General
Black-tailed Gull: Large gull with white head, neck, breast, and underparts; light charcoal-gray wings and back; large yellow bill with black ring above red tip; pale yellow eyes with red orbital ring; short yellow legs and feet; long wings; telltale short black tail with white edge.
Range and Habitat
Black-tailed Gull: Nomadic. Primarily Asian straggler, casual to coastal Alaska and northeastern North America, as far south as Virginia; has been seen in San Diego Bay.
Breeding and Nesting
Black-tailed Gull: Monogamous, colonial. Two to three green to brown eggs with dark spots are laid in a nest of dry grass, on ledges, slopes, and small cliffs hidden by vegetation. Incubation ranges from 24 to 27 days and is carried out by both sexes; young fed by both sexes. First flight at 30 to 40 days.
Foraging and Feeding
Black-tailed Gull: Frequents seashores; often forages while wading, swimming, or walking; eats small fish, especially smelt and greenlings; also eats insects, crustaceans, carrion, and refuse. Will catch insects or other food in flight.
Vocalization
Black-tailed Gull: Very low "kaoo-kaoo."
Similar Species
Black-tailed Gull: Belcher's Gull has darker blackish upperwings and mantle, dark eyes with yellow orbital ring, and longer legs. California Gull has billl with red gonys spot but no red tip and almost no black, dark eye, and lighter mantle.