• 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
C2a(i)	A3bcd+4bcd; B1ab(i,ii,iii,iv,v); C2a(i); D	A2bcd+3bcd+4bcd; B1ab(i,ii,iii,iv,v); C2a(i); D1

Red List history

Year	Category	Criteria
2016	Critically Endangered	C2a(i)
2015	Critically Endangered	C2a(i)
2012	Critically Endangered	C2a(i)
2008	Endangered	A3b,c,d; A4b,c,d; B1a+b(i,ii,iii,iv,v); C2a(i)
2004	Endangered
2000	Endangered
1996	Endangered
1994	Endangered
1988	Lower Risk/Least Concern

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

	Estimate	Data quality
Extent of Occurrence breeding/resident (km2)	930	medium
Number of locations	2-5	-
Severely Fragmented		-

	Value	Data quality	Derivation	Year of estimate
No. of mature individuals	50-249	poor	estimated	2012
Population trend	Decreasing	poor	suspected	-
Decline (3 years/1 generation past)		-	-	-
Decline (5 years/1 generation past)		-	-	-
Decline (10 years/1 generation past)		-	-	-
Decline (10 years/3 generation future)	50-79	-	-	-
Decline (10 years/3 generation past and future)	50-79	-	-	-
Number of subpopulations		-	-	-
Percentage in largest subpopulation		-	-	-
Generation length (yrs)	5.4	-	-	-

Population justification: The population was previously estimated at fewer than 1,000 mature individuals (BirdLife International 2001), but more recent observations indicate that there could now be fewer than 250 mature individuals remaining, thus the population is now placed in the band for 50-249 mature individuals, probably equivalent to a total population of 75-375 individuals.

Trend justification: This species is suspected to be declining rapidly owing to the on-going loss of remaining forest fragments within its small range, as well as hunting pressure. As habitat continues to be lost, the rate of decline is thought to be accelerating.

Country/Territory	Occurrence status	Presence	Resident	Breeding	Non-breeding	Passage
Philippines	N	Extant		Yes

Country/Territory	IBA Name
Philippines	Tawi-tawi Island
Philippines	Simunul and Manuk Manka Islands
Philippines	Sibutu and Tumindao Islands

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Subtropical/Tropical Heavily Degraded Former Forest	suitable	resident
Forest	Subtropical/Tropical Mangrove Vegetation Above High Tide Level	major	resident
Forest	Subtropical/Tropical Moist Lowland	major	resident
Altitude		Occasional altitudinal limits

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%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Agriculture & aquaculture	Wood & pulp plantations - Scale Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Rapid Declines		Medium Impact: 7
		Stresses Reduced reproductive success, Species mortality
Biological resource use	Logging & wood harvesting - Unintentional effects: (large scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Rapid Declines		Medium Impact: 7
		Stresses Ecosystem degradation
Energy production & mining	Mining & quarrying	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion
Residential & commercial development	Commercial & industrial areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion

Purpose	Primary form used	Life stage used	Source	Scale	Level	Timing
Sport hunting/specimen collecting	-	-			Non-trivial	Recent

---

Recommended citation
BirdLife International (2023) Species factsheet: Prioniturus verticalis. Downloaded from http://www.birdlife.org on 25/03/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 25/03/2023.