Many tropical habitats experience pronounced dry seasons, during which arthropod food availability declines, potentially limiting resident and migratory animal populations. In response to declines in food, individuals may attempt alter their space use enhance access resources, but be socially constrained from doing so by con- heterospecifics. If social constraints exist, should result decreased body condition. birds, correlational evidence suggests a link between condition migration timing....

The importance of understanding the geographic distribution full annual cycle migratory birds has been increasingly highlighted over past several decades. However, difficulty tracking small between breeding and wintering areas hindered progress in this area. To learn more about Kirtland's warbler Setophaga kirtlandii movement patterns throughout cycle, we deployed archival light‐level geolocators across their range Michigan. We recovered devices from 27 males analyzed data within a Bayesian...

Abstract Background Weather can have both delayed and immediate impacts on animal populations, species evolved behavioral adaptions to respond weather conditions. has long been hypothesized affect the timing intensity of avian migration, radar studies demonstrated strong correlations between broad-scale migration patterns. How affects individual decisions about initiation migratory flights, particularly at beginning remains uncertain. Methods Here, we combine automated radio telemetry data...

How animals use space has fundamental behavioral and ecological implications. Utilization distributions are among the most common methods for quantifying have advanced our knowledge of animal ecology in a variety ways. However, until recently, they were limited to 2 spatial dimensions (2D), despite fact that taxa their environments all 3 (3D). We (1) created 3D utilization via multivariate kernel density estimator, (2) adapted overlap indices with data, (3) estimated minimum sample sizes...

Abstract Migratory animals experiencing substantial change in diet and habitat across the annual cycle may have corresponding shifts host‐associated microbial diversity. Using automated telemetry radio tags to recapture birds, we examined gut microbiota structure same population often individual of Kirtland's Warblers ( Setophaga kirtlandii ) initially sampled on their wintering grounds The Bahamas subsequently resampled within breeding territories Michigan, USA. Initial sampling occurred...

Abstract The illegal trade of wild birds is a large threat to biodiversity and sellers often use social media traffic wildlife. By monitoring characterizing the domestic on Facebook, we show that this e-commerce remains widespread throughout Argentina, despite decrease in activity 2023 compared 2017, highlighting persistence magnitude issue. In found 96,354 users 127 buying/selling groups 18 provinces, which 61% were public. 2023, 58,647 76 14 66% Analyzing one group 2017 two 67 bird species...

ABSTRACT Species are considered conservation‐reliant when their continued existence is dependent on human assistance. Conservation reliance challenges the conservation community in terms of ability to sustain funding and public‐private partnerships needed for indefinite management. Although increased critical, reducing through adaptive management represents an attractive alternative. We used a large‐scale ecological experiment as case study use reduce reliance. For >40 years, United...

Each spring and fall billions of songbirds depart on nocturnal migrations across the globe. Theory suggests that should migration shortly after sunset to maximize their potential for nightly flight duration or time departure with emergence celestial cues needed orientation navigation. Although captive studies have found during a narrow window sunset, observational wild birds later more asynchronously relative than predicted.We used coded radio tags automated radio-telemetry estimate nearly...

Researchers studying avian space use, dispersal, survival, and migration select tracking tags that optimize tag size (dimensions) mass relative to the focal species minimize risk birds as they move fly. Here we argue antenna length transmitter color are also critical design parameters must be considered. Based on a review of songbird literature unpublished cases, found most cases entanglement, which can result in bird injuries death, occurred with longer antennas (>13 cm). However, such...

Theory predicts that maximal fitness is obtained by individuals who begin to breed immediately upon reaching sexual maturity. However, delayed breeding occurs regularly in some taxa, and birds mammals most often associated with long lifespan and/or limited access suitable habitats. Delayed not expected among relatively short‐lived species such as migratory passerine birds, but this assumption remains untested many species. Here we quantify age at first reproduction an eastern kingbird...

ABSTRACT Among migratory passerines, the first birds to arrive on breeding grounds are usually older males. Early arrival by may be driven experience, age-dependent changes in body condition, access resources during nonbreeding period, or latitudinal segregation age. Males earlier than females (protandry) because males maintain better condition due greater winter, selection favors early arriving that acquire best territories experience enhanced mating opportunities. During a 4-yr study...

Abstract Sexual habitat segregation during the wintering period is a widespread phenomenon and has important implications for ecology conservation of migratory birds. We studied Black-and-white Warblers (Mniotilta varia) in second-growth scrub old-growth mangrove forest Jamaica to quantify sexual explore whether patterns occupation have consequences on physical condition. used this information along with body size analysis simulated territorial intrusions assess behavioral dominance or...

Understanding how migratory animals respond to spatial and temporal variation in habitat phenology is critical for identifying selection pressures tradeoffs at different life history stages. We examined the influence of breeding on timing eastern willet (Tringa semipalmata semipalmata) across a latitudinal gradient sites east coast North America. To describe migration timing, we deployed light-level geolocators willets New Jersey, Massachusetts Maine, USA evaluated additional data...

Abstract By combining all available banding and tracking data, we found that Willets (Tringa semipalmata) have a strong migratory connectivity between breeding nonbreeding locations at the range-wide subspecies levels, exposing two to varying threats such as hunting for eastern semipalmata climatically-altered coastal habitats both subspecies. We western inornata) primarily used along Pacific Coast of United States, although their reported range extends US Atlantic Gulf Coasts Central South...

ESR Endangered Species Research Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsSpecials 38:79-89 (2019) - DOI: https://doi.org/10.3354/esr00937 Revising wintering distribution and habitat use of Kirtland’s warbler using playback surveys, citizen scientists, geolocators Nathan W. Cooper1,*, David N. Ewert2, Joseph M. Wunderle Jr.3, Eileen H. Helmer3, Peter P. Marra1 1Migratory Bird Center, Smithsonian...

Understanding the consequences of global change for migratory birds is complex as individuals are exposed to diverse conditions and experiences that interact across their annual cycle. Species distribution models (SDMs) can serve a powerful tool help us understand how species distributions respond change. However, SDMs applied may fail capture effects seasonal variability on distributional changes, likely due lack appropriate modeling frameworks limited data availability hamper inclusion...

ABSTRACT Devising methods for sampling arthropods presents many challenges, including understanding possible differences in results obtained by different individuals (precision), investigating between estimates and the actual variable of interest (accuracy), assessing effort cost a given method (efficiency). We assessed precision, accuracy, efficiency sweep netting branch clipping, two common arthropods, mangrove second-growth scrub forests Jamaica, West Indies, 2009. Three used both...

Cooper, N. W., D. Ewert, K. R. Hall, S. M. Rockwell, Currie, J. Wunderle, Jr., White, and P. Marra. 2018. Resighting data reveal weak connectivity from wintering to breeding grounds in a range-restricted endangered long-distance migratory passerine. Avian Conservation Ecology 13(1):9. https://doi.org/10.5751/ACE-01159-130109

The relative importance of predators and resources (i.e. food) for the dynamics migratory bird populations is poorly known. Resource availability may be more likely in resource poor environments, but given that nest failure most systems due mainly to predation, predator effects predominate. We document a rapid decline an isolated eastern kingbird Tyrannus tyrannus population breeding Great Basin Desert Oregon, USA, evaluate whether it was driven by limited food (water ~ food), or first‐year...