The crimson-backed sunbird or small sunbird (Leptocoma minima) is a sunbird endemic to the Western Ghats of India. Like other sunbirds, they feed mainly on nectar although they take insects, especially to feed their young. They are tiny birds that are resident and are found in forests but are particularly attracted to gardens at the edge of the forest where people grow suitable flower-bearing plants. They usually perch while taking nectar.
Crimson-backed sunbirds are tiny, even by sunbird standards, and are only 8 cm long. They have medium-length thin down-curved bills and brush-tipped tubular tongues, both adaptations for nectar feeding.
The adult male is velvety red on the mantle and wing coverts and there is a broad red breast band. The crown is shiny green and there are pink-violet patches on the throat and rump. The underside from the breast below is yellowish. There is a black edge to the bib that separates the yellow of the underside. The larger purple-rumped sunbird can appear very similar but this sunbird has a darker maroon on the upper side while the flanks and vent are whitish. The eclipse plumage (non-breeding) of the male has more olive on the head and velvet red is restricted to the lower mantle and wing coverts. The female is olive-brown but the rump is distinctly red. They may be found in good numbers in flower-rich gardens at the edges of forests or plantations.
The calls include short chik calls and longer chee-chee-which-chee. source