The Purple-rumped Sunbird (Leptocoma zeylonica) is a sunbird endemic to the Indian Subcontinent.
Like other sunbirds, they are small in size, feeding mainly on nectar but sometimes take insects, particularly when feeding young. They can hover for short durations but usually perch to feed. They build a hanging pouch nest made up of cobwebs, lichens and plant material. Males are brightly coloured but females are olive above and yellow to buff below.
Purple-rumped Sunbirds are tiny at less than 10 cm long. They have medium-length thin down-curved bills and brush-tipped tubular tongues, both adaptations to their nectar feeding. Purple-rumped Sunbirds are sexually dimorphic. The males have a dark maroon upperside with a blue-green crown that is visible in some angles. There are violet patches on the throat and rump which are visible only in good lighting. There is also a maroon breast band. In the Western Ghats, it can overlap in some areas with the Crimson-backed Sunbird but that species has reddish upper parts. The female has a white throat followed by yellowish breast. There is a bright green shoulder patch. The upper side is olive or brownish. The upper tail coverts are black and a weak super cilium is visible. The nominate form is found in Sri Lanka and has a more bluish violet throat whereas the Indian form flaviventris (two other proposed populations whistleri from Maddur in Karnataka and sola from Pondicherry are subsumed) has a more pinkish tinge. Their call is ptsiee ptsit, ptsiee ptsswit or a sharp twittering tityou, titou, trrrtit, tityou....
They breed through the year and may have two broods but mainly during the monsoons. The nest is made up of fine plant fibres, cobwebs and is studded on the exterior with lichens, bark pieces, flying seeds and other materials. The nest is constructed by the female alone although the male may fly alongside her. The nest is lined with soft fibers from seeds of Calotropis,. The nest is placed on the end of branch and the entrance usually faces a bush. Nests may sometimes be built close to buildings or under open porches. The female stays in the nest at night a couple of day before laying the eggs. The clutch consists of two eggs which are oval pale greenish and white with spots and streaks becoming more dense at the broad end. When collecting cobwebs they are often seen at windows of homes. The eggs are laid mainly in the morning. The eggs are incubated by both the male and female. The incubation period varies from 14 to 16 days. The chicks fledge in about 17 days and continue to be fed by the male for a few days. Helpers, females or possibly juveniles from the previous brood may sometimes assist the parents in feeding the young. Old nests are sometimes reused. Cases of nests being parasitized by the Grey-bellied Cuckoo, are known. In one case the cuckoo was fed by an adult sunbird as well as an adult Common Tailorbird.