Tweeters-

Speaking of albinism

I recently received a call from a local birder (Lacey, WA) who has had an
"albino" Evening Grosbeak and an "albino" sparrow sp. at his feeder this
year. Next, I received a report of an "albino" swallow in a mixed group of
barn, cliff, and violet-green swallows at the mouth of the Nisqually river.
The sighting took place a couple of weeks ago and the reporter is an
experienced and reliable observer. Finally, as I was driving home last
night, there was a flock of about 25 double-crested cormorants perched on a
tree beside Percival Cove (at the mouth of Percival Creek in Olympia). One
of the birds was mostly white with dark grey to black shoulder patches and
greyish streaking on the head. This seemed to be unusual coloring for this
bird (but I am not completely familiar with d-c cormorant life history).

Anyway, what are tweeters thoughts re: albinism and/or these specific
reports?

Scott Morrison
smor461 at ecy.wa.gov
(360) 407-6292 wk
(360) 705-0457 hm

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From: owner-tweeters
To: tweeters
Subject: Re: Intergrades and Morphs
Date: Tuesday, August 22, 1995 2:26PM


Just to add to Joe Morlan's answer to Michael Conner:

> > Is albinism a type of morph?

> No. Albinism is a genetic defect. A morph is a normal genetic variation.

That's right, of course. But suppose in some population albinism had a
selective advantage, or at least wasn't disadvantageous. Then the
population would probably accumulate some albinos and that would be a new
morph. There's no particular genetic difference, just a question of
whether or not selection allows a form to remain in the population.

Burt Guttman guttmanb at elwha.evergreen.edu
The Evergreen State College Voice: 360-866-6000, x. 6755
Olympia, WA 98505 FAX: 360-866-6794