• 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
-	-	D1+2

Red List history

Year	Category	Criteria
2018	Vulnerable	D1+2
2016	Vulnerable	D1+2
2012	Vulnerable	D1+2
2008	Endangered	D1
2006	Endangered
2004	Endangered
2000	Endangered
1996	Critically Endangered
1994	Critically Endangered
1988	Threatened

Migratory status	not a migrant	Forest dependency	high
Land-mass type		Average mass	23 g

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	1,000 km2	medium
Number of locations	2	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	500 mature individuals	good	observed	2016
Population trend	increasing	good	observed	1998-2008
Rate of change over the past 10 years/3 generations (longer of the two periods)	1-19%	-	-	-
Generation length	6.9 years	-	-	-
Number of subpopulations	2	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification: The population was estimated at 306 in August 2004, but a subsequent series of devastating cyclones in early 2005 lead to a decline, especially on Rarotonga. The total population began to increase in 2007 due to good recruitment on Atiu (where 30 birds were transferred in 2001-2003) and a stable population on Rarotonga. In 2011 the population was estimated at c.380 birds, including 69 yearlings (Robertson et al. 2011, H. Robertson in litt. 2011), suggesting a population of c.310 mature individuals. The number of mature individuals is now estimated at 500 (H. Robertson in litt. 2016).

Trend justification: The population has grown rapidly owing to intensive management, particularly predator control, and the transfer of 30 young birds to Atiu Island in 2001-2003. The population on Rarotonga declined as a result of five cyclones in one month in early 2005, and subsequent poor breeding in 2005-2006; however, the population has now been increasing since 2007, owing to intensive conservation action.

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

Country/Territory	IBA Name
Cook Islands	Atiu
Cook Islands	Takitumu Conservation Area, Rarotonga

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Forest	Subtropical/Tropical Moist Lowland	major	resident
Altitude	10 - 250 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Past, Likely to Return		Majority (50-90%)		Slow, Significant Declines		Past Impact
		Stresses Ecosystem degradation
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Rapid Declines		Medium Impact: 6
		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
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Felis catus	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		No decline		Medium Impact: 6
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Herpestes javanicus_old	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Rapid Declines		Medium Impact: 6
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		No decline		Medium Impact: 6
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Slow, Significant Declines		Low Impact: 5
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Rapid Declines		Medium Impact: 6
		Stresses Species mortality
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Urodynamis taitensis	Timing		Scope		Severity		Impact
		Ongoing		Whole (>90%)		Unknown		Unknown
		Stresses Species mortality

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Recommended citation
BirdLife International (2024) Species factsheet: Rarotonga Monarch Pomarea dimidiata. Downloaded from https://datazone.birdlife.org/species/factsheet/rarotonga-monarch-pomarea-dimidiata 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.