Sarkidiornis melanotos

Taxonomy

Assessment Information

Geographic Range

Habitat and Ecology

Threats

View Printer Friendly

Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	AVES	ANSERIFORMES	ANATIDAE

Scientific Name:

Sarkidiornis melanotos

Species Authority:

(Pennant, 1769)

Common Name/s:

English	–	Comb Duck, Knob-billed Duck
French	–	Canard à bosse

Assessment Information [top]

Red List Category & Criteria:

Least Concern ver 3.1

Year Published:

2009

Assessor/s:

BirdLife International

Reviewer/s:

Bird, J., Butchart, S.

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). 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.

History:

2008	–	Least Concern
2004	–	Least Concern

Geographic Range [top]

Countries:	Native: Angola; Argentina; Aruba; Bangladesh; Benin; Bolivia; Botswana; Brazil; Burkina Faso; Burundi; Cambodia; Cameroon; Central African Republic; Chad; China; Colombia; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Ecuador; Eritrea; Ethiopia; French Guiana; Gabon; Gambia; Ghana; Guinea; Guinea-Bissau; Guyana; India; Kenya; Lao People's Democratic Republic; Lesotho; Liberia; Madagascar; Malawi; Mali; Mauritania; Mozambique; Myanmar; Namibia; Nepal; Netherlands Antilles; Niger; Nigeria; Panama; Paraguay; Peru; Rwanda; Senegal; Sierra Leone; Somalia; South Africa; Sudan; Swaziland; Tanzania, United Republic of; Thailand; Togo; Uganda; Uruguay; Venezuela; Viet Nam; Zambia; Zimbabwe Possibly extinct: Pakistan; Sri Lanka Vagrant: Japan; Oman; Sao Tomé and Principe; Trinidad and Tobago
Range Map:	Click here to open the map viewer and explore range.

Countries:

Native:

Angola; Argentina; Aruba; Bangladesh; Benin; Bolivia; Botswana; Brazil; Burkina Faso; Burundi; Cambodia; Cameroon; Central African Republic; Chad; China; Colombia; Congo; Congo, The Democratic Republic of the; Côte d'Ivoire; Ecuador; Eritrea; Ethiopia; French Guiana; Gabon; Gambia; Ghana; Guinea; Guinea-Bissau; Guyana; India; Kenya; Lao People's Democratic Republic; Lesotho; Liberia; Madagascar; Malawi; Mali; Mauritania; Mozambique; Myanmar; Namibia; Nepal; Netherlands Antilles; Niger; Nigeria; Panama; Paraguay; Peru; Rwanda; Senegal; Sierra Leone; Somalia; South Africa; Sudan; Swaziland; Tanzania, United Republic of; Thailand; Togo; Uganda; Uruguay; Venezuela; Viet Nam; Zambia; Zimbabwe

Possibly extinct:

Pakistan; Sri Lanka

Vagrant:

Japan; Oman; Sao Tomé and Principe; Trinidad and Tobago

Range Map:

Click here to open the map viewer and explore range.

Habitat and Ecology [top]

Habitat and Ecology:	Behaviour This species is an intra-African migrant⁶ undertaking poorly-understood^{1, 2, 6} seasonal movements in relation to water availability^{1, 2}. It breeds during the wet season in single pairs or small groups^{1, 2} (harems)², and outside of the breeding season usually occurs in small parties of up to 30-40 individuals⁴. Large flocks also gather in the dry (non-breeding) season² on suitable waters⁴, but these break up and disperse to breeding grounds at the onset of the rains². Habitat This species inhabits grassy ponds or lakes in savanna, open woodlands along large rivers and lakes³, swamps¹, marshes, floodplains, river deltas^{2, 5}, flooded forest, pastures and rice-paddies⁵ and occasionally sandbars and mudflats³. 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)², agricultural grain (e.g. rice, corn, oats³, wheat and groundnuts⁶) as well as aquatic insect larvae and locusts^{1, 2, 3}. Breeding site The species nests close to water^{2, 4, 5}, building rough structures of twigs and coarse grass¹ in large hollow tree cavities^{4, 5}, between 7 and 12 m high², or in holes in the walls of isolated buildings⁴ (or other cavities with a floor diameter of c.200 mm⁵). It may also use the abandoned nests of other bird species, such as Hamerkop Scopus umbretta^{2, 4, 5}, or nest on the ground¹ in the shelter of tall grass or on tree stumps³. When the species is tree nesting, the same cavity may be used from year to year².
Systems:	Terrestrial; Freshwater

Habitat and Ecology:

Behaviour This species is an intra-African migrant⁶ undertaking poorly-understood^{1, 2, 6} seasonal movements in relation to water availability^{1, 2}. It breeds during the wet season in single pairs or small groups^{1, 2} (harems)², and outside of the breeding season usually occurs in small parties of up to 30-40 individuals⁴. Large flocks also gather in the dry (non-breeding) season² on suitable waters⁴, but these break up and disperse to breeding grounds at the onset of the rains². Habitat This species inhabits grassy ponds or lakes in savanna, open woodlands along large rivers and lakes³, swamps¹, marshes, floodplains, river deltas^{2, 5}, flooded forest, pastures and rice-paddies⁵ and occasionally sandbars and mudflats³. 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)², agricultural grain (e.g. rice, corn, oats³, wheat and groundnuts⁶) as well as aquatic insect larvae and locusts^{1, 2, 3}. Breeding site The species nests close to water^{2, 4, 5}, building rough structures of twigs and coarse grass¹ in large hollow tree cavities^{4, 5}, between 7 and 12 m high², or in holes in the walls of isolated buildings⁴ (or other cavities with a floor diameter of c.200 mm⁵). It may also use the abandoned nests of other bird species, such as Hamerkop Scopus umbretta^{2, 4, 5}, or nest on the ground¹ in the shelter of tall grass or on tree stumps³. When the species is tree nesting, the same cavity may be used from year to year².

Systems:

Terrestrial; Freshwater

Threats [top]

Major Threat(s):	The species is threatened by hunting¹ (e.g. in Madagascar)⁵, habitat destruction⁵ (e.g. from deforestation)¹, and indiscriminate use of poison in rice-fields¹. 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)⁷. This species is also susceptible to avian influenza, so is potentially threatened by future outbreaks of the virus⁸.

Major Threat(s):

The species is threatened by hunting¹ (e.g. in Madagascar)⁵, habitat destruction⁵ (e.g. from deforestation)¹, and indiscriminate use of poison in rice-fields¹. 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)⁷. This species is also susceptible to avian influenza, so is potentially threatened by future outbreaks of the virus⁸.

Citation:	BirdLife International 2009. Sarkidiornis melanotos. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 24 May 2012.
Disclaimer:	To make use of this information, please check the <Terms of Use>.
Feedback:	If you see any errors or have any questions or suggestions on what is shown on this page, please fill in the feedback form so that we can correct or extend the information provided