Monday 17 January 2011

Presumed hybrid Lesser Black-backed Gull (Larus fuscus) x European Herring Gull (Larus argentatus) in Aarhus Harbour in 2011

This presumed hybrid Lesser Black-backed Gull (Larus fuscus) x European Herring Gull (Larus argentatus) was photograped in Aarhus Harbour on 11 January 2011.

The possibility of it being a hybrid Lesser Black-backed Gull x European Herring Gull, seems to be the best fit because it was much darker grey compared to local Herring Gulls and a Herring Gull JIZZ with short primary projection and thus not a Lesser Black-backed Gull.

Common Gull (Larus canus) with "retarded" first winter moult

This 1st winter Common Gull was seen in Aarhus Harbor on January 11, 2011. The largely retained juvenile plumage is surprising seen from a Danish point of view as we mostly see individuals that have completed their first winter moult by January. Such “retarded” individuals either belong to northern late breeding populations or they might be eastern ssp. heinei.

Friday 14 January 2011

Field identification guide to large gulls in Israel

This fast identification guide created by Amir Ben Dov and Yoav Perlman aims to assist birders of all levels to find their way through the large gull group occuring in Israel.

Sunday 2 January 2011

Herring Gull (Larus argentatus) with sooty-brown 2cy plumage







Herring Gull (Larus argentatus), 2cy, 3.10.2010, Bagenkop Harbor, Langeland, 7 photos







Herring Gull (Larus argentatus), 2cy, 9.11.2005, Aarhus East Harbor, 5 photos

Saturday 1 January 2011

Caspian Gull (Larus cachinnans), ad, 31.12.2010, Grenaa Harbor

This Caspian Gull was also seen a few weeks ago. The bird is male-like in appearance with strong body, large size and heavy bill.

ID is based on snow white head without traces of streaks and with a relative small and very dark eye, a strong bill though with flat gonys angle. The primary pattern is perfect with the outermost p10 having a large white tip and a grey tongue running up the inner web, isolated white mirror on p9 and broad black band on p5 and even a small black spot on outer edge of p4.



There is broad black band on p5 and even a small black spot on outer edge of p4

P10 has a large white tip and a grey tongue running up the inner web



It has a snow white head without traces of streaks, a relative small and very dark eye and a strong bill though with flat gonys angle



Possible Caspian Gull x Herring Gull hybrid

This 1st winter gull was seen at Odense Kanal north of Odense on December 30, 2010. All photos were taken by local birder and finder Tim Hesselballe Hansen.

There certainly is some cachinnans in it but many things point to at least f1 or f2 parentage of argentatus especially as the dark markings on uppertail coverts are very coarse as in argentatus. The tail band has a lot of thin additional transversal bands towards the base of rectrices which is a kind of a cachinnans "trademark" but the extensiveness in this individual is together with the heavily patterned uppertail coverts and rump much darker than the average cachinnans so, even if we don't really know it things point to a possible hybrid.

Other individuals with quite similar uppertail here, here and here.