When I return to my other home in Issaquah this weekend I will scan one of my
slides of the famous white-winged Heermann's Gulls and see about getting it in
the gallery. I remember the white patch being bigger.

It is my recollection that the majority of Heermann's Gulls nest on one main
island in the Sea of Cortez. Would this play a part in having a number of
birds that have this genetic anomaly? (It is frustrating to be away from my
books on such a regular pattern.)

Jim Rosso
Issaquah/Bellingham


----------
From: TWEETERS-owner at u.washington.edu on behalf of Dennis Paulson
Sent: Wednesday, June 03, 1998 12:21 PM
To: tweeters at u.washington.edu
Subject: white-winged Heermann's

I've been asked to describe the white wing patch that occurs on a small
percentage of Heermann's Gulls. This is from memory, but as I recollect,
it's in the area of the lesser coverts, a conspicuous white patch maybe 4
cm (an inch and a half, for the metrically disadvantaged) in diameter on
top of the wing about a third of the way from the bend to the tip. This
puts it in a very different place from the white primary patches of
jaegers, I should add, but it doesn't destroy my faith in my hypothesis of
jaeger mimicry.

How about reports of such birds this summer? Should we give a large cash
prize for the most reports?

And my last word on this species: when pointing one out, a friend of mine
often converted "Heermann's Gull" into "human skull." Are birders sick, or
what?

Dennis Paulson, Director phone 253-756-3798
Slater Museum of Natural History fax 253-756-3352
University of Puget Sound e-mail dpaulson at ups.edu
Tacoma, WA 98416
http://www.ups.edu/biology/museum/museum.html