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.
Geographic Range
Asities are endemic to and found only in Madagascar.
- 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).
- 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.
- 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.
- 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.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- fertilization
- oviparous
Females are responsible for incubating eggs and raising young. Young are mainly fed
insects.
- 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.
- 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.
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.
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.
- 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.
- 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.
Additional Links
Contributors
Alaine Camfield (author), Animal Diversity Web.
Kari Kirschbaum (editor), Animal Diversity Web.
- Ethiopian
-
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- island endemic
-
animals that live only on an island or set of islands.
- tropical
-
the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.
- terrestrial
-
Living on the ground.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- rainforest
-
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
- sexual ornamentation
-
one of the sexes (usually males) has special physical structures used in courting the other sex or fighting the same sex. For example: antlers, elongated tails, special spurs.
- polygynous
-
having more than one female as a mate at one time
- iteroparous
-
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
- seasonal breeding
-
breeding is confined to a particular season
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- fertilization
-
union of egg and spermatozoan
- internal fertilization
-
fertilization takes place within the female's body
- oviparous
-
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
- female parental care
-
parental care is carried out by females
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- territorial
-
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
- social
-
associates with others of its species; forms social groups.
- visual
-
uses sight to communicate
- acoustic
-
uses sound to communicate
- ecotourism
-
humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
- herbivore
-
An animal that eats mainly plants or parts of plants.
- frugivore
-
an animal that mainly eats fruit
- nectarivore
-
an animal that mainly eats nectar from flowers
- omnivore
-
an animal that mainly eats all kinds of things, including plants and animals
- endothermic
-
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
- bilateral symmetry
-
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- chemical
-
uses smells or other chemicals to communicate
References
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 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 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.
2003. "UNEP-WCMC Species Database: CITES-Listed Species" (On-line). Accessed March 15, 2004 at http://www.cites.org/eng/resources/species.html .