• 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
-	B1ab(i,ii,iii,v)+2ab(i,ii,iii,v); C2a(ii)	B1ab(i,ii,iii,v)+2ab(i,ii,iii,v); C2a(ii); D2

Red List history

Year	Category	Criteria
2021	Endangered	B1ab(i,ii,iii,v)+2ab(i,ii,iii,v); C2a(ii)
2017	Endangered	B1ab(i,ii,iii,v)+2ab(i,ii,iii,v); C2a(ii)
2016	Critically Endangered	B1ab(i,ii,iii,v)
2015	Critically Endangered	B1ab(i,ii,iii,v)
2012	Critically Endangered	B1ab(i,ii,iii,v)
2009	Critically Endangered	B1a+b(i,ii,iii,v)
2008	Critically Endangered
2006	Critically Endangered
2004	Critically Endangered
2000	Critically Endangered
1996	Critically Endangered
1994	Critically Endangered
1988	Threatened

Migratory status	not a migrant	Forest dependency	medium
Land-mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	220 km2	medium
Area of Occupancy (breeding/resident)	280 km2
Number of locations	1	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	2300 mature individuals	medium	estimated	2019
Population trend	decreasing	poor	inferred	2016-2025
Rate of change over the past 10 years/3 generations (longer of the two periods)	1-19%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	1-19%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	1-19%	-	-	-
Generation length	2.5 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: Surveys in 2018-2019 estimated that about 133 km² of suitable habitat exists for this species, in forests between altitudes of 800 m and 2,000 m. The average population density was estimated to be c.27 individuals/km², and the global population was estimated to be 3,452 total individuals (Ibouroi et al. 2019). This is roughly equivalent to 2,300 mature individuals.

Trend justification: This species's population is inferred to be declining due to ongoing habitat loss and degradation within its range. Data from Global Forest Watch (2020) suggests the species's range has experienced a rate of forest loss of 2% over the 10 years between 2009 and 2019. Similarly, Global Forest Watch data suggests that 0.54% of forest was lost between 2016-2019. If this rate is projected forward over 10 years, it equates to a suspected rate of decline of 1.8%. While habitat loss is considered the primary threat, this species is also threatened by competition from invasive species, and as such may be declining at a rate higher than just forest loss alone. The suspected rate of decline has therefore been placed in the band of 1-19% over ten years.

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

Country/Territory	IBA Name
Comoros	Karthala Mountains

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Shrubland	Subtropical/Tropical Dry	suitable	resident
Altitude	650 - 1900 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Scale Unknown/Unrecorded	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		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Livestock farming & ranching - Small-holder grazing, ranching or farming	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: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation
Climate change & severe weather	Habitat shifting & alteration	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Unknown		Unknown
		Stresses Indirect ecosystem effects, Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Acridotheres tristis	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Competition, Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Named species	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Negligible declines		Low Impact: 5
		Stresses Competition, Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Psidium cattleianum	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Negligible declines		Low Impact: 4
		Stresses Ecosystem degradation
Transportation & service corridors	Roads & railroads	Timing		Scope		Severity		Impact
		Future		Minority (<50%)		Slow, Significant Declines		Low Impact: 3
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Grande Comore Scops-owl Otus pauliani. Downloaded from https://datazone.birdlife.org/species/factsheet/grande-comore-scops-owl-otus-pauliani 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.