Censuses of Black Brant at Yaquina Estuary, Lincoln County, Oregon

Abstract

Black Brant (Branta bernicla nigricans) had two different seasonal patterns of occurrence at Yaquina Estuary. At embayment areas with eelgrass (Zostera marina), Brant typically arrived between October 22 and November 4, Brant numbers progressively climbed in November, Brant abundance in December-January was relatively constant, and Brant numbers often fluctuated greatly during spring migration in February-April. At a site near the estuary mouth where there was little eelgrass, Brant customarily only appeared during spring migration. About 300-500 Brant wintered at the Yaquina in the 1980's, and usually fewer than 700 Brant were counted during spring migration.