Bird-of-paradise

The birds-of-paradise are members of the family Paradisaeidae of the order Passeriformes. The majority of species are found in eastern Indonesia, Papua New Guinea, and eastern Australia. The family has 42 species in 15 genera. The members of this family are perhaps best knowing for the plumage of the males of the sexually dimorphic species  (the majority), in particular the highly elongated and elaborate feathers extending from the beak, wings, tail 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-type polygamy.

A number of species are threatened by hunting and habitat loss.

Diet and feeding

The diet of the birds-of-paradise is dominated by fruit and arthropods, although small amounts of nectar and small vertebrates may also be taken. The ratio of the two food types varies by species, with fruit predominating in some species, and arthropods dominating the diet in others. The ratio of the two will affect other aspects of the behaviour of the species, for example frugivorous species tend to feed in the forest canopy, whereas insectivores may feed lower down in the middle storey. Frugivores are social than the insectivores, which are more solitary and territorial.

Even the birds-of-paradise that are primarily insect eaters will still take large amounts of fruit; and the family is overall an important seed disperser for the forests of New Guinea, as they do not digest the seeds. Species that feed on fruit will range widely searching for fruit, and while they may join other fruit eating species at a fruiting tree they will not associate with them otherwise and will not stay with other species long. Fruit are eaten while perched and not from the air, and birds-of-paradise are able to use their feet as tools to manipulate and hold their food, allowing them to extract certain capsular fruit. There is some niche differention in fruit choice by species and any one species will only consume a limited number of fruit types compared to the large choice available. For example, the trumpet manucode and crinkle-collared manucode will eat mostly figs, whereas the Lawes's parotia focuses mostly on berries and the superb bird-of-paradise and raggiana bird-of-paradise take mostly capsular fruit.

Breeding

Most species have elaborate mating rituals, with the Paradisaea species using a lek-type mating system. Others, such as the Cicinnurus and Parotia species, have highly ritualised mating dances. Males are polygamous in the sexually dimorphich species, but monogamous in at least some of the monomorphic species. Hybridisation is frequent in these birds, suggesting the polygamous species of bird of paradise are very closely related despite being in different genera. Many hybrids have been described as new species, and doubt remains regarding whether some forms, such as Rothschild's lobe-billed bird of paradise, are valid. Despite the presence of hybrids, some ornithologist hypothesise that at least some putative hybrids are valid species that may be extinct. 

Birds-of-paradise build their nests from soft materials, such as leaves, ferns, and vine tendrils, typically placed in a tree fork. Clutch size is somewhat uncertain. In the large species, it is almost always just one egg. Smaller species may produce clutches of 2-3. Eggs hatch after 16-22 days, and the young leave the nest at between 16 and 30 days of age.