Justification of Red List Category
This species is poorly known and its status is difficult to assess, not least owing to the paucity of information. However, it is restricted to only one island where it occupies a very small area of forest and consequently it qualifies as Vulnerable. If further research shows that its population is declining or fluctuates with natural events, it may be uplisted to a higher category of threat.
On a recent survey of the Savi'i highlands it was frequently encountered in small flocks, most commonly in the more modified open forests above Asau. Its presence in 38% of 30-minute surveys including 65% at Asau suggests that the species is present in good numbers (Atherton and Jefferies 2012). The population is estimated here to be >1000 mature individuals.
There are no new data on population trends; however, the population is assumed to be stable as there are no known threats.
Zosterops samoensis is endemic to Savai`i, Samoa. In 1987 and again in 1991, it was found to be not uncommon (even though the latter survey was after the severe cyclone Ofa) (Bellingham and Davis 1988, S. Ericsson in litt. 1994). In 2012, it was frequently encountered in small flocks, most commonly in the more modified open forests above Asau (Atherton and Jefferies 2012).
It occurs in the highlands mainly above 900 m where it has been recorded in flocks of 15-20 birds in the canopy of prime upland forests, but has been recorded as low as 780 m, and also in open scrub-like alpine habitat and secondary scrub on the Mata o le Afi lava flow where it forages in low bushes up to several hundred meters from the forest edge.(Bellingham and Davis 1988, S. Ericsson in litt. 1994, Pratt and Mittermeier 2016).
Slash-and-burn cultivation threatens remaining areas of upland forest, as farmers use forestry roads from heavily logged lowland forests to gain access to formerly inaccessible land (Bellingham and Davis 1988). Black rat Rattus rattus may also pose a threat to the species (D. Hobcroft in litt. 2012).
Conservation Actions Underway
Mt Silisili Park, a unique area of montane cloud-forest in central Savai`i, is a refuge for the species (Beichle and Maelzer 1985).
10 cm. Small, warbler-like bird. Olive-green above, dingy white below with yellow tinge to throat and conspicuous, completely white eye-ring. Pale iris. Voice a high-pitched tchee or
cheeer sound, occasionally with a gurgling or buzzy quality (Pratt and Mittermeier 2016) Hints Moves about in small flocks.
Text account compilers
Derhé, M., Dutson, G., Mahood, S., O'Brien, A., Shutes, S., Stattersfield, A.
Hobcroft, D., Ericsson, S.
BirdLife International (2019) Species factsheet: Zosterops samoensis. Downloaded from http://www.birdlife.org on 19/09/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 19/09/2019.