Hippotragus equinus (Geoffroy Saint-Hilaire, 1803)

Don E. Wilson & Russell A. Mittermeier, 2011, Bovidae, Handbook of the Mammals of the World – Volume 2 Hoofed Mammals, Barcelona: Lynx Edicions, pp. 444-779 : 641

134.

Roan Antelope

Hippotragus equinus

French: Rouanne / German: Pferdeantilope / Spanish: Hipotrago

Other common names: Bastergemsbok, Gwanki, Korongo, Kwalataseta

Taxonomy. Antilope equina Geoffroy Saint-Hilaire, 1803 ,

Inconnue. Restricted by Grubb 1n 1999 to “ South Africa, Western Cape Prov., Plettenberg Bay”.

Usually, about six subspecies have been recognized on the basis of differences in pelage. Average color differences exist over the huge area of distribution. Females with tan-colored foreheads are common in Tanzania, Kenya, and the White Nile district (the rest of the face is black, and the foreheads of males are black). Individuals in East Africa average larger than elsewhere. DNA analysis tends to distinguish Roan Antelopes from West Africa from those from central, eastern, and southern Africa. This species is considered monotypic here.

Distribution. From W Africa ( Senegal & Guinea-Bissau) to W Ethiopia, then S through W Uganda, SW Kenya, WC Tanzania (not the coastal region) to Angola, NE Namibia, N Botswana, and Kruger National Park in NE South Africa.

Descriptive notes. Head-body 200-219 cm, tail 60-75 cm, shoulder height 126-145 cm, ear 35-38 cm, hindfoot 52-55 cm; weight 235-300 kg (males) and 215-280 kg (females). Body color from nearly white (with a slight reddish cast) through fawn through medium/dark brown; the face is largely black, this color extending onto the sides of the neck, with white streaks in front of the eyes that extend down onto the sides of the face, and a white muzzle. Neonates are reddish or buffy colored, with at most vague dark markings; by about four months, the young have acquired adult coloration. The ears are very large and slightly curved backward toward the tips, with noticeable tufts. There is an erect brown mane, with whitish hair bases, running along the neck to just behind the withers, and a shorter mane down the throat to the brisket. The tail is blackish with a long black tuft. Both sexes have horns. The horns are relatively short, a little longer than the head, and strongly curved backward, even in a semicircle in some males; they are ridged along almost the entire anterior surface except for the tips. Dental formulais10/3,C0/1,P 3/3, M 3/3 (x 2) = 32.

Habitat. The Roan Antelope occurs mostly in wooded savanna, especially moist savanna, mostly in long-grass areas. It will use semi-arid habitat but nearly always near permanent water, except during rains. It will selectively graze in recently burned areas when the flush of new vegetation appears. At Madrid Game Ranch, South Africa, Roan Antelopes consistently used areas with denser canopy cover than other ungulates and favored bottomlands. In Nylsvley Nature Reserve, South Africa, Roan Antelopes generally used open grasslands more than woodland savanna, and in contrast, they preferred medium-closed to open woodland in Weenen Provincial Nature Reserve, South Africa, where they have been reintroduced.

Food and Feeding. Herbivorous and grazers in most places. Stable isotope analysis of dental enamel from Roan Antelopes indicates that 91% of the diet in southern Africa and as much as 100% in eastern Africa consist of grasses. In Burkina Faso, West Africa, during the hot-dry season, Roan Antelopes adopt a mixed-feeding strategy, consuming legumes and shrubs and less than 50% grass. Roan Antelopes tend to eat the higher parts of grasses, usually down to about 80 mm above the ground; green shoots are cropped down to 20 mm. In Nylsvley Nature Reserve, forage quantity is most important in the late wet and early dry seasons, and food quality is more important in the early wet and late dry seasons. Roan Antelopes may stand in quite deep water to feed on aquatic plants.

Breeding. Breeding is non-seasonal. Females and calves, like males, usually test female urine for hormones. Estrus lasts for one or two days, during which a female copulates frequently. The female performs submissive gestures, and the two circle round each other, the male following and lifting his foreleg, with the knee bent alongside the female’s hindquarters or between her hindlegs. Gestation is 276-287 days. A female moves away from the main herd several days before giving birth, and she stays with the calf for aboutfive days, then leaves it in concealment. Dominant females have a shorter period of isolation than subordinate ones. The mother returns to the calf early in the morning for suckling, and sometimes at night; they contact each other with low calls, or, if they have lost each other, with loud bird-like twitters. Weaning occurs at about six months of age. There is a postpartum estrus. Females ovulate within about a month of calving, and thus may breed every ten months or so. Females become fertile at two years.

Activity patterns. Largely diurnal, grazing until about 10:00 h and then resting in the heat of the day, with additional feeding bouts in late afternoon and evening and often into the night. Roan Antelopes drink frequently, especially in the dry season.

Movements, Home range and Social organization. Roan Antelopes live in herds of 6-20 females and young, but occasionally they aggregate into gatherings of over 100. The herds occupy home ranges of 40-120 km? which include territories of several males, or they may share a territory with a single male, or there may be separate wet and dry season ranges. A herd will stay in a portion of its home range for a considerable period and then move to another part of it. Herd members tend to be fairly widely dispersed. There is a clear dominance hierarchy among members, with frequent supplanting and dominance displays (arched-neck broadside display). The dominant cow leads herd movements; if there is a bull in association, he follows the dominant cow. Juveniles and subadults may move separately from the females for some hours, or even a few days. Males disperse at about two years of age and join bachelor herds, and after about six years of age, they attempt to gain territories. Territorial males patrol the boundaries of their territories, marking them with dung; unlike sable antelopes, the territorial males do not scrape the ground before defecation. They beat bushes and low trees with their horns. A territorial male defends the herd that is in his territory (even if the herd is only there temporarily), together with an area 300-500 m around it (the intolerance zone). Males threaten with the same gestures as do females, and may fight challengers by pushing with horns and forehead, dropping to their knees, lashing their tails, and twitching their prominent ears.

Status and Conservation. Classified as Least Concern on The IUCN Red List. Present numbers across Africa are estimated at about 76,000. Some populations are stable, others declining; 60% of the population is in protected areas. About 500 or fewer remain in South Africa (with a yet unexplained steep decline to near extinction in Kruger National Park, perhaps most related to predation, exacerbated by persistent drought and habitat deterioration), less than 2000 in Zimbabwe, 1000 in Botswana, less than 1000 in Namibia, and somewhat under 2000 in Malawi. Numbers are unknown in Mozambique and Angola. In all these countries of southern Africa,it is threatened, mostly declining. Only in Zambia, where there are over 5000, mainly in the national parks,is its status satisfactory. Farther north, there are fairly large populations in Burkina Faso (more than 7300), Cameroon (more than 6000), and Tanzania (more than 4300). Roan Antelopes have been reintroduced successfully in areas where they once occurred.

Bibliography. Alpers et al. (2004), Estes (1991a, 1991b), Gureja & Owen-Smith (2002), Heitkonig & Owen-Smith (1998), Kingdon (1982), McLoughlin & Owen-Smith (2003), Perrin & Taolo (1999), Roosevelt & Heller (1914), Schuette et al. (1998), Skinner & Chimimba (2005), Sponheimer et al. (2003), Wilson & Hirst (1977).

Figures

134. Roan Antelope (Hippotragus equinus), 135. Southern Sable Antelope (Hippotragus niger), 136. Roosevelt's Sable Antelope (Hippotragus roosevelti), 137. Addax (Addax nasomaculatus)

Distribution. From W Africa ( Senegal & Guinea-Bissau ) to W Ethiopia , then S through W Uganda , SW Kenya , WC Tanzania (not the coastal region) to Angola , NE Namibia , N Botswana , and Kruger National Park in NE South Africa .