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

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 1: Non-passerines. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.

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)	549,000 km2	medium
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	poor	suspected	2016-2030
Rate of change over the past 10 years/3 generations (longer of the two periods)	5-15%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Generation length	4.56 years	-	-	-
Number of subpopulations	5-50	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: The global population size has not been quantified, but the species is described as scarce (Eaton et al. 2021).  However, it was found to be locally fairly common on Mt. Trus Madi, Sabah in 2010 (B. Harris in litt. 2016, D. L. Yong in litt. 2016) and at sites in the Kelabit highlands, Sarawak (D. L. Yong in litt. 2016, eBird 2022). Within its range, c.150,000 km² of forest remains (per Global Forest Wach 2022) at suitable elevations and the population is therefore assumed to be large.

Trend justification: Although there is little doubt that this species' preference for submontane forest buffers it from the worst of Sundaic forest loss, it is nonetheless likely to be impacted, especially at the lower limits of its elevational range. In Indonesia, where the majority of available forest remains, forest loss has so far remained minimal. However, in Malaysia Borneo (mostly Sarawak), the last two decades has seen a large number of logging tracks criss-cross the Central Highlands. Overall, in the three generations (13.7 years; Bird et al. 2020) to 2021, forest cover in this species' range was reduced by 6-8%, depending on the forest cover assumptions used (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein). This is thought to be broadly representative of population declines, which may in fact be steeper than remote sensing data alone suggest once degradation is taken into account. The population decline is therefore suspected to have been equivalent to 5-15% in the past three generations and, based on slightly accelerated (equivalent to 8-10% losses) deforestation between 2016 and 2021, to be 10-19% in the next three generations.

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

Country/Territory	IBA Name
Malaysia	Dulit Range
Malaysia	Hose-Laga mountains
Malaysia	Kelabit Highlands
Malaysia	Mount Kinabalu
Malaysia	Mulu - Buda Protected Area
Malaysia	Trus Madi Range

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	900 - 2400 m	Occasional altitudinal limits	(min) 300 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, Ecosystem conversion
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
Agriculture & aquaculture	Wood & pulp plantations - Small-holder plantations	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		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: Bornean Frogmouth Batrachostomus mixtus. Downloaded from https://datazone.birdlife.org/species/factsheet/bornean-frogmouth-batrachostomus-mixtus on 23/11/2024.
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 23/11/2024.