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A central theme for conservation is understanding how animals differentially use, and are affected by change in, the landscapes they inhabit. However, it has been challenging to develop conservation schemes for habitat‐specific behaviors.Here we use behavioral change point analysis to identify behavioral states of golden eagles (Aquila chrysaetos) in the Sonoran and Mojave Deserts of the southwestern United States, and we identify, for each behavioral state, conservation‐relevant habitat associations.We modeled behavior using 186,859 GPS points from 48 eagles and identified 2,851 distinct segments comprising four behavioral states. Altitude above ground level (AGL) best differentiated behavioral states, with two clusters of short‐distance movement behaviors characterized by low AGL (state 1 AGL = 14 m (median); state 2 AGL = 11 m) and two associated with longer‐distance movement behaviors and characterized by higher AGL (state 3 AGL = 108 m; state 4 AGL = 450 m).Behaviors such as perching and low‐altitude hunting were associated with short‐distance movements in updraft‐poor environments, at higher elevations, and over steeper and more north‐facing terrain. In contrast, medium‐distance movements such as hunting and transiting were over gentle and south‐facing slopes. Long‐distance transiting occurred over the desert habitats that generate the best updraft.This information can guide management of this species, and our approach provides a template for behavior‐specific habitat associations for other species of management concern., Despite the importance of linking habitat use to specific behaviors, this is almost never done, in part because of the many challenges in understanding where and when individual behaviors occur. Here, we use long‐term, short‐interval, and highly precise GPS data as input to recently developed models to interpret animal behavior from telemetry data to identify where and when behavioral states occur. Subsequently, we link these behavioral states to habitat, as a mechanism to identify the environmental correlates of each behavior, and to infer potential threats to these animals based on those behavior‐specific habitat associations.

Scavenging is an important function within ecosystems where scavengers remove organic matter, reduce disease, stabilize food webs, and generally make ecosystems more resilient to environmental changes. Global change (i.e., changing climate and increasing human impact) is currently influencing scavenger communities. Thus, understanding what promotes species richness in scavenger communities can help prioritize management actions. Using a long-term dataset from camera traps deployed with animal carcasses as bait along a 1881 km latitudinal gradient in the Appalachian Mountains of eastern USA, we investigated the relative impact of climate and humans on the species richness and diversity of vertebrate scavengers. Our most supported models for both mammalian and avian scavengers included climatic, but not human, variables. The richness of mammalian and avian scavengers detected was highest during relatively warm (5-10°C) and dry (100-150 mm precipitation) winters, when food was likely limited and both reliance on and detection of carrion was high. The diversity of mammalian and avian scavengers detected was highest under drier conditions. We then used these results to project the future species richness of scavengers that would be detected within our sampling area and under the climate scenario of 2070 (emissions level RCP8.5). Our predictions suggest up to 80% and 67% reductions, respectively, in the richness of avian and mammalian scavengers that would be detected at baited sites. Climate-induced shifts in behavior (i.e., reduction in scavenging, even if present) at this scale could have cascading implications for ecosystem function, resilience, and human health. Further, our study highlights the importance of conducting studies of scavenger community dynamics within ecosystems across wide spatial gradients within temperate environments. More broadly, these findings build upon our understanding of the impacts of climate-induced adjustments in behavior that can likely have negative impacts on systems at a large scale.

Gray fox (Urocyon cinereoargenteus (Schreber, 1775)) populations in portions of the eastern United States have experienced declines whose trajectories differ from those of other mesocarnivore populations. One hypothesis is that gray fox declines may result from interspecific interactions, particularly competition with abundant coyotes (Canis latrans Say, 1823). Alternatively, gray foxes may respond negatively to increased urbanization and reduced forest cover. To evaluate these hypotheses, we used single-species occupancy models of camera trap data to test the effects of habitat covariates, such as the amount of urbanization and forest, on coyote and gray fox occupancy. Additionally, we test the effect of an index based on an N-mixture model of the number of coyotes at each camera trap site on gray fox occupancy. Results indicate that occupancy probabilities of coyote and gray fox relate positively to the amount of forest, but they provided no evidence urban cover impacts gray foxes. Additionally, gray fox occupancy was negatively related to the index of the number of coyotes at each site. Our models support the idea that interactions with coyotes impact gray fox occupancy across the eastern United States. These results illustrate how large-scale studies can relate mechanisms identified within specific landscapes to phenomena observed at larger scales.

Lead poisoning, mainly through incidental ingestion of lead ammunition in carcasses, is a threat to scavenging and predatory bird species worldwide. In Australia, shooting for animal control is widespread, and a range of native scavenging species are susceptible to lead exposure. However, the prevalence of lead exposure in Australia's scavenging and predatory birds is largely unknown. We evaluated the degree to which the Tasmanian wedge‐tailed eagle (Aquila audax fleayi), an endangered Australian raptor and facultative scavenger, showed evidence of lead exposure. We detected lead in 100% of femur and liver tissues of 109 eagle carcasses opportunistically collected throughout Tasmania between 1996 and 2018. Concentrations were elevated in 10% of 106 liver (>6 mg/kg dry wt) and 4% of 108 femur (>10 mg/kg dry wt) samples. We also detected lead in 96% of blood samples taken from 24 live nestlings, with 8% at elevated concentrations (>10 μg/dL). Of the liver samples with elevated lead, 73% had lead207/206 isotope ratios within the published range of lead‐based bullets available in Tasmania. These first comprehensive data on lead exposure of an Australian raptor are comparable to those for raptor studies elsewhere that identify lead‐based ammunition exposure as a conservation threat. Our findings highlight the importance of further research and efforts to address lead contamination throughout the Tasmanian ecosystem and in other Australian regions. Environ Toxicol Chem 2021;40:219–230. © 2020 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Anticoagulant rodenticides (ARs) are commonly used to control rodent pests. However, worldwide, their use is associated with secondary and tertiary poisoning of nontarget species, especially predatory and scavenging birds. No medical device can rapidly test for AR exposure of avian wildlife. Prothrombin time (PT) is a useful biomarker for AR exposure, and multiple commercially available point-of-care (POC) devices measure PT of humans, and domestic and companion mammals. We evaluated the potential of one commercially available POC device, the Coag-Sense® PT/INR Monitoring System, to rapidly detect AR exposure of living birds of prey. The Coag-Sense device delivered repeatable PT measurements on avian blood samples collected from four species of raptors trapped during migration (Intraclass Correlation Coefficient > 0.9; overall intra-sample variation CV: 5.7%). However, PT measurements reported by the Coag-Sense system from 81 ferruginous hawk (Buteo regalis) nestlings were not correlated to those measured by a one-stage laboratory avian PT assay (r = − 0.017, p = 0.88). Although precise, the lack of agreement in PT estimates from the Coag-Sense device and the laboratory assay indicates that this device is not suitable for detecting potential AR exposure of birds of prey. The lack of suitability may be related to the use of a mammalian reagent in the clotting reaction, suggesting that the device may perform better in testing mammalian wildlife

Lead poisoning of scavenging birds is a global issue. However, the drivers of lead exposure of avian scavengers have been understood from the perspective of individual species, not cross-taxa assemblages. We analyzed blood (n = 285) and liver (n = 226) lead concentrations of 5 facultative (American crows [Corvus brachyrhynchos], bald eagles [Haliaeetus leucocephalus], golden eagles [Aquila chrysaetos], red-shouldered hawks [Buteo lineatus], and red-tailed hawks [Buteo jamaicensis]) and 2 obligate (black vultures [Coragyps atratus] and turkey vultures [Cathartes aura] avian scavenger species to identify lead exposure patterns. Species and age were significant (α < 0.05) predictors of blood lead exposure of facultative scavengers; species, but not age, was a significant predictor of their liver lead exposure. We detected temporal variations in lead concentrations of facultative scavengers (blood: median = 4.41 µg/dL in spring and summer vs 13.08 µg/dL in autumn and winter; p =

Lead is toxic to humans and wildlife. Most studies of lead exposure of raptors focus on the winter, non-breeding season when they scavenge heavily. We evaluated blood lead concentrations (BLCs) of red-shouldered hawks (Buteo lineatus) during the non-scavenging season in the eastern United States. BLCs of 53 of 70 hawks were above the limit of detection ($$\bar{x}$$ = 9.25 µg/dL ± 19.81; ± SD). Adult hawks had higher BLCs ($$\bar{x}$$ = 12.86 µg/dL ± 24.72) than did nestlings ($$\bar{x}$$ = 3.25 µg/dL ± 2.62; p ≤ 0.001, χ2 = 13.2). There was no difference in BLCs of adult hawks among physiographic provinces but there were differences between urban and non-urban settings (p = 0.04, χ2 = 4.2). Soils and invertebrate hawk prey also had quantifiable lead concentrations. Our work shows that red-shouldered hawks are exposed to lead when not scavenging, and suggests pathways by which these birds may be exposed.

An animal's movement is expected to be governed by an interplay between goals determined by its internal state and energetic costs associated with navigating through the external environment. Understanding this ecological process is challenging when an animal moves in two dimensions and even more difficult for birds that move in a third dimension. To understand the dynamic interaction between the internal state of an animal and the variable external environment, we evaluated hypotheses explaining association of different covariates of movement and the trade‐offs birds face as they make behavioural decisions in a fluctuating landscape. We used ~870 000 GPS telemetry data points collected from 68 Golden Eagles Aquila chrysaetos to test demographic, diel, topographic and meteorological hypotheses to determine (1) the probability that these birds would be in motion and (2), once in motion, their flight speed. A complex and sometimes interacting set of potential internal and external factors determined movement behaviour. There was good evidence that reproductive state, manifested as age, sex and seasonal effects, had a significant influence on the probability of being in motion and, to a lesser extent, on speed of motion. Likewise, movement responses to the external environment were often unexpectedly strong. These responses, to northness of slope, strength of orographic updraft and intensity of solar radiation, were regionally and temporally variable. In contrast to previous work showing the role of a single environmental factor in determining movement decisions, our analyses support the hypothesis that multiple factors simultaneously interact to influence animal movement. In particular they highlighted how movement is influenced by the interaction between the individual's internal reproductive state and the external environment, and that, of the environmental factors, topographic influences are often more relevant than meteorological influences in determining patterns of flight behaviour. Further disentangling of how these internal and externals states jointly affect movement will provide additional insights into the energetic costs of movement and benefits associated with achieving process‐driven goals.

Sources of lead exposure of many bird species are poorly understood. We analyzed blood lead concentrations from osprey (n = 244; Pandion haliaetus) and bald eagles (n = 68; Haliaeetus leucocephalus) and documented potential sources of lead they may encounter. Adult bald eagles had higher blood lead concentrations than did adult osprey. However, blood lead concentrations of nestlings were similar for both species. Although 62% of osprey had detectable lead concentrations ( x¯ = 1.99 ± 4.02 μg/dL, mean ± standard deviation [SD]), there was no difference in the detection frequency or lead concentrations between osprey adults and nestlings. Likewise, we found no differences in the detection frequency or lead concentrations in osprey adults and nestlings from high- and low-salinity areas. Of the bald eagle samples tested, 55% had detectable lead levels ( x¯ = 6.23 ± 10.74 μg/dL). Adult bald eagles had more detectable and higher lead concentrations than did nestlings or pre-adults. Among environmental samples, paint had the highest lead concentrations, followed by sediment, blue catfish (Ictalurus furcatus), and gizzard shad (Dorosoma cepedianum). There was no correlation between blood lead concentrations of osprey adults and their offspring. Our results indicate that, in the Chesapeake Bay region of Maryland and Virginia (USA), there are multiple sources by which piscivorous raptors may be exposed to lead. Environ Toxicol Chem 2019;38:862-871. © Published 2019 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

Accounting for migration and connectivity of mobile species across the annual cycle can present challenges for conservation and management efforts. The use of stable isotope approaches to examine the movements and ecology of wildlife has been widespread over the past two decades. Hydrogen stable isotope (δ2H) composition, in particular, has been frequently used to provide insight into the origin of migratory species, although isotopes of other elements are sometimes used. These intrinsic markers can yield valuable information about distributions of wildlife on a broad scale, with reduced labor and expense compared to tracking and telemetry. Many of the applications of isotopes to migratory species to date have addressed connectivity and origin, and studies in support of conservation biology are less common. In addition, there are few guides for how to best employ these methods for management. Therefore, we provide an overview for the wildlife conservation and management community on how stable isotope methods may be applied to conservation problems and a primer on the process for assigning geographic origins to terrestrial wildlife. We also discuss best practices for employing environmental isoscapes (isotopic distributions across landscapes), rescaling functions, and the assumptions required for assignment to origin while highlighting emerging issues in the modeling process. Finally, we provide example applications to illustrate these principles, and we explore strengths and limitations of this approach in a conservation context.

Anticoagulant rodenticides (ARs) used to control mammalian pest populations cause secondary exposure of predatory species throughout much of the world. It is important to understand the drivers of non-target AR exposure patterns as context for assessing long-term effects and developing effective mitigation for these toxicants. In Australia, however, little is known about exposure and effects of ARs on predators. We detected AR residues in 74% of 50 opportunistically collected carcasses of the Tasmanian wedge-tailed eagle (Aquila audax fleayi), an endangered apex predator. In 22% of birds tested, or 31% of those exposed, liver concentrations of second generation ARs (SGARs) were >0.1 mg/kg ww. Eagles were exposed to flocoumafen, a toxicant only available from agricultural suppliers, at an exceptionally high rate (40% of birds tested). Liver SGAR concentrations were positively associated with the proportion of agricultural habitat and human population density in the area around where each eagle died. The high exposure rate in a species not known to regularly prey upon synanthropic rodents supports the hypothesis that apex predators are vulnerable to SGARs. Our results indicate that AR exposure constitutes a previously unrecognized threat to Tasmanian wedge-tailed eagles and highlight the importance of efforts to address non-target AR exposure in Australia.

The use of animal-born sensors for location-based tracking and bio-logging in terrestrial systems has expanded dramatically in the past 10 years. This rapid expansion has generated new data on how animals interact with and respond to variation in their environment, resulting in important ecological, physiological, and evolutionary insights. Although understanding the finer details of animal locations has important management relevance, applied studies are not prominent in the movement ecology literature. This is despite the long history of applied studies of animal movement and the urgent and growing need for evidence-based conservation guidance, especially in the challenging field of human-wildlife interactions. The goal of this review is to evaluate the realized contribution of tracking-based animal movement ecology to solving specific conservation problems, and to identify barriers that may hinder expansion of that contribution. To do this, we (a) briefly review the history and technologies used in animal tracking and bio-logging, (b) use a series of literature searches to evaluate the frequency with which movement ecology studies are designed to solve specific conservation problems, and (c) use this information to identify challenges that may limit the applied relevance of the field of movement ecology, and to propose pathways to expand that applied relevance. Our literature review quantifies the limited extent to which research in the field of movement ecology is designed to solve specific conservation problems, but also the fact that such studies are slowly becoming more prevalent. We discuss how barriers that limit application of these principles are likely due to constraints imposed by the types of data used commonly in the field. Problems of scale mismatch, error compounding, and data paucity all create challenges that are relevant to the field of movement ecology but may be especially pertinent in applied situations. Finding solutions to these problems will create new opportunity for movement ecologists to contribute to conservation science.

Ecological “big data” Human activities are rapidly altering the natural world. Nowhere is this more evident, perhaps, than in the Arctic, yet this region remains one of the most remote and difficult to study. Researchers have increasingly relied on animal tracking data in these regions to understand individual species' responses, but if we want to understand larger-scale change, we need to integrate our understanding across species. Davidson et al. introduce an open-source data archive that currently hosts more than 15 million location data points across 96 species and use it to show distinct climate change responses across species. Such ecological “big data” can lead to a wider understanding of change. Science , this issue p. 712

Timing of activity can reveal an organism's efforts to optimize foraging either by minimizing energy loss through passive movement or by maximizing energetic gain through foraging. Here, we assess whether signals of either of these strategies are detectable in the timing of activity of daily, local movements by birds. We compare the similarities of timing of movement activity among species using six temporal variables: start of activity relative to sunrise, end of activity relative to sunset, relative speed at midday, number of movement bouts, bout duration and proportion of active daytime hours. We test for the influence of flight mode and foraging habitat on the timing of movement activity across avian guilds. We used 64 570 days of GPS movement data collected between 2002 and 2019 for local (non‐migratory) movements of 991 birds from 49 species, representing 14 orders. Dissimilarity among daily activity patterns was best explained by flight mode. Terrestrial soaring birds began activity later and stopped activity earlier than pelagic soaring or flapping birds. Broad‐scale foraging habitat explained less of the clustering patterns because of divergent timing of active periods of pelagic surface and diving foragers. Among pelagic birds, surface foragers were active throughout all 24 hrs of the day while diving foragers matched their active hours more closely to daylight hours. Pelagic surface foragers also had the greatest daily foraging distances, which was consistent with their daytime activity patterns. This study demonstrates that flight mode and foraging habitat influence temporal patterns of daily movement activity of birds. We thank the Nature Conservancy, the Bailey Wildlife Foundation, the Bluestone Foundation, the Ocean View Foundation, Biodiversity Research Institute, the Maine Outdoor Heritage Fund, the Davis Conservation Foundation and The U.S. Department of Energy (DE‐EE0005362), and the Darwin Initiative (19-026), EDP S.A. ‘Fundação para a Biodiversidade’ and the Portuguese Foundation for Science and Technology (FCT) (DL57/2019/CP 1440/CT 0021), Enterprise St Helena (ESH), Friends of National Zoo Conservation Research Grant Program and Conservation Nation, ConocoPhillips Global Signature Program, Maryland Department of Natural Resources, Cellular Tracking Technologies and Hawk Mountain Sanctuary for providing funding and in-kind support for the GPS data used in our analyses.

Reliable species identification is vital for survey and monitoring programs. Recently, the development of digital technology for recording and analyzing vocalizations has assisted in acoustic surveying for cryptic, rare, or elusive species. However, the quantitative tools that exist for species differentiation are still being refined. Using vocalizations recorded in the course of ecological studies of a King Rail (Rallus elegans) and a Clapper Rail (Rallus crepitans) population, we assessed the accuracy and effectiveness of three parametric (logistic regression, discriminant function analysis, quadratic discriminant function analysis) and six nonparametric (support vector machine, CART, Random Forest, k‐nearest neighbor, weighted k‐nearest neighbor, and neural networks) statistical classification methods for differentiating these species by their kek mating call. We identified 480 kek notes of each species and quantitatively characterized them with five standardized acoustic parameters. Overall, nonparametric classification methods outperformed parametric classification methods for species differentiation (nonparametric tools were between 57% and 81% accurate, parametric tools were between 57% and 60% accurate). Of the nine classification methods, Random Forest was the most accurate and precise, resulting in 81.1% correct classification of kek notes to species. This suggests that the mating calls of these sister species are likely difficult for human observers to tell apart. However, it also implies that appropriate statistical tools may allow reasonable species‐level classification accuracy of recorded calls and provide an alternative to species classification where other capture‐ or genotype‐based survey techniques are not possible.

Hybridization is common in bird populations but can be challenging for management, especially if one of the two parent species is of greater conservation concern than the other. King rails (Rallus elegans) and clapper rails (R. crepitans) are two marsh bird species with similar morphologies, behaviors, and overlapping distributions. The two species are found along a salinity gradient with the king rail in freshwater marshes and the clapper in estuarine marshes. However, this separation is not absolute; they are occasionally sympatric, and there are reports of interbreeding. In Virginia, USA, both king and clapper rails are identified by the state as Species of Greater Conservation Need, although clappers are thought to be more abundant and king rails have a higher priority ranking. We used a mitochondrial DNA marker and 13 diagnostic nuclear single nucleotide polymorphisms (SNPs) to identify species, classify the degree of introgression, and explore the evolutionary history of introgression in two putative clapper rail focal populations along a salinity gradient in coastal Virginia. Genetic analyses revealed cryptic introgression with site‐specific rates of admixture. We identified a pattern of introgression where clapper rail alleles predominate in brackish marshes. These results suggest clapper rails may be displacing king rails in Virginia coastal waterways, most likely as a result of ecological selection. As introgression can result in various outcomes from outbreeding depression to local adaptation, continued monitoring of these populations would allow further exploration of hybrid fitness and inform conservation management.

Behavior of young birds can have important consequences for population dynamics. We investigated the autumnal post-fledging movements of 3 White-tailed Sea Eagles (Haliaeetus albicilla) hatched in Kazakhstan. All 3 eagles traveled south, flying on average 25–108 km/d. Movement was nonrandom, with eagles generally traveling near mosaics of forest, open areas, and water, and rarely using areas with little vegetation. As the first study of movements of White-tailed Sea Eagles in arid Central Asia, this study provides insight into potential limiting factors and how these birds interact with their environment during long-distance movements.

Characterising the spatiotemporal variation of animal behaviour can elucidate the way individuals interact with their environment and allocate energy. Increasing sophistication of tracking technologies paired with novel analytical approaches allows the characterisation of movement dynamics even when an individual is not directly observable. In this study, high-resolution movement data collected via global positioning system (GPS) tracking in three dimensions were paired with topographical information and used in a Bayesian state-space model to describe the flight modes of migrating golden eagles (Aquila chrysaetos) in eastern North America. Our model identified five functional behavioural states, two of which were previously undescribed variations on thermal soaring. The other states comprised gliding, perching and orographic soaring. States were discriminated by movement features in the horizontal (step length and turning angle) and vertical (change in altitude) planes and by the association with ridgelines promoting wind deflection. Tracked eagles spent 2%, 31%, 38%, 9% and 20% of their daytime in directed thermal soaring, gliding, convoluted thermal soaring, perching and orographic soaring, respectively. The analysis of the relative occurrence of these flight modes highlighted yearly, seasonal, age, individual and sex differences in flight strategy and performance. Particularly, less energy-efficient orographic soaring was more frequent in autumn, when thermals were less available. Adult birds were also better at optimising energy efficiency than subadults. Our approach represents the first example of a state-space model for bird flight mode using altitude data in conjunction with horizontal locations and is applicable to other flying organisms where similar data are available. The ability to describe animal movements in a three-dimensional habitat is critical to advance our understanding of the functional processes driving animalsâ decisions. A plain language summary is available for this article.

Wind energy development is rapidly expanding in North America, often accompanied by requirements to survey potential facility locations for existing wildlife. Within the USA, golden eagles (Aquila chrysaetos) are among the most high-profile species of birds that are at risk from wind turbines. To minimize golden eagle fatalities in areas proposed for wind development, modified point count surveys are usually conducted to estimate use by these birds. However, it is not always clear what drives variation in the relationship between on-site point count data and actual use by eagles of a wind energy project footprint. We used existing GPS-GSM telemetry data, collected at 15 min intervals from 13 golden eagles in 2012 and 2013, to explore the relationship between point count data and eagle use of an entire project footprint. To do this, we overlaid the telemetry data on hypothetical project footprints and simulated a variety of point count sampling strategies for those footprints. We compared the time an eagle was found in the sample plots with the time it was found in the project footprint using a metric we called “error due to sampling”. Error due to sampling for individual eagles appeared to be influenced by interactions between the size of the project footprint (20, 40, 90 or 180 km2) and the sampling type (random, systematic or stratified) and was greatest on 90 km2 plots. However, use of random sampling resulted in lowest error due to sampling within intermediate sized plots. In addition sampling intensity and sampling frequency both influenced the effectiveness of point count sampling. Although our work focuses on individual eagles (not the eagle populations typically surveyed in the field), our analysis shows both the utility of simulations to identify specific influences on error and also potential improvements to sampling that consider the context-specific manner that point counts are laid out on the landscape.

Wind power is a fast-growing energy resource, but wind turbines can kill volant wildlife, and the flight behavior of obligate soaring birds can place them at risk of collision with these structures. We analyzed altitudinal data from GPS telemetry of critically endangered California Condors (Gymnogyps californianus) to assess the circumstances under which their flight behavior may place them at risk from collision with wind turbines. Condor flight behavior was strongly influenced by topography and land cover, and birds flew at lower altitudes and closer to the rotor-swept zone of wind turbines when over ridgelines and steep slopes and over forested and grassland cover types. Condor flight behavior was temporally predictable, and birds flew lower and closer to the rotor-swept zone during early morning and evening hours and during the winter months, when thermal updrafts were weakest. Although condors only occasionally flew at altitudes that placed them in the rotor-swept zone of turbines, they regu...

Capsule: We describe ecological factors associated with movements of a globally declining raptor species, the Eastern Imperial Eagle Aquila heliaca. Aims: To describe the movements, habitat associations and resource selection of Eastern Imperial Eagles marked in Central Asia. Methods: We used global positioning system (GPS) data sent via satellite telemetry devices deployed on Eastern Imperial Eagles captured in Kazakhstan to calculate distances travelled and to associate habitat and weather variables with eagle locations collected throughout the annual cycle. We also used resource selection models to evaluate habitat use of tracked birds during autumn migration. Separately, we used wing-tagging recovery data to broaden our understanding of wintering locations of eagles. Results: Eagles tagged in Kazakhstan wintered in most countries on the Arabian Peninsula, as well as Iran and India. The adult eagle we tracked travelled more efficiently than did the four pre-adults. During autumn migration, telemetered eagles used a mixture of vegetation types, but during winter and summer, they primarily used bare and sparsely vegetated areas. Finally, telemetered birds used orographic updrafts to subsidize their autumn migration flight, but they relied on thermal updrafts during spring migration. Conclusion: Our study is the first to use GPS telemetry to describe year-round movements and habitat associations of Eastern Imperial Eagles in Central Asia. Our findings provide insight into the ecology of this vulnerable raptor species that can contribute to conservation efforts on its behalf.

A male juvenile bald eagle ( Haliaeetus leucocephalus) was admitted to the Wildlife Center of Virginia with a left humeral fracture a large quantity of anthropogenic debris in the ventriculus, a blood lead level of 0.616 ppm, and clinical signs consistent with chronic lead toxicosis. Because of the poor prognosis for recovery and release, the eagle was euthanatized. Lead isotope analysis was performed to identify potential anthropogenic sources of lead in this bird. The lead isotope ratios in the eagle's femur (0.8773), liver (0.8761), and kidneys (0.8686) were most closely related to lead paint (0.8925), leaded gasoline (0.8450), and zinc smelting (0.8240). The lead isotope ratios were dissimilar to lead ammunition (0.8179) and the anthropogenic debris in the ventriculus. This case report documents foreign body ingestion in a free-ranging bald eagle and demonstrates the clinical utility of lead isotope analysis to potentially identify or exclude anthropogenic sources of lead poisoning in wildlife patients.

Resumen El empetrolado de las aves puede tener consecuencias importantes a nivel individual y poblacional. Aunque la mayoria de los ejemplos publicados sobre empetrolado se refieren a la exposicion a fuentes antropicas de hidrocarburos, el empetrolado puede ocurrir naturalmente. Describimos cuatro casos de empetrolado natural de siete pollos de Aquila chrysaetos asi como nuestra intervencion para mitigarlo. En todos los casos, el aceite en estas aves provino casi seguro de sus presas, en su mayoria ardillas terrestres (Otospermophilus beecheyi), aportadas por aguilas adultas en cantidades mayores de las que los polluelos podian consumir. Algunos pollos solo fueron empetrolados levemente. Otros fueron empetrolados tanto que la funcion de las plumas se vio comprometida a un nivel en el que, sin nuestra intervencion, la supervivencia de estos pollos de aguila seguramente hubiera sido afectada. Hasta donde sabemos, este es el primer informe publicado sobre empetrolado de rapaces como consecuencia de un sobre ...

Conservation and management for a species requires reliable information on its status, distribution, and habitat use. We identified occupancy and distributions of king (Rallus elegans) and clapper (R. crepitans) rail populations in marsh complexes along the Pamunkey and Mattaponi Rivers in Virginia, USA by modeling data on vocalizations recorded from autonomous recording units (ARUs). Occupancy probability for both species combined was 0.64 (95% CI: 0.53, 0.75) in marshes along the Pamunkey and 0.59 (0.45, 0.72) in marshes along the Mattaponi. Occupancy probability along the Pamunkey was strongly influenced by salinity, increasing logistically by a factor of 1.62 (0.6, 2.65) per parts per thousand of salinity. In contrast, there was not a strong salinity gradient on the Mattaponi and therefore vegetative community structure determined occupancy probability on that river. Estimated detection probability across both marshes was 0.63 (0.62, 0.65), but detection rates decreased as the season progressed. Monitoring wildlife within wetlands presents unique challenges for conservation managers. Our findings provide insight not only into how rails responded to environmental variation but also into the general utility of ARUs for occupancy modeling of the distribution and habitat associations of rails within tidal marsh systems.

Although poisoning from anthropogenically derived lead threatens wildlife of many species, routes of lead exposure are unclear and rarely empirically tested. We used blood lead concentration and isotope ratio (207Pb/206Pb) data from populations of four species of raptors from across North America to test hypotheses associated with lead exposure via inhalation versus ingestion. Mean variation in blood lead concentration among cohort siblings was non-zero at nests of ferruginous hawks Buteo regalis and osprey Pandion haliaetus (P

Estimates of population abundance are important to wildlife management and conservation. However, it can be difficult to characterize the numbers of broadly distributed, low-density, and elusive bird species. Although Golden Eagles (Aquila chrysaetos) are rare, difficult to detect, and broadly distributed, they are concentrated during their autumn migration at monitoring sites in eastern North America. We used hawk-count data collected by citizen scientists in a virtual mark–recapture modeling analysis to estimate the numbers of Golden Eagles that migrate in autumn along Kittatinny Ridge, an Important Bird Area in Pennsylvania, USA. In order to evaluate the sensitivity of our abundance estimates to variation in eagle capture histories, we applied candidate models to 8 different sets of capture histories, constructed with or without age-class information and using known mean flight speeds ± 1, 2, 4, or 6 SE for eagles to travel between hawk-count sites. Although some abundance estimates were produ...

Movement behavior and its relationship to habitat provide critical information toward understanding the effects of changing environments on birds. The eastern North American population of Golden Eagles (Aquila chrysaetos) is a genetically distinct and small population of conservation concern. To evaluate the potential responses of this population to changing landscapes, we calculated the home range and core area sizes of 52 eagles of 6 age–sex classes during the summer and winter seasons. Variability in range size was related to variation in topography and open cover, and to age and sex. In summer, eagle ranges that were smaller had higher proportions of ridge tops and open cover and had greater topographic roughness than did larger ranges. In winter, smaller ranges had higher proportions of ridge tops, hillsides and cliffs, and open cover than did larger ranges. All age and sex classes responded similarly to topography and open cover in both seasons. Not surprisingly, adult eagles occupied the s...

The movements of animals are limited by evolutionary constraints and ecological processes and are strongly influenced by the medium through which they travel. For flying animals, variation in atmospheric conditions are critically influential in movement. Obligate soaring birds depend on external sources of updraft more than do other flying species, since without that updraft they are unable to sustain flight for extended periods. These species are therefore good models for understanding how the environment can influence decisions about movement. We used meteorological and topographic variables to understand the environmental influences on the decision to engage in flight by obligate soaring and critically endangered California Condors Gymnogyps californianus. Condors were more likely to fly, soared at higher altitudes, and flew over smoother terrain when weather conditions promoted either thermal or orographic updrafts, for example when turbulence and solar radiation were higher and when winds from the east and north were stronger. However, increased atmospheric stability, which is inconsistent with thermal development but may be associated with orographic updrafts, was correlated with a somewhat higher probability of lower flight altitudes and flight over rougher terrain. The close and previously undescribed linkages between Condor flight and conditions that support development of thermal and orographic updrafts provide important insight into the behaviour of obligate soaring birds and into the environmental parameters that may define the currently expanding distribution of Condors within and outside of the state of California. This article is protected by copyright. All rights reserved.

Surveys for secretive marsh birds could be improved with refinements to address regional and species-specific variation in detection probabilities and optimal times of day to survey. Diel variation in relation to naive occupancy, detection rates, and vocalization rates of King (Rallus elegans) and Clapper (R. crepitans) rails were studied in intracoastal waterways in Virginia, USA. Autonomous acoustic devices recorded vocalizations of King and Clapper rails at 75 locations for 48-hr periods within a marsh complex. Naive King and Clapper rail occupancy did not vary hourly at either the marsh or the study area level. Combined King and Clapper rail detections and vocalizations varied across marshes, decreased as the sampling season progressed, and, for detections, was greatest during low rising tides (P < 0.01). Hourly variation in vocalization and detection rates did not show a pattern but occurred between 7.8% of pairwise comparisons for detections and 10.5% of pairwise comparisons for vocalizati...

Conserving wide-ranging animals requires knowledge about their year-round movements and resource use. Golden Eagles (Aquila chrysaetos) exhibit a wide range of movement patterns across North America. We combined tracking data from 571 Golden Eagles from multiple independent satellite-telemetry projects from North America to provide a comprehensive look at the magnitude and extent of these movements on a continental scale. We compared patterns of use relative to four alternative administrative and ecological mapping systems, namely Bird Conservation Regions (BCRs), U.S. administrative migratory bird flyways, Migratory Bird Joint Ventures, and Landscape Conservation Cooperatives. Our analyses suggested that eagles initially captured in eastern North America used space differently than those captured in western North America. Other groups of eagles that exhibited distinct patterns in space use included long-distance migrants from northern latitudes, and southwestern and Californian desert residents....

Migration allows animals to live in resource-rich but seasonally variable environments. Because of the costs of migration, there is selective pressure to capitalize on variation in weather to optimize migratory performance. To test the degree to which migratory performance (defined as speed of migration) of Golden Eagles (Aquila chrysaetos) was determined by age- and season-specific responses to variation in weather, we analyzed 1,863 daily tracks (n = 83 migrant eagles) and 8,047 hourly tracks (n = 83) based on 15 min GPS telemetry data from Golden Eagles and 277 hourly tracks based on 30 s data (n = 37). Spring migrant eagles traveled 139.75 ± 82.19 km day−1 (mean ± SE; n = 57) and 25.59 ± 11.75 km hr−1 (n = 55). Autumn migrant eagles traveled 99.14 ± 59.98 km day−1 (n = 26) and 22.18 ± 9.18 km hr−1 (n = 28). Weather during migration varied by season and by age class. During spring, best-supported daily and hourly models of 15 min data suggested that migratory performance was influenced most st...

Nest box programs are frequently implemented for the conservation of cavity-nesting birds, but their effectiveness is rarely evaluated in comparison to birds not using nest boxes. In the European Palearctic, Red-footed Falcon Falco vespertinus populations are both of high conservation concern and are strongly associated with nest box programs in heavily managed landscapes. We used a 21-year monitoring dataset collected on 753 nesting attempts by Red-footed Falcons in unmanaged natural or semi-natural habitats to provide basic information on this poorly known species; to evaluate long-term demographic trends; and to evaluate response of demographic parameters of Red-footed Falcons to environmental factors including use of nest boxes. We observed significant differences among years in laying date, offspring loss, and numbers of fledglings produced, but not in egg production. Of these four parameters, offspring loss and, to a lesser extent, number of fledglings exhibited directional trends over time. Variation in laying date and in numbers of eggs were not well explained by any one model, but instead by combinations of models, each with informative terms for nest type. Nevertheless, laying in nest boxes occurred 2.10 ± 0.70 days earlier than in natural nests. In contrast, variation in both offspring loss and numbers of fledglings produced were fairly well explained by a single model including terms for nest type, nest location, and an interaction between the two parameters (65% and 81% model weights respectively), with highest offspring loss in nest boxes on forest edges. Because, for other species, earlier laying dates are associated with more fit individuals, this interaction highlighted a possible ecological trap, whereby birds using nest boxes on forest edges lay eggs earlier but suffer greater offspring loss and produce lower numbers of fledglings than do those in other nesting settings. If nest boxes increase offspring loss for Red-footed Falcons in heavily managed landscapes where populations are at greater risk, or for the many other species of rare or endangered birds supported by nest box programs, these processes could have important demographic and conservation consequences. This article is protected by copyright. All rights reserved.

Lead poisoning is a threat to birds, particularly scavenging birds of prey. With the availability of portable lead-testing kits, an increasing number of field researchers are testing wild-caught birds, in situ, for lead poisoning. We describe guidelines for evaluation of lead toxicity in wild raptors by outlining field testing of blood-lead concentrations, presenting criteria for removing a lead-poisoned bird from the wild for treatment, and suggesting strategies for effective treatment of lead intoxicated raptors. Field testing of birds is most commonly accomplished via portable electrochemical analysis of blood; visual observation of condition alone may provide insufficient evidence upon which to make a decision about lead poisoning. Our intended audience is not only the avian research community, but also rehabilitation facilities that may receive apparently uninjured birds. Best practices suggest that birds whose blood-lead levels are 60 μg/dL are potentially lethally poisoned and best served if removed from the wild for appropriate treatment at a licensed rehabilitation facility and later released. We present guidelines for decision-making when treating lead poisoning of wild raptors. Future work based on experimental studies will clarify the role of lead poisoning for specific species and be important to refine these guidelines to improve effectiveness. © 2017 The Wildlife Society.

Raptor migration rarely involves long-distance movements across open oceans. One exception occurs along the East-Asian Oceanic Flyway. We collected migration data at two terrestrial hawkwatch sites along this flyway to better understand open-ocean movements along this largely overwater corridor. At the northern end of the Philippines, at Basco on the island of Batan, we recorded 7587 migratory raptors in autumn 2014. Near the southern end of the Philippines, at Cape San Agustin on the island of Mindanao, we recorded 27,399 raptors migrating in autumn 2012. Chinese Sparrowhawks (Accipiter soloensis) were the most common raptors observed, making up approximately 89% and 92% of total records for Basco and Cape San Agustin, respectively. The Grey-faced Buzzard (Butastur indicus) was the second most common raptor migrant, accounting for 8% of the total counts at both watch sites. The migration period was about 1–2 wk earlier at Basco, the more northerly site, than at Cape San Agustin. Overwater flight...

Animals occupying human-dominated environments show the capacity for behavioral flexibility. Corvids are among the most intelligent synanthropic bird species. During a layover at Schipol Airport in Amsterdam, Netherlands, I photographically documented Eurasian Jackdaws (Corvus monedula) perching upside down from a building cornice. In contrast to other reports of hanging birds, these jackdaws did not forage or play while upside down and appeared to use the perching spot to observe their surroundings. Although Corvids and Psittacines are known to hang upside down, especially in captive situations, such behaviors are rarely documented in the wild, and never before in association with human-built structures.

Populations of the Eastern Whip-poor-will (Antrostomus vociferus) are thought to be declining because of a range of potential factors including habitat loss, pesticide use, and predation. However, this species is nocturnal and, as a consequence, it is poorly studied, and its population status is not well assessed by traditional diurnal bird surveys. We used nocturnal road surveys to study habitat associations and distribution of Eastern Whip-poor-wills to better understand and contextualize their population status and to provide a framework for subsequent research and management. We used occupancy models to associate presence of Eastern Whip-poor-wills with habitat characteristics. Global models with habitat associations at a radius of 1600 m (1.0-ha area) were the best supported by the data, suggesting that this was the scale at which the species responded to the habitat parameters we measured. At this scale, Eastern Whip-poor-wills most frequently occupied areas lower in elevation and character...

Movement and space use are important components of animal interactions with the environment. However, for hard-to-monitor raptor species, there are substantial gaps in our understanding of these key determinants. We used noninvasive genetic tools to evaluate the details of space use over a 3-yr period by White-tailed Eagles (Haliaeetus albicilla) at the Naurzum Zapovednik in northern Kazakhstan. We genotyped, at 10 microsatellite markers and one mitochondrial marker, 859 eagle feathers and assigned naturally shed feathers to individuals. We identified 124 White-tailed Eagles, including both members of 5–10 pairs per year, and were able to monitor birds across years. Distances between eagle nests and hunting perches were always greater than nearest neighbor distances, eagles never used the closest available hunting perch, and hunting perches were always shared with other eagles. When eagles switched nests between years, the nests they chose were almost always well outside the space that theory pre...

Increasing global energy demand is fostering the development of renewable energy as an alternative to fossil fuels. However, renewable energy facilities may adversely affect wildlife. Facility siting guidelines recommend or require project developers complete pre- and postconstruction wildlife surveys to predict risk and estimate effects of proposed projects. Despite this, there are no published studies that have quantified the types of surveys used or how survey types are standardized within and across facilities. We evaluated 628 peer-reviewed publications, unpublished reports, and citations, and we analyzed data from 525 of these sources (203 facilities: 193 wind and 10 solar) in the United States and Canada to determine the frequency of pre- and postconstruction surveys and whether that frequency changed over time; frequency of studies explicitly designed to allow before-after or impact-control analyses; and what types of survey data were collected during pre- and postconstruction periods and how those data types were standardized across periods and among facilities. Within our data set, postconstruction monitoring for wildlife fatalities and habitat use was a standard practice (n = 446 reports), but preconstruction estimation of baseline wildlife habitat use and mortality was less frequently reported (n = 84). Only 22% (n = 45) of the 203 facilities provided data from both pre- and postconstruction, and 29% (n = 59) had experimental study designs. Of 108 facilities at which habitat-use surveys were conducted, only 3% estimated of detection probability. Thus, the available data generally preclude comparison of biological data across construction periods and among facilities. Use of experimental study designs and following similar field protocols would improve the knowledge of how renewable energy affects wildlife. Article Impact Statement Many surveys at wind and solar facilities provide limited information on wildlife use and fatality rates.Limitaciones, Falta de Estandarización y las Mejores Prácticas Recomendadas en Estudios de los Efectos de las Energías Renovables sobre las Aves y los Murciélagos Resumen La creciente demanda global por energía está fomentando el desarrollo de energías renovables como una alternativa a los combustibles fósiles. Sin embargo, las instalaciones de energías renovables pueden afectar de manera adversa a la fauna. Las pautas para la ubicación de dichas instalaciones recomiendan o requieren que los desarrolladores de los proyectos realicen censos previa y posteriormente a la construcción de las instalaciones para pronosticar el riesgo y estimar los efectos de los proyectos propuestos. A pesar de esto, no existen estudios publicados que hayan cuantificado los tipos de censo usados o cómo los tipos de censo están estandarizados para las instalaciones en específico y en general. Evaluamos 628 publicaciones revisadas por pares, reportes sin publicar y referencias y analizamos los datos de 525 de estas fuentes (203 instalaciones: 193 de energía eólica y 10 de energía solar) en los Estados Unidos y Canadá para determinar la frecuencia de los censos previos y posteriores a la construcción y si dicha frecuencia cambió con el tiempo; para determinar la frecuencia de los estudios diseñados explícitamente para permitir los análisis antes-y-después o de control-impacto; y para determinar cuáles tipos de datos fueron recolectados previa y posteriormente a la construcción y cómo aquellos tipos de datos estuvieron estandarizados a través de los periodos y entre las instalaciones. Dentro de nuestro conjunto de datos, el monitoreo posterior a la construcción de las fatalidades faunísticas y el uso de hábitat fue una práctica común (n = 446 reportes), pero la estimación previa a la construcción de la línea base del uso de hábitat por la fauna y la mortalidad estuvo reportada con menor frecuencia (n = 84). Sólo el 22% (n = 45) de las 203 instalaciones proporcionaron datos de los censos previos y posteriores a la construcción y el 29% (n = 59) contó con diseño de estudios experimentales. De las 108 instalaciones en las que se realizaron censos de uso de hábitat, sólo el 3% incluyó la estimación de la probabilidad de detección. Por lo tanto, los datos disponibles generalmente impiden la comparación de los datos biológicos durante los periodos de construcción y entre las instalaciones. El uso del diseño de estudios experimentales y el seguimiento de protocolos de campo similares mejoraría el conocimiento sobre cómo las energías renovables afectan a la fauna.不断增长的全球能源需求正在促进可再生能源作为化石燃料的替代能源的发展。然而, 可再生能源设施可能对野生动物产生不利影响。设施选址指南通常建议或要求项目开发者对施工前后的野生动物进行调查, 以预测风险并估计拟建项目的影响。尽管如此, 目前还没有已发表研究对野生动物调查类型的选择和设施内部、设施之间如何确定标准化调查类型做过定量分析。本研究评估了 628 篇同行评审文献、未发表报告及引文, 并分析了其中美国和加拿大的 525 篇文献或报告的数据 (涉及 203 个设施, 包含 193 个风能和 10 个太阳能设施), 以确定施工前后调查的频率及其随时间的变化;明确设计进行施工前后或影响控制分析的研究的频率;施工前后收集的调查数据类型, 以及这些数据类型在不同时期和不同设施之间的标准化方法。在本研究的数据集中, 设施建设后的野生动物死亡率和栖息地利用的监测是常规标准做法 (446 份报告), 而在建设前对野生动物死亡率及栖息地利用的基线水平的评估较少 (84 份)。 203 个设施中只有 22% (45 个)同时提供了施工前和施工后的数据, 有 29% (59 个) 提供了实验研究设计。在进行了栖息地利用调查的 108 个设施中, 只有 3% 包含了动物发现概率的估计。因此, 现有数据普遍不能在不同建设时期和不同设施之间进行生物学数据的比较。我们建议使用实验研究设计并遵循类似的野外研究方法, 以提高对可再生能源影响野生动物的认识。 【翻译: 胡怡思; 审校: 聂永刚】.

Bird movements vary spatially and temporally, but the primary drivers that explain such variation can be difficult to identify. For example, it is well known that the availability of updraft influences soaring flight and that topography interacts with weather to produce these updrafts. However, the influences of topography on flight are not well understood. We determined how topographic characteristics influenced flight altitude above ground level (AGL) of a large soaring bird, the Golden Eagle (Aquila chrysaetos), over several regions within the State of California, USA. Primary drivers of flight AGL, those to which eagles showed the same response at all spatial scales, were topographic roughness, ground elevation and the east-west component of aspect (eastness). Each of these is related to formation of thermal updrafts. Secondary drivers, those to which eagles showed region-specific patterns, included topographic position, percent slope, and the north-south component of aspect (northness). In contrast to primary drivers, these secondary drivers were related to formation of both thermal and orographic updrafts. Overall, drivers of flight altitudes that were related to thermal updrafts showed different levels of complexity due to spatial and temporal variation of those drivers than did flight altitudes related to orographic updrafts.

Viability selection yields adult populations that are more genetically variable than those of juveniles, producing a positive correlation between heterozygosity and survival. Viability selection could be the result of decreased heterozygosity across many loci in inbred individuals and a subsequent decrease in survivorship resulting from the expression of the deleterious alleles. Alternatively, locus-specific differences in genetic variability between adults and juveniles may be driven by forms of balancing selection, including heterozygote advantage, frequency-dependent selection, or selection across temporal and spatial scales. We use a pooled-sequencing approach to compare genome-wide and locus-specific genetic variability between 74 golden eagle (Aquila chrysaetos), 62 imperial eagle (Aquila heliaca), and 69 prairie falcon (Falco mexicanus) juveniles and adults. Although genome-wide genetic variability is comparable between juvenile and adult golden eagles and prairie falcons, imperial eagle adults are significantly more heterozygous than juveniles. This evidence of viability selection may stem from a relatively smaller imperial eagle effective population size and potentially greater genetic load. We additionally identify ~2000 single-nucleotide polymorphisms across the 3 species with extreme differences in heterozygosity between juveniles and adults. Many of these markers are associated with genes implicated in immune function or olfaction. These loci represent potential targets for studies of how heterozygote advantage, frequency-dependent selection, and selection over spatial and temporal scales influence survivorship in avian species. Overall, our genome-wide data extend previous studies that used allozyme or microsatellite markers and indicate that viability selection may be a more common evolutionary phenomenon than often appreciated.

Renewable energy production is expanding rapidly despite mostly unknown environmental effects on wildlife and habitats. We used genetic and stable isotope data collected from Golden Eagles (Aquila chrysaetos) killed at the Altamont Pass Wind Resource Area (APWRA) in California in demographic models to test hypotheses about the geographic extent and demographic consequences of fatalities caused by renewable energy facilities. Geospatial analyses of δ2H values obtained from feathers showed that ≥25% of these APWRA-killed eagles were recent immigrants to the population, most from long distances away (>100 km). Data from nuclear genes indicated this subset of immigrant eagles was genetically similar to birds identified as locals from the δ2H data. Demographic models implied that in the face of this mortality, the apparent stability of the local Golden Eagle population was maintained by continental-scale immigration. These analyses demonstrate that ecosystem management decisions concerning the effects of local-scale renewable energy can have continental-scale consequences.

Molecular markers can reveal interesting aspects of organismal ecology and evolution, especially when surveyed in rare or elusive species. Herein, we provide a preliminary assessment of golden eagle (Aquila chrysaetos) population structure in North America using novel single nucleotide polymorphisms (SNPs). These SNPs included one molecular sexing marker, two mitochondrial markers, 85 putatively neutral markers that were derived from noncoding regions within large intergenic intervals, and 74 putatively nonneutral markers found in or very near protein-coding genes. We genotyped 523 eagle samples at these 162 SNPs and quantified genotyping error rates and variability at each marker. Our samples corresponded to 344 individual golden eagles as assessed by unique multilocus genotypes. Observed heterozygosity of known adults was significantly higher than of chicks, as was the number of heterozygous loci, indicating that mean zygosity measured across all 159 autosomal markers was an indicator of fitness as it is associated with eagle survival to adulthood. Finally, we used chick samples of known provenance to test for population differentiation across portions of North America and found pronounced structure among geographic sampling sites. These data indicate that cryptic genetic population structure is likely widespread in the golden eagle gene pool, and that extensive field sampling and genotyping will be required to more clearly delineate management units within North America and elsewhere.

Capsule: Red-footed Falcons Falco vespertinus migrating from northern Kazakhstan proceed west before heading south to Africa; their northbound travel follows a different route with passage close to shooting hotspots in the Mediterranean.Aim: To use tracking and ringing data to document for the first time the migration of globally threatened Red-footed Falcons from northern Kazakhstan.Methods: Light-level geolocators were deployed on breeding adults in Kazakhstan and recovered one year later. Ringing and observational data from more than 100 years of Russian-language and other literature were summarized and mapped alongside the geolocator data.Results: Geolocator, ringing and observational data together demonstrate that Red-footed Falcons from northern Kazakhstan have a clockwise loop migration that begins with a long and unusual westward trek around eastern Europe’s large inland seas before continuing to extreme southern Africa. Return migration is farther west and requires crossing two major migr...

Animal movements can determine the population dynamics of wildlife. We used telemetry data to provide insight into the causes and consequences of local and long-distance movements of multiple age classes of conservation-reliant golden eagles (Aquila chrysaetos) in the foothills and mountains near Tehachapi, California. We estimated size and habitat-related correlates of 324 monthly 95 % home ranges and 317 monthly 50 % core areas for 25 birds moving locally over 2.5 years. We also calculated daily, hourly, and total distances traveled for the five of these birds that engaged in long-distance movements. Mean (±SD) monthly home-range size was 253.6 ± 429.4 km2 and core-area size was 26.4 ± 49.7 km2. Consistent with expectations, space used by pre-adults increased with age and was season-dependent but, unexpectedly, was not sex-dependent. For all ages and sexes, home ranges and core areas were dominated by both forest & woodland and shrubland & grassland habitat types. When moving long distances, eagles traveled up to 1588.4 km (1-way) in a season at highly variable speeds (63.7 ± 69.0 km/day and 5.2 ± 10.4 km/h) that were dependent on time of day. Patterns of long-distance movements by eagles were determined by age, yet these movements had characteristics of more than one previously described movement category (migration, dispersal, etc.). Our results provide a context for differentiating among types of movement behaviors and their population-level consequences and, thus, have implications for management and conservation of golden eagle populations.

Birds use atmospheric updrafts to subsidize soaring flight. We observed highly variable soaring flight by Black Vultures (Coragyps atratus) and Turkey Vultures (Cathartes aura) in Virginia, USA, that was inconsistent with published descriptions of terrestrial avian flight. Birds engaging in this behavior regularly deviated vertically and horizontally from linear flight paths. We observed the soaring flight behavior of these 2 species to understand why they soar in this manner and when this behavior occurs. Vultures used this type of soaring mainly at low altitudes (