• 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
-	D	A2ace+4ace; D1+2

Red List history

Year	Category	Criteria
2021	Vulnerable	A2ace+4ace; D1+2
2019	Vulnerable	A2ace+4ace; D1+2
2016	Vulnerable	D1+2
2015	Endangered	D
2012	Endangered	D
2008	Endangered	D1
2005	Endangered
2004	Critically Endangered
2000	Critically Endangered
1996	Critically Endangered
1994	Critically Endangered
1988	Threatened

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

	Estimate	Data quality
Extent of Occurrence (breeding/resident)	1,500 km2	medium
Area of Occupancy (breeding/resident)	88 km2
Number of locations	4-10	-
Severely fragmented?	no	-

	Estimate	Data quality	Derivation	Year of estimate
Population size	220-270, 250 mature individuals	good	estimated	2019
Population trend	stable	good	estimated	2012-2022
Rate of change over the past 10 years/3 generations (longer of the two periods)	30-49%	-	-	-
Rate of change over the future 10 years/3 generations (longer of the two periods)	0-60%	-	-	-
Rate of change over the past & future 10 years/3 generations (longer of the two periods)	30-40%	-	-	-
Generation length	2.6 years	-	-	-
Number of subpopulations	4	-	-	-
Percentage of mature individuals in largest subpopulation	50-60%	-	-	-

Population justification: The populations on each island have been estimated as follows: c.20 birds on Mahé in 2018, 10 to 15 individuals in Conception in late 2018, c.240 individuals on Frégate Island in 2017, and 125-140 individuals on Ile du Nord (North Island) in 2017 (Pietersen, 2017, Rocamora et al. 2018, G. Rocamora in litt. 2019, IBC-UniSey unpubl.). In 2018, 30 individuals from Frégate Island and 17 individuals from Ile du Nord were translocated to Grande Soeur Island (G. Rocamora in litt. 2019, IBC-UniSey unpubl.). The population on Cousine apparently failed, with no more than five individuals recorded there in 2013 (G. Rocamora in litt. 2014), all of which vanished shortly after (G. Rocamora in litt. 2019, IBC-UniSey unpubl.). The newly-translocated population on Grande Soeur was reported to number c.40-45 individuals and to have produced four fledglings in 2019 (G. Rocamora in litt. 2019). However, since this population was reintroduced less than five years ago, it is not included in the current population estimate. The total population size is estimated at c.340-400 individuals. This roughly equates to 227–267 mature individuals, rounded here to 220–270 mature individuals, with the most likely population size placed at 250 mature individuals.

Trend justification: The population on Mahé was estimated to number c.60 birds in 2006, but declined down to 40 birds in 2011-2013 (G. Rocamora in litt. 2014) and c.20 birds by 2018 (G. Rocamora in litt. 2019, IBC-UniSey unpubl.).

The population on Conception was estimated at c.340 individuals in 2009 (Rocamora and Labiche 2009) and c.310 individuals in 2014 (G. Rocamora in litt. 2019). In 2017 it was discovered that Black Rats Rattus rattus had colonised the island, probably about two years before in view of the rat distribution and abundance observed during visits. Subsequently, the population of Seychelles White-eye on Conception was almost eliminated, estimated at 10 to 15 individuals in late 2018 (G. Rocamora in litt. 2019, IBC-UniSey unpubl.).

The transfer of 37 individuals from Conception to Frégate Island in 2001 and 2003 resulted in the establishment of an estimated population of c.100 individuals there in 2007 (G. Rocamora in litt. 2007, Henriette and Rocamora 2011), c.150 individuals in 2010/2011 (G. Rocamora in litt. 2014) and c.240 individuals in 2017 (G. Rocamora in litt. 2019; Rocamora et al. 2018). Thirty individuals were translocated from Frégate Island to Grande Soeur Island in 2018 (G. Rocamora in litt. 2019, IBC-UniSey unpubl.).

In 2007, 25 birds were transferred to Ile du Nord, and 23 to Cousine (Rocamora and Henriette-Payet 2009). The population on Ile du Nord increased to approximately 100 individuals in 2014 (Havemann and Havemann 2014) and 125-140 individuals in 2017 (Pietersen, 2017), 17 of which were translocated to Grande Soeur Island in 2018 (G. Rocamora in litt. 2019). However, the population on Cousine has apparently failed, with no more than five individuals recorded there in 2013 (G. Rocamora in litt. 2014), all of which vanished shortly after (G. Rocamora in litt. 2019, IBC-UniSey unpubl.).

The translocations to Grande Soeur took place less than five years ago, hence the population there is not included in this assessment.

Combining these figures and assuming linear trends, the overall population size is estimated to have undergone a reduction of between 30% and 49% over the last three generations.

If we assume that ongoing subpopulation trends will continue, the overall population size is projected to increase over the next three generations. Both Frégate and Ile du Nord have been estimated to have carrying capacities of several hundred individuals (Rocamora in litt. 2019), so we assume that these subpopulations will continue to grow.

Over a period of three generations which extends from the past and into the future, the maximum population reduction is estimated to be 30-40%, assuming that current subpopulation trends continue.

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

Country/Territory	IBA Name
Seychelles	Conception island
Seychelles	Mahé highlands and surrounding areas

Habitat (level 1)	Habitat (level 2)	Importance	Occurrence
Artificial/Terrestrial	Arable Land	suitable	resident
Artificial/Terrestrial	Plantations	suitable	resident
Artificial/Terrestrial	Rural Gardens	suitable	resident
Forest	Subtropical/Tropical Moist Lowland	suitable	resident
Shrubland	Subtropical/Tropical Moist	suitable	resident
Altitude	0 - 600 m	Occasional altitudinal limits

Threat (level 1)	Threat (level 2)	Impact and Stresses
Agriculture & aquaculture	Annual & perennial non-timber crops - Scale Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Past, Likely to Return		Minority (<50%)		No decline		Past Impact
		Stresses Ecosystem degradation, Ecosystem conversion
Biological resource use	Logging & wood harvesting - Unintentional effects: (subsistence/small scale) [harvest]	Timing		Scope		Severity		Impact
		Past, Likely to Return		Minority (<50%)		No decline		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, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Acridotheres tristis	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		No decline		Low Impact: 5
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus norvegicus	Timing		Scope		Severity		Impact
		Past, Likely to Return		Majority (50-90%)		No decline		Past Impact
		Stresses Reduced reproductive success
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Rattus rattus	Timing		Scope		Severity		Impact
		Past, Likely to Return		Majority (50-90%)		Rapid Declines		Past Impact
		Stresses Species disturbance, Ecosystem degradation, Reduced reproductive success, Species mortality
Invasive and other problematic species, genes & diseases	Invasive non-native/alien species/diseases - Unspecified species	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		Unknown		Unknown
		Stresses Ecosystem degradation, Species mortality
Invasive and other problematic species, genes & diseases	Problematic native species/diseases - Hypsipetes crassirostris	Timing		Scope		Severity		Impact
		Ongoing		Majority (50-90%)		No decline		Low Impact: 5
		Stresses Competition, Reduced reproductive success
Natural system modifications	Fire & fire suppression - Trend Unknown/Unrecorded	Timing		Scope		Severity		Impact
		Future		Majority (50-90%)		No decline		Low Impact: 3
		Stresses Ecosystem degradation

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Recommended citation
BirdLife International (2024) Species factsheet: Seychelles White-eye Zosterops modestus. Downloaded from https://datazone.birdlife.org/species/factsheet/seychelles-white-eye-zosterops-modestus 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.