Eudorcas thomsonii
Thomson's gazelle

Thomson's gazelles are found in eastern Africa, in Kenya, Tanzania, and southern Sudan. ("ARKive: Images of Life on Earth", 2009; African Wildlife Foundation, 1997; Feldhamer et al., 2007)

Thomson's gazelles live in dry, short grasslands and shrubby savannas. They are an arid-adapted species and are able to stay in dry grasslands for longer than other plains ungulates in the same region, which migrate towards more moist habitats. They follow a similar sort of seasonal migratory pattern as other ungulates in their range, but they stay for longer on the wet season range and don't migrate as far north in the dry season. ("ARKive: Images of Life on Earth", 2009; "IUCN 20008 Red List of Threatened Species:Eudorcas thomsonii", 2008; Kingdon, 1997)

Thomson's gazelles are small gazelles, the typical weight range is 15 to 35 kg. Males are larger overall, ranging in weight from 20 to 35 kg, females are from 15 to 25 kg. They have white bellies and reddish-brown backs, divided by a bold, black stripe laterally. Their rumps are white and their tails are black. Thomson's gazelles have reddish-brown fur on their faces, with a broad white stripe that extends from the eye to the nose and is bordered below by a black stripe. Males and some females have horns that curve backwards and are curved forwards distally in males. Females have smaller horns, if any, both lengthwise and in circumference. The horns are arrayed with a series of marked annulations. Thomson's gazelles resemble Grant's gazelles (Nanger granti) somewhat, although Grant's gazelles are larger overall, have horns that curve outwards, and the white of their rump extends to above the tail. Thomson's gazelles have a head and body length of 80 to 120 cm, a tail length of 15 to 27 cm, and height at the shoulder of 55 to 82 cm. They have prominent pre-orbital glands. ("ARKive: Images of Life on Earth", 2009; African Wildlife Foundation, 1997; Dorst, 1969; Kingdon, 1997)

Thomson's gazelles are exceptionally fast runners, able to run at speeds up to 70 km/hour. They can outrun cheetahs if they can evade them for long enough because cheetahs can maintain high speeds for shorter times. (Kingdon, 1997)

Thomson's gazelles typically have a lifespan of 10.5 years in the wild. Approximately half of calves will die within their first year. (African Wildlife Foundation, 1997)

Thomson's gazelles are social animals that are nomadic or migratory and specialized for cursorial locomotion. Thomson's gazelles usually form groups with a fluid association of 5 to 60 individuals, although temporary associations can number in the hundreds. Groups split and join readily and do not seem to have any permanent or exclusive membership or social hierarchy. They are also found in mixed-species herds with impalas (Aepyceros melampus) and Grant’s gazelles (Nanger granti). Males defend small territories during breeding seasons that they hope will attract females for mating opportunities. Outside of the breeding season, males form small bachelor herds or associate with females in loose groups. (African Wildlife Foundation, 1997; Dorst, 1969; Feldhamer et al., 2007)

Home Range

Home range size of Eudorcas thomsonii is not reported.

Thomson’s gazelles are fairly silent animals that communicate more visually. When alarmed they will communicate to conspecifics by stotting, which is a stereotyped series of high jumps with the head held high and the legs stiff. Males communicate to other males and females by marking territories with their scent glands, including preorbital glands that they use to mark grasses and stems. Males also drop dung at spots in their territory to advertise ownership. (Dorst, 1969; Estes, 1967; Kingdon, 1997)

Thomson’s gazelles graze mainly on short grasses. They eat twigs, seeds, and leaves from trees as well, especially during the dry season. Their smaller body size and drought tolerance make it possible for them to persist on arid grasslands that cannot support larger ungulates. Preferred grasses include Themeda, Cynodon, and Harpachne species. Foliage and seeds taken are from Acacia, Balanites, Boscia, Sida, and Solanum species. ("IUCN 20008 Red List of Threatened Species:Eudorcas thomsonii", 2008; African Wildlife Foundation, 1997; Dorst, 1969; Kingdon, 1997)

Predators of Thomson's gazelles include lions, spotted hyenas, wild dogs, cheetahs, leopards, and jackals. During the calving season, the young are easy prey for all of these predators, as well as yellow baboons and pythons. Thomson's gazelles travel in small herds, which helps to protect individuals from predation. They are alert and can run quickly. ("ARKive: Images of Life on Earth", 2009; African Wildlife Foundation, 1997)

Thomson's gazelles are eaten by large predators such as lions, hyenas, and jackals. They modify plant communities through their grazing. ("ARKive: Images of Life on Earth", 2009; African Wildlife Foundation, 1997)

Thomson's gazelles may be killed by farmers who think that they compete with domestic livestock. However, their impact is likely to be negligible. ("ARKive: Images of Life on Earth", 2009; African Wildlife Foundation, 1997; Dorst, 1969)

Thomson's gazelles may be hunted for skin and meat. They are also part of the charismatic African ungulate fauna that supports a huge ecotourism industry in eastern Africa. (Feldhamer et al., 2007; Kingdon, 1997)

According to the IUCN Red List, Thomson's gazelles are listed as near threatened. Although populations are stable in some areas and widespread, some populations have experienced severe declines since the 1970's. If E. thomsonii and E. mongalla (southern Sudan populations) are considered separate species, then E. thomsonii has a small and restricted distribution, which further threatens this species. In Kenya, the largest populations are found in the lands of the Masai Mara, the Masai Mara National Reserve, and the Laikipia and Kajiado rangelands. They occupy about half of their former range in Tanzania. In some areas population declines can be partially attributed to human impacts such as roads, habitat changes, and the impacts of tourism. Large parts of their range are already in protected areas, including the Serengeti National Park and Masai Mara National Reserve. ("IUCN 20008 Red List of Threatened Species:Eudorcas thomsonii", 2008)

Thomson's gazelles were previously recognized as Gazella thomsonii and were also lumped with all red gazelles under Gazella rufifrons. Eudorcas rufina, previously also placed within Gazella rufifrons was known only from Algeria and is presumed extinct. Eudorcas rufifrons, also previously known as Gazella rufifrons, was more widespread, occurring throughout the savannas of central Africa, from Senegal and Mauritania in the west to the western side of the Nile in Sudan and portions of Sudan, Ethiopia, and Eritrea east of the Nile. Populations throughout that range are now highly fragmented and have declined dramatically because of hunting, competition with livestock, and habitat degradation. Some authorities recognize Eudorcas albonotata as a separate species (Sudan populations), here it is recognized as conspecific with Eudorcas thomsonii. ("IUCN 20008 Red List of Threatened Species:Eudorcas thomsonii", 2008; Kingdon, 1997)