Migration Patterns of Black Brant in Boundary Bay, British Columbia

Abstract

Management strategies to address population declines and changing patterns of winter distribution of black brant (Branta bernicla nigricans) require a better understanding of timing of migration and mixing of migrant and wintering birds along the Pacific Coast of North America. We studied migration patterns of brant in Boundary Bay, British Columbia, using population censuses and sightings of individually marked birds during 1994-95 and 1995-96. There was no detectable turnover of individuals through the area in fall, and brant that first arrived in Boundary Bay in November and early December stayed until at least the first week of March. The first spring transients appeared in mid-February 1995 and 1 week later in 1996. The first spring departures coincided with the opening of brant huntin in Boundary Bay in both years suggesting that early migrants stayed for a shorter period of time in 1996. Spring brant hunting could have adverse effects on reproductive success if migrants depart early from staging areas and opportunities to compensate for decreased nutrient intake farther north are limited. The methods we used could be applied by managers in other areas to establish local hunting regulations appropriate for both wintering and spring staging populations.