The waterbuck (Kobus ellipsiprymnus) is a large antelope species with a grey to reddish-brown shaggy coat. It can reach a height of 136 cm (54 in) at the shoulder and a weight of 262 kg (578 lb). Males are generally around 25% larger than females. The waterbuck has white markings over the eyes, around its mouth and on the throat. Only the males have horns, which are curved, have a ringed appearance and can reach a length of 100 cm (40 in). There are two distinct types of waterbuck, the common waterbuck (K. e. ellipsiprymnus) and the defassa waterbuck (K. e. defassa). They are distinguished on the white patches on the rump. The common waterbuck has an elliptical white ring on the rump, while the defassa waterbuck has two white patches on either side of the tail.
Waterbucks are dependent on water and will generally stay in areas in close proximity to permanent water sources. However, waterbucks do not spend much time in water, but will readily jump in to avoid predators. Prefered habitats are open savannah, riverine woodlands and forests with adequate water availability. They are predominantly grazers, but do also feed on leaves from trees and bushes. They are mostly active feeding in the early morning and at night and will rest during the hottest hours of the day.
Male waterbucks hold territories of around 1.2 km², which they will try to defend from other males. Fighting can break out and injuries can be fatal. Females live in larger groups of just a few animals to up to several hundred individuals. These groups have large home ranges and will pass through many male territories. When a group of females pass the territory of a male he will try to keep them within his range and mate with any females that are in heat. Males seldom manage to hold females for longer periods.
Gestation period for waterbuck is 280 days and generally a single calf will be born. As waterbuck inhabit areas close to water it is often rich with resources. This means breeding and birthing can take place throughout the year. Females often mate again just after 2-5 weeks of giving birth, making the waterbuck prone to increase rapidly in numbers. A new-born calf his hidden away by the mother for the first 3 weeks and will be nursed for as long as 6-8 months. Young males often start bachelor groups before they are old enough to hold their own territory and females generally stay within the natal group. They are not fully grown until aged between 3-4 years old. Individuals have been known to live for 18 years in captivity.
Waterbucks are known to secrete a smelly greasy substance when sexually aroused. With time this substance will gradually taint the flesh and make older individuals quite smelly. Because of this, predators are actually known to avoid such individuals. Lion, hyena and leopard commonly hunt waterbuck, but will often go for the younger individuals. Cheetah, wild dog and crocodiles do also hunt waterbuck from time to time.
The waterbuck is quite common within its range in sub-Saharan Africa and quite numerous in many protected areas. There are 13 subspecies within the two forms; defassa and common waterbuck, and none of them are threatened. It is not a popular food source for bushmeat, but males are targeted as trophies. Waterbuck is listed as least concern on the IUCN Red List.