Territory And Social Arrangements
Gazelle social arrangements vary according to the terrain they inhabit. Where food sources are abundant they are found in large herds, but in desert regions their populations are lower. In the savanna areas of Africa, Thomson gazelles are found in large numbers. The size of the territory ranges from 38-150 acres (15-61 hectares; Grant's gazelle, East Africa), to 250-550 acres (101-223 hectares; Edmi gazelles, Middle East), to 325-850 acres, (132-344 hectares; gerenuk or giraffe gazelle, East Africa).
Males establish territories during the mating season and routinely exclude other males. Harem herds of female gazelles with dependent young, are defended by one dominant male. Maternal herds, without a male present in the territory, and bachelor herds of male gazelles are also found. At times there are large mixed herds without a territorial male present, seen during periods of migration.
Gazelles mark their territories in much the same way as other ruminants do. They deposit dung heaps around the territory and they mark bushes with their scent glands. Glands can be found under the eyes (preorbital glands), on the hooves, shins, back and around the genital area depending on the particular species. When another male enters a territorial male's domain, there is no fighting as long as the intruder displays subordinate behavior. A subordinate male will keep his head low with his chin out and will not approach the females of the herd.
One of the smallest species is the Dorcas gazelle (Gazella dorcas) of North Africa (Algeria to Egypt) and Sudan, which is less than 2 ft (0.61 m) at the shoulder. The common gazelles of East Africa include Thomson's gazelle (G. thomsoni), with black flanks and erect horns, and Grant's gazelle (G. granti) which is up to 3 ft (0.915 m) at the shoulder, and the largest of all gazelles. The red-fronted gazelle (G. rufifrons) is found from Senegal to the Sudan.
Males within an all-male herd will frequently display intimidation behavior toward one another, but these do not often lead to attacks or injuries. Bucks will push their foreheads against one another in a display of intimidation. This may lead to interlocking horns, but they usually disengage before any serious damage occurs. Bucks will sometimes stand parallel to one another, head to rump, and walk around each other in circles. They may also engage in a chin-up display where they stretch their necks and bend them backwards towards one another. Within the male herds this behavior establishes dominant and submissive roles.