These antelopes are large, robust animals; males are generally about 25 percent larger than the females. They have large, rounded ears and white patches above the eyes, around the nose and mouth, and on the throat. Only the males have horns, which are prominently ringed and as long as 100 centimeters (40 inches). The horns are widely spaced and curve gracefully back and up. They are sometimes used with lethal results when males fight one another over territories.
They have a shaggy brown-gray coat that emits a smelly, oily secretion thought to be for waterproofing. In East Africa, two types occur: the common waterbuck and the defassa waterbuck, distinguished only by the white pattern on the rump. The common waterbuck has a conspicuous white ring encircling a dark rump, while the defassa has wide white patches on either side of the rump.
This large antelope is considered, by some authorities, to be a distinct species, K. defassa (the common waterbuck found east of the Rift Valley with a white on its rump), but the two races interbreed where they overlap.
Defassa waterbuck live in small herds and are most often seen grazing near water. They are found in suitable habitats in all four of Uganda’s savannah national parks: Murchison Falls, Queen Elizabeth, and Kidepo Valley National Parks and other savannah parks in East africa.