June 21st 2004

© A. R. Dean

These photos show a 'yellow-legged gull' recorded on June 21st, and July 2nd, 12th and 26th 2004. The photos were taken on the first date. It showed characters initially suggestive of Yellow-legged Gull (e.g. mantle darker grey than Herring Gull, distinct yellow legs, extensive black in primaries) but on closer examination it was clear that it was not a typical michahellis.

The bird is rather small, round-headed and short-legged while the shade of grey of the mantle is slightly darker than typical for Mediterranean michahellis. These are characters notionally compatible with birds originating from the west coast of Portugal and this may possibly be the origin of this bird. However, the outer six primaries (at least) are all intact and there is no obvious sign of primary moult. By July 26th this situation remained unchanged. The tip of the tail falls between the tips of p6 and p7.

When confronted by yellow-legged gulls of non-standard appearance, consideration must also be given to the possibility of hybrids between Herring Gull and Lesser Black-backed Gull or even a hybrid between michahellis and one of these species. There are records of Herring Gulls and Lesser Black-backed Gulls hybridising in the Bristol area and, as colour-ringed LBBs and HGs from that area are regularly recorded in the West Midlands, it is clearly necessary to be on the watch for possible hybrids. Also, yellow-legged Herring Gulls of at least two phenotypes exist - the so-called 'omissus' of parts of  Scandinavia and yellow-legged birds originating from the region of Latvia (see Jonsson 1998, Alula 4: 74 -100 for a detailed discussion of these forms).

With its atypical combination of structure, rather dark mantle, and the lack of primary moult by late July, I suspect this individual is of hybrid origin.

If anyone has well-founded opinions on the identity/origins of this bird, then please get in touch via email to: