Justification This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). The population trend appears to be increasing, and hence the species does not approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is very large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.

Family/Sub-family Laridae

Species name author Linnaeus, 1758

Taxonomic source(s) AERC TAC (2003), AOU checklist (1998 + supplements), Cramp and Simmons (1977-1994), Dowsett and Forbes-Watson (1993), Sibley and Monroe (1990, 1993), Stotz et al. (1996)

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

540,000 - 750,000

unset

1,070,000 km²

No

Important Bird Areas Click here to view map showing IBAs where species is recorded and triggers any of the IBA criteria.

Ecology: Behaviour The migratory movements of this species vary throughout its range, with high Arctic breeders migrating south for the winter but southern breeders only dispersing short distances¹. The breeding season starts from early-April or mid-May with the species nesting in solitary pairs amidst colonies of other species or in small mixed-species colonies¹ of up to 50-100 individuals² (e.g. with Herring Gull Larus argentatus)¹ in favourable locations². The autumn migration occurs between July and November (peaking October-November) and the return migration to the breeding grounds occurs between March and April³. Outside of the breeding season the species is largely gregarious³. Habitat The species inhabits rocky or sandy coasts, estuaries and inshore and offshore waters, breeding on vegetated islands, dunes, flat-topped stacks, rocky shores¹, flat beaches⁴ and islands in saltmarsh¹. The species may also breed on undisturbed inland sites including islets in large freshwater lakes and rivers⁴, fields and open moorland¹. Diet The species is omnivorous and opportunistic, its diet consisting of fish, adult and young birds, birds eggs, mammals (e.g. rabbits, lemmings, rats and mice), insects, marine invertebrates (e.g. molluscs), carrion and refuse¹. Breeding site The nest is a shallow cup constructed from grass, moss and seaweed and is positioned on sand, grass or bare rock substrates on vegetated islands, rocky ridges and outcrops, dunes¹, flat beaches⁴ and islands in saltmarsh among scrub¹. The species may also nest in undisturbed inland sites such as islets in large freshwater lakes and rivers⁴, fields and open moorland¹. Management information The breeding densities of this species in the Baltic Sea were unaffected by the removal of the introduced nest predator American mink Neovison vison from small offshore breeding islands⁶. The species is considered to be a threat to other bird species due to its predatory and opportunistic diet¹.

Threats Utilisation The species is hunted for sport in Denmark⁵.

References 1. del Hoyo et al. (1996). 2. Richards (1990). 3. Olsen and Larsson (2003). 4. Snow and Perrins (1998). 5. Bregnballe et al. (2006). 6. Nordstrom et al. (2003).

Further web sources of information

Detailed species account from Birds in Europe: population estimates, trends and conservation status (BirdLife International 2004)

Text account compilers Stuart Butchart (BirdLife International), Jonathan Ekstrom (BirdLife International), Lucy Malpas (BirdLife International)

IUCN Red List evaluators Jeremy Bird (BirdLife International), Stuart Butchart (BirdLife International)

Recommended citation BirdLife International (2009) Species factsheet: Larus marinus. Downloaded from http://www.birdlife.org on 10/2/2010

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

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