Viking Gull ~ Dungeness, Kent - 28.12.13

Monday 30 December 2013

Presumed

Viking Gull ~ Larus hypergentatus

Its a hybrid, of mixed parentage, a cross between Glaucous Gull and Herring Gull.

It could be leucistic ..

It could well be within variation and just be a pale variant of Herring Gull ..

There are however a few features that I believe make a case for a hybrid rather than just a pale bird.


Scapular pattern with the terminal half moon shape
Tertial pattern with bold markings
Primaries with pale edges


Note ... How different the under-wing looks with the way the light hits it !!
Nothing to do with the hybrid but striking how the light changes the way the wing looks ...


The narrow pale markings at the base of the tail band


Tiny dark markings to end each primary & secondary

Is there features strong enough to backup a case for Glaucous hybrid even though they are subtle.

Or is it well within variation ..

Lets see if anybody will comment !!

Here's a few links






  

2 comments:

Alan Tilmouth said...

I've had a few of these over the last couple of years, some (as you know) are slightly more obvious Viking showing some structural evidence of Glauc. Individuals such as the one in your post are more difficult to attribute for sure IMO. I'd throw in the predominantly pale GC too with just a couple of brown spots as another feature. Needs someone to get up amongst the breeding areas and bang some bling on a few more of these, particularly any with clear mixed parentage.

Ana Mínguez Corella said...

Nice pictures .. I wish you a happy 2014 .. Regards from Spain