Thomson's gazelles,also know as Tommies,is the most common type of gazelle in East Africa.
Thomson's gazelle lives in Africa's savannas and grassland habitats, particularly the Serengeti region of Kenya and Tanzania. It has narrow habitat preferences, preferring short grassland with dry, sturdy foundation. It does, however, migrate into tall grassland and dense woodland. Gazelles are mixed feeders. In the wet seasons, they eat mainly fresh grasses, but during the dry seasons, they eat more browse, particularly foliage from bushes, forbs, and clovers. Thomson's gazelles are dependent on short grass. Their numbers are highly concentrated at the beginning of the rains since the grass grows quickly. They follow the larger herbivores, such as plains zebras and blue wildebeests as they mow down the tall grasses.
In the wild, Thomson's gazelles can live 10–15 years. Their major predators are cheetahs, which are able to attain higher speeds, but gazelles can outlast them in long chases and are able to make turns more speedily. This small antelope-gazelle can run extremely fast, from 80 km/h, to 96 km/h and zigzag, a peculiarity which often saves it from predators. Sometimes, they are also chased by leopards, lions, and hyenas, but the gazelles are faster and more agile; these predators attack especially the young or infirm individuals. They can also be prey to crocodiles and pythons, and their fawns are sometimes the prey of eagles, african wild dogs, jackals, and baboons. A noticeable behaviour of Thomson's gazelles is their bounding leap, known as stotting or pronking, used to startle predators and display strength.
When patrolling his territory, a male may use his horns to gore the grass, soil, or a bush. Males also mark grass stems with their preorbital glands, which emit a dark secretion. Territories of different males may share a boundary. When territorial males meet at the border of their territories, they engage in mock fights in which they rush towards each other as if they are about to clash, but without touching. After this, they graze in a frontal position, then in parallel and them in reverse, and move away from each other while constantly grazing. These rituals have no victor, but merely maintain the boundaries of the territories. Territorial males usually do not enter another male's territory. If a male is chasing an escaping female, he will stop the chase if she runs into another territory, but the neighboring male will continue the chase.