Like other sunbirds, the rufous-winged sunbird feeds primarily on nectar (2). Its long, curved bill is perfect for probing the flower and the rufous-winged sunbird also has a specially adapted tongue, divided into three or four flaps at the tip, that allow it to lap up the nectar within (6).
The rufous-winged sunbird typically feeds on tropical mistletoes (Loranthaceae), which it may protect aggressively from other sunbirds (2). When feeding from a flower, pollen may stick to the sunbird’s forehead and be carried to the next flower the sunbird feeds from. In this manner, the sunbird is, unknowingly, an important pollinator of some plants (7). This species also feeds on small insects found in the canopy (2).
Little is known about the rufous-winged sunbird’s reproductive behaviour. Many sunbird species perform intriguing displays to attract a mate, which can include singing, aerial pursuits, bowing or swaying (8). Like other sunbird species, the rufous-winged sunbird probably lays a clutch of two eggs, into a closed nest of moss, lichens, dry leaves, rootlets, fine twigs and grass, which is hung from a branch (8). Typically only the female sunbird incubates the eggs, while the male defends the territory by singing and chasing off intruders. Sunbird eggs are typically incubated for around 14 days, and after hatching the young stay in the nest for around 12 to 15 days before fledging (6).