Yellow-bellied asity  (Neodrepanis hypoxantha)

The yellow-bellied asity is classified as Vulnerable (VU) on the IUCN Red List (1).

The yellow-bellied asity (Neodrepanis hypoxantha) is a tiny and brilliantly coloured bird with a short tail and a long, downward-curved black bill (3). The male yellow-bellied asity has striking plumage, with black upperparts that are speckled with iridescent blue (4). This species acquires its common name from the plumage of the underparts, which are a brilliant, clean yellow. The male has a large wattle that extends from the bill to behind the eyes and is bright blue in colour (2).

The female yellow-bellied asity lacks a wattle and is generally duller than the male, with muted green plumage and a darker yellow breast, an appearance that gives good camouflage within its forest habitat (2) (4).

The yellow-bellied asity is also known as the ‘false sunbird’, but can be distinguished from sunbirds (Nectariniidae species) by the lack of yellow on the primary feathers, a more extensive eye wattle on the male, and a shorter and less curved bill. The yellow-bellied asity also has a shorter tail and is smaller in size than a sunbird (3).

The yellow-bellied asity’s call is a quiet squeak (4).

The yellow-bellied asity is endemic to the island of Madagascar, where it is found in the eastern forests. It is known from the Morojejy and Anjanaharibe-Sud Massifs in the north to the Andohahela Massif in the south (2).

The yellow-bellied asity is typically found in mossy, humid, evergreen woodland, at elevations above 1,200 metres. It is usually found in the canopy and sub-canopy of the forest (2).

As hinted by its long, curved bill, the yellow-bellied asity is primarily a nectar feeder, using its elongated, tube-like tongue to probe the wide variety of plant species that have been recorded as its nectar sources. This species also eats small insects and other arthropods (4).

The yellow-bellied asity has been seen associating with mixed species flocks, probably to provide protection from predators (2).

This small bird species is known for its fearless attitude when defending nectar sources from rivals, the male flashing its bright yellow throat at any intruders (2). The yellow-bellied asity will even aggressively display towards humans (2).

During the breeding season, the vivid male yellow-bellied asity will display to the duller female. In flight, the wings of the displaying male make a loud whirring noise. This seems to be made by a needle-like primary feather, which is only present in the breeding male and so is likely to have a role in sexual display (4).

The female yellow-bellied asity constructs a hanging, pear-shaped, globular nest from interwoven sticks and vegetation, with an entrance hole built into the side (5). This species has been observed nesting between November and January (2).

The yellow-bellied asity has a small range that is severely fragmented and at risk from degradation by fires used for clearing neighbouring farmland (2). Although the higher-elevation forests in eastern Madagascar are generally less threatened then other forests on the island, habitat destruction due to clearance for agriculture is a possible future threat to this species (2) (4).

Many areas that the yellow-bellied asity inhabits are now protected. These include Andohahela National Park, Anjanaharibe Classified Forest, Marojejy National Park, Tsaratanana Strict Reserve, Zahamena National Park, and others (2). However, there is currently little being done to conserve the yellow-bellied asity directly. More research into its population size and behaviour needs to be done to aid any conservation efforts for this species (4).

More information on the yellow-bellied asity:

• BirdLife International – Yellow-bellied asity:
  http://www.birdlife.org/datazone/speciesfactsheet.php?id=4042

Learn more about conservation in Madagascar:

• Wildlife Conservation Society - Madagascar:
  http://www.wcs.org/where-we-work/africa/madagascar.aspx
• Conservation International - Madagascar:
  http://www.conservation.org/where/africa_madagascar/madagascar/Pages/default.aspx