The Olive-backed Sunbird (Cinnyris jugularis), also known as the Yellow-bellied Sunbird, is an Asian sunbird. The Olive-backed Sunbird is common across southern China to the Philippines and Malaysia down to northeast Australia. Originally from mangrove habitat, the Olive-backed sunbird has adapted well to humans, and is now common even in fairly densely populated areas, even forming their nests in human dwellings.
They are small songbirds, at most 4.75 inches long. The underparts of both male and female are bright yellow, the backs are a dull brown color. The forehead, throat and upper breast of the adult male is a dark, metallic blue-black.
The birds mate between the months of April and August. Both the male and the female assist in building the nest which is flask-shaped, with an overhanging porch at the entrance, and a trail of hanging material at the bottom end. After building the nest, the birds abandon the nest for about a week before the female returns to lay one or two greenish-blue eggs. The eggs take a further week to hatch. The female may leave the nest for short periods during the day during incubation. After the chicks have hatched, both male and female assist in the care of the young, which leave the nest about two or three weeks later.
These sunbirds feed largely on nectar, although they will also take insects, especially when feeding young. Their flight is fast and direct on their short wings. Most species can take nectar by hovering, but usually perch to feed most of the time.