Larus canus

Morg
Posts: 18
Joined: Thu Jul 22, 2010 8:23 am

Re: Larus canus

Post by Morg » Sun Dec 12, 2010 12:14 am

Thanks for your very helpful comments and links JanJ and Peter. Common Gulls were not on my agenda until very recently so I am at the stage of rapidly picking up on the massive variety of plumage types. For example, I was unaware of the darker tailed variation in 1st winter Common Gull, but from all your links it seems it is fairly well documented though uncommon perhaps.

JanJ, the link you gave for the Norwegian bird is certainly a close fit to my bird, to say the least. It is useful to see some in the hand pics.
You are also spot on with your query about the less-well marked birds "are they really are the same individual?" Well, after more careful study I think that your suspicion is right and they are 2 different individuals after all - so I have amended the blog entry and think that the angle of view idea of mine is a red herring - just an attempt to make sense of the tails looking so different.... I think that until I photographed the more extreme smoky tailed individual I wasn't even seeing the more subtle ones!

Peter - thanks for the various references to outer tail barring - something I hadn't picked up on. I liked the look of your Birds 1, 4 and 8 and will be keeping an eye out for birds similar to these in future. I am also intrigued by the picture of the skin of heinei. Tantalisingly similar perhaps... Of course, I get the impression that trying to determine any suite of plumage characteristics for heinei is probably a waste of time given the clinal nature and inherent variability of the forms (as well as the fact that many before have looked and found that no definitive characteristics exist...). On the other hand I get the impression that gulling is full of examples of the impossible becoming possible - or maybe less impossible at least!

Geoff

Morg
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Joined: Thu Jul 22, 2010 8:23 am

Re: Larus canus

Post by Morg » Thu Dec 16, 2010 9:29 pm

Here is another 1CY Common Gull with a slightly wider tail band, spotted rump and barred axillaries. Photographed in Edinburgh this week.

Any comments on how regular barred axillaries are in this species?

Geoff

More pictures of this bird at http://morgithology.blogspot.com/2010/1 ... arred.html
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adriaens
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Re: Larus canus

Post by adriaens » Thu Dec 16, 2010 10:14 pm

Hi Geoff,

barring on axillaries is unusual indeed, but I also have a few.
You had already seen birds 4 and 5 at http://picasaweb.google.com/Zorkyyy/CommonGull1stCycle#.
I have added one more example of a bird with barring on axillaries, bird 11.
Keep them coming.

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JanJ
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Re: Larus canus

Post by JanJ » Fri Dec 17, 2010 8:28 pm

Not so easy to come by canus with barred axillaries, less to more obvious.

http://www.pbase.com/peregrine/image/98919113

http://argus21.blogspot.com/2010/10/fir ... -gull.html

Watch out for barring on the lower axillaries which which might in fact be a part of the flank feathering.

http://3.bp.blogspot.com/_wpfoS655UiU/T ... O99734.JPG

One from Sweden:

http://www.artportalen.se/birds/gallery ... eID=113002

Also seen in some kamtschatschensis - bird 3 +4 here.

http://seichoudoku.at.webry.info/200712/article_28.html

JanJ

Morg
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Joined: Thu Jul 22, 2010 8:23 am

Re: Larus canus

Post by Morg » Fri Dec 17, 2010 10:53 pm

Peter/JanJ

Thanks for your responses. Yes, these axillaries do seem to be uncommon - the two UK examples you link JanJ are pretty much the only ones I could find as well. Of course, my surprise is that I saw a bird with them on the first day that I started looking specifically at the axillaries (so maybe that tells us something about how common they are?). And it is not as if there are hundreds of birds to sift through here, just a few dozen that drop in (but maybe from a much larger pool). What has amazed me is that in just a few days looking I have had several fairly extreme looking birds and such a wide range of variation.

As far as I can tell they are all canus - I haven't worked out how to measure their wings while they are in mid-flight! Not that I'm hung up on heinei, but it is not on the Scottish list...

Geoff

Klaas van Dijk
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Joined: Wed Dec 16, 2009 8:32 pm

Re: Larus canus

Post by Klaas van Dijk » Mon Dec 20, 2010 8:45 pm

Morg wrote:In terms of heinei, I have read that this type of pattern could indicate that form but cannot find any definitive heinei pics with anything other than a white rump and uppertail in 1st winter. But heinei pics seem very difficult to source. Are there any galleries on the web? I have seen the Kazakhstan site, a limited number of pics of colour ringed birds in Europe and googled searched with a few of the likely locations but I wonder whether anyone has nice sets of images from their breeding or wintering areas.Geoff

Quite a few pics of 'probable heinei' of various ages and taken in the wintering area, including descriptions etc., can be found in an extensive paper of Kenneth Bengtsson & Lennarth Blomquist (Alderskaraktärer för Fiskmas - gar det att aldersbesträmma subadulta Fiskmasar?), published in 2003 in Anser 42: 73-92. [ Is it possible to age subadult Common Gulls? ] The paper is in Swedish, but the pics have English captions. I only have a black-and-white photocopy of the orgiginal paper. Not yet made a scan of it. I assume you already have read / seen
http://gull-research.org/papers/Heinei% ... 201998.pdf . An extensive paper of Hein & Martens (2002) Corax 19: 49-65, also depict some photo's of heinei.

There are a few recoveries that link Britain with the breeding area in Russia where heinei should occur ('Migration Atlas'.) Or just plan a visit to Copenhagen or Malmö during a period of severe winter weather. Its also not unlikely that right now quite a few heinei are present in The Netherlands.

When it is impossible for you to get a copy of the paper in DB, I am able to scan it and send this scan by e-mail to you.

Klaas

Morg
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Joined: Thu Jul 22, 2010 8:23 am

Re: Larus canus

Post by Morg » Mon Dec 20, 2010 11:00 pm

Many thanks for those links - I will follow them up later.

In the meantime, here are some more 1CY individuals with barred axillaries...

http://morgithology.blogspot.com/2010/1 ... ommon.html

Geoff

Morg
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Joined: Thu Jul 22, 2010 8:23 am

Re: Larus canus

Post by Morg » Wed Dec 22, 2010 9:22 pm

Here is the most strikingly marked bird. Any thoughts?...

Geoff
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adriaens
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Re: Larus canus

Post by adriaens » Thu Dec 23, 2010 12:03 pm

No further thoughts from my side, but Martin Garner has also picked up on the variation in 1w Common Gull:
http://birdingfrontiers.com/2010/12/22/ ... mmon-gull/

omissus
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Joined: Wed Jan 05, 2011 10:46 pm

Re: Larus canus

Post by omissus » Thu Jan 06, 2011 10:48 pm

Hi,

Check out this interesting dark Common Gull from Poland:
http://www.czaplon.most.org.pl/p/mewatorun.htm
(plumage anomaly)

Best regards,

Bram Aarts

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