On Thu, 20 Oct 1994, Dennis Paulson wrote:

> Albinistic mutations are common in birds and are
> usually taken by predators.

Now _that's_ a fascinating statement! Why should this happen? It's
obvious that some pure white birds will be more visible to predators than
their patterned relatives, but when I think about the chickadees hopping
around in the trees outside my window and compare them to chickadees with
a little more white, for instance, I can't see why one would be more
likely to be caught than another. You're really saying that predation is
a strong selective force in maintaining the plumage pattern of a species,
and that it's not just due to continuing sexual selection or some other
factor. Biologists sometimes ask about clear cases of natural selection,
and I don't think I've ever heard of anyone else making this particular
connection.

Burt Guttman guttmanb at elwha.evergreen.edu
The Evergreen State College Voice: 206-866-6000, x. 6755
Olympia, WA 98505 FAX: 206-866-6794