The Blyth's swift (Apus leuconyx), is a species of small swift, superficially similar to a common house martin. It is, however, completely unrelated to those passerine species, since swifts are in the order Apodiformes. The resemblances between the groups are due to convergent evolution reflecting similar life styles. Blyth's swifts breeds from the outer Himalayas through the Assam hills. This species is migratory, and winters in India and Sri Lanka. A 2011 study has many taxonomists splitting this species from the fork-tailed swift complex.