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). The population trend is not known, but the population is not believed to be decreasing sufficiently rapidly to approach the thresholds under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely 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 Brehm, 1831

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?

3,900,000 - 4,200,000

unset

16,900,000 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 fully migratory⁵, although the extent of migration varies between populations¹, and some populations remain predominantly sedentary (e.g. in Spain)^{1, 5}. Autumn movements are often protracted, with dispersal beginning in mid-August and lasting until late-November (peaking in October)⁵, with the return migration beginning in March⁵. The species migratory movements are mainly nocturnal, although diurnal migration is known in the Palearctic¹. It breeds between May and June in the Northern Hemisphere² (although laying dates often vary extensively between years and lakes)², and nests in reed swamps¹ in small or large colonies of up to 2000 nests (although the species may also nest in isolated pairs)². It forages diurnally^{2, 6} and is highly gregarious^{1, 2}, both on migration and during the winter, forming concentrations of hundreds of thousands at certain sites in North America and Asia¹. After arrival in autumn staging grounds (e.g. Mono Lake in California) the species becomes flightless for 3 to 4 months due to loss of weight from the pectoral muscles⁴. Habitat Breeding During the breeding season this species frequents permanent and temporary⁵ small, shallow, highly eutrophic pools with lush vegetation, such as freshwater marshes and lakes¹ with dispersed submergent vegetation and patches of reeds^{2, 3}, as well as ponds and fish ponds, sewage farms, quiet river backwaters and newly flooded areas¹. In southern Russia and Kazakhstan it shows a preference for variably developed reed swamps and gypsotrophic lakes (alkaline waters with rich submergent vegetation such as Chara and Potamogeton pectinatus)². Non-breeding Outside of the breeding season the species moves to salt lakes¹, hyper-saline industrial evaporation ponds² and reservoirs⁵, or to coastal estuaries, arms of the sea, and inshore shallows in bays and channels^{1, 5}. Diet The species is carnivorous, its diet consisting of adult and larval insects (such as aquatic bugs, terrestrial and aquatic beetles, damselflies, dragonflies¹, midges and brine-flies²), molluscs, crustaceans (e.g. brine shrimps), amphibians (e.g. small frogs and tadpoles)¹, nereid worms², snails³ and small fish^{1, 2}. Breeding site It usually nests colonially in thinly spaced, emergent marsh vegetation (such as Scirpus, Typha or sedge Carex), or on dense mats of floating waterweed, sometimes far from the shore². The nest is a floating platform of aquatic vegetation anchored to emergent vegetation^{1, 5} such as reeds².

Threats Huge mortalities are frequently sustained at Salton Sea in southern California for unknown reasons^{8, 9} (possibly an unknown biotoxin, pathogen, impairment of feather waterproofing leading to hypothermia, or a unique manifestation of avian cholera)¹⁴. The species is also vulnerable to oil pollution as it frequently winters on the coast^{1, 4}, and is susceptible to avian cholera^{4, 7}, Erysipelas^{7, 12} and avian botulism¹⁶ so is threatened by future outbreaks of these diseases. Populations have also been known to crash in winter habitats during ENSO events due to reductions in food availability due to warming sea-surface temperatures, although they afterwards rebound¹¹. Local declines of this species are also attributed to human disturbance (especially recreational activities on lakes)¹, and it is commonly killed by collisions with power transmission lines¹⁵. The species is predated by American Mink Mustela vison in the Slonsk Reserve, western Poland¹³ and was threatened in North America by egg collecting and hunting for the millinery (hat making) industry (although this threat has since been removed)¹. Utilisation The species is hunted for commercial and recreational purposes in Gilan Province, northern Iran¹⁰.

References 1. del hoyo et al. (1992). 2. Fjeldsa (2004). 3. Konter (2001). 4. Ogilvie and Rose (2003). 5. Snow and Perrins (1998). 6. Brown et al. (1982). 7. Friend (2006). 8. Cole and Franson (2006). 9. Friend (2002). 10. Balmaki and Barati (2006). 11. Jehl et al. (2002). 12. Jensen and Cotter (1976). 13. Bartoszewicz and Zalewski (2003). 14. Meteyer et al. (2004). 15. Malcolm (1982). 16. van Heerden (1974).

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 nigricollis. 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

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