NT
Atoll Starling Aplonis feadensis



Justification

Justification of Red List Category
Although this species is moderately susceptible to stochastic events and human activities owing to its extremely small range, this is spread out over many small islets, so it qualifies as Near Threatened. Further data are required on its habitat requirements, population size and trends on each island, and movement between these subpopulations. Should the population size be smaller than currently thought, or declining, the species would warrant uplisting to a higher threat category.

Population justification
The species is described as having a small population and is placed in the band 1,000-2,499 individuals.

Trend justification
There are no new data on population trends; however, the population is suspected to be stable.

Distribution and population

Aplonis feadensis is an extreme small-island specialist, occurring on a number of tiny atolls in Papua New Guinea and Solomon Islands. It breeds on islands in the Ninigo (3 km2), Hermit (8 km2), Tench (less than 1 km2), Nissan (37 km2), Nguria (5 km2) and Ontong Java groups (10 km2). It is fairly common on these islands (Bayliss-Smith 1972, Bell 1975, Finch 1986, Coates 1990), with day-counts of c.30 birds on Tench and Nissan in 1998 (G. Dutson pers. obs. 1998) and 15 on Tench in 1999 (Hornbuckle 1999). There is no indication of changes in the population.

Ecology

It is a largely frugivorous starling, usually foraging in pairs in the canopy, but also raiding gardens for bananas and other fruit (Bayliss-Smith 1972, Bell 1975, Finch 1986, Coates 1990, G. Dutson pers. obs. 1998). Its dependence on natural forest or tree species is not known. It nests in holes in old and damaged trees and coconut palms (Dutson 2011). Its dispersal abilities are not well-known beyond flying between islands within a group, but inter-island morphological variation suggests limited gene flow (Coates 1990).

Threats

It is threatened by natural causes such as cyclone damage and colonisation of its islands by Singing Starling A. cantoroides, exacerbated by ongoing habitat changes. It is generally assumed to be unable to compete with A. cantoroides (Bell 1975, Coates 1990), although it coexists with A. metallica on Nissan and apparently with A. cantoroides on some of the Ninigo islands; however, the latter situation may be unstable (Bell 1975, Coates 1990). All the islands except Nissan are tiny and have a high human population pressure on the remaining small and fragmented forested habitats. As well as clearance for agriculture, large areas have been cleared for coconut plantations. It is not known how tolerant it is to habitat change, but its dependence on holes for nesting may be a limiting factor. It is potentially at risk from climate change, as most of the islands it inhabits only rise a few metres above sea-level (G. Dutson in litt. 2004).

Conservation actions

Conservation Actions Underway
None is known.

Conservation Actions Proposed
Re-survey small islets across the species's range. Re-survey distribution of this species and A. cantoroides on the Ninigos. Ascertain area of forest and rates of clearance on all occupied islands. Ascertain habitat requirements. Assess distribution, population level and trends on Nissan. Investigate competition and ecological segregation with A. cantoroides. Relate distribution to that of introduced predatory species. Monitor population trends on Nissan. Advocate retention of natural forest reserves on all islands, regardless of their size. Initiate public awareness and education programmes regarding this species and the threats of introducing exotic species. Assess isolation of sub-populations through comparison of specimens.

Identification

20 cm. Medium-sized, dumpy starling of tiny islands. Adult glossy black with yellow eyes. Immature has paler scales on underparts and duller eyes. Similar spp. Singing Starling A. cantoroides has red eyes and is more elongate, with longer tail and more pointed wings. Metallic Starling A. metallica has red eyes and is slimmer with much longer tail. Extralimital Rennell Starling A. insularis used to be considered conspecific but is structurally and vocally distinct. Voice Range of starling chatters and whistles. Hints Often encountered around gardens and forest edge. Occasionally seen in small flocks.

Acknowledgements

Text account compilers
Harding, M., Derhé, M., Mahood, S., Dutson, G., O'Brien, A., Stattersfield, A.

Contributors
Dutson, G.


Recommended citation
BirdLife International (2019) Species factsheet: Aplonis feadensis. Downloaded from http://www.birdlife.org on 13/11/2019. Recommended citation for factsheets for more than one species: BirdLife International (2019) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 13/11/2019.