Thomson’s Gazelle

  • SCIENTIFIC NAME: Eudorcas thomsonii

  • SWAHILI NAME: Swala tomi

One of the most recognizable of all the African gazelles, Thomson’s gazelles (also called “tommies”) are extremely agile and capable of running 50 miles per hour (80 kph). They rely on speed and an attentive nature to evade predators. They are remarkably resistant to droughts and can survive on plains during the dry season long after other ungulates have moved on in search of better land. During this time, some Thomson’s gazelles may not drink water.

Thomson’s Gazelle

Thomson’s Gazelle



Daily Rhythm




Life span

In the wild: 11 years (oldest found)
In captivity: 20 years

Conservation Status

Near threatened


Male: 38.5 to 51.6 lb (17.5 to 23.4 kg)
Female: 26.7 to 43.9 lb (12.1 to 19.9 kg)


Male: 22.4 to 25.8 in (57.0 to 65.5 cm) high at shoulder
Female: 21.6 to 24.2 in (55.0 to 61.5 cm) high at shoulder

Thomson’s Gazelle

Tracks and Scat

Tracks: Half the size of a Grant's gazelle's, though similar in shape
Scat: Rounded at one end, pointed at the other; half the size of Grant's gazelle dung, though both are often found together

Thomson’s Gazelle tracks

Trivia Question

What are the main predators of the Thomson’s gazelle?


Cheetahs are the main predators of the Thomson’s gazelle. In the Serengeti, gazelles make up almost 90 percent of a cheetah’s diet, while in Nairobi National Park, cheetahs kill between 64 and 92 percent of all adult gazelles every year.

Social Structure

Thomson’s gazelles form different types of herds: mixed herds, female groups, bachelor groups, and single territorial males. The number of individuals in any one group can range from 6 to 60 members, though larger groups of more than 1,000 are known to occur. Membership in any of these groups is fluid and constantly changing. Mixed herds happen most frequently during migration, though they also occur when a bachelor herd merges with a female herd. Female herds are typically mothers with offspring, and these groups settle on the best regions available among the single male territories. Male bachelor herds, on the other hand, are often forced to occupy substandard habitats. A single territorial male fiercely defends his region from any trespasser by displaying his horns to the intruder. This escalates into a battle if the other male presents his horns; otherwise, the intruder will leave the territory without a fight. When fights do occur, male Thomson’s gazelles lock and crash horns. All fights end with a grazing ritual, which begins with both parties eating while facing one another, then alongside each other, and then facing in opposite directions. Such fights are most common between neighboring territorial males needing to establish boundaries.


Thomson’s gazelles do not interact much with one another and even maintain their distance when grazing in the same herd.


Thomson’s gazelles alternate between four behaviors: lying, standing, grazing, and moving. They usually graze in the early morning, at midday, in the evening, or around midnight. They spent the rest of their mornings sunbathing in an open area. Adult tommies spend about half of their time lying down, resting in bouts ranging from half an hour to five hours. While grazing, Thomson’s gazelles are extremely attentive to potential danger, constantly raising their heads to look about. When they spot a predator, individuals take up an alert stance or emit an alarm snort that induces others to flee. How soon they leave depends on how quickly a predator is approaching. When they are fleeing, these gazelles adopt a gait called “stotting,” where they leap with straight, stiff legs. They stott especially when running from hyenas and African wild dogs—two predators that outrun their prey rather than stalk it. This behavior may inform a predator that the gazelles can outrun it. Sometimes a herd will turn the tables and stalk the hunter instead of fleeing. This action, which tells the predator that it has been seen, forces the predator to move away and enables the group to keep a close eye on it. Herds have been known to follow a predator for over an hour, stalking it from a distance of 160 to 330 feet (50 to 100 m).


Thomson’s gazelles are well protected in a number of national parks and other protected areas. However, poaching remains a major issue, and their population may still be declining.

Range & Habitat

Thomson’s gazelles are limited to a compact range located in northern Tanzania and southern Kenya. They prefer high plains and acacia savannas above 1,640 feet (500 m).

Short grassland gives them a solid foundation for sure footing, and they will choose land that has been heavily grazed or even trampled or burned, where new plants are just emerging from the earth. However, they will shift to taller grassland areas and even open woodland when they migrate. Thomson’s gazelles will remain on a plot of grassland long after it has been deserted by other ungulates, often staying as long as there is any semblance of grass remaining.


Thomson’s gazelles have narrower snouts than any other kind of gazelle, which allows these grazers to be extremely selective in their food choices. Given their small stature, tommies can eat only limited amounts of grass, so they choose very high quality vegetation. In the dry season, this includes some grass as well as fruit and flowers, which can compose up to 40 percent of their diet. During the wet season, they switch to a diet that is 80 to 90 percent grass.


Only territorial males mate with females. Female herds move into a male’s territory, where they stay for only a few hours. After driving out any rival males, the resident male attempts to keep the females from leaving by herding them toward the center. Then he chooses a female, and courtship begins. He approaches her with his head and neck outstretched and moves his nose upward. Occasionally, a courting Thomson’s gazelle male will execute a “drumroll,” which is a very quick goose step (a gait where he does not bend his front legs). If the female is receptive to this display, she urinates, and the male, upon sniffing her urine, displays flehmen by curling back his lips. At this point, the male sometimes loses interest in the female and moves on, or he continues to pursue her by repeating his courtship display and even kicking out toward her back with a straight, stiff foreleg. Once the courtship has ended, the male proceeds to mount the female several times while walking. A single calf is born after a gestation period of 180 days. Once born, the calf enters a lying out period, during which it remains hidden except when its mother is cleaning or nursing it. Eventually, the calf joins its mother while she grazes. By the time it is three to six months old, the calf fully participates in herd activities. Young are weaned onto solid food by five to eight months of age and are considered adults by the end of their second year. That’s when males have fully developed, arched horns.

Friends & Foes

Their small size and preference for open habitats makes tommies relatively easy pickings for predators. To compensate, they often group together with other species, particularly Grant’s gazelles but also plains zebras, impalas, waterbucks, wildebeest, and giraffes. Living in these mixed groups helps Thomson’s gazelles by increasing the number of vigilant eyes looking out for predators. Cheetahs actually avoid preying on these mixed groups because the kill rate is very low.

Population in Kenya & Beyond

An estimated 550,000 Thomson’s gazelles remain in the wild, with 2,500 in Kenya’s Laikipia region. The largest population is a migrating herd in the Serengeti-Maasai Mara ecosystem on the Tanzania-Kenya border. This single population boasts 174,015 individuals and lives under heavy protection. The current population of Thomson’s gazelles shows a dramatic decline from only a few decades ago. In the 1970s, their numbers were estimated at 660,000, but fell to under 250,000 by 1985. In Kenya’s Maasai Mara National Reserve, the population plunged from 20,000 in 1977 to a mere 8,100 in 2007.

Thomson’s Gazelle

Did you know?

Young tommies can hide themselves so well that a predator can walk within 16 feet (5 m) and never see them. The tactic is called crypsis.