Gull query (1 Viewer)

[mountain man]

Can't see enough on the bottom bird, but the top 2 look like Atlantic Yellow Legged? I'm not convinced they are Caspian - again, light, judging photos etc...

 

[Jane Turner]

as I said..I as in a hurry

 

[Andrew Whitehouse]

Here's a few pictures of Caspian Gulls from around the web. I guess I should perhaps 'come out' on this now. The picture of the Northants bird is on Surfbirds as a 'probable Caspian Gull'. My contention, I suppose, is to remove the 'probable' bit of that.

A few points to note from what's been said so far (thanks for all the comments by the way):
1. It's an adult. Black in the bill is normal in winter plumaged adults as far as I can gather (see two of the pictures) and the wing tip is adult.
2. I think it's standing in water so the legs are longer than they look.
3. I'm not sure how useful the brightness of the bill is as a character. I get the impression that it's mainly useful as a distinction from Michahellis, which tends to have a very bright almost 'plastic' looking bill colour.
4. The head shape and 'bulk'. In terms of bulk Caspians can be real whoppers (see one of the pictures). The other bird I have seen (see below) was very large and dwarfed a nearby Herring Gull (probably an argentatus as well). With the head shape, I would say this has a fairly sloping forehead (not as abrupt as on most Michahellis anyway). Obviously this is going to vary a bit depending on how it's 'holding' its feathers. I would say it looks similar to some of the other pictures of 'definite' Cachinnans.
5. Jane's question of the stance. I'm no expert on Caspians and in fact had only seen my first one the previous day (assuming that was one too! It's still getting reported as one anyway). What struck me was the very diagonal stance this first bird had, accentuated by the long legs. In these pictures below, they admittedly all seem to have a rather horizontal stance (except perhaps the really big one, where it's hard to tell). Harry mentioned to me in a PM that the diagonal stance has been noted as a feature of Caspian and it certainly struck me that way. Obviously it's a bit variable though!

I should add that I saw the bird in flight and the wing tip looked right for a Caspian with a solidly white tip to p10 and grey 'fingers' extending into the rather limited black.

Look forward to hearing people's comments (any news from Martin yet Jane?). We're all still learning on these.

 

[mountain man]

What does diagonal posture mean? When they are on water they look as though they are toppling forward - I've seen it described as "Slender Billed Gull-like" (which is probably going a bit too far.)
Assessing such things as stance and posture from 1 photo I do think is a little bit unusual.
I don't see what was wrong with this bird being Caspian: the head, bill, eye, sagging belly behind legs, mantle colour and wing tip all indicate Caspian. I've seen plenty of other photos of Caspian with nowhere near as good credentials as this.
I do think that it is important to bear in mind the marked variation in sexes when IDing the big gulls. Fifebirder mentioned how it dwarfed the Herrings - it is probably a male. A small female could be more reminiscent size wise of an LBB Gull when pitted next to a Herring.
Yellow Legged also vary considerably in size. At Dix Pit the variety in size is truly mind boggling!
Bloody Gulls!!!

 

[Andrew Whitehouse]

I would say by diagonal posture I mean that the wing and tail tips are held well below a line from the breast rather than level with it. The second photo (above) shows a more 'horizontal' posture with the breast and wing/tail tip appearing about level. 'My' bird has the wing/tail tip well below this line i.e. more diagonal.

 

[mountain man]

Take a look at this little swine

http://www.martinreid.com/hargap09.html

I'm sure that would stump a few people - myself included.

Okay, I understand the diagonal posture thing now. But go through Martin Reid's website and look at how many do and how many don't show this feature.
Also look at other gulls pics on his website and see how many have diagonal posture.
Repeat: Bloody Gulls!!!

 

[HH75]

Here's a few pictures of Caspian Gulls from around the web. I guess I should perhaps 'come out' on this now. The picture of the Northants bird is on Surfbirds as a 'probable Caspian Gull'. My contention, I suppose, is to remove the 'probable' bit of that.

I would tend to agree,but bear in mind that I've not seen an adult bird,and my experience of cachinnans is limited to a juv in Bulgaria.

1. It's an adult. Black in the bill is normal in winter plumaged adults as far as I can gather (see two of the pictures) and the wing tip is adult.

Agree that adults often show dark in the bill,at least in winter.

2. I think it's standing in water so the legs are longer than they look.

They certainly look 'spindly',with the 'knee' much thicker than the rest of the leg.

3. I'm not sure how useful the brightness of the bill is as a character. I get the impression that it's mainly useful as a distinction from Michahellis, which tends to have a very bright almost 'plastic' looking bill colour.

While I would like an 'ideal' Caspian to have a more green-yellow bill,this doesn't look too bright for one.

4. The head shape and 'bulk'. In terms of bulk Caspians can be real whoppers (see one of the pictures). The other bird I have seen (see below) was very large and dwarfed a nearby Herring Gull (probably an argentatus as well). With the head shape, I would say this has a fairly sloping forehead (not as abrupt as on most Michahellis anyway). Obviously this is going to vary a bit depending on how it's 'holding' its feathers. I would say it looks similar to some of the other pictures of 'definite' Cachinnans.

While the head isn't that small,I think that this is over-rated as a feature,with females having a much more Common Gull-like head than males.

5. Jane's question of the stance. I'm no expert on Caspians and in fact had only seen my first one the previous day (assuming that was one too! It's still getting reported as one anyway). What struck me was the very diagonal stance this first bird had, accentuated by the long legs. In these pictures below, they admittedly all seem to have a rather horizontal stance (except perhaps the really big one, where it's hard to tell). Harry mentioned to me in a PM that the diagonal stance has been noted as a feature of Caspian and it certainly struck me that way. Obviously it's a bit variable though!

The stance is a good supporting feature okay.

I should add that I saw the bird in flight and the wing tip looked right for a Caspian with a solidly white tip to p10 and grey 'fingers' extending into the rather limited black.

This is arguably more important than many of the features listed above.Sounds spot on for Caspian.Also,in the top pic,the underside of P10(on the far wing) shows a typical Caspian pattern.

Harry H

 

[mountain man]

While the head isn't that small,I think that this is over-rated as a feature,with females having a much more Common Gull-like head than males.
Harry H

Definitely.

 

[Edward woodwood]

probably impossible to make assumptions about posture in this bird based in this one shot......from what there is to see it does look fine for Caspian

check out Martin G's paper in BB 1997 vol 1&2

 

[Martin Garner]

Thanks for Jane's request, I'm happy to make a comment on the photograph, but I don't know that I can add much to what's already been helpfully said. Commenting on any photograph always feels a little artificial, as often you can only see a limited number of features - in this case there's no information on the exact primary pattern or comparison of the upper part tone.

That said, my gut reaction, if I saw this bird in the field would be - that looks like a Caspian Gull. Something particularly about the shape of the bill, being parallel sided, a little long and thin, and slightly tapered at the tip. In this case it often looks like no other full form. As for things like head shape, body stance etc. they really do vary. When I was first finding Caspian Gulls, even though some were great big things, and others looked more like big Common Gulls, nevertheless,usually something about them, particularly to do with the bill, said Caspian Gull.

The bright bill colours on this bird are normal for Caspian, and as already indicated the upper part tone, suggestion of what the primary pattern might be, leg colour and 'feel', point towards Caspian. But in real life, I'd only be happy if I saw the wing tip pattern, and only in comparison with other gulls.

A bird with very similar bill colour appears in an excellent photograph by Pete Wragg, on the Sheffield bird study web site. www.sbsg.org.uk click on recent news, and scroll down.

Cheers,

Martin Garner.

 

[Jane Turner]

Thanks Martin...and welcome....


May I drag you towards the Looe Pipit next

 

[Grousemore]

Hi Martin and on behalf of the Moderators and Admin,a warm welcome to Bird Forum.
It is evident that your contributions will be both valued and appreciated.

 

[Andrew Whitehouse]

Thanks for the help there Martin and for mentioning the photograph on SBSG site. I can't provide a really detailed description of the wingtip (something I'm still only just getting the hang of doing), although I would add that there was a largish mirror on p9 as well as an extensively white tip to p10 and the grey 'fingers' intruding into the black.

 

[Adey Baker]

I'd like to extend a warm welcome to Martin and also to say a big 'Thank you' to you Martin for your excellent papers on YLG ID in BB which have helped enormously on clarifying various issues on these fascinating birds

 

[Martin Garner]

Thanks very for the various warm welcomes...very much appreciated, the rate of devlopement of what you can do on the web continues to out- pace me and the Birdforum site is yet another revelation to me of what is possible! Its a fascinating place to expolre..only wish I had more time.

Cheers Martin