Animal Diversity Web

Diversity

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)

Geographic Range

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

• Biogeographic Regions
• ethiopian
  • native

• Other Geographic Terms
• island endemic

Habitat

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)

• Habitat Regions
• tropical
• terrestrial

• Terrestrial Biomes
• forest
• rainforest

Physical Description

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)

• Other Physical Features
• endothermic
• bilateral symmetry

• Sexual Dimorphism
• male larger
• sexes colored or patterned differently
• male more colorful
• ornamentation

Reproduction

Little is known about the breeding behaviors of asities. They are thought to be polygynous, but the mating system may change according to the availability of food. Male asities enlarge their wattles when they display to females and their outer primary feathers produce a buzzing sound when they fly. Velvet asities (Philepitta castanea) seem to form dispersed leks where males hold territories on which they perform mating displays. Their displays have a series of steps and involve performing a perch-somersault where the male flips around a branch. Schlegel’s asities (Philepitta schlegeli) drop their wings, fluff their breast feathers and lift up their tails while squeaking. Common sunbird-asities (Neodrepanis coruscans) and yellow-bellied sunbird-asities (Neodrepanis hypoxantha) perform a hunched display where they lower their bill and tail, raise their crown feathers and sing. Yellow-bellied sunbird-asities (Neodrepanis hypoxantha) also perform a somersault display, although this is thought to be a display to deter other males, not to attract females. (Hawkins, 2003; Lambert and Woodcock, 1996)

• Mating System
• polygynous

The timing of breeding varies from region to region. However, it usually starts with the wet season and coincides with the time of maximum food availability. Females are responsible for nest building. Nests are pear shaped, hanging and are usually made of bamboo, roots, grass, moss, strips of bark, leaves and spider webs. The entrance to the nest is created at the end of nest-building by poking a hole in the side of the structure. The hole is often sheltered by overhanging grass. Nests are usually two to five meters above the ground. Clutch size is not known, but is suspected to be two to three. There is no information available about incubation and fledging times. (Hawkins, 2003; Lambert and Woodcock, 1996)

• Key Reproductive Features
• iteroparous
• seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual
• fertilization
  • internal
• oviparous

Females are responsible for incubating eggs and raising young. Young are mainly fed insects. (Hawkins, 2003)

• Parental Investment
• female parental care

Lifespan/Longevity

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

Behavior

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)

• Key Behaviors
• flies
• motile
• sedentary
• solitary
• territorial
• social

Communication and Perception

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)

• Communication Channels
• visual
• acoustic

• Perception Channels
• visual
• tactile
• acoustic
• chemical

Food Habits

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)

• Primary Diet
• carnivore
  • insectivore
• herbivore
  • frugivore
  • nectarivore
• omnivore

Predation

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

Ecosystem Roles

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

• Ecosystem Impact
• disperses seeds
• pollinates

Economic Importance for Humans: Positive

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)

• Positive Impacts
• ecotourism
• pollinates crops

Economic Importance for Humans: Negative

There are no known adverse affects of asities on humans.

Conservation Status

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)

• IUCN Red List [Link]

  Not Evaluated

Contributors

Alaine Camfield (author), Animal Diversity Web.

Kari Kirschbaum (editor), Animal Diversity Web.

References

2003. "UNEP-WCMC Species Database: CITES-Listed Species" (On-line). Accessed March 15, 2004 at http://www.cites.org/eng/resources/species.html.

Campbell, B., E. Lack. 1985. A Dictionary of Birds. Vermillion: Buteo Books.

Dickinson, E. 2003. The Howard and Moore Complete Checklist of Birds of the World, 3rd edition. London: Christopher Helm.

Hawkins, A. 2003. Family Philepittidae (Asities). Pp. 94-105 in J del Hoyo, A Elliott, D Christie, eds. Handbook of the Birds of the World, Vol. 8. Barcelona: Lynx Edicions.

IUCN, 2002. "The IUCN Red List of Threatened Species" (On-line). Accessed March 15, 2004 at http://www.redlist.org/.

Kemp, A., G. Sherley. 2003. Asities. Pp. 421 in C Perrins, ed. The New Encyclopedia of Birds. Oxford: Oxford Univeristy Press.

Lambert, F., M. Woodcock. 1996. Pittas, Broadbills and Asities. Sussex: Pica Press.

Payne, R. 2003. "Bird Families of the World" (On-line). Accessed March 15, 2004 at http://www.ummz.lsa.umich.edu/birds/Bird_Families_of_the_World.html.

Prum, R., R. Morrison, G. Ten Eyck. 1994. Structural color production by constructive reflective from ordered collagen arrays in a bird (Philepitta castanea: Eurylaimidae). Journal of Morphology, 222: 61-72.

Sibley, C., J. Ahlquist. 1990. Phylogeny and Classification of Birds, A study in Molecular Evolution. New Haven: Yale University Press.