Thayer's Gull

Habitat

During the breeding season, Thayer's Gulls inhabit the Canadian high Arctic, nesting on rocky coastlines of islands. In winter, they can be found around bodies of water near the coast, including estuaries and protected bays. They also spend time far offshore, on freshwater ponds, and garbage dumps near the coast.

Behavior

Thayer's Gulls forage while swimming, walking, or flying. When foraging in flight, they drop to the water's surface or plunge just below it.

Diet

Omnivores, Thayer's Gulls eat small fish, crustaceans, mollusks, carrion, eggs, young birds, and garbage.

Nesting

The breeding characteristics of the Thayer's Gull are not well known. They probably start breeding at four years of age. Typical of gulls, they nest in colonies, often mixed with other gull species. The nest is located on the ledge of a rocky island cliff. Both sexes help build the nest, which is a low mound of plant material, matted down in the middle. The female usually lays 2, or occasionally 3, eggs, and both sexes help incubate the eggs and feed the young. Incubation and fledging periods are not known.

Migration Status

Most Thayer's Gulls nest in the central Canadian Arctic and move southwest to the Pacific coast in winter. The main migration of Thayer's Gulls through Washington in the fall occurs in September, with wintering numbers peaking in December and January. Washington and southern British Columbia are the core of their winter range. They begin leaving for their Arctic breeding grounds in late March, and by May, most are gone from our area.

Conservation Status

The nesting range of the Thayer's Gull has been protected from human impact due to its remoteness. No obvious population trends have been observed although more study is needed. There is still debate about whether the Thayer's Gull is truly a separate species, or if it is a subspecies of Iceland Gull. Some estimates have placed the breeding population at 8,000-12,000 birds, while others claim it is much greater, underestimated due to misidentification.

When and Where to Find in Washington

Thayer's Gulls are regular migrants and winter residents in Washington from October to March in offshore, coastal, and the Puget Trough regions. They are uncommon in April and early May, and are usually absent from mid-May until September. In winter, they can also be seen around the lower Columbia River and the Willamette Valley. The Port of Tacoma area and Ediz Hook at Port Angeles are excellent places to look for Thayer's Gulls. Agricultural areas and garbage dumps are good inland spots to look for them. In late February and early March, hundreds are attracted to the smelt runs on the lower Columbia River.

Washington Range Map

North American Range Map