Lesser black-backed gull

Lesser black-backed gull
Larus fuscus graellsii
Conservation status
Least Concern Least Concern  (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Charadriiformes
Family:	Laridae
Genus:	Larus
Species:	L. fuscus
Binomial name
Larus fuscus Linnaeus, 1758
File:Larus fuscus map.svg

The lesser black-backed gull (Larus fuscus) is a large gull that breeds on the Atlantic and Arctic coasts of Europe. It is migratory, wintering from the British Isles south to West Africa. However, it has increased dramatically in North America, especially along the east coast. Formerly just a winter visitor to North America, it now occurs in large numbers some winters and birds are recorded year-round. However, there is serious concern about decline in many parts of its range. The species is on the UK Amber List because the UK is home to 40 per cent of the European population and more than half of these are found at fewer than ten breeding sites.

Taxonomy

The lesser black-backed gull was one of the many species originally described by Carl Linnaeus in his 1758 10th edition of Systema Naturae, and it still bears its original name Larus fuscus. The scientific name is from Latin. Larus appears to have referred to a gull or other large seabird, and fuscus meant black or brown.

Subspecies

Five subspecies are accepted:

Image	Subspecies	Distribution
File:Larus fuscus on the wall of Mont St Michel.jpg	L. f. graellsii Brehm, 1857	Greenland, Iceland, Faroe Islands, British Isles, western Europe - mantle dark grey
File:Larus fuscus EM1B1660 (40890382754).jpg	L. f. intermedius Schiøler, 1922	Netherlands, Germany, Denmark, southwest Sweden and western Norway - mantle sooty black
File:Larus fuscus, a gull in Helsinki, Finland, 2020 August.jpg	L. f. fuscus Linnaeus, 1758	northern Norway, Sweden and Finland to the White Sea - mantle jet black
File:Sea-Gull.jpg	L. f. heuglini Bree, 1876	northern Russia to north-central Siberia; known as Heuglin's gull, this was previously considered a separate species.
File:Чайка на фоне оголившихся корней сосны.jpg	L. f. barabensis Johansen, 1960	central Asia

Description

The lesser black-backed gull is smaller than the European herring gull. The taxonomy of the herring gull / lesser black-backed gull complex is complicated; different authorities recognise between two and eight species. This group has a ring species 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 an average weight of 824 g (1.817 lb), are slightly larger than females, at an average of 708 g (1.561 lb). The wing chord is 38 to 45 cm (15 to 18 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 is the 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 at which the young peck, inducing feeding (see fixed action pattern). The head is greyer in winter, unlike that of the great black-backed gull. The annual moult for adults begins between May and August and is not complete on some birds until November. A partial prebreeding moult occurs between January and April.

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.

Their call is a "laughing" cry like that of the herring gull, but with a markedly deeper pitch.

Distribution

Lesser black-backed gulls have expanded their range westwards, first colonising Greenland in the 1980s. The species has not yet bred in the United States, although hybrid pairs with American herring gulls have been recorded twice.

Breeding

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.

File:Larus fuscus MWNH 0325.JPG

Eggs, collection Museum Wiesbaden

Feeding

They are omnivores, like most Larus gulls, and eat fish, insects, crustaceans, worms, starfish, molluscs, seeds, berries, small mammals, eggs, small birds, chicks, scraps, offal, and carrion.

Gallery

• L. f. intermedius in flight, Sweden
  L. f. intermedius in flight, Sweden
• Gull incubating eggs in Pälkäne, Finland
  Gull incubating eggs in Pälkäne, Finland
• Mother gull and her baby
  Mother gull and her baby
• Close up
  Close up
• L. f. graellsii adult, Morocco
  L. f. graellsii adult, Morocco
• L. f. graellsii young adult, Morocco
  L. f. graellsii young adult, Morocco
• L. f. graellsii juvenile, Portugal
  L. f. graellsii juvenile, Portugal
• First cycle plumage
  First cycle plumage
• Flying in a lake near the city hall in Reykjavik
  Flying in a lake near the city hall in Reykjavik
• ID composite
  ID composite
• Larus fuscus fuscus - MHNT
  Larus fuscus fuscus - MHNT

External links

• Lesser black-backed gull pages on www.gull-research.org
• Lesser black-backed gulls in Amsterdam
• BirdLife species factsheet for Larus fuscus
• Lesser black-backed gull photo gallery at VIREO (Drexel University)
• Interactive range map of Larus fuscus at IUCN Red List
• Audio recordings of Lesser black-backed gull on Xeno-canto.
• Larus fuscus in Field Guide: Birds of the World on Flickr
• Lesser black-backed gull Structured guide to the species in southern Africa