Subject: Re: w-c sparrows
Date: Apr 15 10:05:36 1994
From: "M. Ross Lein" - mrlein at acs.ucalgary.ca


On Fri, 15 Apr 94 09:14:02 -0700 Dennis Paulson wrote:

> Subject: w-c sparrows
> In response to Al Jaramillo's comments about loral color in
White-crowned
> Sparrows, the black-lored leucophrys and white-lored gambelii
intergrade at
> Churchill, Manitoba, but I'm not sure how this is manifested.

I have been studying the intergrade zone between oriantha
(black-lored) and gambelii (grey-lored = "white"-lored) for a
number of years. There is free interbreeding and full
intergradation of lore color from completely black lores, to
thick black lines joining eye and bill, to thin lines, to broken
lines, to a black spot at the anterior corner of the eye, to
completely grey lores. This would suggest a polygenic control of
lore color rather than a single gene locus as Al suggested.
However, none of this seems to matter to the birds. Mating seems
to be at random with respect to lore color and an individual
female may mate with a "gambelii" male in one year, and an
"oriantha" male the next. Individual males sing one of the two
songs that are heard in oriantha populations south of the
intergrade zone or of gambelii north of the zone. There is no
linkage between lore color and song pattern and females don't
seem to care about song pattern either! An interesting
biological situation.

=================================================================
M. Ross Lein EMAIL: mrlein at acs.ucalgary.ca
Department of Biological Science PHONE: (403)-220-6549
University of Calgary FAX: (403)-289-9311
Calgary, Alberta T2N 1N4, CANADA