The Yellow-legged Gull (Larus michahellis) is a large gull of Europe, the Middle East and North Africa. It is sometimes considered to be part of the same species as the Caspian Gull and the combined species is then called Larus cachinnans.
Classification
The taxonomy of the Herring Gull/Lesser Black-backed Gull complex is very complicated. This group has a ring distribution around the northern hemisphere. Differences between adjacent forms in this ring are fairly small, but by the time the circuit is completed, the end members, Herring Gull and Lesser Black-backed Gull, are clearly different species. However, different authorities recognise up to eight species in this complex.
It is now generally accepted that the Yellow-legged Gull is a full species, but until recently there was much disagreement. For example, the BOU in Great Britain placed the Yellow-legged Gull as a subspecies of the Herring Gull, while British Birds magazine split Yellow-legged Gull from Herring Gull but included the Caspian Gull in the former. However, recent DNA research has shown that Caspian Gull is basal to the complex, and cannot be in the same grouping as the other form.
There are two subspecies of the Yellow-legged Gull: michahellis (named for the German zoologist Karl Michahelles), which breeds in the Mediterranean, and atlantis, of the adjacent Atlantic shores. Birds breeding in Portugal and the Atlantic coast of Galicia (and spreading north from there) are sometimes considered to be a third subspecies: lusitanius. Atlantic Ocean birds have darker wings and back by comparison, creating a more pronounced contrast to the white parts.
Distribution
The breeding range is centred around the Mediterranean Sea. In North Africa it is common in Morocco, Algeria and Tunisia and increasing in places. Recent breeding has occurred in Libya and Egypt. In the Middle East a few breed in Israel and Syria with larger numbers in Cyprus and Turkey. In Europe there are colonies all along the Mediterranean coast and it also breeds on the west side of the Black Sea. Here it overlaps with the Caspian Gull but there is a difference in habitat with the Yellow-legged Gull choosing sea cliffs. In recent decades birds have spread north into central Europe and first bred in Britain in 1995. The Yellow-legged Gull is also common in Gibraltar, the Canary Islands, Madeira Islands and the Azores.
Many birds remain in the same area all year round but others migrate to spend the winter in mild areas of Western Europe or head south as far as Senegal, the Gambia and the Red Sea. It is reported as a vagrant to northeastern North America and Nigeria.
Description
Nominate L. m. michahellis, Elba
Adults are similar to Herring Gulls but have yellow legs. They have a grey back, slightly darker than Herring Gulls but lighter than Lesser Black-backed Gulls. They are much whiter-headed in autumn, and have more extensively black wing tips with few white spots, just as Lesser Black-backed. They have a red spot on the bill as adults, like the entire complex. There is a red ring around the eye like in the Lesser Black-backed Gull but unlike in the Herring Gull which has a dark yellow ring.
First-year birds have a paler head, rump and underparts than those of the Herring Gull. They have a dark bill and eyes, pinkish grey legs, dark flight feathers and a well-defined black band on the tail. They become lighter un the underparts and lose the upperpart pattern subsequently. By their second winter, birds are essentially feathered like adults, save for the patterned feathers remaining on the wing coverts. However, their billtips are black, their eyes still dark, and the legs are a light yellow flesh color.
The call is a loud laugh which is deeper and more nasal than the call of the Herring Gull.
Diet
These are omnivores like most Larus gulls, and they will scavenge on rubbish tips and elsewhere, as well as seeking suitable small prey in fields or on the coast, or robbing plovers or lapwings of their catches.
Reproduction
Yellow-legged Gulls usually breed in colonies. Eggs, usually three, are laid from mid March to early May and are defended vigorously by this large gull. The nest is a sometimes sparse mound of vegetation built on the ground or on cliff ledges. In some places such as Gibraltar they have started nesting on buildings. The eggs are incubated for 27-31 days and the young birds fledge after 35-40 days.
Young L. m. michahellis near Marseille
Juvenile, about 1 year old
Subadult L. m. michahellis (about 2 years old)
Adult, Portugal (L. m. atlantis/lusitanius)
Adult L. m. michahellis, Barcelona
A Yellow-legged Gull on a
guano encrusted rooftop in Gibraltar.
Notes
- ^ BirdLife International (2004). Larus cachinnans. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Database entry includes justification for why this species is of least concern
