They have medium-length thin down-curved bills and brush-tipped tubular tongues, both adaptations for nectar feeding.

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.

[3] The crimson-backed sunbird is an endemic resident breeder in the Western Ghats of India.

Two eggs are laid in a suspended nest on a thin drooping branch of low tree, fern frond or shrub.

[8] Males establish and defend feeding territories on flower bearing shrubs and trees.