Paradisaea regia Linnaeus, 1758
The king bird-of-paradise is a common and wide-ranging species, distributed throughout lowland forests of New Guinea and western satellite islands. Some populations range quite high into the hills and lower mountains, and these are poorly known as yet.
The first captive breeding of this species was by Dr. Sten Bergman of Sweden in 1958. He was awarded a commemorative medal by the Foreign Bird League to mark this achievement.
This so-called "living gem" is the smallest and most vividly colored among birds-of-paradise.
The king bird-of-paradise is small, measuring approximately 6.3-7.5 inches (16-19 cm) long, but 12.2 inches (31 cm) if central rectrices of adult males included. Females weight about 0.08-0.13 pounds (36-59 g), males 0.10-0.14 pounds (45-64 g).
The adult male has a overall metallic crimson color, slightly orange under certain lights, and more particularly so in the crown. They have a narrow, dark green iridescent breast band with whitish lower breast, and green-tipped fan-like plumes on shoulder. The feathers of the undertail and mantle are olive-brown, with iridescent green tips, and violet legs. Bills are ivory-yellow. Females have dull olive head and upperparts with yellowish underparts and violet legs.
The King Bird-of-paradise is distributed throughout the majority of lowland New Guinea mainland, and on the surrounding islands, including Aru, Salawati, Missol, and Yapen, inhabiting mostly lowland rainforests, gallery forests, forest edges, and disturbed and tall secondary forests.
The species is polygynous, with the promiscuous adult males displaying in isolation at exploded leks and in groups at traditional arboreal courts. They are perhaps more persistent callers than any other birds of paradise. Courtship involves complex vocalizations, feather manipulations, and a variety of body posturing and movements, including hanging fully inverted and pendulum-like swinging. An extraordinary courtship display is performed by the male with a series of tail swinging, fluffing of the white abdominal feathers that makes the bird look like a cottonball, and acrobatic movements of their elongated tail wires.
Breeding occurs at least during March through October. The open cup nest is built into a tree cavity (unique within family), within which two eggs are laid. Female builds the nest and cares for the young without male assistance. In captivity, incubation lasted 17 days and the nestling period was 14 days.
The species is tentatively assessed as being in decline due to habitat loss and unsustainable levels of hunting. However, despite the fact that the population trend appears to be decreasing, being a widespread and a abundant species throughout their large habitat range, the king bird-of-paradise is evaluated as Least Concern on the IUCN Red List of Threatened Species. It is listed on Appendix II of CITES.