EN
Mountain Starling Aplonis santovestris



Justification

Justification of Red List category
This species is classified as Endangered on the basis of an estimated very small population which is known from very few locations, and is precautionarily assessed as being in decline owing to the effects of hunting and/or introduced species.

Population justification
Recorded in ones and twos, and reported as 'locally common, not rare' on Santo Pic in August-October 2010 (S. Totterman per G. Dutson in litt. 2016). The population is estimated to number 250-999 mature individuals based on an assessment of known records, descriptions of abundance and range size. This is consistent with recorded population density estimates for congeners or close relatives with a similar body size, and the fact that only a proportion of the estimated Extent of Occurrence is likely to be occupied. This estimate is equivalent to 375-1,499 individuals in total, rounded here to 350-1,500 individuals. However, the population may in fact be smaller given the paucity of recent records and its restriction to an extremely small area of mountain tops (G. Dutson in litt. 2016).

Trend justification
The few records of this species mean it is not possible to assess its recent population trend, but it has clearly declined since historical records and probably since the last record in 1991 (G. Dutson in litt. 2016). There are also plausible threats to the species, with the Man Hill people reportedly eating this species (S. Maturin in litt. 1994). Additionally, a number of other Pacific montane starling species have become extinct, presumably through the introduction of predatory mammals or disease (Pratt et al. 1987), and while Santo has no native land mammals, introduced species such as cats, dogs and rats are now widespread. Therefore, the species may be undergoing a continuous decline, and is precautionarily listed as such, though further work is required to get a better estimate of population trends.

Distribution and population

Aplonis santovestris is endemic to Espiritu Santo, Vanuatu. It has been recorded from three of the highest mountains, Mt. Watiamasan, Mt. Tabwemasana and Peak Santo, in 1934, 1961, and 1991 (Harrison and Marshall 1937, Reside 1991, Bregulla 1992) and again at Pic Santo in 2010 (S. Totterman per G. Dutson in litt. 2016). Local villagers have reported it to be widespread in the western mountain ranges (S. Maturin in litt. 1994). Although some local villagers reported the species to be common, it appears to occur at low population densities and to be very localised (Harrison and Marshall 1937, Reside 1991, Bregulla 1992, S. Maturin in litt. 1994). Despite the recent record in 2010, several observers have trekked to these altitudes and failed to find the species (Barré et al. 2011, L. Szucs per G. Dutson in litt. 2016, J. Mittermeier in litt. 2017). Tracewski et al. (2016) estimated the maximum Area of Occupancy (calculated as the remaining tree area within the species’s range) to be c.21 km2.

Ecology

It forages in singles and pairs in the understorey of cloud-forest above 1,200 m, usually above 1,600 m, on the highest peaks. It is rarely recorded more than 6 m above the ground and is reported to nest in holes low down in trees (Harrison and Marshall 1937, Reside 1991, Bregulla 1992). 

Threats

The Man Hill people at Matantas Big Bay report regularly eating this species (S. Maturin in litt. 1994), however they rarely visit high altitudes and the validity of this report has been questioned (S. Totterman in litt. 2007). Overall, the number of people living at high altitudes on Santo has decreased through the last few decades (Pickering 1985, G. Dutson pers. obs. 1998). Forest on Santo remains largely intact, and has only partially been altered by clearings for pastures and coconut plantations in the lowlands and lower hills (Barré et al. 2011). A number of other montane starling species from the Pacific have become extinct, presumably through the introduction of predatory mammals or disease (Pratt et al. 1987). Santo has no native land mammals but cats, dogs and rats are now widespread. 

Conservation actions

Conservation Actions Underway
None is known.

Conservation Actions Proposed
Survey other mountains in the vicinity. Re-survey the three known locations - local reports that the species is widespread and common in suitable habitat need to be confirmed. Colour-ring birds at these sites to help assess population sizes and longevity. Survey all montane sites for introduced mammalian predators. Discuss the species's status and distribution with local villagers.

Identification

17 cm. Small, rather dumpy, warm-brown forest starling. Adults rich rusty-brown, slightly darker on upperparts and blackish on crown, with white iris. Juveniles undescribed. Similar spp. Rusty-winged Starling A. zelandicus has dark iris, dark mask and is greyish with rusty-brown restricted to wings and rump. Voice Simple, high-pitched, cheeping contact call. Hints Unobtrusive species, which has been seen on only a few expeditions to the highest altitudes.

Acknowledgements

Text account compilers
Symes, A., Derhé, M., Dutson, G., Stattersfield, A., Mahood, S., Ekstrom, J.

Contributors
Totterman, S., Dutson, G., O'Brien, M., Maturin, S., Szucs, L., Barré, N., Mittermeier, J.


Recommended citation
BirdLife International (2024) Species factsheet: Mountain Starling Aplonis santovestris. Downloaded from https://datazone.birdlife.org/species/factsheet/mountain-starling-aplonis-santovestris on 24/12/2024.
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 24/12/2024.