Lesser black-backed gull
|Lesser black-backed gull|
|Larus fuscus graellsii with red and silver leg rings; England|
The lesser black-backed gull (Larus fuscus) is a large gull that breeds on the Atlantic coasts of Europe. It is migratory, wintering from the British Isles south to West Africa. It is a regular winter visitor to the east coast of North America, probably from the breeding population in Iceland.
This species breeds colonially on coasts and lakes, making a lined nest on the ground or a cliff. Normally, three eggs are laid. In some cities the species nests within the urban environment, often in association with herring gulls.
They are smaller than the herring gull. The taxonomy of the herring gull / lesser black-backed gull complex is very complicated; different authorities recognise between two and eight species. 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. The lesser black-backed gull measures 51–64 cm (20–25 in), 124–150 cm (49–59 in) across the wings and weighs 452–1,100 g (0.996–2.425 lb), with the nominate race averaging slightly smaller than the other two subspecies. Males, at average weight of 824 g (1.817 lb), are slightly larger than females, at an average of 708 g (1.561 lb). Among standard measurements, the wing chord is 38.3 to 45 cm (15.1 to 17.7 in), the bill is 4.2 to 5.8 cm (1.7 to 2.3 in) and the tarsus is 5.2 to 6.9 cm (2.0 to 2.7 in). A confusable species in Europe is great black-backed gull. The lesser is a much smaller bird, with slimmer build, yellow rather than pinkish legs, and smaller white "mirrors" at the wing tips. The adults have black or dark grey wings (depending on race) and back. The bill is yellow with a red spot which young peck at, inducing feeding (see fixed action pattern). The head is greyer in winter, unlike great black-backed.
Young birds have scaly black-brown upperparts and a neat wing pattern. They take four years to reach maturity. Identification from juvenile herring gulls is most readily done by the more solidly dark (unbarred) tertial feathers.
The call is a "laughing" cry like that of the herring gull (to which this species is closely related), but with a markedly deeper pitch.
They are omnivores like most Larus gulls, and they will eat fish, insects, crustaceans, worms, starfish, molluscs, seeds, berries, small mammals, eggs, small birds, chicks, scraps, offal, and carrion.
There are three races:
- Larus fuscus fuscus – Baltic Sea, eastern Scandinavia. Mantle jet black.
- Larus fuscus intermedius – Denmark, Netherlands, Norway. Mantle sooty black.
- Larus fuscus graellsii – British Isles, Iceland, northern France. Mantle dark grey.
See also – ring species.
Ireland: Copeland Bird Observatory, Co. Down.
England: Co. Durham.
- "National Geographic" Field Guide to the Birds of North America ISBN 0-7922-6877-6
- Seabirds by Peter Harrison, ISBN 0-7470-1410-8
- Handbook of the Birds of the World Vol 3, Josep del Hoyo editor, ISBN 84-87334-10-5
- "National Audubon Society" The Sibley Guide to Birds, by David Allen Sibley, ISBN 0-679-45122-6
Mayr, E.1964. Systematics and the Origin of Species. Standard Book Number: 486-21212-2 p. 180.
- BirdLife International (2012). "Larus fuscus". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013.
- The Urban Gull – a new phenomenon(retrieved 15 September 2009)]
- Lesser Black-backed Gull, Cornell Lab of Ornithology
- Gulls: Of North America, Europe, and Asia by Klaus Malling Olsen & Hans Larsson. Princeton University Press (2004). ISBN 978-0691119977.
- Harrison, Peter, Seabirds: An Identification Guide. Houghton Mifflin Harcourt (1991), ISBN 978-0-395-60291-1
- CRC Handbook of Avian Body Masses by John B. Dunning Jr. (Editor). CRC Press (1992), ISBN 978-0-8493-4258-5.
- Copeland Bird Observatory. Annual Report 2010
- Bowey, K. and Newsome, M. 2012. The Birds of Durham. Durham Bird Club. ISBN 978-1-874701-03-3
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