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

Taxonomic note

Treron formosae and T. permagnus (del Hoyo and Collar 2014) were previously lumped as T. formosae following Sibley and Monroe (1990, 1993).

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. Lynx Edicions BirdLife International, Barcelona, Spain and Cambridge, UK.
del Hoyo, J.; Collar, N. J.; Christie, D. A.; Elliott, A.; Fishpool, L. D. C. 2014. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Barcelona, Spain and Cambridge UK: Lynx Edicions and BirdLife International.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2016	Near Threatened	C1
2014	Near Threatened	C1

Migratory status	full migrant	Forest dependency	Medium
Land mass type		Average mass	-

	Estimate	Data quality
Extent of Occurrence breeding/resident (km2)	101,000	medium
Number of locations		-
Severely Fragmented		-

	Value	Data quality	Derivation	Year of estimate
No. of mature individuals	unknown	not applicable	not applicable	0
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)		-	-	-
Decline (10 years/3 generation past and future)		-	-	-
Number of subpopulations		-	-	-
Percentage in largest subpopulation		-	-	-
Generation length (yrs)	4.2	-	-	-

Population justification: The global population size has not been quantified, but the species is described as rare on Taiwan and uncommon on the Batanes islands (Gibbs et al. 2001). Brazil (2009) has estimated national population sizes at < c.10,000 breeding pairs in Taiwan.

Trend justification: The species is suspected to be declining at a slow to moderate rate, owing to hunting and habitat degradation.

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

Country/Territory	IBA Name
Philippines	Batanes Islands
Taiwan, China	Lanyu

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Rural Gardens	suitable	breeding
Artificial/Terrestrial	Rural Gardens	suitable	non-breeding
Forest	Subtropical/Tropical Moist Lowland	major	non-breeding
Forest	Subtropical/Tropical Moist Lowland	major	breeding
Forest	Subtropical/Tropical Moist Montane	major	resident
Altitude	0 - 2000 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		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		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 Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation
Residential & commercial development	Tourism & recreation areas	Timing		Scope		Severity		Impact
		Future		Minority (<50%)		Slow, Significant Declines		Low Impact: 3
		Stresses Ecosystem degradation, Ecosystem conversion

Purpose	Primary form used	Life stage used	Source	Scale	Level	Timing
Food - human	-	-	-		Non-trivial	Recent

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Recommended citation
BirdLife International (2023) Species factsheet: Treron formosae. Downloaded from http://www.birdlife.org on 01/04/2023. Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 01/04/2023.