Glaucous-winged Gull
(Larus glaucescens)

Overview

Summary

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Glaucous-winged Gulls breed along the Pacific coast from Alaska to Oregon and most remain close to their breeding areas in winter. Populations are higher than they were historically, having recovered from a low point after the cessation of egg harvesting in the early 1900s (Blight et al. 2015). They are a familiar sight in developed areas. Breeding Bird Survey results suggest little change in the abundance since 1970, while winter surveys suggest range-wide declines since the 1970s, and in British Columbia since the 1990s. Counts of nesting birds at breeding colonies corroborate these more recent declines, potentially related to increasing disturbance and predation by Bald Eagles at breeding colonies. Although the abundance of Glaucous-winged Gulls in Canada remains above historic levels, the best assessment of these varied results suggests a decrease in abundance in Canada since about 1970. This species has been identified as a priority for conservation and/or stewardship in one or more Bird Conservation Region Strategies in Canada.

Designations

Population status

Population estimate

Distribution maps

• BirdLife International / NatureServe

Migration strategy, occurrence

Responsibility for conservation of world population

Conservation and management

Declining numbers of Bald Eagles and increasing availability of garbage may have contributed to the increases in Glaucous-winged Gull abundance observed until the 1990s (Hayward and Verbeek 2008). Conversely, increasing disturbance at nesting colonies from recovering Bald Eagle populations is believed to be contributing to the recent declines in the Strait of Georgia (Blight et al. 2015). Also, studies have documented a significant decline in egg size, clutch size and productivity; this declining investment in reproduction may reflect changes in the availability of their marine prey and an increasing reliance on lower quality non-fish food, which may contribute to observed declines (Blight et al. 2015, Blight 2011).

Bird conservation region strategies

Environment and Climate Change Canada and partners have developed Bird Conservation Region Strategies in each of Canada’s Bird Conservation Regions (BCRs). In these strategies, selected species are identified as priorities for one or more of the following reasons:

• conservation concerns (i.e., species vulnerable due to population size, distribution, population trend, abundance, or threats)
• stewardship responsibilities (i.e., species that typify the regional avifauna or have a large proportion of their range or population in the sub-region)
• management concerns (i.e., species that require ongoing management because of their socio-economic importance as game species, or because of their impacts on other species or habitats)
• other concerns (i.e., species deemed a priority by regional experts for other reasons than those listed above or because they are listed as species at risk or concern at the provincial level)

Select any of the sub-regions below to view the BCR strategy for additional details.

References

• Blight, L.K. 2011. Egg production in a coastal seabird, the Glaucous-Winged Gull (Larus glaucescens), declines during the last century. PLoS ONE 6:e22027. Blight, L.K. 2011. Egg production in a coastal seabird, the Glaucous-Winged Gull (Larus glaucescens), declines during the last century. PLoS ONE 6:e22027. (Link)
• Blight, L.K., M.C. Drever, and P. Arcese. 2015. A century of change in Glaucous-winged Gull (Larus glaucescens) populations in a dynamic coastal environment. Condor 117:108-120. Blight, L.K., M.C. Drever, and P. Arcese. 2015. A century of change in Glaucous-winged Gull (Larus glaucescens) populations in a dynamic coastal environment. Condor 117:108-120. (Link)
• Bower, J.L. 2009. Changes in marine bird abundance in the Salish Sea: 1975 to 2007. Marine Ornithology 37:9-17. Bower, J.L. 2009. Changes in marine bird abundance in the Salish Sea: 1975 to 2007. Marine Ornithology 37:9-17. (Link)
• Hayward, J.L. and N.A. Verbeek. 2008. Glaucous-winged Gull (Larus glaucescens). The Birds of North America Online (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York. Hayward, J.L. and N.A. Verbeek. 2008. Glaucous-winged Gull (Larus glaucescens). The Birds of North America Online (A. Poole, Ed.). Cornell Lab of Ornithology, Ithaca, New York. (Link)
• Sullivan, T.M., S.L. Hazlitt and M.J.F. Lemon. 2002. Population trends in nesting Glaucous-Winged Gull, Larus glaucescens, in the south Strait of Georgia, British Columbia. Canadian Field-Naturalist 116:603-606.
• Vermeer, K. and K. Devito. 1989. Population trend of nesting Glaucous-winged Gulls in the Strait of Georgia. pp. 88-93 in: The Ecology and Status of Marine and Shoreline Birds in the Strait of Georgia, British Columbia. Vermeer, K. and R.W. Butler, Eds. Special Publication of the Canadian Wildlife Service, Ottawa, ON.