Thomson's gazelle

Thomson's gazelles eat plants.

They nibble short grass. In dry times they eat leaves and seeds too.

Thomson's gazelles are grazers: they mostly eat short grasses. In the dry season, they add leaves, twigs, seeds and fruit to their meals.

Because they are small and can cope with drought, they can live on dry grasslands that cannot feed bigger grazing animals. Their grazing also changes which plants grow on the plains.

The species is primarily a grazer of short grasses, adding more forbs and fruits in the dry season (IUCN); Animal Diversity Web also lists twigs, seeds and tree leaves, especially in the dry season. Its small body size and drought tolerance let it persist on arid grasslands that cannot support larger hoofed mammals.

Competition may play a part: the decline in the Serengeti has been suggested to be linked to the rise in wildebeest numbers, since wildebeest compete with gazelles for food (IUCN, citing Foley and colleagues 2014). By grazing, the gazelles also change plant communities.

Thomson's gazelles live in groups.

When they see danger, they jump high with stiff legs.

Thomson's gazelles live in loose herds of about 5 to 60 animals, and sometimes hundreds gather for a while. Animals join and leave the herd freely. They often mix with impalas and Grant's gazelles.

When a gazelle spots danger, it may start stotting: bouncing high into the air with stiff legs and its head held high, which alerts the others. In the breeding season, males guard small territories and mark them with dung and with scent from glands in front of their eyes.

Groups are fluid associations of 5 to 60 individuals, sometimes temporarily hundreds, with no permanent membership or social hierarchy; they also join mixed herds with impalas and Grant's gazelles (Animal Diversity Web). In the breeding season, males hold small territories in good grazing, mark them with preorbital-gland secretions on grass stems and with dung piles, chase rival males and sometimes herd females to keep them longer. Outside the season, males form small bachelor herds or join loose groups with females.

Alarmed gazelles stot, a stereotyped series of high, stiff-legged jumps with the head held high, which signals to other gazelles. Predators include lions, spotted hyenas, African wild dogs, cheetahs, leopards and jackals; calves are also taken by baboons and pythons.

There are still many Thomson's gazelles.

But there are fewer than before. Big parks help keep them safe.

Thomson's gazelle is listed as Least Concern, but its numbers are going down. In the early 1980s about 500,000 lived in the Serengeti; a 2010 survey estimated about 166,000 there. In Kenya, numbers fell from about 147,000 around 1980 to about 44,000 in 2011–2013.

People hunt gazelles for meat and illegal hunting is a problem in parts of the Serengeti–Mara. Many gazelles live in protected areas, such as Serengeti National Park and the Masai Mara National Reserve, where wildlife tourism is the only land use allowed.

The IUCN lists Eudorcas thomsonii as Least Concern (IUCN SSC Antelope Specialist Group; assessed 16 February 2018, published 2018) with a decreasing trend. The global population fell from about 438,650 (1996–1999) to about 225,689 (2002/2003), then levelled off at an estimated 207,361 in 2010–2014, about 145,000 of them mature.

The Serengeti migratory population, Africa's largest gazelle population, was estimated at 165,973 in 2010, down from 500,000 in the early 1980s; Kenya's fell from about 147,000 (1977–80) to about 44,000 (2011–13). No major current threats are known, but declines in some areas have been linked to illegal hunting, water availability, tourism, invasive plants, fire management, roads and competition with wildebeest. Core areas are protected by Serengeti National Park and the Masai Mara National Reserve, surrounded by buffer zones.