The antelopes include the beisa oryx, fairly common and widely distributed; the greater and lesser kudu (the greater kudu is not found on the Ogaden plateau); the Somali hartebeest (Bubalis Swaynei), found only in the Haud and Ogo districts; waterbuck, rare except along the Webi Shebeli and the Nogal; the dol or Somali bushbuck; the dibatag or Clarke's gazelle; the giraffe-like gerenuk or Waller's gazelle, very common; the aoul or Soemmering's gazelle, widely distributed; the dero (Gazella Speki); and the small dikdik or sakaro antelope, found in almost every thicket.
The dibatag or Clarke's gazelle (Ammodorcas clarkei), of Somaliland, forms a kind of connecting link between the true gazelles and the gerenuk, this being especially shown in the skull.
GERENUK, the Somali name of a long-necked aberrant gazelle, commonly known as Waller's gazelle (Lithocranius walleri), and ranging from Somaliland to Kilimanjaro.
The long neck and limbs, coupled with peculiarities in the structure of the skull, entitle the gerenuk, which is a large species, to represent a genus.
Gerenuk are browsing ruminants, and, in Somaliland, are found in small family-parties, and feed more by browsing on the branches and leaves of trees and shrubs than by grazing.
Among the varieties are the greater and lesser kudu (both rather rare); the duiker, gemsbuck, hartebeest, gerenuk (the most common - it has long thin legs and a camel-like neck); klipspringer, found on the high plateaus as well as in the lower districts; and the dik-dik, the smallest of the antelopes, its weight rarely exceeding so lb, common in the low countries and the foothills.
The East African gerenuk, or Waller's gazelle (Lithocranius walleri), of which two races have been named, is a very remarkable ruminant, distinguished not only by its exceedingly elongated neck and limbs, but also by the peculiar hooked form of the very massive horns of the bucks, the dense structure and straight profile of the skull, and the extreme slenderness of the lower jaw.