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 Gaviidae

Species name author (Linnaeus, 1758)

Taxonomic source(s) AERC TAC (2003), AOU checklist (1998 + supplements), Cramp and Simmons (1977-1994), Sibley and Monroe (1990, 1993)

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

280,000 - 1,500,000

unset

18,900,000 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 strongly migratory^{1, 3}. It breeds in isolated solitary pairs^{1, 3} from April onwards², nesting later further to the north depending on the timing of the thaw¹. On migration the species often forms flocks of c.50 individuals¹, generally occurring singly, in pairs or small flocks during the winter³ and occasionally forming large congregations in rich coastal fishing areas¹. Habitat Breeding It breeds on deep, productive, freshwater lakes¹ or extensive pools with islets, peninsulas and other inaccessible nesting sites³. Non-breeding Outside of the breeding season the species is most common on inshore waters along sheltered coasts¹, occasionally also frequenting large inland freshwater bodies^{1, 2} such as natural lakes or barrages, lagoons and large rivers³. Diet Its diets consists predominantly of fish although aquatic insects, molluscs, crustaceans and some plant matter may also be taken¹. Breeding site The nest is a heap of plant matter placed near the water's edge¹ on islets or hummocks emerging from the water, sometimes also on clumps of grass on the shore². Management information In Scotland the construction of floating artificial nesting islands (rafts) on lakes where breeding success was low and/or nests had been flooded succeeded in increasing the breeding success of the species in the area⁸. In Sweden it was also found that nesting islands and areas of surrounding water should be included in sanctuaries for this species⁶.

Threats During the breeding season the species is threatened by the acidification of breeding waters, heavy metal pollution and water level fluctuations¹ especially during the incubation period^{6, 7}. It also suffers from lower reproductive success due to human disturbance¹ (e.g. from tourists or wetland visitors)⁶ and is indirectly affected by breeding habitat alteration (e.g. afforestation)¹. During the winter the species is highly vulnerable to coastal oil spills, especially in rich fishing grounds where large congregation may occur, and is commonly caught and drowned as bycatch in fishing nets¹. The species is also highly sensitive to disturbance from coastal wind farms (wind turbines)⁵ and is susceptible to avian influenza so may be threatened by future outbreaks of the virus⁴.

References 1. del Hoyo et al. (1992). 2. Flint et al. (1984). 3. Snow and Perrins (1998). 4. Melville and Shortridge (2006). 5. Garthe and Huppop (2004). 6. Gotmark et al. (1989). 7. Hake et al. (2005). 8. Hancock (2000)

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: Gavia arctica. 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.

To provide new information to update this factsheet or to correct any errors, please email BirdLife

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