The grey rhebok (Pelea capreolus) is a distinctive antelope species found exclusively in Southern Africa. Locally known as “vaalribbok” in Afrikaans, its Latin name, capreolus, translates to “little goat,” reflecting its agile nature.
Physical Traits
The grey rhebok is a medium-sized antelope, weighing between 19 and 30 kilograms (42-66 pounds) and standing about 70-80 centimeters (28-31 inches) at the shoulder. Its coat is short, dense, and woolly, providing insulation against colder temperatures. The coloration generally ranges through various shades of grey, sometimes with fawn-colored legs and head, and a whitish underside.
A distinguishing feature of the grey rhebok is its long neck and narrow, upright ears. Only the males possess horns, which are straight, slender, and rise vertically from the forehead. These horns are typically ringed at the base and can measure approximately 15-29 centimeters (6-11 inches) in length. The rhebok also has an enlarged black patch of bare skin at its nose, known as a rhinarium, which contrasts with white hairs on its muzzle.
Natural Environment
The grey rhebok is endemic to Southern Africa, with its primary distribution encompassing South Africa, Lesotho, and Eswatini. These antelopes typically inhabit elevated, grassy, montane environments, often found at altitudes of 1,000 meters (3,300 feet) above sea level or higher, such as sourveld grasslands.
While they generally prefer higher elevations, grey rheboks are also observed in other environments, including rocky hills, plateau grasslands, and mountain fynbos. In some areas, such as the coastal belt of the Cape, they can even be found at much lower altitudes, near sea level. They require areas with sufficient grass cover for shelter and to evade predators, although they often feed in more open, steep areas.
Behavior and Lifestyle
Grey rheboks exhibit a social structure that typically consists of small family groups, often comprising one mature male, one to 15 females, and their offspring. This social system, known as female defense polygyny, involves males aggressively defending an exclusive territory, which can be around 0.6 square kilometers, marked with urine and droppings. Non-territorial males usually lead solitary lives.
These antelopes are primarily browsers, feeding on forbs, shrubs, and the leaves and flowers of various plants. They obtain most of their water from food, making them largely water-independent and able to utilize sources far from standing water. While generally diurnal, they may forage at night during hot weather.
Communication among grey rheboks includes snorts, hisses, and groans. When alarmed, they often stamp their feet and emit a loud whistling call. Their strong eyesight allows them to spot stationary objects over 200 meters away and other rheboks from almost 400 meters. Their primary defense mechanism involves a high-bounding leap, allowing them to attain speeds up to 59 kilometers per hour (37 miles per hour) in mountainous terrain.
The breeding season for grey rheboks varies by region, with mating activity typically occurring in summer or autumn. The gestation period lasts approximately seven months, usually resulting in the birth of a single fawn. Fawns remain hidden in grassy cover for about three weeks after birth, becoming fully mobile around six weeks of age. Females reach sexual maturity by 16 months, while males mature between 18 and 24 months, with a life expectancy of 8 to 10 years.
Conservation Outlook
The grey rhebok is currently classified as “Near Threatened” by the IUCN (International Union for Conservation of Nature). This classification reflects an estimated decline of approximately 20% over three generations between 1999 and 2014, observed in subpopulations within 13 protected areas. For instance, the largest protected subpopulation in Maloti-Drakensberg Park experienced an estimated 15-20% decrease.
Despite their habitat in rugged mountainous areas making them somewhat less susceptible to widespread habitat loss compared to other ungulates, they face several threats. Habitat loss due to agricultural expansion and human development contributes to population declines. Poaching for meat and illegal hunting, often involving domestic or feral dogs, pose significant risks. Predation by natural predators such as black-backed jackals, caracals, and leopards can also affect local populations.
Conservation efforts include their presence in protected areas like the Maloti-Drakensberg Park World Heritage Site and Golden Gate Highlands National Park, which hold strongholds for the species with subpopulations exceeding 400 individuals. Establishing long-term monitoring sites is important to quantify population trends and the impact of threats, especially as declines are suspected in areas outside of protected zones.