The common fairywren of lowland and foothill forest edge and thickets. A small, long-tailed bird with a dark blue mask, a pale blue crown, and a cocked tail. Male has otherwise uniform deep blue plumage, and the female rufous brown upperparts with a white breast. Forages in small groups in thick undergrowth. Female similar to Wallace’s Fairywren but Emperor lacks the white wing bars and facial stripe. Song is a jumble of warbled notes, and call a dry “churr.”