Despite its name , the waterbuck is not aquatic but they are frequently found in the vicinity of rivers and lakes. These antelope are sedentary animals. Waterbucks do not migrate or move great distances, so territories are usually held year round. The male does not mark his territory with dung or urine, his presence and smell are sufficient.
At 7 or 9 months, males are driven from their maternal family and join up with a bachelor herd. These groups have a disctinct social hierarchy based on size and strenght, and contests are frequent. At around 6 to 7 years old, males become territorial.
As they lack both speed and endurance they depend a lot on cover as a refuge from predators (lions, leopards, hyenas, wild dogs) and they often venture into water to avoid predators. When sxually excited, the skin of the waterbuck secretes a greasy substance with the odour of musk, giving it the name "greasy kob". The odor is so unpleasant that it repels predators. This secretation also assists in water-proofing the body when the animal dives into water.
The Defassa wterbuck is listed as Near Threatened by the IUCN. Population decrease in lake Nakuru National Park has been attributed to heavy metal poisoning in the animals. While cadmium and lead levels were dangerously high in the kidney and the liver, copper calcium and phosphorus deficiency was noted.
In Kenya, the Defassa waterbuck lives west of the Rift Valley : Masai Mara, Naivasha, Nakuru, Aberdare etc. while the common waterbuck lives east of this limit : Samburu, Tsavo, Meru etc.