Black-tailed Gulls (Larus Crassirostris)
The Black-tailed Gulls (Larus crassirostris) are residents of East Asia, including China, Japan and Korea.
They are vagrants in Alaska and northeastern North America.
These gulls are rare visitors to the United States, a black-tailed gull was spotted from Burlington, Vermont, in October 2005.


Description
The Black-tailed Gull is a medium-sized (46 cm) gull, with a wingspan of 126-128 cm.
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.
It has a black tail – as suggested by its name.
Calls / Vocalizations
The Black-tailed Gull has a cat-like call, giving it its Japanese name — Umineko, “Sea cat” and the Korean name — Gwaeng-yi gull, which means “cat” gull.
Diet / Feeding
The Black-tailed Gull feeds mainly on small fish, mollusks, crustaceans scraps, and carrion. It often follows ships and commercial fishing fleets. It also steal food from other seabirds.
Breeding / Nesting
Like other gulls, the Black-tailed Gull is a colonial nester, with colonies forming in mid-April. 2-3 eggs are laid by early June.
The incubation is undertaken by both parents and lasts approximately 24 days.