Astrapia

Genus of birds

Astrapia (Vieillot, 1816) is a genus of birds of paradise. The genus contains five species, all endemic to New Guinea. The males have highly iridescent plumage and remarkably long tails. Females are duller and have shorter tails. Barnes's astrapia is a hybrid produced by the interbreeding of Princess Stephanie's astrapia and the ribbon tailed astrapia.

The five species of the genus Astrapia are endemic to New Guinea in the mountains of Volgelkop, the central ranges and the Huon Peninsula. Of these, three are allopatric—A. nigra, A. splendidissima and A. rothschildi. The other two—A. mayeri and A. stephaniae—overlap with each other at the margins of their respective elevation ranges in a small part of Papua New Guinea's central highlands. The three allopatric species also have iridescent green lower abdomen. Adult females are duller blackish brown, with smaller, white smudged tails running down their lengths.

Breeding behaviors are not well known, but all species are thought to be polygamous, with promiscuous males that use arboreal display sites, and with females providing all parental care. There are seven distinct male courtship displays that have been documented: perch hopping, pivoting, inverted tail fanning, nape pecking, post copulatory tumbling, upright sleeked posturing and branch sidling. Of the male behaviors, perch hopping is the most broadly distributed among all species but A. nigra. In all of them, the displaying bird moves quickly between multiple branches by hopping or making short flight hops. In A. rothschildi, hopping between perches sometimes includes chasing females (or female plumaged individuals). It is unclear if chasing is a component of perch hopping in the other species. A type of pivot display is known from two species, A. rothschildi and A. mayeri. In both, it involves repeatedly moving in a ritualized fashion from side to side with feet more or less in a fixed position. The most distinctive feature of the A. rothschildi pivot is wing flicking, whereas in A. mayeri the most distinctive features are the very ritualized hunchbacked posture and the highly exaggerated swishing movement of the male's long ribbon like tail. The Arfak astrapia and the Huon astrapia have a distinctive and specialized display behavior, which is called the inverted tail fan display. When the abdominal feathers are sky oriented during the display, their green iridescent feathers (that would appear otherwise dark) become highly visible; the splendid astrapia also has highly iridescent green abdominal plumage, which raises the question about if it too has an undocumented inverted display behavior.