LBBGulls (5/10/13) (1 Viewer)

Saw these two LBBGulls on Swanpool (Falmouth, Cornwall) yesterday and was rather baffled at the huge variation in the two individuals (particularly their build and shading of the mantle).

The darker individual was classic LBBG shape and size whilst the paler bird was approaching Herring Gull proportions and far less slender in appearance.

My camera was playing up so I only managed a brief shot of the darker individual (none of the paler bird and no open wing view of the darker one).

All notes are on the drawing itself but please let me know if some of it is illegible.

Question is, are they both within reasonable variation for LBBGull?

Thanks :t:

without seeing the paler one it's hard to tell but certainly there exist quite pale LBBGs.
in the photo there's a nice 1cy in foreground and the dark adult or 4th calender type looks like a textbook intermedius - but not easy to prove. it has long wings, probably a female. some adults, esp. in nominate baltic don't get more than this smallish p10 mirror. but this one still is a bit young. surely it has longer wings than the presumed male graellsii you saw it with.

Thanks Lou for the help :t:

It did indeed have a longer winged appearance than the paler LBBG.

The mantle colour on the paler LBBG was similar to this "Presumed Lesser Black-backed Gull x European Herring Gull" in the link http://gullstothehorizon.wordpress.com/2012/02/08/a-bit-of-a-mix/

Also, how common is intermedius in the UK? Is it a common winter visitor or are some present at all months of the year?

Samuel

Here are two blog posts with presumed HerringxLBB Gull hybrids in Musselburgh, Lothian earlier this year. Of course these are not adult birds and in mid moult but there is enough mantle to get a good idea of the differences in tone between these birds, Herring Gulls and graellsii LBBGs.

Geoff

http://morgithology.blogspot.co.uk/2013/08/lbb-x-herring-gull-hybrid-musselburgh-8.html

http://morgithology.blogspot.co.uk/2013/08/two-more-herring-x-lbb-gull-hybrids.html

Thanks Geoff for the links,

I'm not usually very keen to jump to the hybrid conclusion but is this pale mantle shading only explained by a HerringxLBB Gull mix?

The bill depth and fleshy base reminded me more of HGull whilst the only explanation for a relatively pale mantle was HGull influence.

I'll hopefully catch up with it again over the next couple nights roosting offshore and will try to get some pics,

Cheers,

Intermedius is very common in England - at least in my bit - throughout the year. This is demonstrated by the number of colour-ringed birds ringed as chicks in Norway, Denmark and northern Germany.

Oddly the latest Cornwall annual bird reports (2006 and 2007) have hardly any records though. Birds on the Hayle estuary last month included plenty though.

Steve