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.
Distribution and population
AERC TAC. 2003. AERC TAC Checklist of bird taxa occurring in Western Palearctic region, 15th Draft. Available at: http://www.aerc.eu/DOCS/Bird_taxa_of _the_WP15.xls.
AOU. 1998. Check-list of North American birds. American Ornithologists' Union, Washington, D.C.
Cramp, S.; Perrins, C. M. 1977-1994. Handbook of the birds of Europe, the Middle East and Africa. The birds of the western Palearctic. Oxford University Press, Oxford.
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.
This species can be found in western Canada
, north-west USA
, eastern Russia
, north-east China
and northern Japan
, wintering from Japan and Korea
through the Aleutian Islands to California (both USA), and off eastern the USA south to Florida. It can also be found in eastern Europe, west and west-central Asia wintering from the North Sea, Black Sea and Caspian Sea (del Hoyo et al.
The global population is estimated to number c.190,000-290,000 individuals (Wetlands International 2006), while national population estimates include: c.10,000-100,000 breeding pairs, c.1,000-10,000 individuals on migration and c.50-1,000 wintering individuals in China; < c.100 breeding pairs, < c.50 individuals on migration and c.1,000-10,000 wintering individuals in Japan and c.10,000-100,000 breeding pairs and c.1,000-10,000 individuals on migration in Russia (Brazil 2009).Trend justification
The overall population trend is decreasing, although some populations have unknown trends (Wetlands International 2006). This species has undergone a small or statistically insignificant increase over the last 40 years in North America (data from Breeding Bird Survey and/or Christmas Bird Count: Butcher and Niven 2007).EcologyBehaviour
This species is fully migratory and breeds from April or May to June or August (del Hoyo et al.
1992) in isolated solitary pairs (Fjeldsa 2004), sometimes also nesting in loose colonies (del Hoyo et al.
1992) of up to c.20 pairs (Snow and Perrins 1998). Post-breeding adults undergo a flightless wing-moulting period (Fjeldsa 2004) after which they migrate south either singly or in small loose flocks (del Hoyo et al.
1992) with concentrations of over 2,000 individuals occurring at favoured staging sites (del Hoyo et al.
1992). During the winter the species typically feeds singly and rarely aggregates into flocks (Fjeldsa 2004). Habitat Breeding
The species breeds on small (less than 3 ha), shallow (less than 2 m deep) inland waters with abundant emergent vegetation (del Hoyo et al.
1992) (e.g. reedbeds) (Fjeldsa 2004) and stretches of open water (del Hoyo et al.
1992), showing a preference for waters in forested areas or in shrub tundra further to the north (del Hoyo et al.
1992). Suitable habitats include small pools and lakes, backwaters of large rivers, pools cut off from the sea in estuaries (del Hoyo et al.
1992) and coastal lagoons (Fjeldsa 2004). In coastal locations the species often makes foraging flights to inland lakes or offshore areas (Fjeldsa 2004), 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 seaweed (Fjeldsa 2004). Non-breeding
When moulting, on passage or during the winter the species frequents large inland lakes (del Hoyo et al.
1992, Fjeldsa 2004) or shallow coastal areas (Fjeldsa 2004) with abundant fish stocks (del Hoyo et al.
1992), often considerable distances from the shore, amongst islands in archipelagos or over drop-off zones (Fjeldsa 2004). 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 seaweed (Fjeldsa 2004). Diet
Its diet consists predominantly of invertebrates (Snow and Perrins 1998) such as adult and larval aquatic insects (e.g. water beetles, water bugs and dragonfly larvae), crayfish and molluscs (Konter 2001), although fish are also be important locally or seasonally (del Hoyo et al.
1992). Breeding site
The nest is a floating platform of plant matter anchored to submerged or emergent vegetation (del Hoyo et al.
1992). The species typically breeds in isolated pairs with more than 50 m between neighbouring nests (Fjeldsa 2004), although in some cases (e.g. on predator-free islands of floating vegetation attached to emergent vegetation beds) semi-colonial nesting may occur (Fjeldsa 2004).Threats
In North America the species is threatened by pollutants such as polychlorinated biphenyls (PCBs) and other pesticides (del Hoyo et al.
1992) (e.g. DDT) (Ogilvie and Rose 2003) which cause reduced reproductive success due to egg sterility and eggshell thinning (del Hoyo et al.
1992, Ogilvie and Rose 2003). The species is also threatened by the modification and degradation of lakes and by human disturbance from water-based recreational activities (del Hoyo et al.
1992). 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) (del Hoyo et al.
Brazil, M. 2009. Birds of East Asia: eastern China, Taiwan, Korea, Japan, eastern Russia. Christopher Helm, London.
del Hoyo, J.; Elliot, A.; Sargatal, J. 1992. Handbook of the Birds of the World, vol. 1: Ostrich to Ducks. Lynx Edicions, Barcelona, Spain.
Delany, S.; Scott, D. 2006. Waterbird population estimates. Wetlands International, Wageningen, The Netherlands.
Fjeldså, J. 2004. The grebes. Oxford University Press, Oxford, U.K.
Konter, A. 2001. Grebes of our world. Lynx Edicions, Barcelona.
Ogilvie, M.; Rose, C. 2003. Grebes of the World. Bruce Coleman, Uxbridge.
Snow, D. W.; Perrins, C. M. 1998. The Birds of the Western Palearctic vol. 1: Non-Passerines. Oxford University Press, Oxford.
Further web sources of information
Detailed species account from Birds in Europe: population estimates, trends and conservation status (BirdLife International 2004)
Text account compilers
Ekstrom, J., Butchart, S., Malpas, L., Calvert, R.
IUCN Red List evaluators
Butchart, S., Symes, A.
BirdLife International (2014) Species factsheet: Podiceps grisegena. Downloaded from
http://www.birdlife.org on 18/04/2014.
Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from
http://www.birdlife.org on 18/04/2014.
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
To contribute to discussions on the evaluation of the IUCN Red List status of Globally Threatened Birds, please visit BirdLife's Globally Threatened Bird Forums.
Additional resources for this species