Apricot-breasted sunbird

German ornithologist Ernst Hartert first described the apricot-breasted sunbird with the scientific name Cinnyris büttikoferi in 1896, using a specimen collected on the Indonesian island of Sumba, which is part of the central Lesser Sunda Islands.[2] It is a monotypic species, though it is sometimes considered conspecific with the olive-backed sunbird.[3]

The genus name Cinnyris is from the Greek kinnuris (κιννυρις), the name given to a small (but unidentified) bird by the Greek author Hesychius.[4] The species name honors Swiss zoologist Johann Büttikofer, who had described several females but refrained from naming them as a new species, as he hadn't seen any males.[2]

The apricot-breasted sunbird is a medium-sized sunbird, measuring 11 cm (4.3 in) in length.[4] The male has an olive-brown back and neck with a greyer-brown crown, a somewhat glossy, blackish tail tipped with brown, and brown flight feathers edged in green. His underparts are largely yellow, though from chin to upper breast is an iridescent purplish-blue, with an orange breast band caudal to that. The female is similar to the male, but her whole underside is yellow, with olive-green sides to the breast. Both sexes have blackish feet and dark brown irises. The male's bill is black, while the female's is dark brown. The juvenile is undescribed.[3]

Endemic to Sumba, the apricot-breasted sunbird is found at elevations ranging from sea level to at least 950 m (3,120 ft).[4]

Though the apricot-breasted sunbird is common on Sumba, with an estimated population of 750,000, little is known about its biology.[3] It is typically conspicuous, and generally found singly or in pairs. Though it forages primarily in the mid-storey to canopy (or occasionally lower), nothing is known about its diet. Its breeding is equally mysterious, with nothing known about courtship behaviour, nest, eggs or young.[4]

Because of its large and apparently stable population, the apricot-breasted sunbird has been rated as a species of least concern by the International Union for Conservation of Nature. Although it is confined to Sumba, it is found all across the island[1] — an area of roughly 13,100 km² (5,100 sq mi).[5]