Females can be easily distinguished from female Purple-rumped Sunbirds by their yellow throats.
Meet the Purple Sunbird
The purple sunbird (Cinnyris asiaticus) is a relatively small member of its species with a square-ended tail exhibiting sexual dimorphism. Only 10 cm long they sport a down-curved bill with a brush-tipped tongue to help in nectar feeding. The male wears glossy metallic bluish to purple plumage with black on the upper parts while the wings are dark brown. When breeding is under parts are also the same purple to black which helps sometimes confuse him with Lotens Sunbird. During the breeding season, the male may also display their yellow pectoral tufts.
Female birds are olive-brown above with a yellowish breast fading to off-white on the belly. Outer tail feathers are tipped in white as are the males. Females also have a pale supercilium beyond the eye.
Juvenile birds look like their female counterparts, though males will get black feathers as they grow.
They can be found in thin forests and garden land, including those in dense urban areas.
Purple sunbirds can often be seen in pairs dining on nectar, however, they will also take insects from time to time as well as some small berries.
During the breeding season, the male puts on a courtship display which involves raising his head, fanning his tail, and fluttering his partly open wings to expose his pectoral tufts and singing to the female. The female then builds a nest in the form of a pouch made from cobwebs, thin strips of vegetation, lichen, and bark, usually suspended from a low branch, often of thorny plants. The male may assist in its construction from time to time. Once the nest is built two eggs are laid within and incubated by the female for 15 to 17 days. Once they hatch the male will assist her in feeding the young.
This bird is regarded as of Least Concern on the IUCN Red List.
You can watch and listen to this bird right here in the video below: