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). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to 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 Pallas, 1773

Taxonomic source(s) AERC TAC (2003), Cramp and Simmons (1977-1994), Dowsett and Forbes-Watson (1993), Sibley and Monroe (1990, 1993)

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

50,000 - 1,100,000

unset

4,880,000 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 This species is fully migratory^{1, 2, 3}, although many immatures over-summer in the winter range². The species begins to arrive in its breeding grounds from early-May; breeding from early-April¹ in large colonies, usually of more than 10 pairs (often 150-300³ or exceptionally up to 3,000 pairs¹) sometimes near, but not with, Larus argentatus^{1, 3}. It may also breed in single pairs, but never nests solitarily (it will always nest within a colony of other gull species)^{1, 3}. Outside of the breeding season the species usually remains solitary or in small parties³ of 2-3 individuals⁴, although it may roost gregariously, and will aggregate into large groups where fish are abundant³. Habitat Breeding The species breeds on barren islands or islets³ in fresh and saline lakes, on inland seas in warm arid steppe^{1, 2}, on rivers and river deltas where ample surface water is available³, and on suitable mountain lakes up to 1,700 m^{2, 3}. It nests in reedbeds, in shrubby vegetation or on bare flat surfaces³. Non-breeding After breeding the species shifts to fish-rich² sea-coasts³, wintering on beaches^{1, 2, 4} and in harbours^{1, 2, 3}. During this season it may also occur inland on beaches⁴ of major rivers^{1, 2}, lakes³ and reservoirs², or at fish ponds^{1, 2} and refuse dumps¹. Diet The species is omnivorous although its diet is dominated by animal material³. It chiefly feeds on fish (particularly dead fish), crustaceans, insects and small mammals, less often taking birds and their eggs, reptiles, and seeds^{1, 3}. It often flies long distances from colonies in the breeding season to feed aerially on swarms of insects^{1, 3}, follows fishing boats and scavenges in harbours¹. Breeding site The nest is a shallow depression³ positioned in the open³ on bare rock, among reeds or scrub vegetation³, or on vegetated sand-dunes¹.

Threats This species is threatened by increasing predation from Larus cachinnans in its breeding range, and by nest predation by mammals (e.g. wild boar Sus scrofa)¹. It is also still persecuted in some regions due to its depredation on commercial fish, and colonies are often subject to flooding following storms¹. The species is susceptible to avian influenza, so may be threatened by future outbreaks of this disease⁵.

References 1. del Hoyo et al. (1996). 2. Olsen and Larsson (2003). 3. Snow and Perrins (1998). 4. Urban et al. (1986). 5. Melville and Shortridge (2006).

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 ichthyaetus. 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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