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THE DODGY SEAGULL PAGE
Text and almost all photos by Keith Vinicombe

Over the years, we have seen a number of unusual gulls at Chew, many of which have been controversial or have defied identification. With the increase in digi-scoping in recent years, more and more of these birds are being photographed and this part of the website is designed to be a repository for such photographs. Hopefully they will be of interest and stimulate wider discussion about the birds' identities.


GULL 1
This peculiar gull has been on Herriott’s Pool for a couple of months. It seems to have broken its wing at some point and it is no longer able to fly. Therefore, it is permanently resident on the pool. The photos were taken on 28th October 2007.

It stands out conspicuously from the graellsii that are present as it is conspicuously smaller: maybe only three-quarters the size. As the photographs clearly show, it has as a rather hunched posture, an attenuated body and primaries, an obviously smaller, slimmer and more pointed bill and a much more rounded head shape. In addition, it has reduced head streaking and, perhaps most significantly, it shows no sign of any primary moult. When it opens its wings, there is very little contrast between the primaries and the rest of the wing. It does have one small white mirror in its outer primaries (at least on one wing).

It is obviously darker and blacker than graellsii, but I am not totally convinced that it is really black enough for fuscus (?).

copyright Keith Vinicombe
Note the small size, slim pointed bill, limited head streaking and the dark mantle.

copyright Keith Vinicombe
Note the unmoulted primaries and its small size compared with the Common Gull behind.


GULL 2
While photographing the odd Baltic-like Gull described above on 28th October 2007, this strange gull came up and stood next to it. It was basically a Lesser Black-back but, as the photos clearly show, it was a big, heavy, powerful bird, with a ‘woolly' head, a deep breast and, most obviously, a very deep, heavy and blunt bill with a marked gonydeal angle. The head streaking was a pale shade of grey and it was rather fine and restricted. There was heavier but rather sparse streaking around the nape. Its mantle was clearly a shade paler than graellsii and this was most obvious when the bird turned back-on. It had thick and obvious tertial and scapular crescents.

Looking at these photos, the bird reminded me very strongly of photos of a Heuglin’s Gull at Ravenna in NE Italy on 24th January 2004 (see http://www.surfbirds.com/blog/birdingitalynet/page2/hisy=& sm=&thisd= - scroll down until you find it). There are also links on that website to photos of Heuglin's Gulls from Oman. The bill shape, head streaking and mantle colours all look similar to those birds, but is the primary moult correct? Like Baltic Gull, Heuglin’s seems to moult its primaries in its winter quarters. Could it be a Yellow-legged x Lesser Black-back hybrid? But if it is, why is it so big and heavy with such a large bill?

copyright Keith Vinicombe
This is a very dark photograph but it shows well the thick blunt bill.

copyright Keith Vinicombe
Note the heavy-breasted look and the rather limited fine grey head streaking.

copyright Keith Vinicombe
Note the thick 'woolly' head and the pale mantle, with contrasting white scapular and tertial crescents.

copyright Keith Vinicombe
Like graellsii, the old primaries have been moulted and the new ones are not yet fully grown.


GULL 3
This unusual gull was seen on Herriott’s Pool on 18th October 2007. The lesser wing coverts and also a single feather on the tertials clearly revealed that it was a this year’s bird. However, all the back, scapulars, greater coverts and tertials had been moulted, the latter showing a strange ‘inbetweeny’ pattern.

In flight it showed pale wings contrasting with a very dark secondary bar as well as obvious pale windows. The bird therefore appeared to be a Yellow-legged Gull but note its small size, short legs and relatively small bill. An adult seen subsequently was similar in size and structure. Late summer Yellow-legged Gulls seen at Chew are large birds and they hang around the lake during the day feeding on fish. Late autumn birds, however, are often smaller and much more similar in size and structure to Lesser Black-backs. What is more, they appear to be mainly field feeders that associate much more with Lesser Black-backs, appearing in the roost with them in the evenings. I have suspected for some time that these smaller birds may have a western Iberian origin, whereas the late summer birds are from the larger Mediterranean population.

The early breeding of Yellow-legged Gulls means that many juveniles commence a body moult very early. A whole series of photographs of such birds can be found on http://www.xs4all.nl/~daarruud/micha/index.html.

copyright John Martin
Although a first-winter bird, note the advanced and rather unusual upperpart plumage.
Photo: John Martin

copyright Keith Vinicombe
A close-up of its rear end.

MORE DODGY SEAGULLS:

Keith's article on the 2004 Caspian Gull can be found here.

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