Nursery herd of Gemsbok (Oryx gazella) calves with an adult in the eastern region of Etosha national park, Namibia, southern Africa. A nursery herd is formed when a group of mothers band together to raise their young. Nursery herds afford greater protection to individuals and it enables the young calves to satisfy their need for social interaction and development. In these herds the young calves will spar with calves of a similar age and the adults can move at a suitable pace to ensure that the calves are properly cared for. It also allows the adults to have a break from being on the lookout for predators as the duties are shared. These large antelopes eat grass and leaves and can go without water for long periods. Both the male and the female have horns, which are effective weapons and are held between their forelegs during conflicts in order to impale the enemy.