Blue bird-of-paradise

The blue bird-of-paradise (Paradisornis rudolphi) is a large species of bird-of-paradise. It is the only species in the genus Paradisornis, but was previously included in the genus Paradisaea.

It is often regarded as one of the most fabulous and extravagant of all birds of the world, with its glorified and fancy flank feathers present only in males and the two long wires also only found in the males.

The blue bird-of-paradise is around 30 cm (12 in) in length (excluding the long tail wires), rivaling some of the Paradisaea and Manucodia species. It typically weighs between 124 and 166 g (4.4 and 5.9 oz). Males tend to be larger than females. This species is sexually dimorphic, though maintains a lot of similarities between the two sexes. Males are glossy black from their heads to mantle with silver-white crescents surrounding the eyes. These feathers are iridescent, ranging from a red gloss on the neck to blues on the mantle. They have a blackish-blue underbelly. Their wings and tails are blue, commonly being a light blue, but can aqua or a sky-baby blue. Unique to the males are its two elongated central tail feathers which are blue-black with iridescent, whitish spatulate tips. These 'wires' are 64 cm (25 in) long. They also sport fine and silky elongated flank plumes that are a dull amber colour on the upper side, a light blue below, and are based by two dark crimson lines on each side of the lower belly. Females are similar in coloration to males; however, their plumage is less iridescent and their underbellies are a chestnut brown. Juvenile females have black barring on their underbelly. Both sexes have a very crow-like, light grey bill. They have purplish-grey legs and feet and greyer claws.