poss Ring-billed hybrid?

[Brian S]

On 28-12-09 Dave Fairhurst found a Ring-billed Gull at Prior Lake just outside Telford. He also saw a gull which may possibly be a Ring-billed hybrid - or is it just a small Herring? This image below shows its small size in relation to LBbG, and a small, stubby bill.

Any comments?

Brian S

[JanJ]

Hi Brian.

I know of no records of RBG x HG, which of course doesn´t mean they don´t exists.
However, seeing Dave's gull I can hardly relate to the theory of a RBG x HG since I have never seen one (to my knowledge). The fine streaking on the head and bill pattern could possible suggest RBG. Pattern on p10 from below as seen here - looks perfect for Herring. Perhaps such a bill pattern in combination with such an adult looking gull is not so good for Herring. Leg colour primary pattern and structure doesn´t give much hint to a RBG in there. Am I the only one seeing a hint of reddish in the orbital ring? It would of course be very nice to see an open wing pattern on this gull.

JanJ

[LeeEvans]

I have seen a few gulls in recent years with this appearance and have put them down as small HERRING Gulls but I certainly see an uncanny resemblance to a Ring-billed Gull in Dave's image.

There must be a strong possibility that the two species could hybridise, particularly when you take into account the Madrid 'hybrid'

[Brian S]

Thanks Jan and Lee

In the Madrid gull forum, I noticed that Alex had written, 'per 'Handbook of avian hybrids of the world' there are cases of hybridisation between Ring-billed Gull and: Kelp Gull (!), California Gull, Mew Gull, Franklin's Gull, Laughing Gull, Franklin's Gull and Black-headed Gull and between Common Gull and: Ring-billed Gull, Lesser Black-backed Gull, Iceland Gull, Kamchatka Gull, Med Gull and Black-headed Gull!'

If Ring-billed can breed with Kelp anything seems possible - though Jan makes some good points on the leg colour.

Brian

[JanJ]

2 of these references:

http://www.pbase.com/ol_coot/tunica_gull&page=all

http://www.birds.cornell.edu/crows/woodburne_gull.htm

JanJ

[Pipixcan]

2400Hi, an interesting bird,as had been said maybe a Ring-billed Gull would influence the leg colour from pink to yellow perhaps.Check out this tiny Yellow-legged Gull which was present in the UK in Feb 2009.This had a very RBG structure but obviously a dark mantle.JanJ has already seen this pic...sorry for the repetition!!

[adriaens]

Just for those interested: Hybrid Common x Black-headed Gull has been well documented from Belgium.
We have an adult bird here that has returned every winter since September 1991. It was already adult at the time, so is now at least 20 years old.

Photos:

http://waarnemingen.be/soort/photos/87973
http://www.natuurdigitaal.be/coppermine/thumbnails.php?album=search&search=kokmeeuw
http://users.skynet.be/ch-web/photos/larridXcan001.htm
http://users.skynet.be/ch-web/photos/larridXcan002.htm
http://users.skynet.be/ch-web/photos/larridXcan003.htm (in breeding plumage!)