The Souimanga Sunbird (Cinnyris sovimanga), is a small passerine bird of the sunbird family, Nectariniidae. It is native to the islands of the western Indian Ocean where it occurs on Madagascar, the Aldabra Group and the Glorioso Islands. The Souimanga Sunbird can be found in a variety of habitats from mountain forests to mangroves and scrubland as well as in parks, gardens and other human-modified ecosystems. Souimanga Sunbirds are one of the most common small land birds across much of their range. Five subspecies are recognized.
The Souimanga Sunbird is 4 inches long. The black bill is long, thin and curved. Males of the nominate subspecies have a metallic green head, back and throat. The breast is blackish with a more or less continuous red band while the belly is yellow and the wings and tail are brown. There are yellow tufts at the sides of the breast which become visible when the birds lift their wings in courtship display. Males presumably molt into a duller eclipse plumage by March-April, losing most of the metallic and red feathering for a few months. Females have gray-brown upperparts, a dull yellow belly and a gray throat and breast with darker markings. Juveniles are similar to the adult females but the chin and throat are sometimes black and the upperparts may be more olive.
This bird has a chirruping flight call and a loud, hoarse alarm call. Only the male sings, which is a fast and scratchy song with frequently repeated phrases. They use their curved bill to probe flowers for nectar and also feed on insects and spiders. They have few natural enemies and their nests are inaccessible to most predators.
The long breeding season lasts from August to March on Aldabra at least. The nest is dome-shaped and has an entrance hole on the side. It is made of plant material such as grass stems, coconut fiber and leaves. It is usually suspended from a branch about 3 to 6.5 feet above the ground but may be built on a building or in a sinkhole within eroded coral. Two eggs are laid and are incubated for 13 to 14 days; they are whitish with reddish mottling. The young birds fledge after 16 to 18 days. Nest-building and incubation of the eggs are done by the female who also plays a greater role than the male in feeding the chicks.