The western or lowland bongo, Tragelaphus eurycerus eurycerus, is a herbivorous, mostly nocturnal forest ungulate and among the largest of the African forest antelope species.
Bongos are characterised by a striking reddish-brown coat, black and white markings, white-yellow stripes and long slightly spiralled horns. Indeed, bongos are the only Tragelaphid in which both sexes have horns. Bongos have a complex social interaction and are found in African dense forest mosaics.Bongos are found in dense tropical jungles with dense undergrowth up to an altitude of 4,000 meters (12,800 ft) in Central Africa, with isolated populations in Kenya, and the following west African countries.The bongo sports a bright auburn or chestnut coat, with the neck, chest and legs generally darker than the rest of the body. Coats of male bongos become darker and buffy as they age until they reach a dark mahogany-brown colour. Coats of female bongos are usually more brightly coloured than those of males.
The pigmentation in the coat rubs off quite easily — there are anecdotal reports that rain running off a bongo may be tinted red with pigment. The smooth coat is marked with 10–15 vertical white-yellow stripes, spread along the back from the base of the neck to the rump. The number of stripes on each side is rarely the same. It also has a short, bristly and vertical brown ridge of hair along the spine from the shoulder to the rump; the white stripes run into this ridge.