Alcelaphus swaynei (Sclater, 1892)

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 : 652

147.

Swayne’s Hartebeest

Alcelaphus swaynei

French: Bubale de Swayne / German: Somalia-Kuhantilope / Spanish: Alcelafo de Swayne

Other common names: Korkay

Taxonomy. Bubalis swayne: Sclater, 1892 ,

Haud, 100 miles from Berbera, Somalia.

Formerly considered a subspecies of A. buselaphus , which is now extinct. In the late 20" century, it was customary for all or most hartebeest to be included as subspecies of A. buselaphus . There seems no particular reason for them to have been placed in a single species, and the more we learn about them the more distinct they are found to be. A recent study found that the surviving populations of this species still retain significant amounts of genetic diversity (mtDNA and microsatellites), and that two of the now-isolated surviving populations have diverged considerably. A phylogeny of hartebeest based on the control region of mtDNA found that two haplotypes of this species were nested within the Kongoni (A. cokii), whereas five others formed a separate subclade. This species is considered monotypic here.

Distribution. C Ethiopia (W side of the Rift Valley).

Descriptive notes. Few measurements available. Head—body 250 cm (adult male), tail 50 cm, shoulder height 124 cm. As in the Kongoni, the horns seen from in front are between a V and a U shape, and horn circumference in males is low relative to skull length. Horn length is also relatively low; pedicle length is low in females (as low as in Lichtenstein’s Hartebeest, A. lichtensteinii ), but not especially so compared to males of other species. Greatest skull length is 40-9—-47-2 cm in males; horn span is 114-148% of basal length in males; and least frontal width is 64-69% of biorbital width. The skull in the female is lightly built compared to most other hartebeest, so sexual dimorphism in skull weight is greater than in any other hartebeest. This is one of the “lightly armed” species. It is much deeper in color than other East African species, chocolate brown with striking black markings on the mid-face and legs. The preorbital secretion is colorless.

Habitat. The Senkele Plains are montane savanna at elevations of 2000 m or more. Preferred habitat of Swayne’s Hartebeest here is fallow land that had been cultivated for about two years, where they find short grasses, especially Eleusine multiflora, Cynodon dactylon, Chloris pycnothrix, Harpachne schimperi, and Rhynchelytrum repens . Although this type of land covers only 10% ofthe area inhabited by hartebeest,it accounted for 80% of their land usage. This preference for short-grass plains differs strongly from other hartebeest, such as the Kongoni.

Food and Feeding. On the Senkele Plains this species feeds on the short, lush grass of the fallow land.

Breeding. Calving lasts from mid-December until mid-February; this implies a relatively short breeding season, though longer than in the Lelwel Hartebeest (A. lelwel), and probably correlated with the fact that it is “lightly armed” but strongly sexually dimorphic.

Activity patterns. There are two activity peaks: 06:00-10:00 h and 16:00-18:00 h. From 14:00 h to 15:00 h, about 40% of the animals are in the shade—another idiosyncratic characteristic ofthis species, and probably related to their need for water conservation. More than half their diurnal activity is spent in feeding.

Movements, Home range and Social organization. In November, they combine into large groups of about 180 individuals; by mid-December, the beginning ofthe calving season, these groups split into small herds of fewer than ten individuals, and there are a few small all-male groups.

Status and Conservation. Classified as Endangered on The IUCN Red List (as A. buselaphus swayner). This species formerly existed from northern Somalia through the Ethiopian Rift Valley at least as far south as Lake Zway. The region north of Lake Stephanie, Ethiopia, is probably a hybrid zone between the Lelwel Hartebeest and Swayne’s Hartebeest. The total population is estimated at only 600 individuals, the majority of which are confined to the Senkele Wildlife Sanctuary and Mazie National Park in Ethiopia, with no subpopulation numbering more than 250 mature individuals. As with other hartebeest species, habitat loss, overhunting, and competition with livestock are thought to be the important causes of population decline.

Bibliography. Capellini & Gosling (2006), Flagstad et al. (2000), Lewis & Wilson (1979), Roosevelt & Heller (1914), Ruxton & Schwarz (1929).

Figures

On following pages: 147. Swayne's Hartebeest (Alcelaphus swaynel); 148. Kongoni (Alcelaphus coki); 149. Lichtenstein's Hartebeest (Alcelaphus lichtensteinii); 150. Red Hartebeest (Alcelaphus caama); 151. Herola (Beatragus hunter).

Distribution. C Ethiopia (W side of the Rift Valley).