The Waterbuck (kobus ellipsiprymnus)is one of the heaviest antelopes with a long upper body, short legs and shaggy hair. Males weigh up to 575 lbs (260 kg) and have curved horns up to 39 inches (99 cm) in length. Waterbucks come in various shades, from gray to a reddish brown, and tend to darken as they age.
The Waterbuck feeds on a variety of green grasses, which helps satiate its need for a diet high in protein. When green grass is unavailable or in short supply, the Waterbuck finds protein in other herbs. The Waterbuck generally feeds at the beginning and the end of the day. Of all the African antelope, Waterbuck are probably the most susceptible to dehydration, requiring them to graze within short distances of water.
Because of their dependence on water and certain vegetation species for food as well as shelter, Waterbucks require a large home territory. There are two standard forms of social units. Females and dominant males form small territorial herds. Bachelors, which are kicked out of the family unit by dominant males when their horns emerge at 8-9 months, form herds with as many as 40 to 60 individuals.
Once a bachelor herd has been set, they are closed to outsiders. Order is maintained by a rank hierarchy based on seniority, although bachelors will spar regularly. Usually the largest male with the biggest horns will exert control.
Waterbuck must protect themselves from predators such as lions, hyenas, and even crocodiles. Anti-predator behavior includes snorting, running and sometimes even courageous self-defense. Males have been observed charging lions that encroach on their territory.