Wednesday, November 26, 2014

Common Tern (pǔtōng yàn-ōu)

Terns are often easily confused with gulls. Both terns and gulls are sea birds which are usually found along the coastlines of most countries. Both types of bird are largely white with long bills and similar black markings. A first time observer of a tern could easily be forgiven for confusing one of these birds for a gull. There are some fundamental differences between gulls and terns, though.

Terns are generally smaller than gulls with sharply pointed wings and deeply forked tails. Their bills come to a sharp point, whereas the bill of gull is rounded at the tip. Their legs are much shorter than a gull’s legs. Like gulls, terns are hunters of fish, and they can often be seen hovering above the surface of lakes and seas prior to diving in their attempts to capture their prey.

Many terns are highly-migratory. In fact, the world champion among the animal world for long migrations is the Arctic Tern, a North American species which migrates between the North and South poles, a distance of 20, 000 km., twice a year.

The Common Tern is also well traveled, moving between their breeding grounds in Northern China and wintering grounds in Southeast Asia. Common Terns are very nearly cosmopolitan and can be found throughout much of the Northern Hemisphere

The Common Tern will breeds in colonies that can exceed 5000 mated pairs of birds. They nest on the ground in freshwater and saltwater environments from coastal sea locations to freshwater lakes. They are quite adaptable and can use human structures as nesting sites as well. The female usually lays three eggs and will be very aggressive in protecting eggs and chicks. They have been known to attack humans who venture too close to their nests.

Photo by Tony Hisgett

No comments:

Post a Comment