Factors influencing farmland habitat use by shorebirds wintering in the Fraser River Delta, Canada

Like many other coastal regions of the world, open-soil agricultural lands in the Fraser River Delta provide roosting and feeding habitat for non-breeding shorebirds that supplements intertidal habitat. Focusing on dunlin (Calidris alpina pacifica), black-bellied plover (Pluvialis squatorola), killdeer (Charadrius vociferus), and their avian predators (raptors), diurnal and nocturnal high tide surveys were conducted across the non-breeding period, October–April (1998–2000). All three shorebirds showed positive relationships with laser leveling, and recent manure and fertilizer application. Day length was negatively related to field use by dunlin, but positively related for black-bellied plover and killdeer. Amount of recent precipitation was positively related to dunlin and negatively related to black-bellied plover and killdeer field use. Results suggest that providing a mosaic of different crop types, autumn mowing, laser leveling, application of fertilizer and manure, and minimizing habitat fragmentation through maintenance of large fields are habitat management strategies that may enhance farmland for shorebirds during the non-breeding season in this region.