See text The waterbuck (Kobus ellipsiprymnus) is a large antelope found widely in sub-Saharan Africa.

The waterbuck cannot tolerate dehydration in hot weather, and thus inhabits areas close to sources of water.

In equatorial regions, breeding takes place throughout the year, but births are at their peak in the rainy season.

The specific name ellipsiprymnus refers to the white, elliptical ring on the rump,[3] from the Greek ellipes (ellipse) and prymnos (prumnos, hind part).

[3] Interbreeding between the two takes place in the Nairobi National Park owing to extensive overlapping of habitats.

[8] On the basis of Valerius Geist's theories about the relation of social evolution and dispersal in ungulates during the Pleistocene,[9] the ancestral home of the waterbuck is considered to be the eastern coast of Africa, with the Horn of Africa to the north and the East African Rift Valley to the west.

A newborn typically weighs 13.6 kg (30 lb), and growth in weight is faster in males than in females.

[13] The facial features include a white muzzle and light eyebrows and lighter insides of the ears.

Herd size increases in summer, whereas groups fragment in the winter months, probably under the influence of food availability.

[17] As soon as young males start developing horns (at around seven to nine months of age), they are chased out of the herd by territorial bulls.

[18] After the age of ten years, males lose their territorial nature and are replaced by a younger bull, following which they recede to a small and unprotected area.

[7] Fights, which may last up to thirty minutes, involve threat displays typical of bovids accompanied by snorting.

[18] Fights may even become so violent that one of the opponents meets its death due to severe abdominal or thoracic wounds.

However, it has been observed that unlike the other members of its genus (such as the kob and puku), the waterbuck ranges farther into the woodlands while maintaining its proximity to water.

[21] With grasses constituting a substantial 70 to 95 percent of the diet, the waterbuck is predominantly a grazer frequenting grasslands.

[16] A study found regular consumption of three grass species round the year: Panicum anabaptistum, Echinochloa stagnina and Andropogon gayanus.

Hyparrhenia involucrata, Acroceras amplectens and Oryza barthii along with annual species were the main preference in the early rainy season, while long life grasses and forage from trees constituted three-fourths of the diet in the dry season.

[26] Though the defassa waterbuck was found to have a much greater requirement for protein than the African buffalo and the Beisa oryx, the waterbuck was found to spend much less time on browsing (eating leaves, small shoots, and fruits) in comparison to the other grazers.

[16] In equatorial regions, breeding takes place throughout the year, and births are at their peak in the rainy season.

The male exhibits flehmen, and often licks the neck of the female and rubs his face and the base of his horns against her back.

Its southern range extends to the Hluhluwe-Umfolozi Game Reserve (KwaZulu Natal) and to central Namibia.

[1] Waterbuck inhabit scrub and savanna areas alongside rivers, lakes and valleys.

[13] Due to their requirement for grasslands as well as water, the waterbuck have a sparse distribution across ecotones (areas of interface between two different ecosystems).

It has been observed that territorial size depends on the quality of the habitat, the age and health of the animal and the population density.

In Queen Elizabeth National Park, females had home ranges 21–61 hectares (0.081–0.236 sq mi; 52–151 acres) in area whereas home ranges for bachelor males averaged between 24–38 hectares (0.093–0.147 sq mi; 59–94 acres).

[1] Population decrease in the Lake Nakuru National Park has been attributed to heavy metal poisoning.

While cadmium and lead levels were dangerously high in the kidney and the liver, deficiencies of copper, calcium and phosphorus were noted.

[29] Over 60 percent of the defassa waterbuck populations thrive in protected areas, most notably in Niokolo-Koba, Comoe, Mole, Bui, Pendjari, Manovo-Gounda St. Floris, Moukalaba-Doudou, Garamba, Virunga, Omo, Mago, Murchison Falls, Serengeti, and Katavi, Kafue and Queen Elizabeth National Parks, the national parks and hunting zones of North Province (Cameroon), Ugalla River Forest Reserve, Nazinga Game Ranch, Rukwa Valley, Awash Valley, Murule and Arly-Singou.

The common waterbuck occurs in Tsavo, Tarangire, Mikumi, Kruger and Lake Nakuru National Parks, Laikipia, Kajiado, Luangwa Valley, Selous and Hluhluwe-Umfolozi game reserves and private lands in South Africa.

[1][16] Scientists with the ICIPE have developed tsetse-fly-repellant collars for cattle based on the smell of the waterbuck.