Black-tailed gull (Mòng bể đuôi đen, Larus crassirostris) 

The black-tailed gull (Larus crassirostris) is a gull native to shorelines of East Asia.
This bird species is resident to coastlines of the East China Sea, Japan, Manchuria and the Kuril Islands.

Charadriiformes, Charadriidae, Charadrius: Late Latin word for a yellowish bird mentioned in the fourth-century Vulgate; from Ancient Greek kharadrios a bird found in ravines and river valleys (kharadra, "ravine").

Laridae:from Ancient Greek laros or Latin larus, which appears to have referred to a gull or other large seabird.

The genus name Larus is from Ancient Greek laros or Latin larus, which appears to have referred to a gull or other large seabird.

Crassirostris is from Latin roots: crassus (thick/fat/stout) + rostrum (beak/snout).