Thursday, March 18, 2010

Cormorants at Lake Ralphine


Howarth Park is home to a small colony of double-crested cormorants (Phalacrocorax auritus). They can be found fishing in Lake Ralphine and roosting in a couple of trees near the parking area.

I found a small rise across from one of the trees and watched and sketched cormorants while Chloe paid close attention to a California ground squirrel den nearby.

A young bird, recognizable by the lighter feathers on it’s breast and shoulders and all yellow beak, sat quite still on an upper branch with it’s neck vibrating soundlessly. Every now and then it would open it’s beak and continue to vibrate then close it back up while still vibrating.

After about an hour sketching birds sitting in the tree I was about ready to leave and had started packing up my gear when I heard a strange guttural sound. I looked up to see that a new cormorant, with white crests, had
landed on a branch next to one of the birds I’d been sketching, a bird with black crests. Black crest was making the strange sound and striking some rather suggestive poses, then the two birds began to dance about very clumsily on the rather flimsy branch. White crest moved closer and black crest sang louder. Much neck rubbing and head bobbing ensued and white crest flew off, only to return a few minutes later and they both danced a bit more until white crest again flew off. Not long after I saw white crest swimming on the lake in the company of several black-crested cormorants.

On land cormorants are awkward and slow-moving but underwater they are apparently fast and graceful. Unlike other water birds their feathers aren’t waterproof. As a consequence, once the bird is out of the water, you’ll often see them perched in trees with their wings spread wide to dry out.

Before DDT was banned in 1972, and PCB’s in 1976, the numbers of double-crested cormorants were profoundly diminished. Today, they’re so numerous and easily found that they’re considered a pest by many humans, especially those who fish.

Visit these sites for more information about double-crested cormorants:
Great Lakes Fact Sheet: The Rise of the Double-crested Cormorant on the Great Lakes: Winning the War Against Contaminants.
The Cormorant: The Devil Undisguised?; Dr. Tom Kazo, Ph.D. and Donna McVicar Cannon Kazo
Double-crested Cormorant;Wikipedia
Double-crested Cormorant;USGS

2 comments:

  1. How facinating, Debbie. When I first read your post I thought the white crests must be a freak. I don't remember ever seeing them. But I dug deep and found there are 4 subpecies in N. Am and only the Pacific Coast one gets white breeding crests ... and only sometimes. Other are black. I love it when I learn something new.
    I wish I had been sitting next to you and Chloe.

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  2. I love these drawings! They have the same kind of life-on-paper that you see in sketches by the classic Disney animators. Great great great, Debbie.

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