• 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
-	B1ab(iii,v)+2ab(iii,v)	B1ab(iii,v)+2ab(iii,v); D2

Red List history

Year	Category	Criteria
2020	Endangered	B1ab(iii,v)+2ab(iii,v)
2016	Critically Endangered	A3ce+4ce
2015	Critically Endangered	A3e+4e
2012	Critically Endangered	A3e+4e
2010	Critically Endangered	A3e
2009	Critically Endangered	A3e
2008	Critically Endangered
2004	Critically Endangered
2000	Vulnerable
1996	Vulnerable
1994	Vulnerable
1988	Lower Risk/Least Concern

Migratory status	not a migrant	Forest dependency	medium
Land-mass type		Average mass	20 g

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	3,100 km2	medium
Area of Occupancy (breeding/resident)	10 km2
Number of locations	3	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	29000-70000 mature individuals	medium	estimated	2020
Population trend	decreasing	poor	inferred	2011-2021
Rate of change over the past 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	10-19%	-	-	-
Generation length	2.84 years	-	-	-
Number of subpopulations	3	-	-	-
Percentage of mature individuals in largest subpopulation	1-89%	-	-	-

Population justification:

The species is considered to be abundant and widespread on Saipan, but less abundant on Aguiguan (MAC Working Group 2014).

On Saipan, surveys in 2007 provided an estimate of 71,997 individuals (95% CI 47,586 – 106,535), with a density of 711.8 ± 112.1 birds/km² (Camp et al. 2009). Analysis of population densities indicated a decline between 1982 and 2007 (Camp et al. 2009) and analysis of data from roadside surveys from 1991-2010 indicated that the population decreased between 2001 and 2010 (Ha et al. 2018). Assuming that this trend has continued, the population on Saipan may now be expected to be smaller than in 2007. Based on the relative population densities recorded in 1997 (995.5 birds/km²; Camp et al. 2009) and 2007 (711.8 birds/km²; Camp et al. 2009), the abundance estimate from 2007 and assuming a constant rate of decline, the current population is estimated to be within the range 30,767 - 68,882 (best estimate: 46,551) individuals.

On Aguiguan, surveys in 2008 estimated 15,499 individuals (95% CI 10,383 - 22,277), with a population density of 2,433 ± 466 birds/km² (Amidon et al. 2014). Analysis of population densities indicated an increase between 1982 and 2008 (Camp et al. 2012, Amidon et al. 2014). Assuming that this trend has continued, the population on Aguiguan may now be expected to be larger than in 2008. Based on the relative population densities recorded in 1995 (1,901 birds/km²; Amidon et al. 2014) and 2008 (2,433 birds/km²; Amidon et al. 2014), the abundance estimate from 2008, and assuming a constant rate of increase, the current population is estimated to be within the range 13,039 - 27,975 (best estimate: 19,463) individuals.

A third population was established on the uninhabited island of Sarigan through translocations of 24 and 50 individuals in 2011 and 2012, respectively, with breeding detected within the first year (Radley 2012, MAC Working Group 2014). There is no more recent population data for the population on Saigan at the time of assessment.

Based on the population sizes described above, the current total population on Saipan and Aguiguan is estimated to be within the range 43,806 - 96,857 (best estimate: 66,014) individuals, which roughly equates to 29,204-64,571 (44,009) mature individuals. There is now an additional small population on Sarigan. The total population size is therefore placed in the band 29,000 - 70,000 mature individuals.

There are three subpopulations, one on each range island.

Trend justification:

On Saipan, surveys by Engbring et al. (1986) in 1982 using point-transect methods estimated the population at 55,500 individuals. Further surveys were carried out in 1997 (USFWS 1998) and 2007 (Camp et al. 2009). The 2007 survey provided an estimate of 71,997 individuals (95% CI 47,586 – 106,535; Camp et al. 2009). Despite the larger population estimate in 2007, the population density was found to have declined from 1,287.3 ± 191.0 birds/km² in 1982 to 995.5 ± 160.0 birds/km² in 1997 and to 711.8 ± 112.1 birds/km² in 2007 (Camp et al. 2009). The difference between the population estimates in 1982 and 2007 was attributed to a difference in the statistical methods used to estimate population size (Camp et al. 2009). Analysis of data from roadside surveys from 1991-2010 indicated that the population has increased from 1991-2000, then decreased between 2001 and 2010 (Ha et al. 2018).

On Aguiguan, surveys using point-transect methods in 1982 resulted in a population estimate of 2,300 individuals (Engbring et al. 1986). The transects were resurveyed in 1992 (Craig et al. 1993), 1995, 2000 (Cruz et al. 2000), 2002 (Esselstyn et al. 2003) and 2008 (Camp et al. 2012, Amidon et al. 2014). All surveys followed standard point-transect methods. The 2008 surveys estimated 15,499 individuals (95% CI 10,383 - 22,277; Amidon et al. 2014). Density estimates were as follows: 1,094 ± 196 birds/km² in 1982; 1,901 ± 382 birds/km² in 1995; 2,224 ± 396 birds/km² in 2000; 1,693 ± 275 birds/km² in 2002, and 2,433 ± 466 birds/km² in 2008 (Amidon et al. 2014). The population density increased significantly between 1982 and 2008 (Camp et al. 2012, Amidon et al. 2014). 

A third population was established on the uninhabited island of Sarigan through translocations of 24 and 50 individuals in 2011 and 2012, respectively, with breeding detected within the first year (Radley 2012, MAC Working Group 2014).

Although the population size appeared to be increasing on Aguiguan (Camp et al. 2012, Amidon et al. 2014), and a new population has been established on Sarigan (Radley 2012, MAC Working Group 2014), the largest subpopulation, on Saipan, was found to be decreasing (Camp et al. 2009, Ha et al. 2018) and overall, the species is inferred to be undergoing a continuing decline in population size.

Based on the relative population densities recorded in Saipan in 1997 and 2007, the relative population densities recorded in Anguiguan in 1995 and 2008, the abundance estimates from 2007 (Saipan) and 2008 (Aguiguan), and assuming that the population on Sarigan has no more than 100 individuals, and that rates of population change have remained constant, the total population is suspected to have undergone a reduction of 10-19% over the past ten years. Assuming the trend continues over the next decade, the population is also suspected to undergo a reduction of 10-19% over the next three generations.

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)	Aguiguan Island and Naftan Rock
Northern Mariana Islands (to USA)	Northern Saipan
Northern Mariana Islands (to USA)	Topachau-Susupe-Kagman

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Plantations	suitable	resident
Artificial/Terrestrial	Subtropical/Tropical Heavily Degraded Former Forest	suitable	resident
Artificial/Terrestrial	Urban Areas	suitable	resident
Forest	Subtropical/Tropical Moist Lowland	major	resident
Shrubland	Subtropical/Tropical Moist	suitable	resident
Altitude		Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Climate change & severe weather	Habitat shifting & alteration	Timing		Scope		Severity		Impact
		Future		Whole (>90%)		Unknown		Unknown
		Stresses Indirect ecosystem effects, Ecosystem degradation
Climate change & severe weather	Storms & flooding	Timing		Scope		Severity		Impact
		Past, Likely to Return		Majority (50-90%)		No decline		Past Impact
		Stresses Ecosystem degradation
Geological events	Volcanoes	Timing		Scope		Severity		Impact
		Past, Likely to Return		Minority (<50%)		Very Rapid Declines		Past Impact
		Stresses Ecosystem degradation, Ecosystem conversion, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Boiga irregularis	Timing		Scope		Severity		Impact
		Past, Likely to Return		Whole (>90%)		Very Rapid Declines		Past Impact
		Stresses Indirect ecosystem effects, Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Capra hircus	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Coccinia grandis	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Lantana camara	Timing		Scope		Severity		Impact
		Ongoing		Minority (<50%)		Unknown		Unknown
		Stresses Ecosystem degradation
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Reduced reproductive success, Species mortality
Residential & commercial development	Commercial & industrial areas	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Residential & commercial development	Housing & urban areas	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Ecosystem degradation, Ecosystem conversion
Residential & commercial development	Tourism & recreation areas	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Slow, Significant Declines		Medium Impact: 6
		Stresses Species disturbance, Ecosystem degradation, Ecosystem conversion

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Recommended citation
BirdLife International (2024) Species factsheet: Golden White-eye Cleptornis marchei. Downloaded from https://datazone.birdlife.org/species/factsheet/golden-white-eye-cleptornis-marchei on 23/12/2024.
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 23/12/2024.