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

Taxonomic note

Metabolus takatsukasae (del Hoyo and Collar 2016) was previously listed as Monarcha takatsukasae.

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
2022	Near Threatened	D2
2016	Vulnerable	A3ce+4be; D2
2012	Vulnerable	A3e+4be;D2
2008	Vulnerable	A3e; ; D2
2004	Vulnerable
2000	Vulnerable
1996	Vulnerable
1994	Vulnerable
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)	1,620 km2	medium
Area of Occupancy (breeding/resident)	190 km2
Number of locations	2-50,11-50	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	33000-66000 mature individuals	good	estimated	2013
Population trend	stable	poor	suspected	1998-2008
Generation length	3.5 years	-	-	-
Number of subpopulations	2	-	-	-
Percentage of mature individuals in largest subpopulation	95-99%	-	-	-

Population justification: The most recent estimate of the Tinian Monarch population on Tinian is 91,420 (95% CI 74,593-110,822) in 2013 (Naval Facilities Engineering Command, Pacific 2014). This is an increase from the last estimate in 2008 of 56, 305 (95% CI 43,343-70,909); however, the long-term trend for the Tinian Monarch population has been stable between 1982 and 2013 (Naval Facilities Engineering Command, Pacific 2014) and these differences are likely born from a difference in survey methodology. A second population was established on Guguan. Although no population estimate has been made of this population since its introduction, the size of the island means that it is unlikely to exceed a few hundred individuals when at carrying capacity, thus is unlikely to exceed 1% of the global population. The global population is placed in the band of 50,000-99,999 individuals, or perhaps approximately 33,000-66,000 mature individuals.

Trend justification: The population is believed to be stable in absence of an acting threat. A five-year monitoring programme, which included surveys and survival studies, was undertaken from 2006 to 2010 as part of the removal of this species from the U.S. Endangered Species List; the study apparently indicated a continuing decline in monarch populations on Tinian (USFWS 2005, Marshall & Amidon 2009, F. A. Amidon in litt. 2012, P. Radley in litt. 2012), although the most recent surveys in 2013 revealed that their numbers are comparable to earlier estimates (Naval Facilities Engineering Command, Pacific 2014).

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Northern Mariana Islands (to USA)	extant	native	yes

Country/Territory	IBA Name
Northern Mariana Islands (to USA)	Tinian Island

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Forest	Subtropical/Tropical Swamp	suitable	resident
Shrubland	Subtropical/Tropical Moist	suitable	resident
Altitude	0 - 170 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Livestock farming & ranching - Small-holder grazing, ranching or farming	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Majority (50-90%)		Slow, Significant Declines		Past Impact
		Stresses Species disturbance, Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Past, Unlikely to Return		Majority (50-90%)		Slow, Significant Declines		Past Impact
		Stresses Ecosystem degradation, Ecosystem conversion
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		Unknown		Unknown
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Boiga irregularis	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Rapid Declines		Medium Impact: 6
		Stresses Species mortality
Residential & commercial development	Commercial & industrial areas	Timing		Scope		Severity		Impact
		Past, Likely to Return		Majority (50-90%)		No decline		Past Impact
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Tinian Monarch Metabolus takatsukasae. Downloaded from https://datazone.birdlife.org/species/factsheet/tinian-monarch-metabolus-takatsukasae 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.