Tuesday 8 November 2011

Gull ID - aaaagggghhhhh, help!

Strange things are happening in gull world. Back in October I was rather chuffed to find three different white-winged gulls in four days. I was happy with their ID, it was pretty much an auto-pilot job to be honest, maybe that's the trouble. I got pix of two of them and another observer saw one of them as well. But now .... I'm struggling for my sanity. Perhaps its a hang-over from all the shannanigans with the wheatear.

A careful look at my photos of the Tesco Corner Iceland of 22nd October leads me to realise I mis-aged it, bill colour is the reliable factor, so despite its whiteness it has to be a first winter.

Have a look on Orkbird at these two pix. Here's the first one - click - This one can't be as labelled can it? That's just got to be hyperboreus.

But then there's this one - click - that's not right either, is it? Legs are too long, especially the tibia, bill is too long, head and body shape is wonky. It has been suggested that this one is a leucistic Herring Gull, I'm not sure and I'd like to see it in the flesh but I'd be surprised if it is an Iceland Gull.

Please post your ideas in the comments ....


Extra - here's a bit more on the gulls, I'm changing my mind again....

Martin,

I'll make comments in amongst your text about this second gull, -A-

--- In Orkbird@yahoogroups.com, "Martin" wrote:

> The bill shape speaks of Iceland, a bit less robust than Herring with an even
curve down to the tip. Quite unlike the sharp drop to the tip of Glaucous and
also lacking the length and parallel-sided (chisel) build of that species.

- A - I disagree with some of this analysis. There is a need to be wary because
of the angle the shot is taken at. Bill shape looks good for Glaucous to my eye,
it may fit some Iceland Gulls though. However bill length looks better for
Iceland, that could be a product of the angle though.

>
> Colour of the basal 2/3rds of the bill being bluey/grey is not a Glaucous
feature at any age., it would show pinky/fleshy bill tones around this age.

- A - But that colour doesn't really fit Iceland too well either. In Glaucous
the brightness of the pink fades from first year (I do agree this is a 2nd CY).
Colour could be a product of water on the bill, gunk on the bill or photographic
aberration... If its real I think its more problematic for Glaucous than Iceland
but its still problematic.


>
> The image where the head is concealed shows a very long forewing from bend to
tip, seems better for Iceland.

- A - I completely disagree, wing shape, both the breadth of the hand and the
arm and length look better for Glaucous but caution again... angle of shot.

>
> Into the realms of the subjective, the head shape and facial expression have a
slight benign quality rather than the angular shape and scowling glare of
Glaucous.

- A - Disagree, looks like it would murder your granny - better for Glaucous.
However, for me the eye is too big in proportion to the bill and head for
Glaucous, much more like Iceland.


>
> So sorry again Alastair, not denying this one yet.

- A - I also don't like the body shape for Iceland, it looks too heavy and big
chested, but maybe its just had a heavy meal.

I will go down there and try and look for this bird when I can, maybe Saturday.
As I said I really don't like id just from photos because I know I'm **** at it.
I think this bird is problematic from the two pictures.


>
> Back in the winter of 1982-83 Orkney experienced an amazing influx of Iceland
Gulls. Both Kirkwall and Stromness harbours held double figures of birds; they
were everywhere. Eric and I spent a great many hours sifting through these,
armed only with the topical writings of the late Peter Grant, the Poyser 'Gull
Identification'. This remains a standard reference today. What became obvious
that winter was the myth that Iceland Gulls are the most effeminate looking of
large gull species was starting to unravel. We found plenty of very large
Icelands and even one corpse which had biometrics indicating either a huge
Iceland or a tiny Glaucous.

- A - I learnt a lot of my birding with Peter (Dungeness). Actually when he
wrote the book he hadn't seen that many Iceland Gulls if I remember correctly.
I've even got a picture published in the book (and its not even blurry, 1st CY
Med). But Olsen and Larsson is the business, to be somewhat disloyal, (as long
as you have the corrected reprint).

>
> That was a long while ago but I carried those memories with me during 15
summers working in the high Arctic and especially when in Greenland. I visited
the east coast more often and here found rather few mostly our slightly built
familiar winter visitors which I called the 'Jessies'. I had to wait until the
summer of 2006 to get into West Greenland and here they were, lots of them, the
'Bruisers'. One of the highlights of my life was sitting in my boat just off
Iqqaluit, West Greenland, throwing fish to a flock of 300 Icelands, great muckle
brutes all. This anecdote suggests to me that the Jessies and the Bruisers come
from different shores of Greenland. My own homespun guess is that the British
Isles is within the routine wintering range of Jessies but not Bruisers. They
only reach us after severe weather (as in 82-83) and as part of a noticeable
influx. Now, of course I know this is back-of-a-fag-packet research but it seems
to work most of the time.

-A- Never been there and never seen any Icelands that look like that. I have
looked at a lot of pix though. Also if Western Greenland Icelands are bigger why
aren't kumlieni bigger?

Anyway, maybe I was hasty, but to suggest this 2nd bird is "undeniably Iceland"
is a touch forward in my view. It could be Glaucous, and brief discussions I've
had with others suggest that there is a body of opinion that thinks that may
well be the case. I like some of your argument, my opinion (for what its worth)
is currently "possibly Iceland". Other opinion, with reasoning, would be very
helpful.

As for the first bird I think there are still issues and I need to see it, the
tibia was well long for Iceland. It's very pale to have a black bill. There is a
suggestion that it is more likely a pale kumlieni and I'm still not 100% on it
being a 1st CY, some 2nd CY kumlieni apparently have black bills, I'm not really
happy to identify this bird until I've seen it. I would value other opinions.

I do find all this stuff fascinating and educative, thanks to both Morris and
Gerry for getting the pix and to Martin for stirring it up.

Alastair

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