Glossy blue-black head, crest and throat; black in wings; silvery-white body, long tail-streamers. In rufous phase white parts replaced by rufous chestnut. Female and young male: 20cm. No tail-streamers; shorter crest; rufous above; ashy-grey throat and nuchal collar; whitish below. Solitary or pairs; makes short sallies; flits through trees, the tail-streamers floating; strictly arboreal, sometimes descending into taller bushes; cheerful disposition.