The Gerenuk is a tall, long neck gazelle-like antelope with long, thin legs and a long, narrow head with large ears and eyes. These defining features these make them one of the world's most easily recognized antelopes. The coat is a short, fine, glossy hair that is evenly distributed over the whole body. The Gerenuk has a throat patch of white as well as its underbelly and inner legs and rump patch. There are small, dark patches of fur on the knees of the forelegs and at the end of the tail. On the head, there is a dark patch around the eyes that pales as it goes outward until it forms a white rim. Only the males have horns, which are stout and scimitar shaped ranging from 10 to 17 inches in length. Both sexes are of similar size but the males are more muscular than females causing them to outweigh them. Weights for a mature animal can reach 125 pounds with a total body length of about 63 inches. The typical lifespan is 10 to 12 years.
Gerenuk inhabits the dry brushy region of east Africa from the Serengeti plains of Tanzania north along the coast through Kenya, Ethiopia and into southern Somalia. They are adaptable and do well in a variety of habitats, provided there is a good supply of succulent plants. Gerenuk are well suited for obtaining forage from their arid habitats. Their long necks, long legs, and the ability to stand on their hind legs allow them to obtain tree leaves that are out of reach for most other antelope species. This permits gerenuks to be selective in the foods they eat and to be efficient browsers of herbaceous plants. Gerenuk are primarily active during the day.
Males are solitary and extremely territorial, only seeking out females during the mating season. Dominant males establish territories by marking trees and shrubs with their pre-orbital gland. Other dominant males will enter another's territory without any aggression or defensiveness being displayed but a young male without its own territory will be run off if it enters a dominant male's territory. Females form small bands of up to about 10 individuals, usually related adults with young. These groups of females and young roam freely throughout male territories.