Rufous-winged sunbird  (Nectarinia rufipennis)

The rufous-winged sunbird is classified as Vulnerable (VU) on the IUCN Red List (1).

Found only in the forests of the Udzungwa Mountains, Tanzania, the rufous-winged sunbird (Nectarinia rufipennis) is a strikingly colourful and increasingly threatened species (2) (3). Males of this medium-sized sunbird possess iridescent royal-blue upperparts, a metallic bronze throat and a blue and red band across the breast. Female rufous-winged sunbirds are drabber, with brown plumage on the upperparts and paler underparts, with slight streaking on the breast (2) (4).

Both sexes have rufous (reddish-brown) wing panels, which is unlike any other species of the sunbird family, and therefore lends this species its common name (2). Like all sunbirds, this species has a long, downward-curved bill (4). Individuals contact each other through soft ‘twisk twisk’ vocalisations (2).

The rufous-winged sunbird is endemic to the forests of the Udzungwa Mountains, Tanzania. The Udzungwa Mountains are situated within a chain of mountains known as the ‘Eastern Arc’, which stretches from southern Kenya to eastern Tanzania. These mountains are home to numerous birds that are found nowhere else in the world (5). 

An inhabitant of subtropical and tropical montane moist forests, the rufous-winged sunbird typically occurs at altitudes between 600 and 1,700 metres (2) (3), although during the cooler, non-breeding season (from June to August), this species often moves to lower altitudes. The rufous-winged sunbird is occasionally seen high in the canopy, but more commonly occurs in the lower canopy of the forest, between two and eight metres above the ground (2).

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).

The greatest threat to the rufous-winged sunbird is the destruction of its forest habitat. Commercial logging, clearing for cultivation, and bushfires all threaten this species’ habitat (2). Bushfires are started to maintain open, easily accessible habitats, and thus large areas of forest on mountain slopes and high ridges are burned annually (3). Charcoal production and exploitation of non-timber forest products also contribute to the degradation the Udzungwa forests in which the rufous-winged sunbird lives (2).

Climate change also poses a long-term threat to this species (2). It has been predicted that a rise in global temperatures will cause an increase in droughts, flooding and extreme weather events (9), ultimately altering or shifting the habitat of the rufous-winged sunbird.

There are no specific conservation measures currently in place for the rufous-winged sunbird, but it does occur within the Udzungwa Mountains National Park, although unfortunately this does not always protect the forest from logging or fires (2).

The Udzungwa Mountains are home to a number of other rare birds, as well as primates and duikers (small antelope species), which are found nowhere else in the world (3). The forests that cover these mountains also act a vital catchment area for large rivers and provide water for nationally important hydropower stations. Thus, conservation of the Udzungwa Mountains is essential not just to protect the animals that live there, but also to ensure the continued provision of drinking water, irrigation and power to thousands of people (3).

Conservation projects in the Udzungwa Mountains should integrate conservation with development, and concentrate their activities in villages adjacent to forests (3). Conservation priorities include fire management, plans for forest regeneration, and raising awareness about sustainable forest use (3).

Discover more about conservation in the Udzungwa Mountains and the Eastern Arc:

• Eastern Arc Mountains Conservation Endowment Fund:
  http://www.easternarc.or.tz/
• WWF – Udzungwa Mountains National Park:
  http://wwf.panda.org/who_we_are/wwf_offices/tanzania/index.cfm?uProjectID=TZ0044