SITE FIDELITY AND LOCAL MOVEMENTS OF MIGRATING WESTERN SANDPIPERS ON THE FRASER RIVER ESTUARY

Abstract The Western Sandpiper (Calidris mauri) is the most numerous shorebird on the Pacific coast of North America during spring migration. Twenty-six sandpipers carrying miniature radio transmitters on northward migration across the Fraser River delta, British Columbia, remained on or near to the section of beach where they were first detected through their entire stay. They traveled about 4–6 km each day, following the tide up and down the beach. Although some Western Sandpipers were present on all beaches of the delta, our results suggest that individuals do not roam widely once they settle. The widespread distribution of sandpipers in mud, marsh, and sand habitats suggests that all regions of the Fraser River delta are required to support the large number of Western Sandpipers during spring migration.