• 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., 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
-	C2a(i)	C2a(i)

Red List history

Year	Category	Criteria
2024	Endangered	C2a(i)
2016	Endangered	C2a(ii)
2012	Endangered	C2a(ii)
2008	Endangered	C2a(ii)
2004	Endangered
2000	Endangered
1996	Endangered
1994	Endangered
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	870 km2	medium
Area of Occupancy (breeding/resident)	240 km2
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	1000-2499 mature individuals	medium	estimated	1990
Population trend	decreasing	poor	inferred	-
Generation length	3.83 years	-	-	-
Number of subpopulations	5-15	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: The population has not been robustly estimated since 1984 when numbers were estimated at 2,168 (Engbring et al. 1990). In the absence of more recent and complete data, and accounting for the fact that only a proportion likely refer to mature individuals, the population is tentatively placed in the range 1,000-2,499 mature individuals. There is evidence however that the species has likely declined since the 1984 estimate (see Population trend), and an up-to-date quantification of the population size is urgently required. There is an urgent need to collect up-to-date information on populations from the Faichuk group, particularly Tol South and Polle where relatively large numbers were recorded in 1984.

Trend justification: This species is thought to occur at highest densities in native forest which is subject to deforestation and contains non-native species (Engbring et al. 1990, SPREP 2001), and may continue to be under threat from population pressures which are causing ongoing habitat degradation throughout Chuuk (R. Davis in litt. 2023). Observations in 2001 suggested that it had declined to lower population densities compared to 1984 (G. Dutson in litt. 2003). On Tol South, no birds were found in a visit in 1991 and only 3-4 birds in 1993, although birds were seen again in 2005 (C. Collins in litt. 2005). It was thought to have been extirpated from Weno after a major fire destroyed the patch of forest where it was uncommon in the 1970s (H. D. Pratt in litt. 1994); however, two males were seen in Sopo Forest in 2005 (C. Collins in litt. 2005). The species now appears to be rare on Weno (C. Collins in litt. 2011), and according to local people it is becoming rarer on Tol South (D. Scott in litt. 2011). It was not found in 2010 in an area on Dublon Island where it had been seen in 2008 (D. Scott in litt. 2011). In 2022, sound recorders were used to capture the aural landscape at stations previously surveyed in 1984, however difficulties regarding access permissions meant that only 130 of 579 stations could be resurveyed (O'Brien 2023). The species was present at 17 of these 130 stations in 1984, but no calls were isolated from the recordings made in 2022 (O'Brien 2023). Although this may be partly due to restricted knowledge of the repertoire of this species, it is a considerable concern especially considering the overall lack of monitoring data and no access to the population currently being possible. Precautionarily therefore, the population is inferred to be declining overall.

Country/Territory	Presence	Origin	Resident	Breeding visitor	Non-breeding visitor	Passage migrant
Micronesia, Federated States of	extant	native	yes

Country/Territory	IBA Name
Micronesia, Federated States of	Mount Winipot / Tol South
Micronesia, Federated States of	Pata Island
Micronesia, Federated States of	South Weno Ridge

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Plantations	marginal	resident
Forest	Subtropical/Tropical Dry	suitable	resident
Forest	Subtropical/Tropical Mangrove Vegetation Above High Tide Level	major	resident
Forest	Subtropical/Tropical Moist Montane	major	resident
Rocky areas (eg. inland cliffs, mountain peaks)		suitable	resident
Shrubland	Subtropical/Tropical Moist	suitable	resident
Altitude	0 - 435 m	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
		Past, Unlikely to Return		Majority (50-90%)		Slow, Significant Declines		Past Impact
		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
Biological resource use	Hunting & trapping terrestrial animals - Intentional use (species is the target)	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Species disturbance, Species mortality
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
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Ongoing		Unknown		Unknown		Unknown
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation, Reduced reproductive success, Species mortality
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation, Ecosystem conversion

Purpose	Scale
Sport hunting/specimen collecting	subsistence

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