Thomson's gazelle  (Gazella thomsonii)

Despite its limited distribution this is by far Africa's most abundant gazelle (3). The ‘tommy', as it is locally known (3), has a distinct black band running along the side of the body that divides the yellowish-fawn to reddish-fawn upperparts from the clean white underparts (2). The white buttocks are edged with black (2), extending to the short, black tail which is constantly flicking (3). Both sexes of the Thomson's gazelle have long, strongly ringed horns that grow fairly close together, although those of the ewe are generally shorter, thinner, and frequently deformed (3). The face is boldly marked with white, fawn, dark brown and black, and varies between individuals (2).

Thomson's gazelle occurs in Kenya and Tanzania, whilst subspecies G. t. albonotata inhabits south-eastern Sudan and possibly south-western Ethiopia (3).

Thomson's gazelle inhabits dry grasslands and shrubby steppes. It prefers heavily grazed, trampled or burnt grasslands, or naturally open steppe, and can stay on pastures long after large herbivores have deserted it (2).

Thomson's gazelles form small herds but are socially very flexible (2) (3). Herds of females overlap with other herds, and movement between herds is common. Within their shared home range the females rest, move between pastures and visit waters (2). Males are a little less flexible and mature males fight to obtain and defend territories within the female's favourite pastures (2). They denote the boundaries of their territory with dung and by marking grass stems and twigs with secretion from the scent glands beneath their eyes (2). Territoriality in males' peaks during mating periods when frequent fights and stand-offs occur between neighbouring males, and males attempt to mate with any receptive female that enters their area (2) (3).

Lambs may be born at any time of the year, but birthing often occurs towards the end of the rainy season (3). Females are pregnant for 188 days, after which a single lamb weighing two to three kilograms is born (3). Thomson's gazelles feed on fresh green grass whenever possible, but during the dry season, feeding on seeds and the foliage of shrubs is necessary (2). Thomson's gazelles need to drink water every day or two, and in its dry grassland habitat this sometimes requires making round trips of ten miles or more (4).

The Thomson's gazelle was once widespread throughout its range, but now occurs in fragmented populations, in ever-declining areas (2). This is likely to be due to the encroachment of man onto their habitat (5), and hunting (1).

Whilst in many areas Thomson's gazelles have declined, in some areas the species remains common, particularly in protected areas (2), such as the Serengeti National Park. The continued protection and management of such areas is likely to be vital for the conservation of Thomson's gazelle.

For further information on Thomson's gazelle see:

• African Wildlife Foundation:
  www.awf.org/content/wildlife/detail/thomsonsgazelle

Authenticated (25/02/08) by Dr. David Mallon, Co-Chair, IUCN/SSC Antelope Specialist Group.