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 Podicipedidae

Species name author (Boddaert, 1783)

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?

190,000 - 290,000

unset

18,600,000 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 and breeds from April or May to June or August¹ in isolated solitary pairs², sometimes also nesting in loose colonies¹ of up to c.20 pairs⁵. Post-breeding adults undergo a flightless wing-moulting period² after which they migrate south either singly or in small loose flocks¹ with concentrations of over 2,000 individuals occurring at favoured staging sites¹. During the winter the species typically feeds singly and rarely aggregates into flocks². Habitat Breeding The species breeds on small (less than 3 ha), shallow (less than 2 m deep) inland waters with abundant emergent vegetation¹ (e.g. reedbeds)² and stretches of open water¹, showing a preference for waters in forested areas or in shrub tundra further to the north¹. Suitable habitats include small pools and lakes, backwaters of large rivers, pools cut off from the sea in estuaries¹ and coastal lagoons². In coastal locations the species often makes foraging flights to inland lakes or offshore areas², and if foraging at sea it shows a preference for sub-tidal locations down to a depth of 15 m with sand or gravel substrates, scattered rocks and patches of seaweed². Non-breeding When moulting, on passage or during the winter the species frequents large inland lakes^{1, 2} or shallow coastal areas² with abundant fish stocks¹, often considerable distances from the shore, amongst islands in archipelagos or over drop-off zones². When foraging at sea the species shows a preference for sub-tidal locations down to a depth of 15 m with sand or gravel substrates, scattered rocks and patches of seaweed². Diet Its diet consists predominantly of invertebrates⁵ such as adult and larval aquatic insects (e.g. water beetles, water bugs and dragonfly larvae), crayfish and molluscs³, although fish are also be important locally or seasonally¹. Breeding site The nest is a floating platform of plant matter anchored to submerged or emergent vegetation¹. The species typically breeds in isolated pairs with more than 50 m between neighbouring nests², although in some cases (e.g. on predator-free islands of floating vegetation attached to emergent vegetation beds) semi-colonial nesting may occur².

Threats In North America the species is threatened by pollutants such as polychlorinated biphenyls (PCBs) and other pesticides¹ (e.g. DDT)⁴ which cause reduced reproductive success due to egg sterility and eggshell thinning^{1, 4}. The species is also threatened by the modification and degradation of lakes and by human disturbance from water-based recreational activities¹. It may also be threatened by future oil spills at sea during the winter (although during this season the species is widely scattered along coasts, so the effects of oil spills are likely to be small)¹.

References 1. del Hoyo et al. (1992). 2. Fjeldsa (2004). 3. Konter (2001). 4. Ogilvie and Rose (2003). 5. Snow and Perrins (1998).

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: Podiceps grisegena. 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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