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Assemblages in seasonal ecosystems undergo striking changes in species composition and diversity across the annual cycle. Despite a long‐standing recognition that seasonality structures biogeographic gradients in taxonomic diversity (e.g., species richness), our understanding of how seasonality structures other aspects of biodiversity (e.g., functional diversity) has lagged. Integrating seasonal species distributions with comprehensive data on key morphological traits for bird assemblages across North America, we find that seasonal turnover in functional diversity increases with the magnitude and predictability of seasonality. Furthermore, seasonal increases in bird species richness led to a denser packing of functional trait space, but functional expansion was important, especially in regions with higher seasonality. Our results suggest that the magnitude and predictability of seasonality and total productivity can explain the geography of changes in functional diversity with broader implications for understanding species redistribution, community assembly and ecosystem functioning. [ABSTRACT FROM AUTHOR]

Chewing lice infesting avian hosts can significantly affect host health and fitness. Here, we present quantitative data on host body condition and louse abundance observed from 121 Rough-legged Hawks (Buteo lagopus) sampled across the North American nonbreeding range. Among hawks examined, louse prevalence was 71%, with a mean abundance and intensity of 9.1 and 12.8 lice, respectively. We identified lice as Craspedorrhynchus sp., either Craspedorrhynchus dilatatus ог Craspedorrhynchus taurocephalus, dependent on future taxonomic revision of the genus. Female and juvenile hawks had greater louse intensity and prevalence compared with male and adult hawks, respectively. Host body condition, measured as a breast muscle score (keel score), was negatively correlated with louse abundance after controlling for host age and sex. Possible explanations for these patterns include the following: sex-biased louse transfer between adults and nestlings, when female nestlings experience increased transfer loads; body size differences between males and females, when females are larger than males in each life stage; and preening limitations in females and juveniles, when both spend more time hunting and less time preening relative to adult males. Our results corroborate previous studies suggesting that the primary sources of intraspecific variation in louse abundance are host body size and preening limitations. [ABSTRACT FROM AUTHOR]

Over-summering of shorebirds refers to the phenomenon where certain species of shorebirds, primarily migratory, remain on their non-breeding grounds during the summer months for one or more years instead of migrating to their breeding grounds. The present study investigates the presence and abundance of over-summering shorebird species at four distinct sites covering 24 scanning points along the southeastern coasts of Tamil Nadu for 2017-2023. A total of 13 species were observed over-summering, with Lesser Sand Plover being the most dominant species, followed by Greater Sand Plover. Notably, 10 species were found across all four sites, while three species--Black-tailed Godwit, Bar-tailed Godwit, and Common Sandpiper--were exclusive to Dhanushkodi Lagoon, observed only during 2023. The study examined the year-wise abundance of these species, revealing a decline in over-summering shorebirds across all study sites. The Eurasian Curlew, Curlew Sandpiper, Bar-tailed & Black-tailed Godwits are the 'Near Threatened' species observed during the study. Furthermore, the research highlighted variations in Shannon species diversity index (H) location-wise and year-wise - Manoli Island (H = 2.25) in 2023; Dhanushkodi Lagoon (H = 1.8) in 2023; Valinokkam Lagoon (H = 1.63), and Pillaimadam Lagoon (H = 2.08) in 2017. Key findings are that among the study sites, in Pillaimadam Lagoon all 10 species' abundance declined; in Valinokkam Lagoon, Greater Sand Plover and Little Stint marginally increased, and eight species declined; Common Redshank and Ruddy Turnstone marginally increased in Manoli Island, while other eight species declined; Grey Plover population increased in Dhanushkodi Lagoon along with a marginal decrease in Common Redshank and Ruddy Turnstone as other species declined, over the years of study. [ABSTRACT FROM AUTHOR]

Automated remote sensing has revolutionized the fields of wildlife ecology and environmental science. Yet, a cost-effective and flexible approach for large scale monitoring has not been fully developed, resulting in a limited collection of high-resolution data. Here, we describe BioSense, a low-cost and fully programmable automated sensing platform for applications in bioacoustics and environmental studies. Our design offers customization and flexibility to address a broad array of research goals and field conditions. Each BioSense is programmed through an integrated Raspberry Pi computer board and designed to collect and analyze avian vocalizations while simultaneously collecting temperature, humidity, and soil moisture data. We illustrate the different steps involved in manufacturing this sensor including hardware and software design and present the results of our laboratory and field testing in southwestern United States.

Historically, Andaman Teal Anas albogularis have been primarily found in South Andaman. However, the land uplifts and subsidence resulting from the 2004 tsunami and the earthquake have created new wetlands across the island. These wetlands became suitable habitats for the Andaman Teal, leading to population expansion within South Andaman and a range shift to North Andaman. [ABSTRACT FROM AUTHOR]

Context: Artificial light at night (ALAN) is increasing worldwide, with many ecological effects. Aerial insectivores may benefit from foraging on insects congregating at light sources. However, ALAN could negatively impact them by increasing nest visibility and predation risk, especially for ground-nesting species like nightjars (Caprimulgidae). Objectives: We tested predictions based on these two alternative hypotheses, potential foraging benefits vs potential predation costs of ALAN, for two nightjar species in British Columbia: Common Nighthawks (Chordeiles minor) and Common Poorwills (Phalaenoptilus nuttallii). Methods: We modeled the relationship between ALAN and relative abundance using count data from the Canadian Nightjar Survey. We distinguished territorial from extra-territorial Common Nighthawks based on their wingboom behaviour. Results: We found limited support for the foraging benefit hypothesis: there was an increase in relative abundance of extra-territorial Common Nighthawks in areas with higher ALAN but only in areas with little to no urban land cover. Common Nighthawks’ association with ALAN became negative in areas with 18% or more urban land cover. We found support for the nest predation hypothesis: the were strong negative associations with ALAN for both Common Poorwills and territorial Common Nighthawks. Conclusions: The positive effects of ALAN on foraging nightjars may be limited to species that can forage outside their nesting territory and to non-urban areas, while the negative effects of ALAN on nesting nightjars may persist across species and landscape contexts. Reducing light pollution in breeding habitat may be important for nightjars and other bird species that nest on the ground. [ABSTRACT FROM AUTHOR]

This article, titled "Editorial: Bird movements and migration under global environmental change: current and future implications," explores the impact of global environmental changes on bird movements and migration patterns. The authors discuss how climate change, urbanization, pollution, and habitat degradation are affecting the natural pathways and stopovers that birds rely on during migration. They also highlight the importance of technological advancements in studying avian migration and emphasize the need for tailored conservation strategies that consider seasonal dynamics and regional variation. The article concludes by emphasizing the role of data-driven science in understanding and mitigating the effects of global change on bird populations. [Extracted from the article]

Grassland birds in North America have declined sharply over the last 60 years, driven by the widespread loss and degradation of grassland habitats. Climate change is occurring more rapidly in grasslands relative to some other ecosystems, and exposure to extreme and novel climate conditions may affect grassland bird ecology and demographics. To determine the potential effects of weather and climate variability on grassland birds, we conducted a systematic review of relationships between temperature and precipitation and demographic responses in grassland bird species of North America. Based on 124 independent studies, we used a vote‐counting approach to quantify the frequency and direction of significant effects of weather and climate variability on grassland birds. Grassland birds tended to experience positive and negative effects of higher temperatures and altered precipitation. Moderate, sustained increases in mean temperature and precipitation benefitted some species, but extreme heat, drought, and heavy rainfall often reduced abundance and nest success. These patterns varied among climate regions, temporal scales of temperature and precipitation (<1 or ≥1 month), and taxa. The sensitivity of grassland bird populations to extreme weather and altered climate variability will likely be mediated by regional climates, interaction with other stressors, life‐history strategies of various species, and species' tolerances for novel climate conditions. [ABSTRACT FROM AUTHOR]

Climate change is driving increases in forest fire activity around the world. Consequently, recent and future research into the implications for affected biota, and its translation into policy and management, is of vital importance for the conservation of forest biodiversity. The dry sclerophyll forests of south-eastern Australia are affected by changing fire regimes, including having recently been extensively burnt. In this review, we synthesise contemporary research into the responses of dry sclerophyll forest birds to fire regimes, with a focus on contrasts in levels of time since fire, fire severity, fire frequency, and their interactions. We identify and discuss high-priority knowledge gaps and management issues in this domain. Recent studies have gained insights into the complexity of the effects of fire on birds by, for example, showing how avian fire responses are influenced by climate variability. In dry sclerophyll forests, most species that responded to time since fire were less likely to occur where it was short. There were mixed positive and negative responses to increasing fire severity and/or frequency among species in these forest bird assemblages. Given that quantification of the risk of extinction of rare and uncommon birds under increased fire activity is challenging, options for investigating their fire response are proposed. Availability of habitat for birds that flourish where fire is recent, severe and/or regular is unlikely to decline given current trends. We present a management approach that conceptualises large blocks of biologically connected forest with longer fire ages, but otherwise differing fire histories, as biodiversity reservoirs. Synthesis of contemporary research into the effects of fire on dry eucalypt forest birds is imperative, given that wildfire activity is increasing across south-eastern Australia. Recent studies have gained insights into the complexity of avian fire responses. We identify and discuss high-priority knowledge gaps and management issues in this domain. [ABSTRACT FROM AUTHOR]

Aim: Species distributions across islands are shaped by dispersal limitations, environmental filters and biotic interactions but the relative influence of each of these processes has rarely been assessed. Here, we examine the relative contributions of island characteristics, marine subsidies, species traits, and species interactions on avian community composition. Location: Central Coast region of British Columbia, Canada. Taxon: Terrestrial breeding birds. Methods: We observed 3610 individuals of 32 bird species on 89 islands that spanned multiple orders of magnitude in area (0.0002–3 km2). We fit a spatially explicit joint species distribution model to estimate the relative contributions of island physical characteristics, island‐specific inputs of marine subsidies, species' traits, and biotic interactions on species distributions. Biogeographic characteristics included island area, isolation, and habitat heterogeneity, while marine influence was represented by forest‐edge soil δ15N, wrack biomass, shoreline substrate, and distance to shore. This approach also allowed us to estimate how much variation in distributions resulted from species' biological traits (i.e. body mass, feeding guild, feeding height, and nesting height). Results: Bird species distributions were determined almost equivalently by island biogeographic characteristics (23.5% of variation explained) and marine influence (24.8%). We detected variation in species‐specific responses to both island biogeographic characteristics and marine influence, but no significant effect of any biological trait examined. Additionally, we found evidence that habitat preferences were a more important driver than competitive interactions. Main Conclusions: Although most island biogeographic studies focus only on islands' physical characteristics, we found evidence for an equivalent role of marine subsidy in structuring island bird communities. Our study suggests that for small islands, disentangling the effects of island biogeographic characteristics, marine inputs, and biotic interactions is a useful next step in understanding species distributions. [ABSTRACT FROM AUTHOR]

Chewing lice (Phthiraptera, Ischnocera and Amblycera) are permanent ectoparasites of birds and primarly feed on the feathers and scales of birds. To detect the chewing lice species found on birds in Aras basin, Igdir, Türkiye, a total of 240 birds represented by 61 species belonging to 30 families in 13 orders were examined during the 2021 bird migration season. A total of 531 (186 females, 136 males and 209 nymphs) lice were collected from 75 individuals (31,25% of birds examined) of 26 species, 21 families and 10 orders. Thirty-one lice species (11 amblyceran and 20 ischnoceran species) in 22 genera were identified. Of these, 15 lice species were reported for the first time in Türkiye, namely Cuculiphilus fasciatus, Pseudomenopon qadrii, Philopterus sp., Ricinus serratus, Philopterus picae, Rostrinirmus buresi, Sturnidoecus sp., Philopterus excisus, Philopterus microsomaticus, Philopterus coarctatus, Brueelia fuscopleura, Sturnidoecus pastoris, Brueelia currucae, Penenirmus auritus and Strigiphilus tuleskovi. In addition, new host associations were reported for the lice species Kurodaia fulvofasciata, Degeeriella rufa and Myrsidea rustica. [ABSTRACT FROM AUTHOR]

Abstract Alien species can be damaging to native biodiversity, human well‐being and the economy. Identifying the complete range of impacts they cause, and the ways that these impacts are connected, may inform the prioritisation of management actions to mitigate impacts. Using datasets on the biodiversity impacts and monetary costs (damage and management costs) of alien birds, we aimed to establish whether species with the most severe biodiversity impacts also had the highest costs; whether types of biodiversity impact were associated with high costs; and whether specific factors associated with alien species are linked to both damaging biodiversity impacts and high costs. We identified a positive relationship between a specific type of biodiversity impact (predation) and costs, possibly because predation by alien birds can be severely damaging to native species and therefore attracts management actions. However, predation impacts are likely to occur more frequently and to be easier to identify than some other impact mechanisms such as hybridisation and transmission of diseases, and they are therefore likely to be more frequently managed and hence to have costs. We identified a specific species characteristic (generalism) to be associated with severe biodiversity impacts and high costs, probably because generalist species have greater opportunity to cause impacts, whether they be on biodiversity or the economy, or both. We also found widely distributed alien birds to be associated with high costs, probably because these species also have greater opportunity to cause impacts. Management interventions that prevent the introduction of both predatory and generalist alien bird species, or that reduce their geographic distribution at early stages of invasions, may have significant biodiversity and economic benefits. Read the free Plain Language Summary for this article on the Journal blog.

Coastal, and to a lesser extend inland wetlands, are critical habitats for wintering shorebirds. Given the significant population declines of most shorebird species worldwide, the current degradation of coastal habitats through climate change and human activities raises severe conservation concerns. In order to ensure sufficient and adequate habitats and maintain the populations, a thorough understanding of space use by wintering shorebirds is urgently required. However, overwintering strategies have rarely been investigated throughout the entire range of a shorebird species. This study thus aimed to investigate the spatio-temporal use of wintering habitats by Eurasian curlew Numenius arquata on a European scale, using a large international dataset. A total of 204 adult curlews were tagged with GPS devices at different wintering and breeding sites across Europe between 2014 and 2021, and the data were used to analyse home range size, habitat use, and phenology. The birds were faithful to their wintering sites throughout the winter. Their home ranges were small compared with other shorebirds but highly variable between individuals (533 ± 449 ha). Winter home range areas did not differ in relation to sex or body mass, but were weakly related to the wintering latitude, particularly linked to the many birds wintering in the Wadden Sea. Curlews used a high diversity of coastal and inland habitats, with higher occurrences on mudflats and saltmarshes. Despite the inter-individual variability in space use, the high wintering-site fidelity shown by this near-threatened species raises concerns about its capacity to respond to environmental modifications in coastal regions. [ABSTRACT FROM AUTHOR]

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Spatial population synchrony is common among populations of the same species and is an important predictor of extinction risk. Despite the potential consequences for metapopulation persistence, we still largely lack understanding of what makes one species more likely to be synchronized than another given the same environmental conditions.Generally, environmental conditions in a shared environment or a species' sensitivity to the environment can explain the extent of synchrony. Populations that are closer together experience more similar fluctuations in their environments than those populations that are further apart and are therefore more synchronized. The relative importance of environmental and demographic stochasticity for population dynamics is strongly linked to species' life‐history traits, such as pace of life, which may impact population synchrony. For populations that migrate, there may be multiple environmental conditions at different locations driving synchrony. However, the importance of life history and migration tactics in determining patterns of spatial population synchrony have rarely been explored empirically. We therefore hypothesize that increasing generation time, a proxy for pace of life, would decrease spatial population synchrony and that migrants would be less synchronized than resident species.We used population abundance data on breeding birds from four countries to investigate patterns of spatial population synchrony in growth rate and abundance. We calculated the mean spatial population synchrony between log‐transformed population growth rates or log‐transformed abundances for each species and country separately. We investigated differences in synchrony across generation times in resident (n = 67), short‐distance migrant (n = 86) and long‐distance migrant (n = 39) bird species.Species with shorter generation times were more synchronized than species with longer generation times. Short‐distance migrants were more synchronized than long‐distance migrants and resident birds.Our results provide novel empirical links between spatial population synchrony and species traits known to be of key importance for population dynamics, generation time and migration tactics. We show how these different mechanisms can be combined to understand species‐specific causes of spatial population synchrony. Understanding these specific drivers of spatial population synchrony is important in the face of increasingly severe threats to biodiversity and could be key for successful future conservation outcomes. [ABSTRACT FROM AUTHOR]

Context: Within dynamic ecosystems, research into how land use changes and patterns affect species diversity has led to a suite of ecological hypotheses to assess species-landscape associations. The Habitat Amount Hypothesis suggests that it is the total amount of habitat, regardless of configuration, whereas the Multi-dimensional Hypothesis suggests it is the suite of local, landscape, and landform characteristics that have the greatest influence on species diversity within its local landscape. Objectives: Our study aims to understand how landscape pattern influences species abundance, in the context of these two competing hypotheses on priority avian species in working forest landscapes of the southeastern United States. Methods: To examine these hypotheses, we conducted bird point counts and vegetation surveys in short-rotation loblolly pine (Pinus taeda) forests in east-central Mississippi during 2019–2020 and used abundance and richness models to assess avian species associations to amount vs. configuration of habitat in a 2 km2 landscape. Results: We found that habitat amount alone did not exhibit consistent positive associations with species abundance for both early-successional and mature forest associated avian communities. Most target species exhibited positive associations with patch proximity, measured by Euclidean distance, and proximity-area index. However, measures of species richness showed no association with amount or proximity. Associations with landform features generally had positive influences on early-successional species than mature-pine priority species. Conclusions: The dynamic mosaic of forest stand ages may be sufficient in providing habitat needs such that measures of richness are not driven by amount and proximity at the 2 km2 scale in this working landscape. However, influences of proximity and landform on priority species abundance warrant further research to assess potential drivers of associations with stand proximity and effects of amount and proximity on measures of species diversity across scales. Given the growing demand for forest products, sustainable forestry guidelines that consider proximity of stands in similar age classifications could enhance landscape suitability for some target species. [ABSTRACT FROM AUTHOR]

Body condition is a frequently used physiological indicator of avian health and can be affected by an array of environmental variables. Although a number of studies have investigated the specific effects of individual weather variables on body condition in birds, few have analyzed the effects of both temperature and precipitation within the context of an extreme weather event such as hurricanes. In this study, we examined the relationship between breeding‐season body condition and daily maximum temperature, daily minimum temperature, and monthly total precipitation for three passerine bird species at the Welder Wildlife Refuge near Rockport, Texas. We also evaluated yearly changes in body condition over a 12‐year period for northern cardinals (Cardinalis cardinalis), painted buntings (Passerina ciris), and white‐eyed vireos (Vireo griseus), focusing on the extreme precipitation event of Hurricane Harvey, which caused heavy localized flooding. We found that body condition declined with average daily minimum and maximum temperatures, while precipitation had varied, species‐specific effects in the three species analyzed. Our results also suggest that northern cardinals experienced a notable reduction in average body condition in the 2 years following Hurricane Harvey. Taken together, we conclude that short‐term precipitation and temperature drivers can be important correlates of body condition in songbirds and that severe weather events may reduce body condition in some bird species. [ABSTRACT FROM AUTHOR]

Stable isotope analysis of feathers is widely used in bird ecology. Generally, studied birds should be captured to collect feather samples in a way that clarifies the attribution of feather samples. As some endangered birds cannot be captured, feather sampling is the only feasible method for isotopic research. However, whether it can be used for research on individuals remains to be clarified. In this study, the values of d13C and d15N of the rachises and barbules of 27 feathers from 3 pigeons were measured, and cluster analysis of these samples was carried out by using the system clustering method. The results showed a significant difference between the isotope values of the rachis and barbules from the same feather. In addition, the isotope values of the rachises and barbules differed between individuals, although the food sources of the samples might be slightly different. Based on the above results, the cluster analysis was able to distinguish individuals, with the highest accuracy of 85%; the more factors that were used, the higher the accuracy of the clustering. [ABSTRACT FROM AUTHOR]

Grassland bird populations are being lost at an alarming rate due to human modifications to grassland ecosystems. Grassland restoration has been shown to mitigate population declines for many species that use these habitats at some point in their annual cycles. We examined capture rates of adult, breeding, and hatch-year birds at a restored grassland site in the piedmont of central Georgia to determine whether colonization, breeding success, hatching success, and recruitment processes were impacting populations of grassland birds. We banded birds approximately twice per month from January 2009 through December 2021 at Panola Mountain State Park. Restoration efforts started in 2001, and include annual prescribed burns, control of invasives, and revegetation with native grassland plants. We documented an increase in total capture rates when all grassland species were combined (p=0.03, r²=0.37) and for several grassland species, including Chipping Sparrows (p=0.01, r²=0.44) and Marsh Wrens (p=0.004, r²=0.55). Capture rates of grassland birds in breeding condition increased as well, including when grassland species were combined (p=0.01, r²=0.45), Common Yellowthroats (p=0.05, r²=0.30), Indigo Buntings (p=0.04, r²=0.34), and Field Sparrows (p=0.002, r²=0.59). Capture rates of hatch-year birds increased for Chipping Sparrows (p=0.02, r²=0.39). Species-specific responses to restoration occur at different rates depending on habitat preferences, yet the only species that significantly declined was the Red-winged Blackbird, a bird more associated with water than grasslands. We attribute these increases and, importantly, the lack of significant declines, to successful ongoing restoration, which is providing adequate and appropriate resources for grassland birds. If managers identify target species, we recommend that restoration efforts include activities that are aimed at species-specific habitat requirements and habitat-level threats of those target species. [ABSTRACT FROM AUTHOR]

Abstract Body condition is a frequently used physiological indicator of avian health and can be affected by an array of environmental variables. Although a number of studies have investigated the specific effects of individual weather variables on body condition in birds, few have analyzed the effects of both temperature and precipitation within the context of an extreme weather event such as hurricanes. In this study, we examined the relationship between breeding‐season body condition and daily maximum temperature, daily minimum temperature, and monthly total precipitation for three passerine bird species at the Welder Wildlife Refuge near Rockport, Texas. We also evaluated yearly changes in body condition over a 12‐year period for northern cardinals (Cardinalis cardinalis), painted buntings (Passerina ciris), and white‐eyed vireos (Vireo griseus), focusing on the extreme precipitation event of Hurricane Harvey, which caused heavy localized flooding. We found that body condition declined with average daily minimum and maximum temperatures, while precipitation had varied, species‐specific effects in the three species analyzed. Our results also suggest that northern cardinals experienced a notable reduction in average body condition in the 2 years following Hurricane Harvey. Taken together, we conclude that short‐term precipitation and temperature drivers can be important correlates of body condition in songbirds and that severe weather events may reduce body condition in some bird species.

How human modification of native habitats changes the feeding patterns and nutritional ecology of tropical birds is critical to conserving avian biodiversity, but tropical bird diets are laborious to investigate using the traditional methods of diet analysis. Stable isotope analysis provides a cost-effective and efficient proxy to identify general foraging patterns, especially when dietary shifts spanning multiple trophic levels have occurred due to ecosystem disturbance or transformation. To characterize the diets of forest bird species that persist in tropical agricultural countryside, we compared feather carbon (δ13C) and nitrogen (δ15N) isotope values of four species caught and radio-tracked in a 270 hectare forest reserve, smaller forest remnants (including mature forest, secondary forest, and riparian strips), and coffee plantations in mid-elevation (ca. 800–1,400 m) southern Costa Rica. Bird habitat choice had a significant effect on diet composition as revealed by δ13C and δ15N values. Three of the four species studied showed evidence of significantly reduced consumption of invertebrates in coffee plantations, with the isotope values of two species (Tangara icterocephala and Mionectes oleaginous) indicating, by comparison, nearly a doubling of invertebrate consumption in forest remnants. Our results suggest that coffee plantations are deficient in invertebrates preferred by forest generalist birds that forage in both native forest remnants and coffee plantations. In this region, typical of mountainous American tropics, small forest remnants and a larger forest reserve provide critical dietary resources for native forest birds that utilize the agricultural countryside.

Vultures are among the most vulnerable birds in the world. The bearded vulture (Gypaetus barbatus) is among the threatened species of vultures and listed as Near Threatened. The species is widely distributed across the Palearctic, Afrotropical, and Indomalayan regions. The species faces several threats such as poisoning, direct persecution, habitat degradation, and collisions with powerlines and wind power farms. Thus, knowing the global habitat suitability of the species and environmental predictors of the species distribution can facilitate the species conservation. In this study, we applied a maximum entropy approach, 10,585 distribution records, and 10 environmental variables to model the bearded vulture's global habitat suitability at high spatial resolution [30-arc-second (1 km)]. We also estimated protected area coverage for the species' suitable habitats. We identified 8,117,231 km2 of suitable habitat for the species across its global range in Europe, Asia, and Africa. The results showed that topographic diversity is the most important predictor of the species distribution across its distribution range. Results of estimating the area of suitable habitats of the bearded vulture within protected areas revealed that only 16.26% of the species' suitable habitats are protected. The areas that were identified to have the highest suitability for the species have high priority for the conservation of this iconic species thus these areas should be included in the network of protected areas.

Snow cover dynamics (i.e. depth, duration and variability) are dominant drivers of ecological processes during winter. For overwintering species, changes and gradients in snow cover may impact survival and population dynamics (e.g. facilitating survival via thermal refugia or limiting survival via reduced resource acquisition). However, snow cover dynamics are rarely used in species distribution modelling, especially for overwintering birds. Currently, we lack understanding of how snow cover gradients affect overwintering bird distributions and which functional traits drive these associations at regional and continental scales. Using observations from eBird, a global community science network, we explored the effects of snow cover dynamics on continental patterns of occurrence and counts for 150 bird species. We quantified the relative importance, species‐specific responses and trait‐based relationships of bird occurrence and abundance patterns to ecologically relevant snow cover dynamics across the United States. Snow cover dynamics were important environmental predictors in species distributions models, ranking within the top three predictors for most species occurrence (> 90%) and count (> 79%) patterns across the contiguous United States. Species exhibited a gradient of responses to snow cover from snow association to snow avoidance, yet most birds were limited by long, persistent snow seasons. Duration of winter and percent frozen ground without snow structured species distributions in the eastern USA, whereas snow cover variability was a stronger driver in the western USA. Birds associated with long, persistent snow seasons had traits associated with greater dispersal capacity and dietary diversity, whereas birds inhabiting regions with variable snow cover were generally habitat generalists. Our results suggest that various snow cover dynamics are important ecological filters of species distributions during winter. Global climate change is rapidly degrading key characteristics of seasonal snow cover. A changing cryosphere may elicit variable distributional changes for many overwintering birds, potentially accelerating range shifts and novel community assemblages. [ABSTRACT FROM AUTHOR]

The first Black-headed Penduline Tit (Remiz macronyx) in Turkey was recorded in April 2022, where it was captured and ringed at the Aras River Ornithological Research Station. This is a poorly studied species with a disjunct range consisting of four subspecies. We provide an overview of how to identify, age, and sex individuals within this species in comparison to the similar Eurasian Penduline Tit (Remiz pendulinus), as well as insight into the age and sex of our bird, and summarize current knowledge on the taxonomic situation and challenges of identifying this species. This study brings awareness to a poorly known species and can be useful for others that may either be looking for or potentially encounter this species as a vagrant in the Caucasian region. [ABSTRACT FROM AUTHOR]

Recent studies have revealed concerning declines in bird populations in Europe and other parts of the world. In understudied but biodiverse regions, especially those that are located along key migratory flyways, there is an unmet need to evaluate the status of resident and migratory birdlife for avian conservation ecology. This is especially urgent at a time when recent regional studies have highlighted the scale of the decline of the European and Palearctic avifauna. Rapidly growing community science datasets may help bridge the gaps in our understanding of long-term regional avifaunal trends. In this study, we used eBird data submitted by observers in Türkiye to undertake the first long-term assessment of the state of the country's birds from 2001 to 2022. We evaluated population trends based on presence-absence data of species to determine if any birds have significantly increased or decreased in the country so far this century. We provide a list of trends for 418 bird species that had large enough sample sizes of eBird observations from Türkiye, and highlight which species have significantly declined or increased. We found that 63 species have significantly declined in detection while 120 have significantly increased during the study period. Our findings provide a baseline for the future monitoring of Türkiye's birds and help contextualize population changes of birds in Türkiye against those occurring at the continental (Palearctic) scale. Additionally, we include movement classifications for all of the bird species in this study. We also provide a framework to effectively use eBird data to assess long-term avifaunal changes at the country-level in other understudied regions. Finally, we highlight ways in which eBirders in Türkiye and elsewhere can strengthen the quality and value of community ornithology data for population assessments and avian conservation ecology.

Niche partitioning is a widespread ecological strategy within trophic guilds, ensuring the coexistence of sympatric species by reducing interspecific competition. Stable isotope analysis of carbon and nitrogen and isotopic niche metrics (width and overlap) are used as a proxy to investigate niche partitioning among species of a guild. In our study, we investigated if niche partitioning was an ecological mechanism contributing to the coexistence of granivorous birds from the same geographic region along time, employing an isotopic approach. We sampled and isotopically analyzed (δ13C and δ15N values) wing feathers from 58 specimens of granivorous birds collected between 1900 and 1966 in southeastern Brazil. We grouped birds according to the main habitat type used by them (forest: Cyanoloxia brissonii, Leptotila rufaxilla, and Leptotila verreauxi; and grassland: Columbina squammata and Sicalis flaveola). We used the Isotopic Richness (IRic) metric to measure the isotopic niche width and the Isotopic Similarity (ISim) and Isotopic Nestedness (INes) metrics to measure the niche overlap between groups and species. The results of low isotopic niche overlap suggest that common granivorous birds had a clear niche partitioning in southeastern Brazil in the late past, especially through foraging in distinct habitat types (forest and grassland; ISim ​= ​0.1, INes ​= ​0.2). Niche overlaps in almost all species-by-species comparisons were low (ISim ≤0.3, INes ≤0.4), except between C. brissonii and L. verreauxi (ISim ​= ​0.6, INes ​= ​1.0). These results suggest that these birds, belonging to the same trophic guild, coexisted through niche and resource partitioning. Despite being considered a plastic trophic guild, the isotopic niche partitioning among granivorous birds indicates that each of these species uses a set of specific resources and habitats. This raises an ecological concern about the homogenization of landscapes across the Neotropics, oversimplifying food resources and habitats to granivorous birds.

Automated remote sensing has revolutionized the fields of wildlife ecology and environmental science. Yet, a cost-effective and flexible approach for large scale monitoring has not been fully developed, resulting in a limited collection of high-resolution data. Here, we describe BioSense, a low-cost and fully programmable automated sensing platform for applications in bioacoustics and environmental studies. Our design offers customization and flexibility to address a broad array of research goals and field conditions. Each BioSense is programmed through an integrated Raspberry Pi computer board and designed to collect and analyze avian vocalizations while simultaneously collecting temperature, humidity, and soil moisture data. We illustrate the different steps involved in manufacturing this sensor including hardware and software design and present the results of our laboratory and field testing in southwestern United States., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)

As the world becomes more urbanized, identifying traits that allow some species to thrive in cities will be key to predicting which species will probably remain common and which may require conservation attention. Large, diverse, widely distributed and readily documented raptors represent an ideal taxonomic group to understand how species persist and thrive in urban areas. Global community science datasets can reveal patterns that might be obscured in studies limited to a small number of locations, those relying on presence/absence data or those conducted by a small number of observers. We analysed 127 species of raptors (hawks and related species; Family: Accipitridae) using recent community‐science (eBird) records from 59 cities on five continents, modelling two indices of occurrence with five ecological and life history traits, and incorporating phylogenetic relatedness. Based on previous studies of avian traits in urban vs. rural populations, and well as our casual observations of birds in cities across the USA and around the world, we hypothesized that urban raptor communities would be dominated by smaller, ecological‐generalist species regardless of the regional species pool. We defined urban occurrence in two ways: urban abundance (the frequency of breeding season reports within 10 km of a city centre) and species proportion (the relative abundance of each species in the local raptor community). We did not detect a strong phylogenetic signal for either urban occurrence index, suggesting that various unrelated raptor species may become common in cities of the world. In the best‐performing models, both urban indices were significantly negatively associated with body mass, and significantly positively associated with habitat breadth; species proportion was also significantly associated with nest substrate breadth. Our analysis suggests that there may be an 'archetypal urban raptor' and that species lacking these traits (e.g. large, specialist taxa) may be at greater conservation risk as global urbanization increases. [ABSTRACT FROM AUTHOR]

Despite posing a serious threat to global biodiversity, national and international management efforts have not been able to limit the spread of most invasive species. In highly dispersive species, local invasions may be followed by regional range expansion that crosses international borders. In such cases, independent management efforts of the invading population may be futile unless international collaboration is practiced.We focus on the ongoing human‐mediated invasion of the common myna Acridotheres tristis into the Mediterranean basin, a region rich in overall numbers of species and endemic species, where common mynas have been introduced into a handful of countries. Some introductions were followed by subsequent range expansions into neighbouring countries. This species poses major threats to the biodiversity of the Mediterranean which is already susceptible to biodiversity loss as the result of ongoing land use and climate changes. Without action, this species and possibly others similar to it, could have severe consequences for native ecosystems.Policy implications. Given the regional scope of its invasion in the Mediterranean basin, common myna management requires an international collaboration to successfully prevent additional introductions and range expansions and to avoid accelerating threats to Mediterranean biodiversity, already at risk as a result of ongoing changes in land use and climate. We argue that international reciprocal transfer of information and the development of regional mitigation are essential for the successful management of the invasion of the common myna and other species into the Mediterranean. [ABSTRACT FROM AUTHOR]

Numerous avian species use anthropogenic materials in constructing nests, particularly in urbanized environments. Researchers have demonstrated anthropogenic materials, including plastics, to have both beneficial and harmful effects on survival and reproduction. During the spring of 2018, we collected 45 black-crested titmouse Baeolophus atricristatus nests in San Marcos, Texas, with two objectives: 1) to assess and compare the mass and proportion of nest materials along an urban gradient and 2) to examine the relationship between nest materials, clutch size, and hatching success. We categorized each nest based on collection location as urban, residential, park, or rural and separated nest materials into six categories: leaves, snake skin, twigs, moss, plastic, and nonplastic artificial materials. We then compared raw mass and proportion of mass of each nest material among urbanization categories. Nests in the urban category were 1.6–1.9 times lighter in mass than nests in other locations along the urban gradient (P = 0.01) and contained 4–5 times greater proportion, but not mass, of plastic compared to nests in all other locations. Nests in residential areas contained the greatest mass of combined anthropogenic materials. Neither clutch size nor hatching success differed based on urbanization category, nest mass, or proportions of anthropogenic or natural nest materials. The differences in mass of nests and increased proportion of plastics could have been due to a lack of natural nesting materials; however, we did not estimate availability of nesting materials at any location. Results add to the growing literature that the use of anthropogenic materials in nests varies across an urban gradient, and the effect of anthropogenic materials on nesting parameters varies among species. [ABSTRACT FROM AUTHOR]

Abstract Background A challenge faced by animals living in groups with stable long-term membership is to effectively coordinate their actions and maintain cohesion. However, as seasonal conditions alter the distribution of resources across a landscape, they can change the priority of group members and require groups to adapt and respond collectively across changing contexts. Little is known about how stable group-living animals collectively modify their movement behaviour in response to environment changes, such as those induced by seasonality. Further, it remains unclear how environment-induced changes in group-level movement behaviours might scale up to affect population-level properties, such as a population’s footprint. Methods Here we studied the collective movement of each distinct social group in a population of vulturine guineafowl (Acryllium vulturinum), a largely terrestrial and non-territorial bird. We used high-resolution GPS tracking of group members over 22 months, combined with continuous time movement models, to capture how and where groups moved under varying conditions, driven by seasonality and drought. Results Groups used larger areas, travelled longer distances, and moved to new places more often during drier seasons, causing a three-fold increase in the area used at the population level when conditions turned to drought. By contrast, groups used smaller areas with more regular movements during wetter seasons. Conclusions The consistent changes in collective outcomes we observed in response to different environments raise questions about the role of collective behaviour in facilitating, or impeding, the capacity for individuals to respond to novel environmental conditions. As droughts will be occurring more often under climate change, some group living animals may have to respond to them by expressing dramatic shifts in their regular movement patterns. These shifts can have consequences on their ranging behaviours that can scale up to alter the footprints of animal populations.

Context: Identifying factors driving patterns of species communities in heterogenous human-dominated landscapes remains elusive despite extensive research. Biodiversity is thought to decrease with habitat modification, as sensitive species are lost. Conversely, diversity has also been shown increase at moderate levels of landscape modification where greater habitat heterogeneity supports a diverse suite of species. Objectives: We explore patterns of avian diversity and abundance in heterogenous landscapes using a novel integration of multiple dimensional gradients of human-mediated modification. Methods: We attempt to identify aspects of landscape heterogeneity driving patterns of avian diversity and abundance in agro-urban–rural systems. Specifically, we utilize an intuitive multi-dimensional gradient distinguishing between two axes of human-influence, variation in the built environment (hard–soft) and in agricultural development (green–brown). We use these as covariates in community N-mixture models to describe variation in species abundance and diversity. Results: Avian richness was greatest in more heterogeneous regions of the landscape. Responses of individual species were variable, with sensitive species declining, while generalist species increased, leading to higher overall diversity in human-dominated regions. Conclusions: Species abundance and diversity is maximized in more heterogeneous parts of landscape mosaics. By characterizing distinct axes of human influence that capture spectrum of land use, we can identify differential effects confounded in traditional landscape metrics. Critically, we demonstrate that multi-dimensional landscape gradients provide a more nuanced understanding of how patterns of biodiversity emerge. Acknowledging that biodiversity is not always negatively impacted by habitat modification offers encouraging insight to guide conservation and management in human-dominated landscapes. [ABSTRACT FROM AUTHOR]

Information on how urban areas affect bird communities during winter in the boreal region is still scarce. With the aim of assessing such role of the urban habitats on over-wintering boreal birds, I focused on a city-wide approach in the city of Lahti (southern Finland) and two nearby forests (as controls). Point count surveys were conducted in 157 sites within the city and 30 in the control forests. In order to achieve comparable sets of data to contrast with the reference forests, I randomly selected five 30 point count sub-samples from the Lahti city-wide survey. Species richness was, in general, higher in the sub-samples from the city of Lahti. Such pattern did not show relationship with the built cover of the studied sites. Bird abundances were 3.3–5.9 times higher in the urban sub-samples when contrasted with the forest ones. Although results of this study are limited to a single city and consider one wintering season, they clearly illustrate the important role of urban systems as habitat for wintering birds in boreal systems. [ABSTRACT FROM AUTHOR]

Many bird species are vulnerable to environmental change, so knowledge of their diet and its variation can help understand population status and flexibility to respond to change. Insectivorous species are predicted to have a flexible diet within and between individuals, which can respond to naturally fluctuating prey abundance, thus allowing opportunistic exploitation of available resources. We analysed the diet of a nocturnal, aerial insectivore, the European Nightjar Caprimulgus europaeus, using high‐throughput metabarcoding. We quantified diet diversity and composition of 130 faecal samples from nests and roosts on a northern breeding site in the UK from 2015 to 2018, and compared differences among individuals and years. Although dominated by moths, diet varied significantly between individual faecal samples and between years and months. Prey species composition varied between years, and was more variable between samples in 2017 than in other years. Faecal samples were significantly more likely to contain moth species with a wingspan of > 60 mm and less likely to contain moth species of < 25 mm wingspan. This indicated size‐selective foraging, which also varied between months and years. Diet was driven by interindividual variation, indicating population‐level flexibility in prey choice. Metabarcoding provided a valuable tool in the exploration of insectivorous diets, but efforts are needed to build comprehensive reference libraries in order to compile full prey species lists. [ABSTRACT FROM AUTHOR]

Overcoming low breeding success is a major challenge for reversing population decline in threatened species. High nest predation rates are a common cause of low productivity in birds, but implementing evidence‐based management actions to reduce nest predation is challenging. Targeted breeding management requires a good understanding of where threatened species breed, the identity and distribution of nest predator species and the impact of these nest predators on breeding success. For rare and nomadic species, this information is hard to come by. The breeding success of regent honeyeater Anthochaera phrygia has declined over recent decades, and nest predation is the primary cause of breeding failure. We conducted point‐count surveys of nine avian and three mammalian nest predator species across 80% of the regent honeyeater's contemporary breeding area in south eastern Australia. We used occupancy models to determine the presence of predator species at survey sites and spatial models to predict predator abundance and species richness across the breeding area. We incorporated predator predictions for regent honeyeater nest locations into nest fate and daily nest survival models. Predator abundance was correlated positively with tree hollow abundance and proximity to water and negatively with shrub cover. Regent honeyeater nest success showed no significant relationship with predator abundance or predator species richness. Given how abundant and widespread avian and mammalian nest predators were throughout the breeding area, improving regent honeyeater nest success is likely to require implementation of simultaneous nest protection measures to avoid potential compensatory nest predation. Further research is required to better understand the relationship between nest predator abundance and regent honeyeater nest success. [ABSTRACT FROM AUTHOR]

Abstract Background Among urban stimuli, anthropogenic noise has been identified to be one of the behavioral drivers of species that rely on acoustic signals for communication. Studies have shown both species-specific and assemblage responses to urban noise, ranging from the modulation of their acoustic frequencies and spatiotemporal adjustments to declines in species richness. In this study, we assessed the citywide relationship between two anthropogenic noise variables (noise levels recorded during bird surveys and daily average noise levels) and vegetation cover with bird species richness. Methods This study was conducted in the city of Xalapa (Mexico) through a 114 citywide point-count survey. We recorded bird communities at each sampling site. We measured noise levels using a sound level meter while performing point-counts. Then, we generated a map of average daily noise of the city using an array of 61 autonomous recording units distributed across the city of Xalapa and calculated daily noise levels for the 114 points. We ran a linear model (LM) to assess potential relationships between both point-count and daily (24 h) noise values and vegetation cover with bird richness. Results Results from the LM show: (1) a negative relationship between maximum point-count noise and avian species richness, (2) no relationship between 24 h noise and bird species richness, and (3) a positive relationship between vegetation cover and bird species richness. Conclusions Results provide evidence that decreases in urban bird species richness do not necessarily imply the permanent absence of species, suggesting that birds can temporarily fly away from or avoid sites when noisy, become cryptic while noisy events are occurring, or be undetected due to our inability to record them in the field during noisy events.

Abstract Abundance–occupancy (A–O) relationships are widely documented for many organismal groups and regions, and have been used to gain an understanding of regional population and community trends. Monitoring changes in abundance and occupancy over time may be what is required to document changes in conservation status and needs for some species, communities, or areas. We hypothesize that if there is a higher proportion of declining species in one group of species compared with another (e.g., migratory species vs. permanent residents), then a consequence of that difference will be vastly different abundance–occupancy relationships. If this difference persists through time, then the resulting A–O relationships between the groups will continue to diverge. For neotropical migrants, short‐distance migrants, and permanent resident birds of North America, we assess the numbers of declining species over 1969–2009. We further test for differences in the A–O relationship across these three groups, and in rates of change in abundance and occupancy separately. We find significant differences in numbers of declining species across the migratory groups, a significant decline in the A–O relationship for permanent residents, a significant increase for Neotropical migrants, and a nonsignificant decline for short‐distance migrants over the 40 years. Further, abundances are not changing at different rates but occupancies are consistently greater over time for neotropical migrants versus permanent residents, likely driving the changes in A–O relationships observed. In these analyses, we documented changing A–O trends for different groups of species, over a relatively long time period for ecological studies, one of only a few studies to examine A–O relationships over time. Further, we have shown that a temporally unvarying abundance–occupancy relationship is not universal, and we posit that variability in A–O relationships is due to human impacts on habitats, coupled with variation in species' abilities to respond to human impacts.

Wildfire risks and losses have increased over the last 100 years, associated with population expansion, land use and management practices, and global climate change. While there have been extensive efforts at modeling the probability and severity of wildfires, there have been fewer efforts to examine causal linkages from wildfires to impacts on ecological receptors and critical habitats. Bayesian networks are probabilistic tools for graphing and evaluating causal knowledge and uncertainties in complex systems that have seen only limited application to the quantitative assessment of ecological risks and impacts of wildfires. Here, we explore opportunities for using Bayesian networks for assessing wildfire impacts to ecological systems through levels of causal representation and scenario examination. Ultimately, Bayesian networks may facilitate understanding the factors contributing to ecological impacts, and the prediction and assessment of wildfire risks to ecosystems. Integr Environ Assess Manag 2021;17:1168–1178. Published 2021. This article is a U.S. Government work and is in the public domain in the USA. KEY POINTS: The ladder of causation has broad implications for understanding the role of models in supporting assessment and decision‐making goals.Each of the rungs of the ladder is examined in terms of environmental assessment and decision models.Our case studies focus on managing wildfire risks for ecological endpoints but will be broadly applicable to other environmental issues.Establishing a causal hierarchy for environmental models will benefit future environmental assessment and management endeavors. [ABSTRACT FROM AUTHOR]

Multiple lineages of birds have independently evolved foraging strategies that involve catching aquatic prey by striking at them through the water’s surface. Diurnal, visual predators that hunt across the air-water interface encounter several visual challenges, including sun glint, or reflection of sunlight by the water surface. Intense sun glint is common at the air-water interface, and it obscures visual cues from submerged prey. Visually-hunting, cross-media predators must therefore solve the problem of glint to hunt effectively. One obvious solution is to turn away from the sun, which would result in reduction of glint effects. However, turning too far will cast shadows over prey, causing them to flee. Therefore, we hypothesized that foraging herons would orient away from, but not directly opposite to the sun. Our ability to understand how predators achieve a solution to glint is limited by our ability to quantify the amount of glint that free-living predators are actually exposed to under different light conditions. Herons (Ardea spp.) are a good model system for answering questions about cross-media hunting because they are conspicuous, widely distributed, and forage throughout a variety of aquatic habitats, on a variety of submerged prey. To test our hypothesis, we employed radiative transfer modeling of water surface reflectance, drawn from optical oceanography, in a novel context to estimate the visual exposure to glint of free-living, actively foraging herons. We found evidence that Ardea spp. do not use body orientation to compensate for sun glint while foraging and therefore they must have some other, not yet understood, means of compensation, either anatomical or behavioral. Instead of facing away from the sun, herons tended to adjust their position to face into the wind at higher wind speeds. We suggest that radiative transfer modeling is a promising tool for elucidating the ecology and evolution of air-to-water foraging systems. [ABSTRACT FROM AUTHOR]

Multiple lineages of birds have independently evolved foraging strategies that involve catching aquatic prey by striking at them through the water’s surface. Diurnal, visual predators that hunt across the air-water interface encounter several visual challenges, including sun glint, or reflection of sunlight by the water surface. Intense sun glint is common at the air-water interface, and it obscures visual cues from submerged prey. Visually-hunting, cross-media predators must therefore solve the problem of glint to hunt effectively. One obvious solution is to turn away from the sun, which would result in reduction of glint effects. However, turning too far will cast shadows over prey, causing them to flee. Therefore, we hypothesized that foraging herons would orient away from, but not directly opposite to the sun. Our ability to understand how predators achieve a solution to glint is limited by our ability to quantify the amount of glint that free-living predators are actually exposed to under different light conditions. Herons (Ardea spp.) are a good model system for answering questions about cross-media hunting because they are conspicuous, widely distributed, and forage throughout a variety of aquatic habitats, on a variety of submerged prey. To test our hypothesis, we employed radiative transfer modeling of water surface reflectance, drawn from optical oceanography, in a novel context to estimate the visual exposure to glint of free-living, actively foraging herons. We found evidence that Ardea spp. do not use body orientation to compensate for sun glint while foraging and therefore they must have some other, not yet understood, means of compensation, either anatomical or behavioral. Instead of facing away from the sun, herons tended to adjust their position to face into the wind at higher wind speeds. We suggest that radiative transfer modeling is a promising tool for elucidating the ecology and evolution of air-to-water foraging systems.

Background: A challenge faced by animals living in groups with stable long-term membership is to effectively coordinate their actions and maintain cohesion. However, as seasonal conditions alter the distribution of resources across a landscape, they can change the priority of group members and require groups to adapt and respond collectively across changing contexts. Little is known about how stable group-living animals collectively modify their movement behaviour in response to environment changes, such as those induced by seasonality. Further, it remains unclear how environment-induced changes in group-level movement behaviours might scale up to affect population-level properties, such as a population's footprint. Methods: Here we studied the collective movement of each distinct social group in a population of vulturine guineafowl (Acryllium vulturinum), a largely terrestrial and non-territorial bird. We used high-resolution GPS tracking of group members over 22 months, combined with continuous time movement models, to capture how and where groups moved under varying conditions, driven by seasonality and drought. Results: Groups used larger areas, travelled longer distances, and moved to new places more often during drier seasons, causing a three-fold increase in the area used at the population level when conditions turned to drought. By contrast, groups used smaller areas with more regular movements during wetter seasons. Conclusions: The consistent changes in collective outcomes we observed in response to different environments raise questions about the role of collective behaviour in facilitating, or impeding, the capacity for individuals to respond to novel environmental conditions. As droughts will be occurring more often under climate change, some group living animals may have to respond to them by expressing dramatic shifts in their regular movement patterns. These shifts can have consequences on their ranging behaviours that can scale up to alter the footprints of animal populations. [ABSTRACT FROM AUTHOR]

Habitat selection is an important process in birds that influences individual survival and fitness, and ultimately shapes population dynamics. As a consequence, strong selective pressures apply to favor strategies allowing individuals to choose high-quality habitat for foraging while reducing predation risk and competition. In long-distance migratory birds, such as shorebirds, the non-breeding period is considered as a key period of their annual cycle with reported effects on individual survival and subsequent reproduction. Site selection by non-breeding shorebirds should depend on habitat quality for them to ensure survival until the next breeding season. More specifically, birds should distribute in space and time according to their resource availability and specialize on feeding habitats or/and prey to reduce intraspecific competition. To test this hypothesis, we studied Bar-tailed Godwits (Limosa lapponica) at one of their main non-breeding sites along the French coast. We first used GPS tracking to investigate their foraging and roosting home ranges as well as core sampling to define the diversity of available habitats and their quality as feeding resources. We then compared individual habitat selection in relation to feeding home range sizes and benthic macrofauna abundances. Our results provide the first fine scale definition of shorebird movements and distribution along the non-breeding period. We found that godwits showed an extreme fidelity to restricted feeding areas (about 3.4 km2) during winter, with low overlap between individual feeding home ranges. Each bird appeared to mainly use 4–6 of the 11 available foraging habitats, with a specialization on 1 to 2 main habitats and their associated prey. However, our results did not emphasize a clear relationship between home range sizes and the quality of bird feeding sites. This study thus demonstrates the high specialization of individual non-breeding Bar-tailed godwits relying on specific foraging grounds and habitats, with important implications for the conservation of this species. [ABSTRACT FROM AUTHOR]

Protected areas are one of the primary conservation tools used worldwide. However, they are often embedded in a landscape that is intensely used by people, such as for agriculture or urban development. The proximity of these land-use types to protected areas can potentially affect the ecological effectiveness (or conservation effectiveness) of protected areas. In this article, we examine to what degree adjacent agricultural and urban land uses affect the ecological effectiveness of protected areas over the greater Gauteng region of South Africa. We selected 198 common, resident bird species, and analysed detection/non-detection data for these species collected over regular grid cells (approximately 61 km² in area). For each species, we estimated abundance per grid cell with the Royle-Nichols model in relation to the proportion of protected area as a covariate. Our study focused on how this relationship between proportion of protected area and abundance (which we term the ‘protection–abundance relationship’) changed as a function of other land-use types in the grid cell. Specifically, we examined the interaction effects between protected area and both urban and agricultural land-use type per grid cell on bird abundance. We assigned each species to one of seven guilds, namely: frugivores, gleaners, granivores, ground-feeders, hawkers, predators and vegivores, and examined how the protection–abundance relationship varied across guilds in relation to agriculture and urban area. As urban area within a grid cell increased, the protection–abundance relationship became more positive for 58% of all species. At the level of guilds, the protection–abundance relationship became more positive for two guilds (granivores and ground-feeders), more negative for frugivores, and remained unchanged for the other four guilds (gleaners, hawkers, predators and vegivores). As agricultural area within a grid cell increased, the protection–abundance relationship became more positive for 49% of all species. At the guild level, the protection–abundance relationship became more positive for six guilds (frugivores, gleaners, ground-feeders, hawkers, predators and vegivores) and remained unchanged for the granivores. Our results show land-use type near protected areas modified the effect protected areas had on bird abundances, and hence the ecological effectiveness of protected areas. Our results suggest that protected areas should be viewed as constituents within the landscape, rather than islands of protection. [ABSTRACT FROM AUTHOR]

Tropical mountains are global hotspots for birdlife. However, there is a dearth of baseline avifaunal data along elevational gradients, particularly in Africa, limiting our ability to observe and assess changes over time in tropical montane avian communities. In this study, we undertook a multi-year assessment of understory birds along a 1,750 m elevational gradient (1,430-3,186 m) in an Afrotropical moist evergreen montane forest within Ethiopia's Bale Mountains. Analyzing 6 years of systematic bird-banding data from 5 sites, we describe the patterns of species richness, abundance, community composition, and demographic rates over space and time. We found bimodal patterns in observed and estimated species richness across the elevational gradient (peaking at 1,430 and 2,388 m), although no sites reached asymptotic species richness throughout the study. Species turnover was high across the gradient, though forested sites at midelevations resembled each other in species composition. We found significant variation across sites in bird abundance in some of the dietary and habitat guilds. However, we did not find any significant trends in species richness or guild abundances over time. For the majority of analyzed species, capture rates did not change over time and there were no changes in species' mean elevations. Population growth rates, recruitment rates, and apparent survival rates averaged 1.02, 0.52, and 0.51 respectively, and there were no elevational patterns in demographic rates. This study establishes a multi-year baseline for Afrotropical birds along an elevational gradient in an under-studied international biodiversity hotspot. These data will be critical in assessing the long-term responses of tropical montane birdlife to climate change and habitat degradation. [ABSTRACT FROM AUTHOR]

Residential communities are the primary living spaces for people in China. Their associated greenspaces are important elements of the urban ecosystem, providing neighborhood ecosystem services and hosting bird populations of differing community structures compared with other urban green areas. This study analyzes avian community characteristics within residential communities and their differences compared with urban parks in Beijing. Furthermore, we assess the key environmental factors determining species composition and population sizes and the spatial scales at which these factors are most significant. We randomly selected 27 residential communities to assess the habitat structure and landscape characteristics that underpin residential avian assemblages across multiple spatial scales. Independent sample t-test and model selection methods based on AICc were used for data analysis. Eurasian Tree Sparrow (Passer montanus) (hereafter ETS) alone accounted for 91.0% of total individuals. Compared with urban parks, more migrants and omnivores were found in residential communities. Within-site forest patch connectivity simultaneously decided resident species diversity and individual abundance, with the exception of ETS. Tree species richness and coverage are key predictors for resident species richness and ETS numbers, respectively. Even in the most urbanized species, ETS retained ecological attributes found in “wilder” settings. Residential communities skewed toward avian communities with dominant numbers of ETS. In these low-quality habitats, our results suggest that landscape configuration is more important than local habitat structure. Within-site habitat connectivity and the number of surrounding forest patches with shorter between-patch distances deserve more attention in future landscape design for residential communities.

The interaction between fruit chemistry and the physiological traits of frugivores is expected to shape the structure of mutualistic seed dispersal networks, but it has been understudied compared with the role of morphological trait matching in structuring interaction patterns. For instance, highly frugivorous birds (i.e., birds that have fruits as the main component of their diets), which characteristically have fast gut passage times, are expected to avoid feeding on lipid-rich fruits because of the long gut retention times associated with lipid digestion. Here, we compiled data from 84 studies conducted in the Neotropics that used focal plant methods to record 35,815 feeding visits made by 317 bird species (155 genera in 28 families) to 165 plant species (82 genera in 48 families). We investigated the relationship between the degree of frugivory of birds (i.e., how much of their diet is composed of fruit) at the genus level and their visits to plant genera that vary in fruit lipid content. We used a hierarchical modeling of species communities approach that accounted for the effects of differences in body size, bird and plant phylogeny, and spatial location of study sites. We found that birds with a low degree of frugivory (e.g., predominantly insectivores) tend to have the highest increase in visitation rates as fruits become more lipid rich, while birds that are more frugivorous tend to increase visits at a lower rate or even decrease visitation rates as lipids increase in fruits. This balance between degree of frugivory and visitation rates to lipid-poor and lipid-rich fruits provides a mechanism to explain specialized dispersal systems and the occurrence of certain physiological nutritional filters, ultimately helping us to understand community-wide interaction patterns between birds and plants. [ABSTRACT FROM AUTHOR]

Joint encounter (JE) models estimate demographic rates using live recapture and dead recovery data. The extent to which limited recapture or recovery data can hinder estimation in JE models is not completely understood. Yet limited data are common in ecological research. We designed a series of simulations using Bayesian multistate JE models that spanned a large range of potential recapture probabilities (0.01–0.90) and two reported mortality probabilities (0.10, 0.19). We calculated bias by comparing estimates against known probabilities of survival, fidelity and reported mortality. We explored whether sparse data (i.e., recapture probabilities

The common pheasant is listed as a nationally protected species in Iran because it faces many threats such as habitat destruction, pollution from pesticides and overhunting. The species’ habitat selection remains unknown in Iran; consequently, conservation planning for the species is hampered by this lack of information. In this study we used predictor variables including topographic, anthropogenic, land cover and climate and 122 occurrence points to model the distribution of common pheasant (subspecies P. c. talischensis), in Gilan province, Iran. The results showed that distance to agriculture and orchards as well as distance to plantation forests were the most important variables in predicting species distribution. Furthermore, we found that the total potential suitable habitat for the species in Gilan province is 315,990 hectares. We observed a shift of the species to higher altitudes in the province. We recommend raising awareness about the presence of the species especially among private landowners, creating a network of protected areas on private land, and changing land-use policies at the provincial level as essential measures for the conservation of the species in Gilan province. Our results can be applied to management and conservation of the species in other modified or rapidly changing landscapes.