The birds-of-paradise are members of the family Paradisaeidae of the order Passeriformes.
The majority of species in this family are found on the island of New Guinea and its satellites,
with a few species occurring in the Moluccas of Indonesia and eastern Australia. The family
has forty species in 13 genera. The members of this family are perhaps best known for the plumage
of the males of most species, in particular highly elongated and elaborate feathers extending
from the beak, wings or head. For the most part they are confined to dense rainforest habitat.
The diet of all species is dominated by fruit and to a lesser extent arthropods.
The birds-of-paradise have a variety of breeding systems, ranging from monogamy to lek based polygamy.
The family is of cultural importance to the inhabitants of New Guinea.
The trade in skins and feathers of the birds-of-paradise has been going on for two thousand years,
and the birds have been of considerable interest to western collectors, ornithologists and
writers as well. A number of species are threatened by hunting and habitat loss.
Description
Birds of paradise are generally crow-like in general body-form, and, indeed are the brother
group to the corvids (crows and jays). Birds-of-paradise range in size from the King Bird-of-paradise
at 50 g (1.8 oz) and 15 cm (5.9 in) to the Curl-crested Manucode at 44 cm (17 in) and 430 g (15 oz).
The male Black Sicklebill, with its long tail, is the longest species at 110 cm (43 in).
In all the males are larger and longer than the female, the differences ranging from slight to extreme.
The wings are rounded and in some species structurally modified on the males in order to make sound.
There is considerable variation in the family with regard to bill shape. Bills may be long and decurved,
as in the sicklebills and riflebirds, or small and slim like the Astrapias. As with body size
on average bill size varies with sex, although species where the females have larger bills than
the male are more common, particularly in the insect eating species.
Plumage variation between the sexes is closely related to breeding system. The manucodes and Paradise-crow,
which are socially monogamous, are sexually monomorphic. So are the two species of Paradigalla,
which are polygamous. All these species have generally black plumage with varying amounts of green and blue iridescence.
Habitat and distribution
The centre of bird-of-paradise diversity is the large island of New Guinea; all but two
genera are found in New Guinea. The two that are not are the monotypic genera Lycocorax and
Semiptera, both of which are endemic to the Moluccas, to the west of New Guinea. Of the
riflebirds in the genus Ptiloris, two are endemic to the coastal forests of eastern Australia,
one occurs in both Australia and New Guinea, and one is only found in New Guinea. The only
other genus to have a species outside New Guinea is Manucodia, one representative of which is
found in the extreme north of Queensland. The remaining species are restricted to New Guinea
and some of the surrounding islands. Many species have highly restricted ranges, particularly
a number of species with restricted habitat types such as mid-montane forest (like the Black Sicklebill)
or island endemics (like the Wilson's Bird-of-paradise).
The majority of birds-of-paradise live in tropical forests, including rainforest, swamps and moss forest.
Several species have been recorded in coastal mangroves. The southernmost species, the Paradise Riflebird
of Australia, lives in sub-tropical and temperate wet forests. As a group the manucodes are the most
plastic in their habitat requirements, with in particular the Glossy-mantled Manucode inhabiting both
forest and open savanna woodland. Mid-montane habitats are the most commonly occupied habitat,
with thirty of the forty species occurring in the 1000–2000 m altitudinal band.