Black-tailed gull

The black-tailed gull (Larus crassirostris) is a type of gull that lives near the shorelines of East Asia. This bird is known for its beautiful appearance and interesting behaviors. Gulls like the black-tailed gull are often seen near the ocean, lakes, and rivers, where they search for food. These birds play an important role in their environment by helping to keep the ecosystem healthy. Learning about birds such as the black-tailed gull helps us understand and appreciate the natural world around us.

Description

The black-tailed gull is a medium-sized bird, about 46 cm long with a wingspan of 126–128 cm. It has yellow legs and a special mark — a red and black spot — at the end of its bill. Both male and female black-tailed gulls look the same, but males are a bit larger. It takes four years for this gull to grow its full adult feathers. As its name suggests, it has a black tail. The bird makes a call that sounds like a cat, which is why it is called umineko ("sea cat") in Japan and gwaeng-yi gull ("cat" gull) in Korea. In Hachinohe, Japan, the sounds of these gulls are considered one of the important natural sounds of the country.

Distribution and habitat

The black-tailed gull lives along the coastlines of the East China Sea, Japan, Manchuria, and the Kuril Islands. It sometimes appears far away from its home, like in Alaska and North America, and has even been seen in the Philippines.

In Japan, this bird is very common. It nests from Hokkaido to Western Kyushu and has sometimes caused plane delays at Haneda Airport in Tokyo. One special place for these birds is Kabushima in Hachinohe, Aomori. For over 700 years, people there have respected the black-tailed gull. Every summer, more than 40,000 of these birds nest near a Shinto shrine and are very friendly to people. They are a big attraction for visitors.

The bird is also common along the shores of Korea and on many islands. There are over 20,000 black-tailed gulls on Liancourt Rocks, and their numbers keep growing because there are no animals that hunt them. In 2008, the bird was chosen as a mascot for Liancourt Rocks. Other places where they nest include Nando and Hongdo islands.

It is very rare to see a black-tailed gull in the United States. One was spotted in Burlington, Vermont in October 2005, and it has been seen a few times in Illinois.

Ecology

The black-tailed gull mainly eats small fish, molluscs, crustaceans, scraps, and carrion. These birds often follow ships and fishing boats and sometimes take food from other seabirds. They live in groups and start nesting in mid-April, laying 2–3 eggs by early June. It takes about 24 days for the eggs to hatch.

Black-tailed gulls make many different sounds to talk to each other. Young birds can recognize their parents by their voice and looks about 10 to 15 days after hatching. They also have special calls to warn of danger, show aggression, or talk to each other when they are together. One common sound is a cat-like "mew call" used often when coming back to the nest with food or taking care of their young.

Images

• Black-tailed Gull, immature plumage

• Black-tailed Gull in Tokyo Bay

• Black-tailed Gull in Hachinohe, Aomori

• Black-tailed Gulls at entrance to Kabushima Shrine