Estimates of breeding season location for 4 mesic prairie bird species wintering along the Gulf Coast

Abstract

During the last 2 centuries, widespread declines have been observed in migratory species, and these declines have largely been linked to anthropogenic causes. Migrants move across multiple spatiotemporal scales with wide-ranging movements that can cross multiple jurisdictions. Consequently, conservation and management require the incorporation of these wide-ranging movements. However, for many nongame species, basic information on migration and wintering ecology is poorly known. Yellow Rails (Coturnicops noveboracensis), LeConte's Sparrows (Ammospiza leconteii), Nelson's Sparrows (A. nelsoni), and Sedge Wrens (Cistothorus stellaris) represent a diverse avian assemblage that breeds in prairie potholes, boreal forest, and coastal areas of northern and eastern Canada and winters in coastal prairies in the southern United States. We used a stable deuterium isotope (δ2Hf) analysis to assign breeding season locations for individuals captured wintering in the southeastern US. We obtained deuterium values from secondary feathers of birds spending the nonbreeding season from Oklahoma and Texas east to Florida. We found substantial differences in the δ2Hf values of Yellow Rails and Nelson's Sparrows, with birds wintering in Oklahoma and the western Gulf of Mexico having δ2Hf values that were probabilistically assigned to the western half of their breeding range, while birds wintering in Florida were probabilistically assigned to the eastern portion of their breeding range. LeConte's Sparrow breeding season assignments for birds wintering in Texas and Oklahoma overlapped. Sedge Wrens did not exhibit spatial variation in isotope values.