The relative frequency of the rufous and white plumage types varies geographically. Rufous adult Flycatcher males are predominant not only in Sri Lanka, but also in northern India, Central Asia and parts of China. Furthermore, Sri Lanka is not the only region were Paradise Flycatchers of both colours live side by side. Both white and rufous adult males occur in Kashmir and Punjab and in Sichuan, too. Some biologists interpret this phenomenon even as two distinct sympatric species.
The eye-catching characteristic of adult male Paradise Flycatchers in general is: Full-plumaged males of both races have the middle tail feathers 20 cm long, forming ribbon-like streamers of up to 30 cm length. But young males, looking very much like females, are rufous and have short tails. They acquire long tails - and possibly white colour - not before their third year. Streamers are not full until after the second moult. Females lack this very long tail.
A Paradise Flycatchers seems to be active all day long, it covers a large extent of country in the course of a day. The food consists entirely of insects, which are captured in the air, usually from higher branches amd often below densely canopied trees. Only aoocasionally they feed on the ground. Paradise Flycatchers are noisy birds. Both sexes frequently utter a loud “chreech”, the males have also a more musical “peety-too-whit”. Towards evening, the Paradise Flycatcher takes its regular bath by plunging into a pool and diving quickly under water, almost in the manner of a kingfisher, but not hunting fish, only bathing. Paradise Flycatchers are not shy.
Their habitat are forests, but not only wild areas, also parks in towns. In the north-east monsoon from November till February, Paradise Flycatchers may be seen in almost every climate zone of the island, up to 1700m, though normally not much above 1000 m. About March or April the migrant race returns to India. Flycatchers of both races live solitary or in pairs. In the breeding season from April to July and in the south-west monsoon from June to September, Paradise Flycatchers are rarely seen outside the lowlands in the dry zone and the eastern foothills.
Paradise Flycatchers are monogamous. Both sexes take part in nest-building, incubation, and feeding of the young. The nest is a cup placed in forks of downward-hanging branches or liana, they are not concealed. But the nest is sometimes built in the vicinity of a breeding pair of drongos, which keep predators away. The incubation period is a fortnight and the nestling period of two or three fledgelings lasts 9 to 12 days.