Meeting Abstract

P2.31  Tuesday, Jan. 5  Who travels where: unraveling population structure, migratory connectivity, and song patterns in Western Sandpipers SCHWARZ, B.**; LANK, D.B.; IRWIN, D.E.; Simon Fraser University, Canada; Simon Fraser University, Canada; University of British Columbia, Canada bschwarz@sfu.ca

Western Sandpipers (Calidris mauri) are long-distance migrants that breed in Western Alaska and Eastern Siberia. In the winter they migrate south to sites along the west coast from southern North America to northern South America. A small part of the population winters on the east coast and in the Caribbean. Data on morphological differences gathered on various wintering grounds indicate that different subpopulations may exist in this species. In addition, juveniles that winter further south seem to show a profoundly different life history than those wintering further north in that they are more likely to remain on the non-breeding grounds throughout the summer and not reproduce until their second year. We are currently investigating the genetic population structure of Western Sandpipers. We will determine the degree of genetic variation between different breeding sites and develop suitable markers for each site. We will then use these markers to determine the breeding origin of birds on the wintering grounds and at migratory stopover sites to detect possible patterns of migratory connectivity. If population differentiation exists in this species, it might be maintained through differences in mating vocalizations. During the breeding season, male Western Sandpipers perform display flights during which they emit a species-specific song. We will analyze recordings from major breeding sites to investigate whether songs differ between these sites. We will then compare acoustic and genetic data sets to investigate whether population differentiation in shorebirds might be maintained by similar mechanisms as those shown for songbirds.