Friday, March 26, 2004

Vultures and Crows

There are a lot of crows (or are they ravens?) around this part of Canberra at the moment. I saw some on my way back to my car after work yesterday, near the old "East Block" (now Australian Archives) here in Inner South Canberra. And now one of these birds has just stopped by my window.

I noticed the heavy feathering around their necks, which made me wonder why scavengers like crows would not have bare necks like vultures. The usual explanation for the vulture's naked neck is that feathers would get too messy when the bird was feeding deeply inside carcases. So why don't crows also have bare necks? Instead they actually have heavily feathered necks.

I suppose the vulture story is true. The only other possibility that occurs to me is that maybe having bare necks would mean that other vultures competing for the same carcase would not be able to peck at their feathers (in the way that caged hens do to each other) - but I don't know if vultures do, in fact, fight over carcases.

[Note added later, 29 July 2004]  I just saw a documentary on vultures. It seems clear that most vultures fight over carcases, as expected. So the idea that they have bare heads and necks to avoid having feathers plucked out in fights seems possible.



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