Estimating Migratory Connectivity of Gray Catbirds (Dumetella carolinensis) using Geolocator and Mark–recapture Data

Abstract

Resumen.-Comprender la conectividad entre poblaciones reproductivas y no reproductivas de aves migratorias es fundamental para nuestro conocimento de fenómenos biológicos como la dinámica poblacional y la dispersión. Además, nuestra habilidad para cuantificar la conectividad migratoria tiene consecuencias inevitables para la conservación y el manejo de especies que utilizan distintas localidades geográficas. La tecnología está causando avances rápidos en nuestra habilidad para seguir aves a lo largo de su ciclo anual y para recolectar datos sobre el grado de conectividad entre poblaciones reproductivas y no reproductivas. Combinamos dos métodos directos, marcado-recaptura (n = 17) y geolocalización (n = 6), para estimar la conectividad migratoria de poblaciones reproductivas y no reproductivas de Dumetella carolinensis. Los datos de los geolocalizadores indican que las aves que crían en el Atlántico medio pasan el invierno en Cuba y el sur de Florida. Los datos de marcado-recaptura apoyaron nuestros resultados basados en geolocalizadores pero además brindaron una perspectiva espacial más amplia al documentar que las poblaciones del Atlántico medio y del medio oeste ocupan localidades geográficas distintas durante el período no reproductivo. Esta investigación resalta la importancia de los geolocalizadores y de otras herramientas para incrementar nuestro conocimiento sobre la conectividad migratoria. Finalmente, nuestros resultados destacan el valor potencial de los datos de marcado-recaptura del U.S. Geological Survey (USGS) Bird Banding Laboratory, que con frecuencia son subutilizados en investigaciones ornitológicas.-448 - Abstract.-Understanding the connectivity between breeding and nonbreeding populations of migratory birds is fundamental to our knowledge of biological phenomena such as population dynamics and dispersal. Moreover, our ability to quantify migratory connectivity has inevitable consequences for both conservation and management of species that utilize distinct geographic locations. Technology is rapidly advancing our ability to track birds throughout the annual cycle and to collect data on the degree of connectivity among breeding and nonbreeding populations. We combined two direct methods, mark-recapture (n = 17) and geolocation (n = 6), to estimate the migratory connectivity of breeding and nonbreeding populations of Gray Catbirds (Dumetella carolinensis). Data from geolocators show that birds breeding in the Mid-Atlantic overwinter in both Cuba and southern Florida. Mark-recapture data supported our geolocator results but also provided a broader spatial perspective by documenting that Mid-Atlantic and Midwestern populations occupy distinct geographic localities during the nonbreeding period. This research underscores the importance of geolocators, as well as other tools, to advance our understanding of migratory connectivity. Finally, our results highlight the potential value of U.S. Geological Survey (USGS) Bird Banding Laboratory mark-recapture data, which are often underutilized in ornitho...

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Continent-wide tracking to determine migratory connectivity and tropical habitat associations of a declining aerial insectivore

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How do en route events around the Gulf of Mexico influence migratory landbird populations?

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