A nomadic species, the slender-horned gazelle wanders widely in search of food, grazing on grass, and browsing on succulents, herbs and shrubs (7) (8). Although it gains enough moisture from its food to survive, it will drink water when it is available. It feeds mainly during the night and early morning, retiring to rest in the shade through the hottest hours of the day. The slender-horned gazelle is specially adapted for its desert lifestyle, with the nose enlarged to allow the blood to cool in a network of blood vessels (3).
Like other desert gazelles and antelopes, social organisation is likely to be flexible and adaptable to variation in conditions. But in general they are observed to form groups of three to ten individuals, made up of one dominant male, several females and their young (3) (7). If conditions are good the slender-horned gazelle may become territorial during the mating season, typically from August to September (3) (7). The male attempts to herd more females into his territory to gain extra mating opportunities, but not all females will co-operate all of the time and younger satellite males may try to intervene in the confusion (7). After a gestation period of 156 to 169 days, females give birth to one, or sometimes two calves during January and February (3). The calves are weaned at three months, but do not mature until six to nine months in females and 18 months in males (3). Young males usually form bachelor herds until they can successfully compete for females. Adult males occasionally battle brutally to assert their dominance. Slender-horned gazelles were formerly preyed upon by cheetahs throughout their range, and may have encountered Cape hunting dogs, lions, leopards and spotted hyenas in some of the more southerly parts of the distribution (2) (7).