Sangihe White-eye Zosterops nehrkorni Scientific name definitions

10·5–12 cm. Has black forehead and forecrown, contrasting sharply with bright golden-olive of rear crown; upperparts rich yellowish olive-green (paler than Z. atrifrons), brighter on lower back, rump and uppertail-coverts; white eyering rather narrow (on skins) to wide (in the field), olive side of face clearly demarcated from throat by almost blackish moustachial streak; tail feathers brownish-black, edged greenish; chin, throat and undertail-coverts bright canary-yellow, remaining underparts pearly white, flanks grey, becoming darker ventrally; iris light brown to red-brown; bill and legs relatively pale orange-flesh. Sexes alike. Juvenile undescribed.

Mt Sahendaruman and adjacent Mt Sahengbalira, on Sangihe I, N of Sulawesi.

Primary ridgetop (low-stature) forest and broadleaf-trophophyllous hill rainforest, with considerable density of Pandanus, at c. 750–920 m; absent from secondary habitats such as mixed plantations, and seems to be confined to submontane low-stature forest in S of island. Not found near lower limit of presently existing forest, where one would expect it had it ever occurred in low-elevation forest.

Presumed sedentary.

Insects. Forages in groups of three, in dense canopy and subcanopy; gleans leaves.

Song sounds thinner, more tinkling and less warbling than that of Z. atrifrons, and having first notes more constant in frequency and terminal section falling strongly. Contact calls described as thinner and higher-pitched than those of Z. atrifrons; also three high-pitched “swiit…swiit…swiit” calls, c. 2 seconds in duration, similar to calls of some flowerpeckers (Dicaeum) but higher and sharper.

Singing by three birds in Feb strongly suggests breeding or pre-breeding activity. No other information.

CRITICALLY ENDANGERED. Restricted-range species: present in Sangihe and Talaud EBA. Rare. Had been known only from a single specimen, collected in late 1886, but rediscovered during two-week survey on Mt Sahengbalira in Aug 1996, when three individuals were observed on two consecutive days. During a subsequent survey on the mountain for two weeks in Nov 1996, three birds seen only once, at same locality; during 60 days spent in same area between Aug 1998 and Feb 1999, a sight record of a single individual and aural records on three consecutive days. Numerous other observers in recent times failed to see the species. The very few records suggest that this species is now extremely rare, and may already have been so for a long time. It may be wide-ranging in search of fruits, and the small area of suitable habitat (800 ha) remaining within its present range, which is under pressure from small-scale agricultural encroachment by local farmers, may critically restrain the population. It is the least known and possibly the most threatened of Sangihe I endemics. Conservation of remaining forest is vital for the survival of this species, which is the only white-eye on Sangihe I.