Hi, tweeters.

Not sure if anyone out there has the new gull book by Olsen and Larsson that
was pulled off the market, but I do have a copy, as my sweet wife happened
to be in a book store just about the day it arrived and bought it for me.
Then all the fecal material hit the rotatory device, and it was recalled.
However, I was able to exchange just the title page for my money back, so I
have it to use as a reference while waiting for version 2.0.

That book says that hybridization between Great Black-backed and Glaucous
gulls is actually fairly common in Greenland. Hybridization is less common
with American Herring Gull, not surely known with European Herring Gull. But
of course hybrids are far, far less common than parental types, so are MUCH
less likely to be seen anywhere. Nevertheless, the argument that a hybrid
might be more likely to stray out of range than a parental species should
not be dismissed.

The gull book says nothing about second-winter birds acquiring such an
extensively pink-based bill, but they certainly have some pink at the base,
and we all know how variable gulls are. I also agree with those who have
said this bird's pattern is a bit "soft" for Great Black-backed, not as
contrasty as most. But again we know how much gulls vary.

Is this bird encompassed within the variation of GBB enough so that we can
rule out hybridization? I can't answer that question at my present level of
knowledge, but as several people have written, when the Washington Bird
Records Committee meets, we will have to deal with it. If we decide the bird
is 90% Great Black-backed, isn't that enough to put it on the state list?
;-)

Also, vis-?-vis migration distance, I would agree completely with whoever
said that Herring migrates farther than Great Black-backed and
Glaucous-winged migrates farther than Western (check the range maps in
Sibley). GBB reaches Florida in winter but in very small numbers, while
Herring is abundant there and occurs in small numbers all the way down into
the West Indies and both coasts of Mexico (and even Costa Rica). And its
breeding range actually extends farther north than that of GBB.

Also, many more Glaucous-winged Gulls make it to southern California than
northern (occidentalis) Western Gulls, and many more Glaucous-winged wander
into the interior of North America. Furthermore, Glaucous-winged breeds way
up into the Bering Sea, and I think at least some of those individuals
migrate down to the Lower 48. Some of the GWs at the Cedar River mouth have
wonderfully pale wingtips, as is typical of Alaska breeders. I've had a lot
of time to look at Glaucous-winged in my six hours so far at that river
mouth.

Dennis Paulson
--
Netta Smith and Dennis Paulson
1724 NE 98 St.
Seattle, WA 98115