hybrid Herring X GBBG?

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Kent Olsen
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Joined: Wed Dec 02, 2009 11:07 pm

hybrid Herring X GBBG?

Post by Kent Olsen » Tue Jan 06, 2015 10:02 pm

During Christmas holiday I went through my hard drive and found a (probable) Herring x GBBG hybrid that I photographed some years back:

#1 (Vejle Harbour): http://gulldk.blogspot.dk/2015/01/presu ... -gull.html

In the beginning of the video one gets a brief view of the open wing

Please comment especially if you disagree with the ID.

Cheers

Kent

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marsmuusse
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Re: hybrid Herring X GBBG?

Post by marsmuusse » Tue Jan 13, 2015 10:10 am

Difficult bird Kent. Somehow the wingtip does not recall any marinus influences, like the white indentations from the white tip eating into the subterminal black (http://gull-research.org/gbbg/gbbg5cy/je001.html).
But maybe that was more obvious in the field and doesn't let detailed reproduction in these images? And in what way should it be necessary to inherit such characteristics?
There is a ringed hybrid here: http://www.gull-research.org/hg/hg5cy/ht252852.html which show more like a paler marinus, but longer winged and more elegant.
Difficult material. The bird is obvious dark and it makes sense to suspect hybridisation with a dark-winged taxon.

Kent Olsen
Posts: 46
Joined: Wed Dec 02, 2009 11:07 pm

Re: hybrid Herring X GBBG?

Post by Kent Olsen » Sun Jan 18, 2015 6:46 pm

Yes, very difficult. I am definitely not sure that the parental combination includes GBBG. At first I thought that it included LBBG, and that could still be the case rather than GBBG, but the possible LBBG X EUHG that I have seen, have all had a more delicate structure than this one.

I suggested GBBG influence solely based on structure and size. However, we all know hove significant the sexual dimorphism is in LWGU so make the ID only on size is properly not safe.

I did not see en clear influence from GBBG in the primary pattern; they were actually very similar to the LBBG X EUHG candidates that I have seen.

Would you suggest that LBBG X EUHG would make more sense?

Cheers

Kent

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marsmuusse
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Re: hybrid Herring X GBBG?

Post by marsmuusse » Sun Jan 18, 2015 10:37 pm

Hi Kent,
I don't know really. Like you, I just document these birds and try to get them at rest as well as in flight / open wings. For the time being, a label as hybrid will do and then I put it away. Found another candidate, on the Tarsiger page: http://www.tarsiger.com/gallery/index.p ... DESC&sel=2

It's about this bird, Great Black-backed Gull, Larus marinus X Herring Gull, Larus argentatus July 15th 2011 Espoo, Ämmässuo, Finland ©Matti Koivula digipicture url Nikon D300, AF-S Nikkor 300/2.8+1.4x.Mystery gull. Presumed hybrid. :
Larus_15_07_2011_2.jpg
Larus_15_07_2011_2.jpg (105.92 KiB) Viewed 5770 times
Larus_15_07_2011_3.jpg
Larus_15_07_2011_3.jpg (105.73 KiB) Viewed 5770 times
Although there is no certainty about the true nature of this bird, I can very much live with argentatus x marinus for this one, as it really is in between what you would expect (like the ringed bird from Finland is). Thus, my question mark after hybrid? would be much smaller in these two Finnish birds (but still present of course, as long as I have no information about that ringed bird's papers).

To be honest, I've got quite a few of these question marks in birds photographed myself. Sometimes I look at them again and hopefully one day one may fall in place because of new insight (or missed details previously). There is not much wrong with question marks, in my view...

Kent Olsen
Posts: 46
Joined: Wed Dec 02, 2009 11:07 pm

Re: hybrid Herring X GBBG?

Post by Kent Olsen » Mon Jan 19, 2015 8:57 am

Thank for this very nice example. Unfortunately, the bird that I documented was only seen at distance and the details in the photos thus of less quality. Nevertheless there is some similarity in the primary pattern as seen below. Maybe we will have a higher degree of confidence with possible hybrids over time, let’s see ;-)
hybrid1.jpg
hybrid1.jpg (294.72 KiB) Viewed 5767 times

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