Habitat and space use by long-billed curlews (Numenius americanus) in California’s Central Valley

A significant number of the world's population of long-billed curlews (Numenius americanus) winter in California's Central Valley amidst a variety of human-altered habitats. I used satellite telemetry to study non-breeding habitat use and space use of 10 (5 male, 5 female) long-billed curlews over three years. Individual curlews varied in size of their home range and core use areas. Males had significantly smaller home ranges and core use areas than females. Curlews showed fidelity to their home ranges from year to year, but use of individual fields within those home ranges changed by season and year. Male curlews exhibited stronger site fidelity than females. I used resource utilization functions to examine variation in individual habitat use. Curlews used a variety of agricultural habitats, including alfalfa, irrigated pasture, rice, and field crops such as wheat. In the late summer and fall curlews used alfalfa and pasture more than other available crop types. This trend continued into the winter, but curlews also increased their use of other crop types. This study represents a first opportunity to follow individual shorebird movements and habitat use throughout the non-breeding season over multiple annual cycles.