Sunday, June 22, 2014

Pelicans and Cormorant

On 18 May 2014, John Holden and I encountered a Double-crested Cormorant that seemed to be conducting a chorus of silent American White Pelicans. All but the pelican on the far left appeared to be following the gaze of their conductor. “Why do cormorants hold their wings out like that?” asked John. Like many a professor, I answered and then verified my reply later. Turns out that cormorants have relativelty little preening oil with which to water-proof their feathers. To keep dry, cormorants have to hang their feathers out to dry. Allaboutbirds.com continues, “though this seems like a problem for a bird that spends its life in water, wet feathers probably make it easier for cormorants to hunt underwater with agility and speed.”
The pelicans, who were really not paying much attention to the cormorant, performed various maintenance behaviors. It looks like a pelican has to be an adept acrobat to scratch its neck, all the while standing on one leg and not falling forward from the weight of its bill. The horn on the White Pelican’s bill, by the way, is present only during breeding season. The horn is present on both sexes and is shed after egg laying. As I have written previously, the exact function of the horn is unknown.

2 comments:

  1. I knew this fact about cormorants and have shared it with my kids. But then we saw a flock flying on a rainy day and my oldest (10 years) asked "How can they be flying if they need to dry out their feathers?"

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    1. Good question. I suppose the answer is they just were not wet enough not to be able to fly. Possibly a more serious question would be how a wet cormorant avoids hypothermia...

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