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 (Pontoppidan, 1763)

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?

200,000 - 590,000

unset

22,700,000 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, with inland populations moving south or to the coast after breeding¹. The species breeds from May onwards, nesting later further to the north depending on the timing of the thaw¹. It usually nests solitarily on smaller waters but may nest in loosely colonial groups on larger waters (e.g. several pairs nesting a few metres apart on the same lake)³. On migration large flocks of 200-1,200 individuals may form, with similar concentrations occurring on rich marine fishing grounds during the winter¹. The species is most commonly observed singly, in pairs or in small scattered flocks during this season however³. Habitat Breeding The species breeds on freshwater pools or lakes in open moorland, blanket bogs¹ or open and wet peatland habitats⁶. It will nest on pools as small as 10-20 m long or on lakes up to 5 ha in area, showing a preference for those in treeless areas that have well-vegetated margins and low islets or promontories on which to nest³. It generally avoids waters with dense floating or emergent vegetation and steep rocks above the water³, and if feeding conditions are inadequate in the pool chosen for breeding the species may fly to the coast or to lakes with higher abundances of fish in order to feed³. Non-breeding Outside of the breeding season the species frequents inshore waters along sheltered coasts, occasionally occurring inland¹ on lakes, pools, reservoirs and rivers³. Diet Its diet consists predominantly of fish as well as crustaceans, molluscs, frogs, fish spawn¹, aquatic insects, annelid worms³ and plant matter¹. Breeding site The nest is a small depression^{2, 3} or a mound of plant matter^{1, 3} built in shallow water up to 10 m from the shore³ or very near the water's edge^{1, 2, 3} on islets or small promontories². Nesting pairs will often re-use the same site in successive years³. Management information In Scotland attempts have been made to implement education schemes for fishermen and land-owners to try to reduce disturbance and mortality of the species on breeding lakes⁶. The introduction of floating artificial nesting rafts may also be successful in increasing the species's breeding success⁶.

Threats When breeding the species is threatened by water level fluctuations^{1, 6}, acidification of breeding waters^{1, 6}, heavy metal pollution¹ and the afforestation of peatland or moorland habitats⁶. It is also sensitive to human disturbance from recreational activities¹ and shoreline development (e.g. construction work near breeding lakes)⁵ and will desert sites if there is too much human activity¹. During the winter the species is highly vulnerable to coastal oil spills, especially in areas where large concentrations form (e.g. on rich fishing grounds)¹, and is highly sensitive to disturbance from coastal wind farms (wind turbines) during this season⁴. The species suffers mortality at sea and on large lakes due to entanglement and drowning in inshore fishing nets¹ and is susceptible to avian influenza so may be threatened by future outbreaks of the virus⁷.

References 1. del Hoyo et al. (1992). 2. Flint et al. (1984). 3. Snow and Perrins (1998). 4. Garthe and Huppop (2004). 5. Meek et al. (1993). 6. Campbell (1987). 7. 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: Gavia stellata. 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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