• Summary
• Text account
• Data table and detailed info
• Distribution map
• Reference and further resources

Taxonomic note
Sarkidiornis melanotos and S. sylvicola (del Hoyo and Collar 2014) were previously lumped as S. melanotos following Sibley and Monroe (1990, 1993), and prior to that had been split as S. melanotos and S. sylvicola in Collar and Andrew (1988). Notes updated from Illustrated Checklists: Usually treated as a subspecies of S. melanotos. Occasional treatment as full species, most recently in a 2005 monograph (Kear 2005), justifiable on basis of slightly smaller size (mean male wing 336 vs 360, mean male bill 56 vs 62) (allow 1); glossy blackish-grey vs matt greyish-white flanks (3); glossy blackish-grey vs matt greyish-white back and rump (extension of flanks, but notable in flight and wing-flapping; score 1); fully developed comb proportionately different, rising more at right angles from forehead and usually curving over more smoothly, forming disc-shape more than sail-shape, whereas in melanotos it rises at a forward angle in a longer straight line, curving at apex more sharply, so that surface area is larger and leading edge forms a longer vertical (2). Further differences, not scored, include the much bluer, less blue-green, coloration of the upperparts in sylvicola, and also its yellow, rather than orange-rust, fleck on the sides of the undertail (the consistency of this needs checking but it appears to be so). Studies of voice and behaviour to supplement these distinctions needed. Proposed subspecies carunculatus is invalid. Monotypic.

Taxonomic source(s)
Handbook of the Birds of the World and BirdLife International. 2023. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 8. Available at: https://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v8_Dec23.zip.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2024	Least Concern
2016	Least Concern
2014	Least Concern
2012	Not Recognised
2008	Not Recognised
2004	Not Recognised
2000	Not Recognised
1994	Not Recognised
1988	Near Threatened

Migratory status	full migrant	Forest dependency	does not normally occur in forest
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	16,300,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	16700-66700 mature individuals	poor	estimated	2023
Population trend	decreasing	-	suspected	-
Generation length	8.63 years	-	-	-

Population justification: The global population size is estimated at 25,000-100,000 individuals (Wetlands International 2023), which equates to 16,700-66,700 mature individuals. The overall population trend is considered to be decreasing over three generations (25.89 years) (Wetlands International 2023).

Trend justification:   .

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Argentina	extant	native	yes
Bolivia	extant	native	yes
Brazil	extant	native	yes
Colombia	extant	native	yes
Ecuador	extant	native	yes
French Guiana	extant	native	yes
Guyana	extant	native	yes
Panama	extant	native	yes
Paraguay	extant	native	yes
Peru	extant	native	yes
Trinidad and Tobago	extant	vagrant
Uruguay	extant	native	yes
Venezuela	extant	native	yes

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Aquatic & Marine	Artificial/Aquatic - Irrigated Land (includes irrigation channels)	suitable	non-breeding
Artificial/Aquatic & Marine	Artificial/Aquatic - Irrigated Land (includes irrigation channels)	suitable	breeding
Artificial/Terrestrial	Arable Land	suitable	non-breeding
Artificial/Terrestrial	Arable Land	suitable	breeding
Artificial/Terrestrial	Pastureland	suitable	non-breeding
Artificial/Terrestrial	Pastureland	suitable	breeding
Grassland	Subtropical/Tropical Seasonally Wet/Flooded	suitable	non-breeding
Grassland	Subtropical/Tropical Seasonally Wet/Flooded	suitable	breeding
Wetlands (inland)	Bogs, Marshes, Swamps, Fens, Peatlands	suitable	non-breeding
Wetlands (inland)	Bogs, Marshes, Swamps, Fens, Peatlands	suitable	breeding
Wetlands (inland)	Permanent Freshwater Lakes (over 8ha)	suitable	non-breeding
Wetlands (inland)	Permanent Freshwater Lakes (over 8ha)	suitable	breeding
Wetlands (inland)	Permanent Freshwater Marshes/Pools (under 8ha)	suitable	non-breeding
Wetlands (inland)	Permanent Freshwater Marshes/Pools (under 8ha)	suitable	breeding
Wetlands (inland)	Permanent Rivers/Streams/Creeks (includes waterfalls)	suitable	non-breeding
Wetlands (inland)	Permanent Rivers/Streams/Creeks (includes waterfalls)	suitable	breeding
Wetlands (inland)	Seasonal/Intermittent Freshwater Marshes/Pools (under 8ha)	suitable	non-breeding
Wetlands (inland)	Seasonal/Intermittent Freshwater Marshes/Pools (under 8ha)	suitable	breeding
Altitude	0 - 1200 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species mortality
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species disturbance, Ecosystem degradation
Invasive and other problematic species, genes & diseases	Viral/prion-induced diseases - Avian Influenza Virus (H5N1 subtype)	Timing		Scope		Severity		Impact
		Future		Minority (<50%)		Rapid Declines		Low Impact: 4
		Stresses Species mortality
Natural system modifications	Dams & water management/use - Large dams	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Indirect ecosystem effects, Ecosystem degradation, Ecosystem conversion
Pollution	Agricultural & forestry effluents - Herbicides and pesticides	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Species mortality

Purpose	Scale
Food - human	subsistence, national
Pets/display animals, horticulture	subsistence, national

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Recommended citation
BirdLife International (2024) Species factsheet: Comb Duck Sarkidiornis sylvicola. Downloaded from https://datazone.birdlife.org/species/factsheet/comb-duck-sarkidiornis-sylvicola on 22/12/2024.
Recommended citation for factsheets for more than one species: BirdLife International (2024) IUCN Red List for birds. Downloaded from https://datazone.birdlife.org/species/search on 22/12/2024.