Sunday, November 19, 2006

Cormorants

The first sighting of double-crested cormorants happened this past Friday, November 17. Most cormorants are seabirds, but this one lives and nests inland as well, here in the West as well as on the lakes of the Plains States east down the Great Lakes and St. Lawrence.

These birds are mostly black, goose sized but slender, and up to nearly a yard (9 dm) tall. Weight is up to 5.5 pounds (2.5 kg).These birds swim low on the water, seeming smaller because of this. From the water's surface they leap and then dive into the water to start chasing their fish prey. Surprisingly their feathers are not waterproof. It may be that this makes them less buoyant and faster underwater. They are often seen holding their wings outstretched apparently to dry them. This habit is unique among our local birds, and is no doubt needed without the waterproofing of most diving birds. Two small crests of feathers on the head lead to the name.

We first noticed them about 8 years ago, when they seemed to be strictly winter visitors. This past season they stayed into late Spring. This is one bird whose numbers are increasing, and is actually expanding its range, especially in the Midwest where introduced fish are providing food absent before. Despite much useful habitat for them, they are migrants here.

They seem wary and I haven't gotten a photo yet. As soon as possible a fresh photo or two will be posted.

In ancient times and up into the 1600's it was thought cormorants were a type of raven. The Ancient Greeks called it the bald raven, and the Romans sea raven. In the Germanic languages similar names were originally attached to these birds. Crested kinds were called shags for the topknot, but with the discovery of more species worldwide the distinction and the naming has not held. Indeed one widespread species, the great cormorant, has no crest in Europe but does in Asia.

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