Segregation of Brent Geese Branta bernicla wintering and staging in Puget Sound and the Strait of Georgia

Abstract

The distribution of Brent Geese from different breeding stocks was studied in Puget Sound and the Strait of Georgia from autumn 1987 to spring 1988.  Breeding origins were determined from the belly colour of free-living and shot Brent, from sightings of colour-ringed birds, and from ring recovery information (including recoveries from pre-1987 bandings).  The largest wintering flock (c.15,000) during 1987-88 inhabited Padilla Bay, Washington, and was made up almost exclusively of grey-bellied Brent from the western Canadian High Arctic.  The few other wintering flocks were smaller (<100-1400), occurred almost entirely in Washington State, and were composed of dark-bellied birds (Black Brant) originating from the western Canadian Low Arctic and Alaska.  During spring migration, Low Arctic Brent from Canada and Alaska staged along the east coast of Vancouver Island, British Columbia.  This high degree of segregation between High and Low Arctic Brent will allow more refined management of the individual stocks.