Yellow-legged Gull
Larus michahellis
The Yellow-legged Gull is a large gull species that closely resembles the European Herring Gull but is distinguished by its bright yellow legs and a sturdier bill. It primarily inhabits the Mediterranean coasts but has significantly expanded its range into Central Europe in recent decades. As an opportunistic omnivore, it exploits both natural food sources and human-generated waste in urban areas.
Details
Identification
Yellow legs, pale grey mantle, red gonys spot on a yellow bill, white iris, black wingtips with white mirrors.
Social behavior
Highly social and colonial breeder; exhibits strong territorial behavior and complex communication through vocalizations.
Diet
Omnivore: fish, mollusks, crustaceans, insects, small vertebrates, eggs, carrion, and organic waste.
Hunting strategy
Plunge-diving, surface-dipping, kleptoparasitism (stealing food from other birds), and opportunistic ground foraging.
Overwintering
Overwinters in ice-free coastal regions, on large rivers, lakes, or at landfill sites.
Ecology
Ecological role
Top predator and important scavenger; regulates populations of smaller animals and removes organic remains.
Natural predators
Large raptors (e.g., Eagle Owl), foxes (for eggs/chicks), and occasionally larger gull species.
Competitor species
Herring Gull (Larus argentatus), Caspian Gull (Larus cachinnans), Lesser Black-backed Gull (Larus fuscus).
Ecosystem service
Removal of carrion and waste in coastal and urban areas.
Threats
Loss of natural nesting sites, poisoning by pollutants in food, closure of open landfill sites.
Scientific profile
Morphology & ID
Breeding plumage
White head, neck, and underparts. Medium grey mantle and upperwings. Black wingtips with white mirrors. Bright yellow legs. Yellow bill with a prominent red gonys spot.
Non-breeding plumage
Similar to breeding plumage; the head usually remains pure white or shows only very fine, barely visible streaking, unlike the Herring Gull (L. argentatus).
Juvenile plumage
Mottled brown-grey with a dark bill and pinkish to greyish legs. The plumage appears overall darker and more contrasted than in juvenile Herring Gulls.
Sexual dimorphism
Slight; males are on average slightly larger and heavier than females, while the plumage is identical in both sexes.
Distinguishing features
Adults are characterized by bright yellow legs, a robust yellow bill with a red spot, and a medium grey mantle. The head remains mostly pure white even in winter.
Confusion species
Herring Gull (Larus argentatus), Caspian Gull (Larus cachinnans), Lesser Black-backed Gull (Larus fuscus).
Bill
Robust and yellow with a prominent red spot at the gonys (angle of the lower mandible).
Vocalization
Song
No song in the classical sense; instead complex territorial calls, especially the 'long-call'.
Call
A deep, laughing 'Kyow' or 'Gau-gau-gau'. Calls are deeper and more powerful than those of the Herring Gull.
Distribution & migration
Breeding range
Originally Mediterranean and Black Sea coasts, as well as Atlantic coasts (Iberia to France). Significant expansion into Central Europe at inland waters (e.g., Lake Constance, Danube, Rhine).
Wintering range
Largely overlapping with the breeding range, but dispersal northwards to the North and Baltic Seas as well as ice-free inland waters.
Migration details
Resident in southern regions; partial migrant in Central Europe. Juveniles often show extensive dispersal movements in all directions.
Habitat
Breeding habitat
Rocky coasts, islands, gravel roofs in cities, gravel pits, and increasingly buildings in urban areas. More rarely in silting zones with reeds.
Foraging habitat
Coastal marine waters, harbors, landfills, agricultural land, urban squares, and fishing vessels.
Breeding biology
Nest construction
A shallow scrape lined with available material such as grasses, algae, feathers, or anthropogenic debris.
Eggs
Olive-green, brownish, or bluish with irregular dark spots and dots for camouflage.
Parental care
Both parents share incubation and feeding of the chicks by regurgitating food.
Diet & behaviour
Diet breeding
Opportunistic omnivore: Fish, marine invertebrates, eggs and chicks of other birds, small mammals, insects, and organic waste.
Diet winter
Similar to the breeding season, but with a higher proportion of waste from landfills and fishery bycatch.
Feeding technique
Plunge-diving, surface-picking, kleptoparasitism (stealing food), and foraging on foot.
Foraging strategy
Generalist and opportunistic hunter and gatherer.
Sociality
Highly social; breeds in colonies and forms large flocks at roosting and feeding sites.
Flock behaviour
Forms dense breeding colonies and coordinated flight formations during foraging; often associated with other gull species.
Protection & threats
Main threats
Closure of open landfills (food loss), direct persecution in cities, bioaccumulation of pollutants, and predation by invasive species on islands.
Population trend
Stable to increasing; shows significant range expansion to the north and an increase in breeding pairs inland.
Conservation measures
Protection of key breeding sites, population monitoring, management of human-wildlife conflicts in urban areas.