Population trends of nesting Glaucous-winged Gulls, Larus glaucescens, in the southern Strait of Georgia, British Columbia

Abstract

Between 1986 and 1999, the number of nesting Glaucous-winged Gulls (Larus glaucescens) at fourteen breeding colonies declined by 31% (1610 nests) in the southern Strait of Georgia, British Columbia.Declines in the number of nesting pairs at surveyed colonies ranged between 6% and 81% with the smallest change occurring on the largest breeding colony in the study area.We suggest that Glaucous-winged Gull breeding population declines in the southern Strait of Georgia may be due to increased frequency of colony disturbance, in particular increased disturbance by Bald Eagles (Haliaeetus leucocephalus).