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

Taxonomic note

Carterornis castus (del Hoyo and Collar 2016) was previously listed as Monarcha castus.

Taxonomic source(s)
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A., Fishpool, L.D.C., Boesman, P. and Kirwan, G.M. 2016. HBW and BirdLife International Illustrated Checklist of the Birds of the World. Volume 2: Passerines. Lynx Edicions and BirdLife International, Barcelona, Spain and Cambridge, UK.

Red List criteria met

Critically Endangered	Endangered	Vulnerable
-	-	-

Red List history

Year	Category	Criteria
2023	Near Threatened	B1b(i,ii,iii)
2016	Least Concern
2012	Least Concern
2009	Least Concern
2008	Least Concern
2004	Least Concern
2000	Lower Risk/Least Concern
1994	Lower Risk/Near Threatened
1988	Lower Risk/Least Concern

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	5,800 km2
Area of Occupancy (breeding/resident)	4,240 km2
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	unknown	-	-	-
Population trend	decreasing	-	suspected	2016-2026
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	3.14 years	-	-	-
Number of subpopulations	1	-	-	-
Percentage of mature individuals in largest subpopulation	100%	-	-	-

Population justification: The global population size has not been quantified, but the species is reported to be moderately common (Coates et al. 1997; Eaton et al. 2016, 2021).

Trend justification: Data on population trends are lacking but moderate declines are suspected on the basis of ongoing forest loss. Remote sensing data (Global Forest Watch 2022, based on data from Hansen et al. [2013] and methods disclosed therein) indicate that in the ten years to 2022, forest cover in the species' range reduced by 5-6%. This species is considered highly forest dependent (Haryoko et al. 2021), and these forest losses are suspected of having had a broadly similar (1-9% over ten years) reduction in the species' population size. Forest loss appears to be ongoing and the same rate is therefore suspected to continue into the future.

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

Country/Territory	IBA Name

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Subtropical/Tropical Heavily Degraded Former Forest	suitable	resident
Forest	Subtropical/Tropical Moist Lowland	major	resident
Altitude	0 - 320 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
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		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Tanimbar Monarch Carterornis castus. Downloaded from https://datazone.birdlife.org/species/factsheet/tanimbar-monarch-carterornis-castus on 22/12/2024.
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 22/12/2024.