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

Taxonomic note
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
2023	Least Concern
2016	Near Threatened	A2c+3c+4c
2013	Near Threatened	A2c+3c+4c
2012	Near Threatened	A2c+3c+4c
2008	Near Threatened	A2c; A3c; A4c
2004	Near Threatened
2000	Lower Risk/Near Threatened
1996	Data Deficient
1994	Data Deficient
1988	Lower Risk/Least Concern

Migratory status	not a migrant	Forest dependency	high
Land-mass type	shelf island	Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	175,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	poor	suspected	2010-2024
Rate of change over the past 10 years/3 generations (longer of the two periods)	1-9%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	1-9%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	1-9%	-	-	-
Generation length	4.7 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: There are no data available from which to estimate this species' population size, but was described as 'uncommon' by Eaton et al. (2021). In suitable habitat, however, it is regularly observed across its range (eBird 2022). The area of suitable habitat is very large (nearly c.40,000 km²; per Global Forest Watch 2022) and although no density data are available, it is considered highly unlikely that the number of mature individuals is fewer than 10,000.

Trend justification: The population is suspected to be declining slowly due to habitat loss at the lower elevations of its range (it has occasionally been recorded at c.600 m). In the three generations (14 years; Bird et al. 2020) to 2022, forest cover loss in its range was 3-6% (Global Forest Watch 2022, based on Hansen et al. [2013] and methods disclosed therein), depending on the assumptions used, and this is thought to have had only minor impacts on the population. The population size is therefore suspected of declining at a past and future rate of 1-9% over three generations.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Indonesia	extant	native	yes

Country/Territory	IBA Name
Indonesia	Gunung Leuser
Indonesia	Hutan Raya Bukit Barisan
Indonesia	Kayan Mentarang
Indonesia	Kerinci Seblat
Indonesia	Malampah Alahan Panjang
Indonesia	Meratus Hulu

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	1200 - 2000 m	Occasional altitudinal limits	(min) 600 m

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Agro-industry farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation
Agriculture & aquaculture	Annual & perennial non-timber crops - Small-holder farming	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Sumatran Frogmouth Batrachostomus poliolophus. Downloaded from https://datazone.birdlife.org/species/factsheet/sumatran-frogmouth-batrachostomus-poliolophus on 23/12/2024.
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 23/12/2024.