Hippotragus roosevelti (Heller, 1910)

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 : 642

136.

Roosevelt's Sable Antelope

Hippotragus roosevelti

French: Hippotrague de Roosevelt / German: Ostafrika-Rappenantilope / Spanish: Hipotrago sable oriental

Taxonomy. Ozanna roosevelti Heller, 1910 ,

Shimba Hills, Kenya.

Formerly included as a subspecies of H. niger . In western Tanzania, there are small populations that appear to have replaced populations of the Southern Sable Antelope ( H. niger ), because many individuals have the mtDNA typical of H. niger varian : instead of the very distinctive mtDNA of the eastern populations of H. roosevelti. Monotypic.

Distribution. SE Kenya (Shimba Hills) and E Tanzania (Sadani, Songea & Selous Game Reserve); in 1994 one was photographed N of Voi in Tsavo East National Park, Kenya.

Descriptive notes. Head-body 175-182 cm,tail 52-53 cm, shoulder height c. 128 cm, ear 23-24 cm, hindfoot 51-53 cm; weight 165-180 kg (based on two males). This species is noticeably smaller than the Southern Sable Antelope , with much shorter horns, and the distance across the horn basesis less. Females are almost invariably a relatively pale golden-red color, dramatically contrasting with the nearly black color of the male, although an occasional very dark female has been recorded. As noted above, the West Tanzanian Roosevelt's Sable Antelope , although externally typical of this species, may have resulted from an ancient mixture between H. roosevelt: and a now-vanished population related to H. niger variani. Dental formulais10/3,C0/1,P3/3,M 3/3 (x2) = 32.

Habitat. In Kenya, Roosevelt's Sable Antelope prefers more open grasslands, a habitat preference apparently unlike that of the Southern Sable Antelope .

Food and Feeding. Stable isotope analysis of enamel indicates that the diet of this species consists of 100% grass.

Breeding. Unlike the Southern Sable Antelope , there appear to be no breeding peaks. A female has a postpartum estrus and may breed every ten months or so. Newborn calves appearto join the herd quickly rather than hiding.

Activity patterns. There is no information available for this species.

Movements, Home range and Social organization. Home ranges of the herds are 10-25 km?, overlapping by as much as 20%. A herd’s home range will include territories of 2-5 males. The males’ territories are 4-9 km?. The social organization is much like that of the Southern Sable Antelope . The oldest, most dominant female, in one field study, remained at a distance of about 20 m from other members of the herd and was much more vigilant. At times, two females may dispute dominance, and a herd may divide into two smaller herds, each with its own home range.

Status and Conservation. The IUCN Red List does not classify Roosevelt's Sable Antelope separately from the Southern Sable Antelope . However,it is quite scarce with only 100-200 individuals remaining in its northernmost outpost in Kenya.

Bibliography. Estes (1991a, 1991b, 2000), Kingdon (1982), Roosevelt & Heller (1914), Sponheimeret al. (2003).

Figures

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

Distribution. SE Kenya (Shimba Hills) and E Tanzania (Sadani, Songea & Selous Game Reserve); in 1994 one was photographed N of Voi in Tsavo East National Park, Kenya .