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Dark Herring Gul?

Posted: Sun Feb 07, 2010 4:07 pm
by paseriformes
Sighted today in Madrid. I think that is a dark L.argentatus.
Delfín

Re: Dark Herring Gul?

Posted: Sun Feb 07, 2010 4:57 pm
by Ruud Altenburg
It just does look odd for a 3cy Herring Gull. What were the characters for American Herring Gull of this age again..?

Re: Dark Herring Gul?

Posted: Sun Feb 07, 2010 5:52 pm
by Jonas Landolt
Hi

I'm not a gull expert and I don't have experience with AHg except this possible smithsonianus 2007 in Switzerland: http://www.pbase.com/dinah_saluz/goelan ... thsonianus_ And I don't have much experience with Hg as there are only little numbers wintering in Switzerland, but I can cite some features from the Article "Identification of Ahg in a western European context" written by Pat Lonergan and Killian Mullarney:
- much greater tendency of smith. to have dense brownish colouration on the lower hindneck and the upper mantle, extending onto the underparts
--> Well shown in this bird

- more extensively and solidly dark-centred tertials than Ehg --> corresponding reduction in the extend of pale at the tips
--> Well shown in this bird

- Undertail coverts: Often as in first winter birds --> intricate or closely spaced bars
--> Not shown or not visible in this bird

- heavily patterned rump and uppertailcoverts
--> looks good

- practically all-dark uppertail.
--> uppertail in this bird looks ok

- extensively pale based bill, often not as fleshy as in Ehg

- no mirror on P10

- underwing cov. more solidly dark than in Ehg

- Greater coverts: slightly darker and more uniform than in Ehg
--> Gc look very bleached in this bird, bu they are quiet uniform and not barred

Pattern of the scapulars looks ok for Ahg, I think.

In my opinion there are different features, which fit quiet well for Ahg.
Anyway it is a very interesting bird.

Re: Dark Herring Gul?

Posted: Sun Feb 07, 2010 6:08 pm
by JanJ
Simple statement and question. To eliminate second cycle (2nd winter - 3cy) argentatus would be difficult from these pic. However, is a similar aged smithsonianus likewise impossible to exclude? Some more pic. Delfin?

Jan

Re: Dark Herring Gul?

Posted: Sun Feb 07, 2010 7:03 pm
by paseriformes
Yes. I send more pictures.
Delfín

Re: Dark Herring Gul?

Posted: Sun Feb 07, 2010 7:16 pm
by adriaens
I would be in a state of sheer panic if I saw a bird like that in Belgium (where we get lots of argentatus)...
I think this bird looks good for smithsonianus !

Re: Dark Herring Gul?

Posted: Sun Feb 07, 2010 7:55 pm
by JanJ
After seeing more pic. and looking more closely I would like to refrase my statement."To eliminate a second cycle smithsonianus would be difficult from all these pic. However, is a similar aged argentatus entierly impossible to exclude? ;)

Jan

Re: Dark Herring Gul?

Posted: Sun Feb 07, 2010 8:16 pm
by adriaens
I am quite convinced that argentatus can be eliminated, Jan.
The dense, rather irregular brown pattern on the under tail-coverts, for instance, would be odd for that taxon. Jonas has aptly summarized the other important characters.
Note also the all-dark outer edge of the tail, lack of streaking on breast and lower hindneck, as well as pale grey scapulars (hardly darker than in the nearby Black-headed gulls).

Re: Dark Herring Gul?

Posted: Sun Feb 07, 2010 8:37 pm
by Ruud Altenburg
Besides all the characters listed by Jonas and Peter, it's the 'quilted' appearance that I have never seen in any Herring here in the Netherlands.

Re: Dark Herring Gul?

Posted: Sun Feb 07, 2010 8:37 pm
by JanJ
adriaens wrote:I am quite convinced that argentatus can be eliminated, Jan.
The dense, rather irregular brown pattern on the under tail-coverts, for instance, would be odd for that taxon. Jonas has aptly summarized the other important characters.
Note also the all-dark outer edge of the tail, lack of streaking on breast and lower hindneck, as well as pale grey scapulars (hardly darker than in the nearby Black-headed gulls).
´
I´m convinced Peter! In the second pic. of the 8 last once, I noticed the pale scapulars but thought maybe this was due to a trick of the light.
Otherwise, argentatus are surprisingly odd at times!

Jan