Family Philepittidae
asities
(Also: asity and false sunbird)

Asities belong to the order Passeriformes and the family Philepittidae. There are currently 2 recognized genera and 4 species of asities. The four species are: velvet asity (Philepitta castanea), Schlegel’s asity (Philepitta schlegeli), common sunbird-asity (Neodrepanis coruscans) and yellow-bellied sunbird-asity (Neodrepanis hypoxantha). All four species are endemic to Madagascar and are found primarily in rainforests. They are small to medium sized birds (9 to 16.5 cm long) with short tails. Males are brightly colored and have blue or green wattles around their eyes. The sunbird-asities have long downcurved bills that are well suited for extracting nectar from flowers. Asities also eat fruit, berries and insects. Little is known about the breeding behavior of asities. However, they are thought to be polygynous. (Dickinson, 2003; Hawkins, 2003; Lambert and Woodcock, 1996)

Asities are endemic to and found only in Madagascar. (Campbell and Lack, 1985; Hawkins, 2003; Lambert and Woodcock, 1996; Sibley and Ahlquist, 1990)

Asities are found in habitats where flowering parasitic and epiphytic plants are in high abundance. They prefer rainforest habitat but can also be found in dry deciduous forest and humid valleys. Asities are found from lowlands to high altitudes (up to 2650 m). (Hawkins, 2003)

Asities are in the order Passeriformes, suborder Eurylami and family Philepittidae. They are sometimes considered to be a subfamily Philepittinae within the family Eurylaimidae. The two genera within Philepittidae are sometimes treated as two subfamilies. In the past, the genus Philepitta has been placed in the family Sternidae (starlings), the family Paradisaeidae (birds-of-paradise) and the family Nectariniidae (sunbirds). The genus Neodrepanis has been placed in the family Nectariniidae (sunbirds). Members of the genus Neodrepanis were placed with the family Nectariniidae based on similar bill shape and tongue morphology. However, these similarities are the result of convergent evolution; both groups feed primarily on nectar and have evolved feeding structures that allow them to exploit this food source. Asities’ closest relatives are actually pittas (Pittidae) and broadbills (Eurylaimidae).

Asities are distinguishable from their closest relatives because: they have 12 tail feathers, their tarsi have regular scutes, they have a short tail and long outer primary feathers, the uppermost bronchial ring of the syrinx is heavy, the tongue is forked and brush-like at the tip and the color on the males’ wattles is produced by “ordered hexagonal arrays of parallel collagen fibers” (Prum et al. 1994). Asities are the only animal to use this mechanism to produce color. (Hawkins, 2003; Kemp and Sherley, 2003; Lambert and Woodcock, 1996; Payne, 2003; Prum, Morrison, and Ten Eyck, 1994; Sibley and Ahlquist, 1990)

Asities are small to medium sized birds. They are 9 to 16.5 cm long and weigh 6.2 to 38 g. There is marked sexual dimorphism in all four species; males are brighter and larger. Males have blue and/or green wattles around their eyes that are highly visible during breeding and are virtually absent at other times. Members of the genus Neodrepanis also have a bright patch of skin at the base of their beaks. They also have a small, short tail, short legs, and a long decurved bill. Their tubular tongue helps them to extract nectar from flowers. They molt twice a year, the first molt, after breeding, gives the males their eclipse plumage.

Members of the genus Philepitta are round birds with a short tail and short wings. They have yellow, black and iridescent blue feathers. Their beaks are much smaller than species in Neodrepanis and they lack the tubular tongue. They molt once a year; on males, the new feathers have a yellowish fringe that wears away over time, leaving the males all black by breeding season. Females are generally much duller in color (olive colored with some yellow or streaking on the breast) and the wattle, if present, is much less pronounced. Some males have delayed plumage maturation and may resemble females even though they are sexually mature. (Campbell and Lack, 1985; Hawkins, 2003; Kemp and Sherley, 2003; Lambert and Woodcock, 1996; Sibley and Ahlquist, 1990)

We do not have information on lifespan/longevity for this family at this time.

In general, asities are sedentary, though some may make altitudinal movements as food resources shift. Common sunbird-asities (Neodrepanis coruscans) may move up to 150 km within their range. Velvet asities (Philepitta castanea) are solitary and are known to be tame and approachable. Occasionally they feed in mixed-species flocks. Schlegel’s asities (Philepitta schlegeli) are usually found in the canopy. They are found in mixed-species flocks when not breeding, but are usually solitary when breeding. Males will defend feeding areas around flowering trees. Sunbird asities (genus Neodrepanis) are aggressive and compete with other species for food. They are found in mixed-species flocks when not breeding. They tend to be hostile toward humans. (Campbell and Lack, 1985; Hawkins, 2003)

The outer primary feathers make a buzzing sound when asities fly. This buzzing likely has a function in courtship. Males also enlarge their wattles to display to females and other males. All species also seem to have some form of courtship display (see Mating Systems).

For the most part, asities have quiet, squeaky calls. Some males have louder whistle calls. Velvet asities (Philepitta castanea) have a repeated “whee-doo” call, or a series of “wheet” notes. Common sunbird-asities (Neodrepanis coruscans) make a series of hisses and single, quiet, squeaky calls. Yellow-bellied sunbird-asities (Neodrepanis hypoxantha) sound like tree frogs with repeated single note calls. (Hawkins, 2003; Lambert and Woodcock, 1996)

Members of the genus Philepitta are primarily frugivores. They eat fruit from the families Rubiaceae, Euphorbiaceae, Piperaceae, Melastomataceae and Apocynaceae. They usually perch and pick fruit or quickly pick it while hovering in front of the plant. They also eat insects, spiders and nectar. Members of the genus Neodrepanis are primarily nectivores, although they do eat fruit. They feed on mistletoes (especially in the genus Bakerella), Balsaminaceae, Zingiberaceae, Melastomataceae and Rubiaceae. They also eat insects and other invertebrates.

The tongues of all four species are forked with a brush-like tip. This helps them to extract nectar from flowers. Common sunbird-asities (Neodrepanis coruscans) and yellow-bellied sunbird-asities (Neodrepanis hypoxantha) also have tubular shaped tongues that further aid in nectar feeding. (Hawkins, 2003; Lambert and Woodcock, 1996)

We do not have information on predation for this family at this time.

Asities have an impact on forest regeneration. They are important in both seed dispersal and pollination. (Hawkins, 2003)

There are no known adverse affects of asities on humans.

Asities help pollinate commercially important species such as Greuillea, Albizia and Eucalyptus. They are also important in ecotourism and are sought out by birders. (Hawkins, 2003)

Asities are vulnerable to human activity because they live in forests that are being cleared for agriculture, mining and timber. Their already small ranges are becoming increasingly fragmented. Yellow-bellied sunbird-asities (Neodrepanis hypoxantha) are listed as endangered by the IUCN and Schlegel’s asities (Philepitta schlegeli) are listed as near threatened. ("UNEP-WCMC Species Database: CITES-Listed Species", 2003; Campbell and Lack, 1985; Hawkins, 2003; IUCN, 2002; Kemp and Sherley, 2003)