Regular visitor in small numbers in late summer and winter - possibly more than one phenotype involved.

Yellow-legged Gull breeds in the Mediterranean basin from the Atlantic seaboard in the west, east to the southern Black Sea.

Historically, it was considered to be a subspecies of the Herring Gull but, more recently, morphological and behavioural studies have indicated that it should be regarded as a good species in its own right. This has been further confirmed by DNA studies, which show that michahellis is genetically differentiated from argentatus. See Caspian Gull for further notes on the taxonomy of the yellow-legged group of 'large white-headed gulls'.

Compared with Herring Gull, Yellow-legged Gull is on average more elegant, with a fuller, squarer, more flat-topped head-shape and relatively longer wings and legs. The upperparts are a darker shade of grey than Herring Gull, obviously so compared with British argenteus though approached by darker examples of nominate argentatus. The wing-tip pattern displays more black and less white than Herring Gull. There is generally black on six, sometimes seven, outermost primaries. The black band across the tip of p5 is generally quite thick and unbroken, so that the extent of black on this primary and on p6 is more extensive than on nominate argentatus. The pattern of black is not, however, so distinct from that of argenteus but that race has relatively pale grey upperparts so confusion should generally not arise. In winter, the head of michahellis remains relatively white and unstreaked compared with the generally well-streaked and messy head-pattern of Herring Gull, though when freshly moulted in autumn michahellis often does show limited head-streaking. This tends to take the form of rather neat streaking around the eye and across the centre of the crown, and this in itself can be quite distinctive. [Conversely, Herring Gulls can become very white-headed by mid to late December, and such individuals can look very different from surrounding Herring Gulls with well-streaked heads. There is a very real danger of such birds being misidentified as Yellow-legged Gulls by the incautious.]

 The orbital ring of Yellow-legged Gull is generally blood-red, creating a darker-eyed appearance compared with Herring Gull. In adults the legs are a rich yellow, though less intense during the winter months and throughout the year in sub-adult birds. The yellow legs in combination with the relatively dark grey upperparts are often the features which initially attract attention on a standing bird. Note, however, that Herring Gulls sometimes display yellow-legs, particularly individuals of the nominate form from certain areas of Scandinavia and eastern Baltic region, so it is essential to use a full suite of characters when identifying Yellow-legged Gull.  The timing of the full post-breeding moult is somewhat earlier than in Herring Gull, reflecting it's slightly earlier breeding season. Birds appearing in Britain in late June and early July generally show obvious signs of primary moult, with one or more central primaries 'missing' (in fact present but only part grown or just out of 'pin' and so hidden by overlapping 'inner' primaries). When preening, the state of moult and the pattern of the primary tips can often be determined.

In recent years, Yellow-legged Gulls have been arriving in Britain in increasing numbers in late summer and early autumn, as part of the species' northward  post-breeding moult migration. The largest numbers are to be found in the south-east coastal counties but smaller numbers regularly reach the West Midlands Region. Intriguingly, comparable numbers are observed in the midlands during winter, whereas on the south coast the majority of Yellow-legged Gulls disperse in late autumn and few are recorded during the winter months. It is possible that individuals recorded in the midlands during winter originate from a different population from those occurring in late summer, and arguably there are phenotypic differences between 'typical' individuals observed during the two seasons.

A full analysis of the status of Yellow-legged Gull in the West Midlands Region up to the year 2000 has been published in the West Midland Bird Report for 2002, and is reproduced here .

In 2004, a count of 18 on August 31st at Chasewater constituted a regional record. During 2005, 16 were counted at Draycote on August 3rd, comprising four adults, one fourth year, three third-years, four second-years and four first-years. This total equalled the previous county record, also from Draycote in January 1998.

The five-yearly mean maximum counts from selected sites during 2001 - 2005 are presented in Table 1.

Table 1. Five-yearly mean maximum counts of Yellow-legged Gulls at selected sites in the West Midlands Region, 2001 - 2005.

It is considered that there is significant 'turn over' of Yellow-legged Gulls visiting the region and that, during the course of a year, the number of individual Yellow-legged Gulls visiting the region may well be two or three times the maximum day/site counts, as presented in the Table.

See also a selection of  images in the Photo Gallery, to illustrate the appearance of Yellow-legged Gulls and to facilitate considerations of origins and phenotypic variation.