[CT Birds] Long Beach gull is a puzzler (way too long)

Comins, Patrick PCOMINS at audubon.org
Tue Feb 26 07:24:26 EST 2013


You are right Charlie, this is a very interesting gull.  One thing is certain, it is not a Glaucous Gull.  There are very few absolutes in the world of Gull ID, but at least Glaucous offers a couple (I think), pure Glaucous have pure white primaries and immature Glaucous don't have bills that are darker than the typical bill pattern.  I.E. just the distal end being dark, with the zig-zag clean cut-off, being more black on the lower mandible than upper:
http://www.freewebs.com/richbonser/Glaucous%20Gull%20Dingle%20copy.JPG

Donna had first found this bird in January and sent me a single photo, which at the time I identified as Iceland Gull from the single photo.   The other day, she posted more photos on the Gull ID site on Facebook (neither of us realizing it was the same bird).  After the second photo, I blurted out Glaucous, but then saw a good photo of the bill and realized it wasn't.

So what is this bird?  Not having seen it in the field, any answer I give is tentative.   The bird appears quite large, but Iceland Gulls can in extreme circumstances be just as large as Herring Gulls and larger than some individuals.  This bird seems to be in that size category, but there are some other funky features for Iceland Gull, namely the apparently short primary projection beyond the tail and the head and bill shape.  I had toyed with the idea of a leucistic Herring Gull (and it may still be), but the plumage doesn't fit that well (especially in the January photos).  That leaves us with a couple of choices.  Either the gull is an extremely large Iceland Gull, or some sort of hybrid.   

In Iceland, where in the winter, Reykjavik Harbor is covered in gulls, mostly being Glaucous Gulls, a few European Herring Gulls and hybrids of such and some Iceland Gulls mixed in, they key you use to pick out the Iceland Gulls, which are entirely white-winged there, is how they sit on the water.  Glaucous Gulls tend to sit flat in the water and have short primary projections, whereas Iceland sit with their tails and primaries pointed up.  The long primaries and posture make them stand out like sore thumbs.   In some of the photos of the Stratford bird, this floating posture appears good, in others, not so much.  

Iceland certainly has to be our default here, why isn't the bird just a large Iceland Gull?  If not, is it possibly a Herring Gull with plumage irregularities?  The plumage patterns that have not entirely faded speak to a white-winged gull, tail pattern, wing coverts and perhaps the scapulars, but irregularities are just that, irregular.   So if it isn't a Glaucous (it isn't), it isn't an Iceland (not quite ready to say that) and it isn't an abnormal Herring Gull (not quite ready to say that), what could it be?   

The most common hybrid combinations in this part of the world are Herring X Glaucous.   They come in three general flavors Most American hybrids have a Glaucous like bill pattern and otherwise resemble Glaucous, but have some brown or gray tones in the primaries (perhaps even some with black primaries).  Some individuals look more like plain Herring Gulls, but are much paler and recall a pale Thayer's (note we aren't really sure if these birds are actually a result of this hybrid combination).   In Europe, the situation is different (and one reason why I have unofficially split American Herring Gull or Smithsonian Gull from European Herring Gull, or Herring Gull).  The hybrids look entirely different, looking more like faded European Herring Gulls.  These so-called Viking Gulls can be very cool looking birds:
http://cyberbirding.uib.no/gull/ind_ufo.php  This bird does not fit neatly into either category, but I suppose a recessive combination similar to Lawrence's Warbler is possible.

The second most often encountered hybrid possibility in North America, that could produce a bird that looks like this is Glaucous X Glaucous-winged.   Aside from that being an even more remote possibility than a Slaty-backed Gull on the East Coast, I would expect one of those to be even bigger than this bird and have some features more akin to Glaucous-winged: http://farm8.staticflickr.com/7224/7025481539_f147022578_z.jpg

Aside from that, what else, I don't think hybrid Iceland X Glaucous have been documented, but it is something to perhaps consider, and I'm not sure what a hybrid Glaucous X Vega Gull or Glaucous X Thayer's would look like.  

This may all be a very long way of saying, "the bird could just be an abnormally large Iceland Gull or even just an unusual Herring Gull", but the main point is that it is an interesting gull and I hope it gets some careful observation.  

I for one, am taking a day off today and spending some time up in Windsor trying to relocate that possible Yellow-legged Gull....too big a prize to let lie, even if that bird might just be a hybrid, but I hope some more folks will get down there and observe and photograph this bird.   My 2 1/2 cents. 


Patrick Comins, Meriden


________________________________________
From: CTBirds [ctbirds-bounces at lists.ctbirding.org] on behalf of charles barnard jr [chbarnjr at gmail.com]
Sent: Monday, February 25, 2013 11:12 PM
To: ctbirds at lists.ctbirding.org
Subject: [CT Birds] Long Beach gull is a puzzler

I haven't been able to get down to Long Beach in Stratford to view the gull
variously indentified as Iceland and then Glaucous. However, I have viewed
many good photos of it, thanks to Donna C and Frank M. I don't feel that
the bird is either an Iceland or a pure Glaucous. There has been much
discussion off of this list as to the bird's identifty, but no conclusion
has been reached. I have concluded that I don't know what it is; I just
feel that it is not an Iceland at all and not a pure Glaucous either. Get
down there in person to view it if you can -especially if knotty
identification problems are what you thrive on. Get a good look and then
bang your head against a rock 3 times. Maybe an answer will pop out.

Charlie Barnard Jr.
Stratford
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