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The ivory gull ( Pagophila eburnea) is a small gull, the monotypic in the genus Pagophila. It is a resident breeding bird in the high Arctic and has a circumpolar distribution through Greenland, northernmost North America, and Palearctic.
This gull has traditionally been believed to be most closely related to either the , Sabine's gull, or Ross's gull. It differs anatomically from the other genera by having a relatively short tarsometatarsus, a narrower os pubis, and potentially more flexibility in skull kinetic structure. Structurally, it is most similar to the kittiwakes; however, recent genetic analysis based on mtDNA sequences shows that Sabine's gull is the ivory gull's closest relative, followed by the kittiwakes, with Ross's gull, little gull, and swallow-tailed gull sharing a clade with this group. Pagophila is maintained as a unique genus because of the bird's morphological, behavioural and ecological differences from these species.
Colloquial names from Newfoundland include slob gull (from "slob", a local name for drift ice) and ice partridge, from a vague resemblance to a ptarmigan.
This species is easy to identify. It has a different, more pigeon-like shape compared to the Larus gulls, an impression reinforced by its short legs. The adult has completely pure white plumage, lacking the grey back of other gulls. The thick beak is blue with a yellow tip (occasionally with a reddish tip), and the legs are black. The eyes are dark, with a narrow dark red orbital ring. Juvenile and first-winter birds have a dusky face and variable amounts of black flecking in the wings and tail; they take two years to attain full adult plumage, with second-winter yearlings having an intermediate plumage with smaller dark spots and a less dusky face, though some second-winters resemble adults. In flight, it has long, broad-based wings, with a strong wingbeat reminiscent of . Its flight call bird song is a harsh, tern-like keeeer. It has many other calls, including a warbling "fox-call" that indicates potential predators such as an arctic fox, polar bear, glaucous gull, or human near a nest; a "long-call" given with wrists out, elongated neck and downward-pointed bill, given in elaborate display to other ivory gulls during breeding, and a plaintive begging call given in courtship by females to males, accompanied by head-tossing. There are no differences in appearance across the species' geographic range.
During the winter, ivory gulls live near , or a large area of open water surrounded by sea ice. North American birds, along with some from Greenland and Europe, winter along the 2000 km of ice edge stretching between 50° and 64° N from the Labrador Sea to Davis Strait that is bordered by Labrador and southwestern Greenland. Wintering gulls are often seen on the eastern coasts of Newfoundland and Labrador and occasionally appear on the north shore of the Gulf of St. Lawrence and the interior of Labrador. It also winters from October through June in the Bering Sea and . It is most widespread throughout the polynyas and pack ice of the Bering Sea. It is also vagrant throughout coastal Canada and the northeastern United States, though records of individuals as far south as California and Georgia have been reported, as well as the British Isles, with most records from late November through early March. Juveniles tend to wander further from the Arctic than adults.
Illegal hunting may be one of the causes of the decline in the Canadian population, but the main cause of the species' global decline is the decline in sea ice due to human-induced global warming. Ivory gulls breed near to sea ice and the loss of ice makes it difficult for them to find enough food to feed their chicks. There is a high risk that the ivory gull could become the first vertebrate to become extinction due to human-induced global warming.
The species is classified by the International Union for Conservation of Nature as "Near Threatened".
Literary appearances
An ivory gull is the inspiration for the eponymous carving in Holling C. Holling's classic Newbery Medal-winning children's book, Seabird.
Further reading
(2025). 9780662432678, Committee on the status of endangered wildlife in Canada. . ISBN 9780662432678
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