Odd, all-black swallow with a long forked tail. Shows geographical variation: most have a dark underwing, but in some areas, there is a white or pale gray patch on the front of the underwing. Found in and over forest, plantations, and thick woodland. Usually seen in flight or perched on a dead tree. Has an odd, weak flight style that is different from that of a typical swallow. Similar to White-headed Sawwing, but has an all-dark head and a longer tail.