Distribution and prey of migratory shorebirds on the northern coastline of Singapore

Abstract

Singapore is a part of the East Asian-Australasian Flyway. The identification and continued protection of breeding, wintering and stopover sites within the flyway are essential for the survival of the flyway's migratory shorebirds. Here, we conducted 11 monthly (March 2003 to January 2004) high tide and low tide surveys of shorebirds in eight wetland sites (comprising mainly mangroves and intertidal mudflats) along the northern coast of Singapore. Internationally important numbers of common redshank, common greenshank and Pacific golden plover were found during the southward migration period in two sites. Other common shorebird species in our sites were: whimbrel, marsh sandpiper, common sandpiper, curlew sandpiper and lesser sand plover. Our data suggest that at least common redshank and Pacific golden plover used Singapore's wetlands for staging during southward migration. Two species, curlew sandpiper and lesser sand plover, did not use our sites for wintering, although the latter were found in other, sandier intertidal habitats in Singapore during countrywide winter counts. Mud coring and diet analysis revealed that polychaetes (in particular Family Nereididae) were dominant members of the benthic infauna, and were commonly depredated by shorebirds. The benthic infauna communities of the study sites were rich, with sites containing polychaetes belonging to 8-15 families. At the level of ponds or mudflat patches, we found a weak positive influence of nereidid polychaete density on shorebird abundance during low tides. Given the recent loss of natural habitats from Singapore's shores, we suggest that some of these sites be protected to serve conservation and educational purposes.