The Splendid astrapia, a medium-sized bird-of-paradise, is the smallest member of its genus. The male is particularly noted for its iridescent plumage, which is arguably the most resplendent within the Paradisaeidae family. The male's head and mantle boast a shimmering iridescent light bluish-green to yellow-green hue, while the chin and throat display a metallic turquoise to shiny green. A coppery-red gorget graces the throat, extending up to the eyes. The underparts are a silky dark-green, with lower tail-coverts of a lighter brownish shade. The upperparts, including wings and back, are a more subdued brown to darkish brown. The tail features two long, white plumes with black spatulate tips and a violet iridescence. In stark contrast, the female is much drabber, with a dark brown to blackish head, lighter wings and back, and dusky light brown underparts with heavy barring. Her tail is similar to the male's but lacks the spatulate tip and has less white.
Males can be identified by their striking iridescent plumage and long white tail plumes with black spatulate tips. Females are more subdued with heavy barring on the underparts. The subspecies helios is larger than splendidissima, with males exhibiting a more blue than yellow-green crown and larger spatulate tips on the tail feathers. Females of this subspecies have darker upperparts.
The Splendid astrapia inhabits mid to upper montane and subalpine tropical forests, forest edges, and secondary growth, typically found at elevations ranging from 1750 to 3450 meters, but most commonly between 2100 and 2700 meters.
This species is endemic to the central and western highlands of New Guinea. The nominate race, splendidissima, is found from the Weyland Mountains to the Paniai Lakes, while race helios is found east of the Paniai Lakes to the Hindenburg Range, and possibly extending to the Victor Emanuel Range.
The Splendid astrapia is known for its elusive nature, making it one of the least known within its family and genus.
The Splendid astrapia's vocal repertoire includes a distinctive, insect-like "tik to-keet" with the "keet" sounding like a brief whistle. They also emit frog-like croaks, yelps of "wroo-wree woo," and simpler "teeks" and "toks."
The Splendid astrapia is classified as Least Concern on the IUCN Red List of Threatened Species, indicating it is a widespread and common species throughout its range. It is also listed on Appendix II of CITES, reflecting international agreement on its protection.