I noticed some discussion on this bird- presumably the one I saw a week or so
ago - and it being described as a Glaucous Gull. I do a lot of gulling both
here and overseas so am well aware of the difficulties in assigning some
immature birds- particularly badly worn ones such as this - to species but
would have trouble calling it a Glaucous Gull for at least two reasons, the
size of the bird and the pattern of the bill. I also believe it is a bird in
its 1st summer.
I saw the bird several times over two days and had the chance to compare it
both to Herring Gull and Lesser Black-backed Gull. It was the same size - in
terms of body - as the Lesser Black-backs and distinctly smaller than any
Herring Gulls around. While one can expect to see Glaucous Gulls in the size
range of a typical group of Herring, seeing one as small as a Lesser Black-back
would be highly unusual. On the other hand that's the right body size for
Iceland.
The bill pattern and color would also be very atypical for Glaucous which have
a bubble gum pink basal 2/3 and a very sharply defined black tip in their 1st
year (and decreasing black thereafter). The messy merge between pink and black
and the dull pink color on this bird would, if seen on a large, Glaucous- sized
white bird, make me think it was not a pure Glaucous but had Herring genes
mixed in there as well. The bill pattern is however fine for an Iceland in its
1st year.
I can't see anything wrong for this bird being an Iceland gull. The size is
correct. Primary projection is variable but these are so worn it is hard to
tell but looks OK. There is no significant tertial "step" which one would
expect on a bulky bird like Glaucous - instead it has a very flat backed look
typical of the smaller "large" gulls. The bill also looks within the range of
Iceland to me - it is exaggerated in size in some views because the forehead
and nape have lost feathers but if you look at it compared to the Herrings in
the link below you can see it is not a large bill. Finally it had a very
distinctive chesty look in flight quite typical of Iceland rather than the
bulkier look of Glaucous.
http://harrisbirds.com/Kumliens%20Jun%20Va1.htm
It looks more likely a 1st summer bird to me given the dark eye and lack of
pale tip to the bill, though one can't rule out a 2nd summer. The heavily worn
plumage is perhaps also more likely on a 1st summer bird which has weaker
plumage than an older bird.
But I'd very much welcome anyone making a case for a Glaucous on this bird.
Regards
Clive Harris
Cabin John, MD----- Forwarded Message -----
From: Clive Harris <clivegharris@xxxxxxxxx>
To: VA Birds <va-bird@xxxxxxxxxxxxx>
Sent: Monday, June 27, 2011 10:18 PM
Subject: Chincoteague NWR - Iceland Gull and some other birds
I spent the last 3 days at Chincoteague on a family vacation and did a very
limited amount of birding chiefly at the ocean end of Swan Cove where it
adjoins the beach and the adjacent beach area.
There was good gull diversity. I was surprised to see a heavily worn 1st cycle
Iceland Gull on the beach near the parking lot at the top end of Swan Cove but
when I checked the list serv saw that it had been reported the previous week.
It is missing chunks of feathers off the forehead and nape so the bill looks
proportionately larger than it would normally. I noted a Glaucous Gull had
been reported as well recently - I did not see this. Over the 3 days I saw at
least 4 different immature Lesser Black-backed Gull, as well as a couple of
Ring-billed Gulls to add to Laughing, Herring and Greater Black-backs.
Pictures of the Iceland Gull are here:
http://harrisbirds.com/Kumliens%20Jun%20Va1.htm
In contrast tern variety was less than I had expected, with 6 species (Least;
Common; Forster's; Royal; Sandwich - max of 3; and Caspian - max of 3 as well).
Shorebirds included:
2 Marbled Godwit, seen this morning flying over Swan Cove, both in heavy wing
molt so presumably 1st summer birds
10 Short-billed Dowitcher, one in typical breeding plumage for griseus and the
rest with very limited breeding type feathers
Willet - all seemed to be Eastern that I could see
Black-bellied Plover -c.10 one day roosting in Swan Cove, two of which in
dullish breeding plumage
Semipalmated Plover - one on Saturday 25th
Piping Plover - 3 different birds seen
American Oystercatcher
Black-necked Stilt - on causeway, 2 young seen with one pair
Regards
Clive Harris
Cabin John, MD
