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 Anatidae

Species name author Linnaeus, 1758

Taxonomic source(s) AOU checklist (1998 + supplements), Cramp and Simmons (1977-1994), Dowsett and Forbes-Watson (1993), SACC (2005 + updates), Sibley and Monroe (1990, 1993), Stotz et al. (1996)

Taxonomic note Although Anas crecca was split by Sangster et al. (2001) into A. crecca and A. carolinensis and this treatment was followed in BirdLife International (2004), AOU (1998) do not adopt this treatment and this source is now followed here.

Population estimate

Population trend

Range estimate (breeding/resident)

Country endemic?

5,900,000 - 6,900,000

unset

31,800,000 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 Northern breeding populations of this species are highly migratory³ although populations in more temperate regions are sedentary¹ or locally dispersive⁵. The species breeds from May onwards³ in single pairs or loose groups¹. Once females have started incubating² (from June or early-July)⁵ males congregate² and undertake extensive moult migrations or remain near the breeding grounds³ to undergo a flightless moulting period lasting for c.4 weeks⁵ (the females moult on the breeding grounds)³. After the post-breeding moult migratory populations of the species migrate south, the peak of the autumn migration occurring between October and November⁵. It returns to the breeding areas from late-February onwards (peaking March-April)⁵. Outside of the breeding season the species forms large concentrations, with large flocks of 30-40 and sometimes hundreds of individuals gathering at winter roosting sites^{3, 6}. The species forages at night during the winter (especially during the hunting season) but forages by day during the breeding season². Habitat Breeding The species shows a preference for shallow^{2, 3} permanent waters⁴ in the breeding season^{3, 7}, especially those in the vicinity of woodlands with fairly dense herbaceous cover available nearby for nesting⁴. Small freshwater lakes and shallow marshes with abundant emergent vegetation^{1, 4} are preferred to open water⁴, as are small waterbodies forming part of a larger wetland, lake or river system, especially in the valleys of small forested rivers⁷. Other suitable habitats include small ponds, pools^{3, 7}, oxbow lakes, lagoons⁷ and slow-flowing streams^{6, 7}. Non-breeding Outside of the breeding season the species frequents similar habitats to those in which it breeds⁶, including marsh and lake habitats and other sheltered waters with high productivity and abundant vegetation² as well as flooded fields and artificial waters (e.g. reservoirs)⁷. During the winter the species also occurs along the coast^{1, 5} on saline⁷ or brackish lagoons with abundant submergent vegetation², saltmarshes³, tidal creeks⁴, intertidal mudflats^{2, 4}, river deltas³, estuarine waters^{2, 3} and even sheltered coastal bays³, although it does show a preference for marshes with mud flats for foraging rather than more saline or open-water habitats⁴. Diet Breeding In spring and summer the diet of the species consists predominantly of animal matter such as molluscs, worms, insects and crustaceans¹. Non-breeding During winter the species mainly takes the seeds of aquatic plants¹ (e.g. emergent and submerged macrophytes)², grasses, sedges and agricultural grain¹ (cereals and rice)². Breeding site The nest is a hollow in the ground placed amongst dense vegetation¹ or under bushes close to water (rarely more then 100 m away)². Neighbouring pairs may sometimes nest only 1 m apart although the species is not colonial⁷. Management information A study in the Czech Republic found that fish ponds with a fish stock density of less than 400 kg ha¹, water transparency of more than 50 cm, mixed fish stocks (e.g. tench and pike or perch) rather than monospecific stocks (e.g. of carp), and systems that include ponds with fish fry (to provide areas with low fish competition and high invertebrate availability) are more successful in supporting breeding pairs of this species¹¹. Studies in Danish coastal wetlands found that the spatial restriction of shore-based shooting was more successful at maintaining waterfowl population sizes than was the temporal restriction of shooting, and therefore that wildfowl reserves should incorporate shooting-free refuges that include adjacent marshland in order to ensure high waterfowl species diversity²⁰.

Threats This species is threatened by lowland habitat loss and degradation (e.g. through wetland drainage)¹¹ and by upland habitat loss due to afforestation and other land-use changes². The species suffers mortality as a result of lead shot ingestion (France)²³ and from poisoning by white phosphorous ingestion (from firearms) in Alaska²¹. It is also intensively hunted in its winter quarters¹. The species is threatened by disturbance from human recreational activities¹⁹, hunting²⁰ and construction work (UK)¹⁸. The species is susceptible to avian botulism⁹ and avian influenza^{10, 17} so may be threatened by future outbreaks of these diseases. Utilisation The species is hunted for sport in North America^{8, 12}, Denmark¹³, France¹⁴ and Italy¹⁵, and is hunted commercially and recreationally in Iran¹⁶. The eggs of this species were (and possibly still are) harvested in Iceland²².

References 1. del Hoyo et al. (1992). 2. Kear (2005b). 3. Madge and Burn (1988). 4. Johnsgard (1978). 5. Scott and Rose (1996). 6. Brown et al. (1982). 7. Snow and Perrins (1998). 8. Baldassarre and Bolen (1994). 9. Rocke (2006). 10. Melville and Shortridge (2006). 11. Musil (2006). 12. Padding et al. (2006). 13. Bregnballe et al. (2006). 14. Mondain-Monval et al. (2006). 15. Sorrenti et al. (2006). 16. Balmaki and Barati (2006). 17. Gaidet et al. (2007). 18. Burton et al. (2002). 19. Pease et al. (2005). 20. Bregnballe et al. (2004). 21. Steele et al. (1997). 22. Gudmundsson (1979). 23. Mondain-Monval et al. (2002). 24. Wetlands International (2002).

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), Sally Fisher (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: Anas crecca. 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.

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