CONFIRMATION OF ELLIPTIC MIGRATION IN A POPULATION OF SEMIPALMATED SANDPIPERS

Using measurements and observations of marked birds we verified the el liptical migration route of some Semipalmated Sandpipers. Bill lengths of spring migrants in Saskatchewan averaged longer than those of fall migrants, suggesting a mix of short-billed western and longer-billed central Arctic breeders in the spring, and a greater proportion of wes tern breeders in the fall. A number of birds captured during spring mi gration in Saskatchewan (presumably central Arctic breeders) were foun d staging in eastern Canada in the fall. In contrast, no birds capture d during fall migration in Saskatchewan were seen north of Maryland on the east coast in the fall. Other Saskatchewan spring migrants (presu mably western breeders) returned south through the prairies. These fin dings emphasize the inter-relatedness of major migratory staging areas during spring and fall migration for this species.