richness patterns of breeding birds along elevational gradients and explore its drivers in the Horn of Africa region. Location Horn of Africa region. Taxon Breeding birds. Methods Distributional data for breeding birds were collected. Elevational distribution data were extracted, interpolated, and assembled for all birds, passerines, and nonpasserines. In order to tease apart how different environmental factors contributed to the variation in species richness, we found it is necessary to divide the area into four subregions with different climatic regimes and topographic structure, namely western slope, eastern slope, wet side, and dry side. Then, the species richness in each 100‐m elevational band was counted along the elevational gradients of each subregion. Pearson's correlation analyses and ordinary least squares (OLS) regressions were used to examine the relationships between species richness and factors. Results The variation in species richness followed hump‐shaped patterns for all subregions, although with peak values at different elevations. The bird species groups on the western and eastern slopes showed low and high plateaus with mid‐elevation peaks, respectively, but very low species diversities at the highest elevations. Species richness was significantly correlated with temperature range and productivity in each subregion. The temperature range, area, and productivity explained 82% of the species richness variations for all birds on the western slope. Main conclusions The separate analyses of four area subdivisions provide strong indications of how various factors interact. Productivity and temperature range were the major driving factors for shaping the richness patterns, but deviations from expected patterns suggest modifying roles of mist formation zones in the valleys that deeply intersect the large highlands in the west and rich riparian vegetation where water from cool and humid environments at high elevation reaches lower elevations in the arid east. Conservation is recommended in each subregion based on the elevational richness scenarios.

In recent decades, concern for migratory birds has stimulated research assessing the relationships between forest management and bird populations. The Missouri Ozark Forest Ecosystem Project (MOFEP) is a long-term, landscape-scale experiment designed to examine the effects of even-aged (i.e., clearcutting), uneven-aged (i.e., selection cutting), and no-harvest forest management on ecosystem-level processes. The management systems were randomly assigned to three sites each (mean area = 400 ha) with harvest occurring on a different portion of trees every 15 yr over a 100-yr rotation. We used non-metric multidimensional scaling and linear mixed models to investigate the effects of silvicultural treatment and year-since-harvest on bird communities over a 24-yr period, before and after two harvests (1996 and 2011). Bird community compositions diverged among treatments immediately post-harvest, but the differences in community composition and structure began to diminish by 8 yr post-harvest. Species richness was higher in treated stands than no-harvest controls and lowest approximately 10 yr post-harvest regardless of treatment. Species diversity showed a linear decrease with year-since-harvest. Our findings demonstrate that even-aged and uneven-aged forest management can affect bird community composition and structure within the early post-harvest period, but differences may diminish relatively quickly as harvested stands regenerate. We recommend using a variety of silvicultural methods to provide the diversity of habitats needed for the conservation of diverse forest bird communities. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ecology & Rural Environment is the property of Journal of Ecology & Rural Environment Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Successful conservation strategies depend on the correct identification of animal species and populations at a higher risk of extinction. But not all species are equally sensitive to environmental changes. Specialist species are often considered more prone to extinction than generalist species. However, even considering the importance of the link between specialization and population trends of species (a potential proxy for extinction risk), only a few studies have provided evidence supporting this relationship.Here, we tested whether the population trend of breeding birds in Europe is linked to a specific category of species’ specialization, using continuous measures of avian specialization based on a trait-approach. We focused on five different indices of avian specialization: diet, foraging behavior, foraging substrate, habitat selection, and nesting site selection. We calculated the mean value and the standard deviation of the population trend for 139 bird species. Then, we tested for the presence of a phylogenetic signal in bird population trends, in order to investigate if the tendency for related species to resemble each other, often demonstrated regarding phenotypes, is present also for the species’ trends in Europe.We found evidence that bird species with negative trends were characterized by higher ecological specialization than species with positive trends. Specifically, population trends were negatively associated with nesting site specialization. We highlight that the species’ degree of specialization can be used as a proxy for that species’ ability to adapt and persist to environmental changes. Finally, the lack of a phylogenetic signal in either the mean value or standard deviation of the bird population trend suggests that the current status of a species is not strongly associated with the degree of phylogenetic relatedness.

Abstract Understanding the ecological mechanisms behind biological invasions remains a major focus of conservation biology and ecosystem management. Several hypotheses highlight that different facets of native biodiversity affect the establishment and spread of alien species. Here, we approach this question by examining the spatiotemporal relationship between alien bird species richness and different facets of biodiversity (taxonomic, functional, and phylogenetic) using breeding bird atlases for three U.S. states and for two time periods in each state. We associated native species richness, and functional and phylogenetic diversity with alien species richness, using generalized least squares models. Our results show that, consistently, across the three states and two time periods examined, alien species richness is positively associated with native diversity, and particularly with phylogenetic diversity. The relative importance of biodiversity metrics reflecting the functional or phylogenetic range occupied by the assemblage seems to advocate in favor of the importance of resource diversity as a main driver of both native and alien diversity. The secondary importance of biodiversity facets reflecting species functional or phylogenetic similarity, along with the lack of importance of functional or phylogenetic clustering or overdispersion, implies that if this relationship is shaped by biotic interactions, then biotic interactions facilitating coexistence (including even processes like predator‐mediated coexistence) are far more important than adversarial interactions like competition, at least at the scale of our analysis. Finally, the dominance of phylogenetic metrics over functional ones highlights the adaptive potential of a community accumulated over long lineage history may play an additional role as a source of information on evolutionary processes driving diversity patterns.

Summary: Farmland bird populations in Germany are declining at a higher speed than species inhabiting other habitats. We studied potential causes for bird population changes based on data from standardised German breeding bird monitoring schemes. We related population trends to covariates describing the changes in the agricultural landscape in Germany, weather conditions during the breeding season and for some migratory species, conditions at stopover and wintering sites. Linear mixed effect models were used to analyse effect strength at species level and conclusions are drawn for the overall group of farmland bird species. The area of grassland and fallow land was shown to have the strongest positive effects and the area of maize and rapeseed the strongest negative effects on farmland bird population trends. The results obtained also indicate that despite the consistent influence of weather conditions during the breeding season, land-use changes had a stronger impact on bird populations than weather. Conditions at Sahel wintering sites did not show a consistent effect on population trends. Based on these findings the study quantitatively underpins and ranks key factors shaping farmland bird populations in Germany. [ABSTRACT FROM AUTHOR]

The relationship between the abundance of breeding birds on the studied islands and the topographic variables (surface and distance from the continent) was tested via data on the breeding birds of 11 islands in Algeria. A nestedness calculator program was used to study the nestedness of breeding birds. Islands' surface conditions and their isolation explain clearly the richness of breeding birds. The distribution of island breeding birds showed a strong nested structure that differs significantly from the distribution of the random model. [ABSTRACT FROM AUTHOR]

Context: Urban densification has been argued to increase the contrast between built up and open green space. This contrast may offer a starting point for assessing the extent and magnitude of the positive influences urban green infrastructure is expected to have on its surroundings. Objectives: Drawing on insights from landscape ecology and urban geography, this exploratory study investigates how the combined properties of green and grey urban infrastructures determine the influence of urban green infrastructure on the overall quality of the urban landscape. Methods: This article uses distance rise-or-decay functions to describe how receptive different land uses are to the influence of neighbouring green spaces, and does this based on integrated information on urban morphology, land surface temperature and habitat use by breeding birds. Results: Our results show how green space has a non-linear and declining cooling influence on adjacent urban land uses, extending up to 300–400 m in densely built up areas and up to 500 m in low density areas. Further, we found a statistically significant declining impact of green space on bird species richness up to 500 m outside its boundaries. Conclusions: Our focus on land use combinations and interrelations paves the way for a number of new joint landscape level assessments of direct and indirect accessibility to different ecosystem services. Our early results reinforce the challenging need to retain more green space in densely built up part of cities. [ABSTRACT FROM AUTHOR]

Biotic homogenization reduces the regional distinctiveness of biotas with significant ecological and evolutionary consequences. The outcome of this process may depend on the spatial scale of inquiry (both resolution and extent), the selected taxon and dissimilarity index as well as on the contribution of species extinctions and introductions. In the present research, we try to disentangle the effects of these factors on homogenization patterns comparing six taxonomic groups (pteridophytes, spermatophytes, breeding birds, mammals, reptiles and non‐marine molluscs) within and between five Atlantic archipelagos of the Macaronesian Region. Taxonomic homogenization was analyzed by partitioning β‐diversity into spatial turnover of species composition and nestedness. Total compositional change was divided into changes related to extinctions/extirpations of native and to introductions of alien species. Analyses were carried out at two different spatial resolutions (island versus archipelago unit) and geographic extents (within each archipelago and across the whole Macaronesian Region). Pteridophytes and reptiles tended to taxonomic differentiation, while mammals and molluscs showed homogenization regardless of scale and resolution. For spermatophytes, the most species‐rich group, taxonomic heterogenization traded off with homogenization from the local to regional extent. Birds revealed heterogenization at the island, but not at the archipelago resolution. Extirpations of native species generally led to homogenization at the local extent, whereas the effect of alien introductions varied according to taxon and spatial scale. Furthermore, overall changes in species pool similarities were driven both by spatial turnover and nestedness. We demonstrate that biotic homogenization after human colonization within Macaronesia clearly depended on taxon, spatial scale and the dissimilarity measure. We suggest that homogenization of island biotas is first conditioned by initial dissimilarity related to taxon characteristics, such as dispersal capacity or endemicity, evolutionary processes, archipelago configurations and environmental variation along spatial scales. Thus, similarity change is the outcome of the impacts of number, proportion and distribution type of lost and gained species. Rare extirpated and common introduced species homogenize, while common extirpated and rare introduced species differentiate island biotas. Partitioning of beta diversity helps to improve our understanding of the homogenization process. [ABSTRACT FROM AUTHOR]

Understanding the ecological mechanisms behind biological invasions remains a major focus of conservation biology and ecosystem management. Several hypotheses highlight that different facets of native biodiversity affect the establishment and spread of alien species. Here, we approach this question by examining the spatiotemporal relationship between alien bird species richness and different facets of biodiversity (taxonomic, functional, and phylogenetic) using breeding bird atlases for three U.S. states and for two time periods in each state. We associated native species richness, and functional and phylogenetic diversity with alien species richness, using generalized least squares models. Our results show that, consistently, across the three states and two time periods examined, alien species richness is positively associated with native diversity, and particularly with phylogenetic diversity. The relative importance of biodiversity metrics reflecting the functional or phylogenetic range occupied by the assemblage seems to advocate in favor of the importance of resource diversity as a main driver of both native and alien diversity. The secondary importance of biodiversity facets reflecting species functional or phylogenetic similarity, along with the lack of importance of functional or phylogenetic clustering or overdispersion, implies that if this relationship is shaped by biotic interactions, then biotic interactions facilitating coexistence (including even processes like predator-mediated coexistence) are far more important than adversarial interactions like competition, at least at the scale of our analysis. Finally, the dominance of phylogenetic metrics over functional ones highlights the adaptive potential of a community accumulated over long lineage history may play an additional role as a source of information on evolutionary processes driving diversity patterns. [ABSTRACT FROM AUTHOR]

Usutu virus (USUV) is an emerging mosquitoborne flavivirus with an increasing number of reports from several countries in Europe, where USUV infection has caused high avian mortality rates. However, 20 years after the first observed outbreak of USUV in Europe, there is still no reliable assessment of the large-scale impact of USUV outbreaks on bird populations. In this study, we identified the areas suitable for USUV circulation in Germany and analyzed the effects of USUV on breeding bird populations. We calculated the USUV-associated additional decline of common blackbird (Turdus merula) populations as 15.7% inside USUV-suitable areas but found no significant effect for the other 14 common bird species investigated. Our results show that the emergence of USUV is a further threat for birds in Europe and that the large-scale impact on population levels, at least for common blackbirds, must be considered.

Field margins are inherent elements of European agricultural landscapes, thought to be crucial for maintaining a high biodiversity level. The interactions between the structure of field margins and biota have been recognized, yet the understanding of the importance of various components of the margins and adjacent areas is still incomplete. The aim of our study was therefore to determine the relative importance of structural features of the margins and diversity of adjacent crops for birds breeding in field margins. The study was carried out in 70 field margins covered with semi-natural vegetation, situated in SW Poland. Both the number of species and bird density were most strongly positively related to the development of tree and shrub layers, while presence of ditches and percentage of reed cover (positive effects) had much less importance. Analyses conducted at the species level revealed the complexity of bird-habitat interactions resulting from various requirements of individual species. Overall, for 22 abundant species and for the threatened species, the development of the shrub layer turned out to be a particularly important feature of field margins positively associated with occurrence of e.g. Emberiza citrinella, Linaria cannabina and Streptopelia turtur. Other significant positive effects had the development of the tree layer (e.g. Turdus merula and Turdus philomelos), presence of ditch (e.g. Acrocephalus palustris, Sylvia communis), and number of gaps in woody vegetation (e.g. Lanius collurio). The diversity of adjacent crops had positive effects only to some threatened species (e.g. L. collurio and E. calandra). Abundances of common and threatened birds were not correlated, which reflects different habitat demands of these two groups. Because of diverse bird-habitat relationships, maintaining a variety of field margins (in particular the shrubby ones), should be accepted as a rule in biodiversity-oriented management of agricultural landscapes. [ABSTRACT FROM AUTHOR]

Housing a growing human population is a global issue and designing environmentally friendly developments requires identifying the species likely to be negatively impacted and finding mitigation solutions. Existing studies that consider fragmentation of natural habitats have limited application in countries such as Britain where a prime target for development is agricultural land where decades of intensive management have already diminished biodiversity. Here I used citizen science data on the abundance of 146 breeding and wintering birds to develop models linking abundance to human population density and habitat features. I used these as a proxy for the urbanisation process, finding that impacts of urbanisation were species-specific and context dependent. Low-density developments benefited a high proportion of birds, with wetland birds benefitting most and farmland birds least, but as human densities increased further, up to 75% of species were negatively impacted. Almost half of species currently occurring at 14 flagship residential development sites were predicted to decline based on projected human population density increases, with a third predicted to increase. Presence of wetlands, canopy cover and patches of trees all benefited certain species but efforts to identify more detailed habitat associations were hampered by collinearity among variables. I conclude that even in heavily degraded agricultural landscapes, a high proportion of species will be negatively impacted by residential development and that some will require spared land to persist in the wider landscape. As no single habitat benefited the entire bird community, urban planners wishing to design bird-friendly developments will need to make difficult decisions over which aspects of the bird community to prioritise. [ABSTRACT FROM AUTHOR]