The Grant’s gazelle is found in East Africa and inhabits semiarid, open savannas, and treeless plains. They avoid acacia forests unless they are traversed by well-traveled paths. They are migratory animals, but travel in the opposite direction of most of the other ungulates, such as Thomson’s gazelles, zebras, and wildebeest, which are more water dependent. They can subsist on vegetation in waterless, semiarid areas, where they face little competition.
They are both browsers and grazers feeding on a variety of plant parts including leaves, shoots, fallen flowers and fruits. They are generally drought tolerant species requiring very little water. They meet their water requirements mostly from the plant parts they consume.
Grant’s gazelles are migratory and they move seasonally throughout their range, except in areas with year-round supplies of forage. They migrate in groups and some groups establish home ranges. Herds may segregate into separate groups of bachelor males and females with dominant males. Social rank in this species can be seen in the way males are organized when migrating. The less dominant, younger males are towards the front of the unit, whereas the more dominant males are in the back. This organization also results in equally matched opponents in fights, as it is more likely that nearby males will display dominance and fight one another.
Territorial males mark areas with a combination of feces and urine. This type of marking requires the gazelle to advertise his white rump. As a result of this advertisement, other grant’s gazelle either show interest or withdraw.
One way in which these antelopes show dominance is through side-by-side strutting. In strutting alongside other territorial males a male may express his dominance by raising his neck and tilting his horns slightly. A second method by which Grant’s gazelles show dominance is through fighting. When two males approach each other to fight, they quickly move their heads downwards and towards one another as one tries to throw the other off balance. Fighting displays the contender’s neck muscles.
As a form of anti-predatory behavior, Nanger granti use alert posture, alarm snorts and stamping as signals of a predator in the vicinity. They avoid water holes, where predators are plentiful and prey are vulnerable. Females may resist when a fawn is captured by a predator, cooperating with other females to fiercely defend the abducted fawn. This defense often chases the predator away, leaving the fawn unharmed.
Nanger granti, along with many other ungulates, display an anti-parasitic behavior of selective defecation. Grant’s gazelles defecate in specific locations in order to keep the parasites associated with dung piles away from other members of the herd. Additionally, Nanger granti avoid foraging in locations where selective defecation has taken place.