[Two male paradise riflebirds stand on a branch. One is a subadult, as its feathers are a dull brown, not black. The bird with the black and iridescent plumage of an adult displays, bringing his wings in an arc in front of him and over his head. He then moves his head quickly from one side to the other. He lowers his wings and moves his head several more times before flying away. The subadult practices his display by mimicking these movements. He arches his wings in front of him, and moves his head from side to side, much more slowly. Another subadult male flies in. He preens, then approaches the displaying male. The displaying male starts moving through his display more quickly. The second bird also starts displaying. The first bird stops to watch.] [Explore MacaulayLibrary.org]End of transcript
Before gaining their final adult plumage, many birds pass through a subadult phase. In the case of this Paradise Riflebird, the subadult male is a dull brown, lacking the satin black and iridescent blue feathers of an adult male. Nonetheless, he practices his courtship dance with other males in an attempt to have it mastered by the time he molts and gains his adult plumage, which can take up to 5 years.