Fork-tailed Drongo-cuckoo (Surniculus dicruroides)

Closely related to S. lugubris, S. velutinus and S. musschenbroeki, with which commonly considered conspecific, but evidence assembled by recent authors#R#R indicates that it differs in its distinct song (allow 3); forked tail (2); finer bill and shorter primary extension than lugubris (1+1=2) and glossy crown and mantle vs matt velvet black in musschenbroeki and velutinus (2). HBW recognized no variation within populations of S. dicruroides; subsequently, however, one author recognized race barussarum and treated stewarti as a race of S. lugubris#R, while another treatment transferred barussarum to S. lugubris but placed stewarti with present species#R. Latter arrangement followed here, but situation complex and further substantiation desirable. Two subspecies recognized.