Aplonis metallica and A. circumscripta (Handbook of the Birds of the World and BirdLife International 2020) have been split from Aplonis metallica (del Hoyo and Collar 2016), after an assessment of 24 specimens in four museums and literature review (Collar 2018).
A. circumscripta is consistently diagnosed from metallica by its (1) short-feathered clear-cut inverted-U-shaped purple chin-patch, (2) large purple mantle-patch and correspondingly very narrow green hind-collar, and (3) average shorter bill and wings but, in males, notably longer central rectrices, strongly indicating that species rank is indeed appropriate for the taxon, for which the vernacular name Purple-chinned Starling is proposed.
Handbook of the Birds of the World and BirdLife International. 2020. Handbook of the Birds of the World and BirdLife International digital checklist of the birds of the world. Version 5. Available at: http://datazone.birdlife.org/userfiles/file/Species/Taxonomy/HBW-BirdLife_Checklist_v5_Dec20.zip.
Red List criteria met
Red List history
IUCN Red List criteria met and history
||not a migrant
Population justification: The species was recently split, previously being lumped with Purple-chinned Starling (A. circumscripta) under A. metallica (Collar 2018). The global population size of Metallic Starling has thus not been quantified, but is considered to be generally common across most of its range. The species also occurs at higher densities in secondary habitats such as coconut plantations and mangroves (G. Dutson in litt. 2020). Population density estimates measured at 3 birds/hectare in primary lowland forests and 1-7.5 birds/hectare in degraded lowland habitats and mangroves on Kolombangara (Buckingham et al. 1990) therefore suggest that the overall population may be large and numerous. Recent surveys in New Britain, Papua New Guinea also showed that the species remains common in oil palm plantations, being recorded in 60% of all forests observed (R. Davis in litt. 2020).
Trend justification: The population trend is difficult to determine because of uncertainty over the impacts of habitat modification on population sizes. However, assuming that population declines are occurring at the same rate as forest loss, recent forest loss analysis (per Tracewski et al. 2016, Global Forest Watch 2020) suggests the species is undergoing a decline at a rate of c. 14% over a three-generation period (11.4 years; Bird et al. 2020). Pressures from hunting for food may additionally exacerbate population declines over forest loss alone. However, as the species commonly occurs in plantations and secondary forests however, it is though to be tolerant of some degraded habitats. The rate of decline is therefore tentatively placed in the band of 10-15%.
Important Bird and Biodiversity Areas (IBA)
BirdLife International (2023) Species factsheet: Aplonis metallica. Downloaded from
http://datazone.birdlife.org/species/factsheet/metallic-starling-aplonis-metallica on 03/12/2023.
Recommended citation for factsheets for more than one species: BirdLife International (2023) IUCN Red List for birds. Downloaded from
http://datazone.birdlife.org on 03/12/2023.