Overview
AT A GLANCE
- Common Name: Thomson’s Gazelle
- Scientific Name: Eudorcas thomsonii
- Category: Mammals
- Subcategory: Even-toed Ungulates
- Size: Shoulder height: 22–32 in (55–82 cm); Head-body length: 31–47 in (80–120 cm)
- Weight: 33–77 lb (15–35 kg); males are noticeably larger than females
- Lifespan: 10–12 years in the wild; up to 15 years in protected reserves
- Diet: Herbivore / Selective short-grass grazer (tender nutrient-rich short grasses, clover, seeds, and seasonal green herbs)
- Habitat: Short-grass open savannas, dry acacia bushland, and grazed grassland plateaus
- Range: East Africa (primarily Kenya and Tanzania)
- Conservation Status: Least Concern (IUCN Red List)
Thomson’s Gazelle (Eudorcas thomsonii), affectionately known throughout East Africa and across the world as the ‘Tommie’, is a quintessential, small-bodied antelope that symbolizes the vibrant wildlife spectacles of the African savanna. Roaming the iconic plains of the Serengeti and Masai Mara, this energetic, fawn-colored ungulate is instantly recognized by its bright white underparts, a bold, jet-black horizontal stripe running across its flanks, and a short black tail that wags in continuous, nervous motion like a metronome. It represents one of the most populous and visible antelopes in Africa.
As an integral participant in the world-famous Great Serengeti Migration, hundreds of thousands of Thomson’s gazelles follow behind the massive herds of blue wildebeest and plains zebras. By feeding selectively on the tender, protein-rich young grass shoots exposed only after larger herbivores have grazed down the coarse tall grasses, the Tommie occupies a specialized ecological feeding niche. However, its immense abundance also establishes it as the primary prey item in the ultimate high-speed evolutionary arms race of the savanna: the life-or-death sprint duels against the cheetah.
Biology and Physical Characteristics
The physical morphology of Eudorcas thomsonii is engineered for sustained high-speed pursuit evasion and acute sensory vigilance. While a sprinting cheetah possesses higher acceleration, the Thomson’s gazelle can sustain speeds of 50 to 55 miles per hour (80–90 km/h) for far longer periods, executing sharp, instantaneous 90-degree lateral turns that cause heavier predators to lose their footing. Both sexes bear strongly ringed, backward-curving horns, though the horns of adult males are significantly longer, heavier, and curved forward at the tips for territorial sparring. Its large eyes are mounted high on the cranium, providing a 360-degree panoramic field of vision.
Behavior and Ecology
Thomson’s gazelles are diurnal and highly gregarious, aggregating in herds of several dozen to several thousand individuals during migration. Males are strongly territorial during green seasons, marking boundary twigs with black, tarry secretions from their preorbital glands and defecating in ritualized dung piles. When a predator like a cheetah or wild dog is detected, gazelles engage in ‘stotting’—bounding stiff-legged high into the air with arched backs—which signals to the predator that it has been spotted and that the individual is in peak physical condition to outrun it. Following a 6-month gestation, females drop a single fawn, hiding it in tall grass for several weeks.
Conservation and Human Impact
Eudorcas thomsonii is currently evaluated as Least Concern on the IUCN Red List, with a population estimated around 500,000 individuals, predominantly concentrated within the protected borders of Serengeti National Park, Ngorongoro Conservation Area, and the Maasai Mara National Reserve. However, populations outside protected reserves have experienced steep historical declines due to livestock fencing that disrupts traditional migration corridors, agricultural expansion, and widespread bushmeat snaring.
Interesting Factoid
Thomson’s gazelles constantly wag their little black tails back and forth like a windshield wiper—over thousands of times a day—to communicate alertness to other herd members and signal to cheetahs that they are ready to run.