Black-headed Gull – Common Bird of Eurasia
A Seagull that Frequents Inland Waters and Human Developments
Jun 5, 2009
Like the Herring Gull, the Black-headed Gull, Larus ridibundus, has adapted well to human communities, frequenting sewer outflows, landfill sites, and farmers fields in search of food. This partly explains why the bird is so familiar to residents of Europe, where the highest populations of Black-headed Gulls are found. The other reason is that this gull is very common, with an estimated global population of 7,300,000 to 11,000,000 birds.
Black-headed Gulls are found mostly in the northern hemisphere—throughout Eurasia, and in northern Africa. A few, probably migrants from the far north, visit coastal North America in winter. They rarely venture inland on that continent. A small number reside year round in Eastern Canada, breeding in Newfoundland.
The Black-headed Gull’s Name
Both the common and scientific names of this bird seem designed to create confusion. First, the gull does not have a black head: the breeding adult has a chocolate brown head, while immature’s and non-breeding adult’s heads are white with dark markings. And while we associate gulls with the ocean, this species spends much of its life on shore and inland. The scientific name, Larus ridibundus, can be translated as “laughing sea bird,” not to be confused with the very similar Laughing Gull, Larus atricilla!
What Do Black-headed Gulls Eat?
Black-headed gulls eat insects, worms, and other invertebrates, snatching some food either from the air or water surface while in flight. In water, they dip their heads to catch prey near the surface, and in shallow water or on land, they cast about with their feet or probe with their long beaks. In farmer’s fields, they opportunistically feed on worms after the plow has passed. They’ll take fish, small rodents, and berries, and they forage for scraps in garbage dumps.
The small resident population in Atlantic Canada tends to blend in with flocks of Bonaparte’s gulls, and do not frequent human land fills or fields.
Black-headed Gull Habitat
Because it feeds at the surface of both land and water, the Black-headed Gull is usually found in fairly flat open areas near water: mudflats and beaches, dunes, salt marshes, wetlands, estuaries, even sewage lagoons and artificial waterways. Similarly, the species prefers to breed near shallow still water, and may even nest on tussocks in a marsh or flooded wetland.
Black-headed Gull Breeding
Like most gulls, Black-headed Gulls form monogamous pairs, and breed in colonies, frequently mixing in with other gulls and terns. They build a shallow scrape lined with plant material, which is built up off the ground where there is danger of flooding. The female typically lays two or three eggs, which hatch after about three and a half weeks of incubation. The young are able to leave the nest at about ten days of age and fledge at five weeks.
Do Black-headed Gulls Migrate?
Some Black-headed Gulls live in arctic regions where winters are harsh and food becomes scarce outside the breeding season. These birds migrate south for the winter and return north to breed. More southerly populations, however, tend stay in one region year round.
Threats to Black-headed Gulls
The global population of Black-headed Gulls is thought to be declining though the species is not considered threatened. Its ability to adapt to a human presence supported a population increase in the past, and numbers may still be above normal.
Threats to Black-headed gulls include coastal oil pollution and chemical pollutants in water, diseases such as botulism and avian flu, and egg collecting in breeding colonies.
Sources:
“Larus ridibundus.” The IUCN Red List of Threatened Species
“Black-headed Gull.” Cornell Laboratory of Ornithology
Sea & Coastal Birds of North America. Leslie, Scott. Toronto: Key Porter, 2008.
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