email a friend
printable version
Comb Duck Sarkidiornis melanotos

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.

Taxonomic source(s)
AOU. 1998. Check-list of North American birds. American Ornithologists' Union, Washington, D.C.
Dowsett, R. J.; Forbes-Watson, A. D. 1993. Checklist of birds of the Afrotropical and Malagasy regions. Tauraco Press, Li
SACC. 2006. A classification of the bird species of South America. Available at:
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.
Stotz, D. F.; Fitzpatrick, J. W.; Parker, T. A.; Moskovits, D. K. 1996. Neotropical birds: ecology and conservation. University of Chicago Press, Chicago.

Taxonomic note
Sarkidiornis sylvicola, previously treated as a species in Collar and Andrew (1988), is now considered a subspecies of S. melanotos following Sibley and Monroe (1990, 1993).

Trend justification
The overall trend is decreasing, although some populations may be stable (Wetlands International 2006).

Behaviour This species is an intra-African migrant (Hockey et al. 2005) undertaking poorly-understood (Brown et al. 1982, del Hoyo et al. 1992, Hockey et al. 2005) seasonal movements in relation to water availability (Brown et al. 1982, del Hoyo et al. 1992). It breeds during the wet season in single pairs or small groups (Brown et al. 1982, del Hoyo et al. 1992) (harems [Brown et al. 1982]), and outside of the breeding season usually occurs in small parties of up to 30-40 individuals (Madge and Burn 1988). Large flocks also gather in the dry (non-breeding) season (Brown et al. 1982) on suitable waters (Madge and Burn 1988), but these break up and disperse to breeding grounds at the onset of the rains (Brown et al. 1982). Habitat This species inhabits grassy ponds or lakes in savanna, open woodlands along large rivers and lakes (Johnsgard 1978), swamps (del Hoyo et al. 1992), marshes, floodplains, river deltas (Brown et al. 1982, Kear 2005a), flooded forest, pastures and rice-paddies (Kear 2005a) and occasionally sandbars and mudflats (Johnsgard 1978). Diet Its diet consists largely of vegetable matter, including the seeds of grasses and sedges, the soft parts of aquatic plants (e.g. water-lilies [Brown et al. 1982]), agricultural grain (e.g. rice, corn, oats [Johnsgard 1978], wheat and groundnuts [Hockey et al. 2005]) as well as aquatic insect larvae and locusts (Johnsgard 1978, Brown et al. 1982, del Hoyo et al. 1992). Breeding site The species nests close to water (Brown et al. 1982, Madge and Burn 1988, Kear 2005a), building rough structures of twigs and coarse grass (del Hoyo et al. 1992) in large hollow tree cavities (Madge and Burn 1988, Kear 2005a), between 7 and 12 m high (Brown et al. 1982), or in holes in the walls of isolated buildings (Madge and Burn 1988) (or other cavities with a floor diameter of c.200 mm [Kear 2005a]). It may also use the abandoned nests of other bird species, such as Hamerkop Scopus umbretta (Brown et al. 1982, Madge and Burn 1988, Kear 2005a), or nest on the ground (del Hoyo et al. 1992) in the shelter of tall grass or on tree stumps (Johnsgard 1978). When the species is tree nesting, the same cavity may be used from year to year (Brown et al. 1982).

The species is threatened by hunting (del Hoyo et al. 1992) (e.g. in Madagascar [Kear 2005a]), habitat destruction (Kear 2005a) (e.g. from deforestation [del Hoyo et al. 1992]), and indiscriminate use of poison in rice-fields (del Hoyo et al. 1992). The species has declined in the Senegal Delta following the damming of the Senegal River (which has resulted in habitat degradation and loss from vegetation overgrowth, desertification processes and land conversion to agriculture [Triplett and Yesou 2000]). This species is also susceptible to avian influenza, so is potentially threatened by future outbreaks of the virus (Gaidet et al. 2007).

Brown, L. H.; Urban, E. K.; Newman, K. 1982. The birds of Africa vol I. Academic Press, 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.

Gaidet, N.; Dodman, T.; Caron, A.; Balança, G.; Desvaux, S.; Goutard, F.; Cattoli, G.; Lamarque, F.; Hagemeijer, W.; Monicat, F. 2007. Avian Influenza Viruses in Water Birds, Africa. Emerging Infectious Diseases 13(4): 626-629.

Hockey, P. A. R.; Dean, W. R. J.; Ryan, P. G. 2005. Roberts birds of southern Africa. Trustees of the John Voelcker Bird Book Fund, Cape Town, South Africa.

Johnsgard, P. A. 1978. Ducks, geese and swans of the World. University of Nebraska Press, Lincoln and London.

Kear, J. 2005. Ducks, geese and swans volume 1: general chapters; species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, U.K.

Madge, S.; Burn, H. 1988. Wildfowl. Christopher Helm, London.

Triplett, P.; Yesou, P. 2000. Controlling the flood in the Senegal Delta: do waterfowl populations adapt to their new environment? Ostrich 71((1-2): 106-111.

Text account compilers
Ekstrom, J., Butchart, S., Malpas, L.

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

Recommended citation
BirdLife International (2014) Species factsheet: Sarkidiornis melanotos. Downloaded from on 11/07/2014. Recommended citation for factsheets for more than one species: BirdLife International (2014) IUCN Red List for birds. Downloaded from on 11/07/2014.

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

ARKive species - Comb duck (Sarkidiornis melanotos) 0

Key facts
Current IUCN Red List category Least Concern
Family Anatidae (Ducks, geese and swans)
Species name author (Pennant, 1769)
Population size mature individuals
Population trend Decreasing
Distribution size (breeding/resident) 28,200,000 km2
Country endemic? No
Links to further information
- Additional Information on this species
- Climate change species distributions