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The Greater Racket-tailed Drongo (Dicrurus paradiseus) is a medium-sized Asian bird which is distinctive in having elongated outer tail feathers with webbing restricted to the tips. They are placed along with other drongos in the family Dicruridae.
They are conspicuous in the forest habitats often perching in the open and by attracting attention with a wide range of loud calls that include perfect imitations of many other birds.
One hypothesis suggested is that these vocal imitations may help in the formation of mixed-species foraging flocks, a feature seen in forest bird communities where many insect feeders forage together.
These drongos will sometimes steal insect prey caught or disturbed by other foragers in the flock and another ideas is that vocal mimicry helps them in diverting the attention of smaller birds to aid their piracy. They are diurnal but are active well before dawn and late at dusk.
Owing to their widespread distribution and distinctive regional variation, they have become iconic examples of speciation by isolation and genetic drift.
In most of its range in Asia, this is the largest of the drongo species and is readily identifiable by the distinctive tail rackets and the crest of curled feather that begin in front of the face above the beak and along the crown to varying extents according to the subspecies.
The tail with twirled rackets is distinctive and in flight it can appear as if two large bees were chasing a black bird. In the eastern Himalayas the species can be confused with the lesser Racket-tailed Drongo, however the latter has flat rackets with the crest nearly absent.
Their calls are extremely varied and include monotonously repeated whistles, metallic and nasal sounds as well as more complex notes and imitations of other birds. They begin calling from as early as 4 am in moonlight often with a metallic tunk-tunk-tunk series. They have an ability to accurately mimic alarm calls of other birds that are learnt through interactions in mixed-species flocks.
This is quite unusual, as avian vocal mimicry has hitherto been believed to be ignorant of the original context of the imitated vocalization.
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