Subject: Re[2]: hybrid gulls
Date: Dec 22 11:33:55 1994
From: Skip_Russell at intersolv.com - Skip_Russell at intersolv.com


Thanks, Dennis, for an excellent summary of NW gulls. I think your
posting should be made into a "FAQ" sheet (FAQ=frequently asked questions)
for new NW birders.

I'd like to add a couple of points. You mentioned that W/GW hybrids are
still a minority on the outer coast. In the interior, however, my feeling
is that the vast majority of Western-looking gulls have more than a little
Glaucous-winged blood. This is largely true even in the ocean bays. Any
distance upstream, away from the ocean, and true Westerns become quite
rare, while hybrids aren't all that uncommon.

Regarding Thayer's, I think something that many birders are surprised to
discover is that at rest, the primary tips of the folded wing usually
look as dark as those of a Herring Gull, especially at a distance. Some
of the field guides are misleading on this point. Also, a good mark to
look for when scanning adult gulls for Thayer's is a dark hood of winter
streaking about the head.

A question: You mentioned that hybrid Herring/Glaucous "maybe aren't as
big as typical glaucous". Most of the H/G hybrids I've seen in Oregon
have been even larger than _our_ typical glaucous. I seldom see Herring
Gull sized hybrids. My hypothesis is that the Glaucous Gulls that tend
to hybridize originate further east, where the subspecies is larger,
whereas the majority of Glaucous Gulls that make it to our region are
rather small, indicating perhaps that they originate further west. We
very often see diminutive Glaucous Gulls with tiny bills which are
undoubtedly of the race 'barrovianus'. Comments?

Skip
--
Skip_Russell at intersolv.com
Aloha, Oregon