The Black-tailed Gull Larus crassirostris is endemic to North-East Asia, breeding on sandy and rocky shores, islands and cliffs in the Sea of Japan/East Sea and wintering south as far as Hong Kong where it is a scarce visitor. It has not yet been recorded in Europe, but is an increasingly identified vagrant to North America, where it has appeared as far inland as the Great Lakes.

It is one of the few gull taxa to have a black tail - with a broad white terminal band - in adult plumage, and with their dark mantles, amber-yellow legs, and long, multi-coloured bill an adult Black-tailed Gull is pretty much unmistakeable. Non-adults are not so immediately identifiable, but they are long-winged gulls which always look distinctively “white-faced” even from a distance, have mostly black tails, darkish-grey mantles, and long, pale-green bils with an obvious dark tip.

The species is the commonest “large” gull in Japan in the winter, and dominates the harbours and ports where they are abundant scavengers. At Choshi it is by far the most numerous gull, and flocks of several hundred commonly swarm around incoming fishing boats (along with a few Vega and Slaty-backed Gulls).

To make download times shorter I’ve posted photos of adults here.

Non-adult Black-tailed Gulls Larus crassirostris
Choshi Port, Chiba Prefecture, Japan. 30 January 2006

 

 

 

 

 

 

 

All photographs copyright Charlie Moores