Damaliscus eurus (Blaine, 1914)

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 : 659

159.

Ruaha Topt

Damaliscus eurus

French: Topi du Ruaha / German: Ruaha-Topi / Spanish: Topi de Ruaha

Taxonomy. Damaliscus korrigum eurus Blaine, 1914 ,

Upper Ruaha River, Tanzania.

Formerly in the synonymy of D. jimela . Monotypic.

Distribution. SE Tanzania (Upper Ruaha/ Lake Rukwa ecosystem). It is not known if there are any populations between this area and the Serengeti ecosystem where the Serengeti Topi ( D. jimela ) occurs.

Descriptive notes. Head—body 195-223 cm (males) and 185-204 cm (females); tail c. 45 cm; weight 136-168 kg (males) and 120-139 kg (females). Size and color are as in the Uganda Topi (D. ugandae), but noticeably paler, bright reddish-bay in the posterior dorsal region. Skull characters of the Ruaha Topi are, in some respects, intermediate between the Serengeti Topi and the Uganda Topi, butit has very long, broad nasals.

Habitat. Like other large species of Damaliscus , the Ruaha Topi lives in edaphic grasslands. In the Rukwa Valley, it inhabits valley grasslands, extending into parklands and occasionally open woods, in periodically flooded country. Every 30 years or so, the lake dries up completely, extending the amount of open grassland.

Food and Feeding. Grazes on floodplain grasses, following the flooding of Lake Rukwa. Favored grasses include Cynodon, Chloris, and Brachiaria, whose growth is stimulated by the trampling of rank herbage.

Breeding. Seasonal. Around Lake Rukwa, the number of Ruaha Topi on the lek fluctuates greatly according to the water level of the lake, down to 500 in a time of high water in 1950, but up to 6000 in 1961 during a relatively dry period. Calving occurs at the end of the dry season.

Activity patterns. Ruaha Topi move back and forth according to the fluctuations of Lake Rukwa. When the lake levelis high, the population is concentrated on two small areas of high ground; when the water level is so high that most of the traditional grazing areas are inundated, there is high mortality.

Movements, Home range and Social organization. The groups of Ruaha Topi spread out when the lake levels are low, feeding on new growth, and are concentrated on areas of high ground when the lake floods.

Status and Conservation. Classified as Least Concern on The [UCN Red List (under D. korrigumjimela). Part of the habitat in the Lake Rukwa region is protected by the Katavi-Rukwa National Park and Rukwa Game Reserve. In 2004, there were on the order of 13,000 individuals in these regions. The numbers may have declined slightly over the previous six years, but poaching was not significant (unlike other large mammals in the ecosystem), and any decline may simply have been a result of predation.

Bibliography. Vesey-Fitzgerald (1964, 1965).

Figures

152. Bontebok (Damaliscus pygargus), 153. Blesbok (Damaliscus phillipsi), 154. Western Tsessebe (Damaliscus lunatus), 155. Bangweulu Tsessebe (Damaliscus superstes), 156. Korrigum (Damaliscus korrigum), 157. Tiang (Damaliscus tiang), 158. Uganda Top 1 (Damaliscus ugandae), 159. Ruaha Topt (Damaliscus eurus), 160. Serengeti Topi (Damaliscus jimela), 161. Coastal Topt (Damaliscus topr)

Distribution. SE Tanzania (Upper Ruaha/ Lake Rukwa ecosystem). It is not known if there are any populations between this area and the Serengeti ecosystem where the Serengeti Topi ( D. jimela ) occurs.