The Black-tailed Gull (Larus crassirostris) is a medium-sized (46cm) gull, with a wingspan of 126-128 cm. The bird is resident in East Asia, including China, Japan and Korea. It is a vagrant to Alaska and northeastern North America.

It has yellow legs and a red and black spot at the end of the bill. This gull takes 4 years to reach full adult plumage. As the name suggests, it has a black tail. The bird has a cat-like call, giving it its Japanese name "? Umineko, "Sea cat" and Korean name "? Gwaeng-yi gull, which means "cat" gull.

The Black-tailed Gull feeds mainly on small fish, molluscs, crustaceans and offal. It often follows ships and commercial fishing fleets. It does steal food from other seabirds.

It is a colonial nester, with colonies forming in mid-April. 2-3 eggs are laid by early June. Incubation lasts approximately 24 days.

A rare visitor to the United States, a black-tailed gull was spotted from Burlington, Vermont, in October 2005. Pictures from that sighting can be seen here

Black tailed gull, immature plumage