species of forest-dwelling African antelopes (Tragelaphus angasi); reach about 3 ¹/₂ ft (107 cm) at shoulder; has crest of hair reaching from head to tail; male has spiraled horns and long fringe of fur at throat and underparts; is dark brown with white on face and neck and white stripes on body; female is reddish brown with more conspicuous stripes; mountain nyala of Ethiopia is grayish brown with white on head, neck, and body; nyala live alone or in small groups.