Rodrigues Warbler Acrocephalus rodericanus Scientific name definitions

13·5 cm; 11–13 g. A medium-sized warbler with relatively long bill and legs, long graduated tail , short wings. Has yellowish supercilium, short dark eyestripe; crown and upperparts uniformly olive-brown , with paler cheek and pale yellow lores; below, pale lemon-yellow in fresh plumage, greyish-white with only slight wash of yellow when plumage worn; iris dark; bill mostly pinkish-yellow with dark culmen; legs grey, soles yellowish. Sexes alike. Juvenile undescribed.

Rodrigues I, in E Mascarene Is.

Dense thickets and woodland dominated entirely by non-native trees and shrubs; in 1999 survey, 78% of population found in habitat dominated by rose-apple (Eugenia jambos). Breeds also, but at much lower densities, in plantations dominated by mahogany (Swietenia mahogoni), tecoma (Tabebuia pallida) and Norfolk Island pine (Araucaria cunninghamii). Seems to prefer dense vegetation with access to clearings or forest edge.

Sedentary.

Mainly insects, including homopteran bugs, and adult and larval lepidopterans. Forages in canopy and subcanopy, by gleaning. Tail habitually jerked up and down.

Song  , heard infrequently, is soft and melodic. Harsh, chattering alarm.

Season late Sept to Mar; two broods perhaps usual. Breeds as pairs, but occasional co-operative breeding probable. Territorial. Nest a small cup, rather deep inside, lined with a few feathers, external structure may be quite tall, giving impression of inverted cone, but often the nest is squat and more or less flat-bottomed; 0·5–9 m above ground, supported in fork of two or more slender branches of tree, e.g. strawberry guava (Psidium cattleianum), rose-apple or tecoma. Usual clutch probably 2–3 eggs; incubation by both sexes, period not documented; nestling period c. 14 days.

Not globally threatened. Currently considered Near Threatened. It has been downlisted from Endangered following evidence that its population is increasing and is now much larger than previously thought. CITES III. Restricted-range species: present in Rodrigues EBA. Confined to a few valleys in centre of island. In 1999 survey, total population not exceeding c. 200 individuals, and density ranged from 2·3 birds/ha in optimal habitat to 0·5/ha in less suitable habitat. Rodrigues is one of world’s most devastated tropical islands, its native forest having been completely destroyed since human colonization three centuries ago. Present species was thought to be very common in 1875, but by 1960s considered to be on brink of extinction, and in early 1970s population estimated at maximum of 30 individuals. Since 1982, a steady increase in numbers and range has taken place. Main current threat is predation of nests by introduced rats (Rattus) and feral cats, also competition from other introduced animal species; human disturbance and the destruction and further degradation of remaining suitable habitat are additional threats, as also are sustained periods of drought (which reduce invertebrate abundance) and damaging effects of cyclones. Two Conservation Management Areas have been established; these sites are fenced in order to exclude grazing animals and wood-gathering humans, and exotic plants have been removed and native species replanted. The population has risen rapidly and was estimated at 4,000 indibiduals by 2012 External link .