Winter abundance and distribution of shorebirds and songbirds on farmlands on the Fraser River delta, British Columbia, 1989-1991

The winter distribution of common shorebirds and songbirds in farmlands on the Fraser River delta, British Columbia, is described for 1989-1991. Most Dunlin (Calidris alpina) and Black-bellied Plovers (Pluvialis squatarola) roosted in large flocks (median=6450 birds) on beaches during high tides. Smaller flocks (median=507 birds) that flew tofarmlands settled in ploughed fields, turf grass and pasture within 2 km of Boundary Bay. Dunlin and Black-bellied Plovers that flew to farmlands mostly foraged there between November and March. The seasonal use of farmlands by Dunlins is probably a trade off between food energy requirements and predation risk from falcons. Forty-five speciesof songbirds were recorded in farmland hedgerows. Song Sparrow (Melospiza melodica), American Robin (Turdus migratorius), White-crowned Sparrow (Zonotrichia leucophrys), and European Starling (Sturnus vulgaris) accounted for over two-thirds of all birds recorded. Shrub hedgerows supported 30 species with a mean of 7.9 individuals detected percensus stop versus 40 species with a mean of 18.0 individuals per census stop in tree-hedgerows. [ABSTRACT FROM AUTHOR]