Rwanda, Uganda, Tanzania, Ethiopia and Sudan.
It is a large, robust animal; males are generally about 25 percent larger than the females. Waterbucks 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 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.
Despite its name, the waterbuck is not truly aquatic nor as much at home in water and swamps as is the sitatunga or lechwe. It does, however, take refuge there to escape predators.
As its name would indicate, the waterbuck inhabits areas that are close to water in savanna grasslands, gallery forests and riverine woodlands south of the Sahara. Such habitats not only provide sustenance but long grasses and watery places in which to hide from predators.
Although males do compete for and hold territories, the waterbuck is generally a quiet, sedentary animal. Like some other antelopes, the male does not mark his territory with dung or urine, as his presence and smell are apparently sufficient. He tries to retain females that wander into his area, but is seldom successful for long, since the females have large home ranges and, in herds of five to 25, are constantly crossing in and out of males territories. Waterbucks do not migrate or move great distances, so territories are usually held year round.
The waterbuck's habitat furnishes them with a year-round source of food. Mainly grazers, they consume types of coarse grass seldom eaten by other grazing animals and occasionally browse leaves from certain trees and bushes. They feed in the mornings and at night, and rest and ruminate the remainder of the time.
Calves are generally born throughout the year, although breeding becomes more seasonal in some areas, after which a single young is born. The mother hides her young for about 3 weeks, returning three to four times a day to suckle it. Each suckling session lasts only about five minutes, during which time the mother cleans the calf so that no odor is left to attract predators. Even so, there is a high rate of calf mortality.
Although the calves begin to eat grass when they are young, they are nursed for as long as 6 to 8 months. After weaning, they begin to wander-off young males often form all-male groups near the occupied territories, while the young females stay in their mother's group. The waterbuck does not reach adult weight until about 31/2 years. Females mate again soon after bearing young (within 2 to 5 weeks) so the population can increase rapidly.
Hyenas, lions, and leopards are the major predators, but crocodiles, hunting dogs and cheetahs also take waterbuck.
The meat of older waterbuck takes on an unpleasant odor from the waterproofing secretions of its sweat glands, prompting predators to choose other prey.
If the defessa and common waterbucks have bordering ranges they often interbreed; as a result, some scientists consider the two groups as a single species.