Adult Indian paradise flycatchers are long. Their heads are glossy black with a black crown and crest, their black bill round and sturdy, and their eyes black. Females are rufous on the back with a greyish throat and underparts. Their wings are long. Young males look very much like females but have a black throat and blue-ringed eyes. As adults, they develop up to long tail feathers with two central tail feathers growing up to long drooping streamers. Young males are rufous and have short tails. They acquire long tails in their second or third year. Adult males are either predominantly bright rufous above or predominantly white. Some specimens show some degree of intermediacy between rufous and white. Long-tailed rufous birds are generally devoid of shaft streaks on the wing and tail feathers, while in white birds the shaft streaks, and sometimes the edges of the wing and tail feathers are black. In the early 1960s (before the recognition of Blyth's and Amur paradise flycatchers as separate species), 680 long-tailed males were examined that are contained in collections of the
British Museum of Natural History,
Chicago Natural History Museum,
Peabody Museum,
Carnegie Museum,
American Museum of Natural History,
United States National Museum, and
Royal Ontario Museum. The specimens came from almost the entire range of the species, though some areas were poorly represented. The relative frequency of the rufous and white plumage types varies geographically. Rufous birds are rare in the extreme southeastern part of the species' range. Throughout the Indian area and, to a lesser extent, in China, asymmetrically patterned intermediates occur. Intermediates are rare or absent throughout the rest of the range of the species. In general, long-tailed males are • predominantly rufous with some white in wings and tail—collected in Turkestan,
Kashmir, northern India,
Punjab,
Maharashtra,
Sikkim, and in Sri Lanka • predominantly rufous with some white in wings—collected in Iran, Afghanistan,
Baluchistan, Punjab, Kashmir, northern and central India,
Rajasthan, Maharashtra,
Bihar, and Nepal • predominantly rufous with some white in tail—collected in Punjab, northern and central India,
Kolkata, Sri Lanka, and in the Upper
Yangtze Valley in China • predominantly white with some rufous in tail and wings—collected in Kashmir, Maharashtra,
Sichuan, and North China • predominantly white with some rufous in tail—collected in Maharashtra and
Fuzhou, China • predominantly white with back partly rufous—collected in Punjab and
Chennai • moulting from rufous into white plumage—collected in North Bihar Possible interpretations of this phenomenon are: males may be polymorphic for rufous and white plumage colour; rufous birds may be sub-adults; and there may even be two
sympatric species distinguishable only in the male. ==Distribution and habitat==