Description

The gerenuk is a notably tall, slender antelope that resembles gazelles. It is characterised by its long, slender neck and limbs, the flat, wedge-like head and the large, round ears. Males are nearly 89–105 centimetres (35–41 in) tall, and the shorter females 80–100 centimetres (31–39 in); the head-and-body length is typically between 140 and 160 centimetres (55 and 63 in). Males weigh between 31 and 52 kilograms (68 and 115 lb); females are lighter, weighing 28–45 kilograms (62–99 lb). The species is sexually dimorphic. The tail, that ends in a black tuft, measures 25–35 centimetres (9.8–13.8 in). 

Two types of colouration are clearly visible on the smooth coat: the reddish brown dorsal parts (the back or the "saddle"), and the lighter flanks, fawn to buff. The underbelly and insides of the legs are cream in colour. The eyes and the mouth are surrounded by white fur. Females have a dark patch on the crown. The horns, present only on males, are lyre-like ("S"-shaped). Curving backward then slightly forward, these measure 25–44 centimetres (9.8–17.3 in). 

The gerenuk resembles the dibatag, with which it is sympatric in eastern and central Somalia and southeastern Ethiopia. Both are brachyodonts and share several facial and cranial features, along with a two-tone colouration of the coat and strong thick horns (only in males). However, there are also some features distinguishing it from the gerenuk, including major morphological differences in horns, horn cores, tail, postorbital area and basioccipital processes. The gerenuk has a longer, heavier neck and a shorter tail. A finer point of difference is the absence of an inward-curving lobe in the lower edge of the ear (near its tip) in the gerenuk. The subspecies of the gerenuk are similar in colouration; the southern gerenuk is the smaller of the two. 

Fun Facts

The gerenuk is a diurnal animal (active mainly during the day), though it typically stands or rests in shade during the noon. Foraging and feeding is the major activity throughout the day; females appear to spend longer time in feeding. The gerenuk may expose itself to rain, probably to cool its body. The social structure consists of small herds of two to six members. Herds typically comprise members of a single sex, though female herds additionally have juveniles. Some males lead a solitary life.

Fighting and travel are uncommon, possibly as a strategy to save energy for foraging. Both sexes maintain home ranges 3–6 square kilometres (1.2–2.3 sq mi) large, and might overlap. Those of males are scent-marked with preorbital gland secretions and guarded - hence these may be termed territories. The sedentary tendency of the antelope appears to increase with age