- Larus glaucescens
Identification
61–68 cm (24-26¾ in)
A sturdy robust gull; about the size of the Herring Gull or a bit larger and stockier looking.
Adults have a pale gray mantle and wings, about the same shade as a Herring Gull or a bit darker. The wing tips are patterned with gray. In pure birds this is about the same shade as the rest of the wing. Those with darker primary tips indicate some hybrid origin. The majority of adults have dark brown eyes but a few can show dirty yellow to quite clear yellow eyes as well. The bill is large and thick with pronounced bulbous gonys. There is a red gony spot near the tip of the lower mandible. It's legs are fleshy pink, like those of Herring, Western and Glaucous Gulls. It's head is rather large but rounded, this as well as the dark eye give it a rather gentle and unimposing expression.
In winter, it's head is smudged with gray-brown. This is much less mottled looking than in other gulls, often appearing as if it were smeared on sometimes in thin lines. The bill becomes a pale straw color like the Herring Gulls but unlike the Western Gulls which remains bright yellow year round. There is often a thin zig-zag band near the end of the bill at this time as well. In flight, Glaucous-Winged looks very much like a Glaucous Gull with it's pale plumage, powerful flight and often translucent wing tips from below.
First winter birds are rather uniformly gray with fine mottling over most of the plumage. Some take on a pale buff color and can often resemble the other white-winged gulls. Glaucous-Winged however usually has a cold gray undertone even on buff colored birds. The bill is usually all black but a few can show a pinkish base.
Second winter birds resemble first winter most of the time but often show a pale gray saddle. Many are often very pale buff and superficially resemble Iceland Gull. Often by late spring they may develop distinctive dark patches on the scapulars. The bill usually has a pinkish base, fading to black near the tip.
Third winter birds are much like adults but the bill is often bi-colored or even tri-colored; having a broad black band near the tip and being mostly pinkish. Sometimes the yellow of adulthood begins to show as well. There is still some buff coloring, mainly on the underparts and wing coverts and around the head and neck.
In all plumages pure Glaucous-Winged Gull is uniformly pale without showing any contrasting dark or light areas.
Hybrid: Often hybridizes with the Western Gull, a combination known as the "Olympic Gull. Gallery Image"
Distribution
Bering Sea to north-western Oregon; winters to Japan and north-western Mexico
Taxonomy
This is a monotypic species.
Habitat
Saltwater shorelines. Breeds in estuaries and bays and on rocky islands.
Behaviour
Breeding
Usually nests in high densities in colonies on offshore islands, although it has recently started nesting on roofs of waterfront buildings. Usually monogamous with pairs remaining together for several years. Each pair can produce up to three young in a season. Eggs are greenish marked with brownish blotches and spots/
Diet
A varied diet, including offal, shellfish and road kill.
Vocalisation
Long call has the first two sounds drawn out and coarser than the others; the sounds become progressively shorter at the end. A variety of shorter calls, similar to other large gulls have been described.
Movements
Some birds remain on territory all winter but many move south. Some wander south of the Bering Sea into the open ocean in the North Pacific.
References
- Clements, J. F., T. S. Schulenberg, M. J. Iliff, S. M. Billerman, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2019. The eBird/Clements Checklist of Birds of the World: v2019. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/
- Burger, J., Gochfeld, M. & Garcia, E.F.J. (2020). Glaucous-winged Gull (Larus glaucescens). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/53976 on 9 March 2020).
- Hayward, J. L. and N. A. Verbeek (2020). Glaucous-winged Gull (Larus glaucescens), version 1.0. In Birds of the World (S. M. Billerman, Editor). Cornell Lab of Ornithology, Ithaca, NY, USA. https://doi.org/10.2173/bow.glwgul.01
- Howell, S.N.G. and Dunn, J. (2007) A Reference Guide to the Gulls of the Americas. Peterson Field Guides, New York.
- Malling Olsen, K. & Larsson, H. (2003) Gulls of Europe, Asia and North America. Christopher Helm, London.
- BirdForum Member observations
Recommended Citation
- BirdForum Opus contributors. (2024) Glaucous-winged Gull. In: BirdForum, the forum for wild birds and birding. Retrieved 23 April 2024 from https://www.birdforum.net/opus/Glaucous-winged_Gull
