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LC
Pacific Black Duck Anas superciliosa

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 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.

Taxonomic source(s)
Christidis, L.; Boles, W. E. 2008. Systematics and taxonomy of Australian birds. CSIRO Publishing, Collingwood, Australia.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.
Turbott, E. G. 1990. Checklist of the birds of New Zealand. Ornithological Society of New Zealand, Wellington.

Identification
55 cm. Large brown and buff duck. Whole body streaked and spotted dark brown and buff; head pale with distinctive dark stripes; green speculum; sexes alike; interbreeds with Mallard A. platyrhynchos which produces paler birds with lkess distinct facial stripes and blue speculum. Similar species: . Hints: . Voice: Male high-pitched 'quek'; female 'quack, quack'.

Distribution and population
This species breeds in Indonesia from south Sumatra, Java and Sulawesi, through to Irian Jaya, Papua New Guinea (including New Britain and New Ireland), Solomon Islands, Vanuatu, New Caledonia (to France), Australia, Caroline Islands (Federated States of Micronesia), Palau, Fiji, Tonga, Samoa and American Samoa, Cook Islands (New Zealand), Society Islands (French Polynesia) and New Zealand. It occurs as three subspecies, with pelewensis found in the south-west Pacific Islands and north New Guinea, rogersi found in the Indonesian region, south New Guinea and Australia, and the nominate superciliosa occurring in New Zealand and associated larger offshore islands (del Hoyo et al. 1992).

Population justification
The species currently has a large global population estimated to be 180,000-1,200,000 individuals (Wetlands International 2006). Both superciliosa and rogersi have undergone significant declines in the last 20 years (Marchant and Higgins 1990). In New Zealand, the superciliosa population was estimated at 1.5 million birds in 1970, decreasing to 1.2 million by 1981, and less than 500,000 in the 1990s (Heather and Robertson 1997). A second estimate placed numbers at between 80,000 and 150,000 in 1993 (Rose and Scott 1997). Subspecies pelewensis was estimated at 10,000-25,000 birds and is considered stable (Rose and Scott 1997).

Trend justification
The overall trend is uncertain, as some populations are decreasing, while others are stable or fluctuating (Wetlands International 2006).

Ecology
The species has a broad habitat tolerance, breeding and feeding in a wide range of terrestrial and marine wetlands and estuaries. It also utilises artificial habitats such as farm dams and drains. In New Zealand, however, agricultural regions are now largely dominated by the introduced Mallard A. platyrhynchos, and A. superciliosa has become increasingly restricted to undeveloped areas. Nests tend to be built away from water, and are often in tree holes. Ten to 12 eggs are usually laid. Young are capable of breeding in the first year, but about 65% of young die before starting to breed. Adults live 21 months on average in New Zealand, but the oldest bird in the wild was at least 20 years of age.

Threats
The species is believed to be declining throughout its range due to a combination of competition and hybridisation with A. platyrhynchos (Heather and Robertson 1997). This introduced species is most common in developed areas and, in New Zealand at least, numbers are still increasing (Marchant and Higgins 1990). Also in New Zealand, loss of wild habitats is considered to be a leading cause in declines (Heather and Robertson 1997), and there is a slow decline through Melanesia due to hunting and habitat degradation (G. Dutson in litt. 1999). Such habitat destruction is also occuring in Australia, but birds there have proved to be more able to utilise artificial habitats (Marchant and Higgins 1990).

References
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.

Heather, B. D.; Robertson, H. A. 1997. The field guide to the birds of New Zealand. Oxford University Press, Oxford, UK.

Marchant, S.; Higgins, P. J. 1990. Handbook of Australian, New Zealand and Antarctic birds, 1: ratites to ducks. Oxford University Press, Melbourne.

Rose, P. M.; Scott, D. A. 1997. Waterfowl population estimates. Wetlands International, Wageningen, Netherlands.

Wetland International - China Office. 2006. Relict Gull surveys in Hongjianao, Shaanxi Province. Newsletter of China Ornithological Society 15(2): 29.

Further web sources of information
Explore HBW Alive for further information on this species

View photos and videos and hear sounds of this species from the Internet Bird Collection

Text account compilers
Ekstrom, J., Butchart, S., Harding, M.

IUCN Red List evaluators
Butchart, S., Symes, A.

Recommended citation
BirdLife International (2014) Species factsheet: Anas superciliosa. Downloaded from http://www.birdlife.org on 28/12/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 28/12/2014.

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.

Key facts
Current IUCN Red List category Least Concern
Family Anatidae (Ducks, Geese, Swans)
Species name author Gmelin, 1789
Population size mature individuals
Population trend Unknown
Distribution size (breeding/resident) 8,850,000 km2
Country endemic? No
Links to further information
- Additional Information on this species