Roan antelope numbers have declined drastically over the last 30 years in the Kruger National Park (KNP). Various hypotheses have been tested and suggested as reasons for their sharp decline. A change in habitat structure and nutrient deficiencies were among the factors considered for their population decline. The aim of this research was to study the influence of habitat structure on habitat selection in the absence of predators by two separate roan populations in predator-proof enclosures on the northern plains of the KNP. Seasonal variations in the nitrogen, macro-and micronutrient concentrations of the preferred grass species in every enclosure were determined. Faecal samples were collected and pooled seasonally in order to link nutrient concentrations in faeces with that in grass. Water and soil samples were also collected and analysed. The nutrient concentrations of grass and faeces in the wet-and dry season were compared with nutrient concentrations collected similarly from a roan antelope population at Vaalbos National Park, Northern Cape Province, South Africa. Where possible, serum samples were also collected and analysed for macro-and micronutrient concentrations. Results indicated that roan antelope disregard habitat structure in the selection of vegetation type or foraging areas in the absence of predators. This behaviour may jeopardise survival if captive bred roan are released to supplement free roaming roan populations in the KNP since previous studies indicated that free roaming roan antelope in the KNP prefer lightly wooded areas with a fairly high visibility. Results from grass, faecal and serum analyses indicated that some nutrient deficiencies might occur in each of the populations studied during specific times of the year and especially in animals in nutrient challenging production phases. Results suggested a possible induced copper deficiency in roan at N'washitsumbe in the KNP, mainly from a Cu-Mo-S interaction. Wet season faecal nitrogen levels of roan at N'washitsumbe was marginal to deficient and that of the Graspan population at Vaalbos National Park was marginal. Phosphorus levels of all the populations were sufficient in faeces despite low dietary intakes. Results were compared with faecal and serum nutrient levels of supplemented roan and sable antelope at Sable Ranch, Northwest Province, South Africa. In general, supplemented roan and sable antelope had a significantly higher nutrient status than un-supplemented populations. Significant species and gender differences in serum and faecal nutrient concentrations were identified in supplemented animals at Sable Ranch. Copyright / Dissertation (MScAgric)--University of Pretoria, 2009. / Animal and Wildlife Sciences / unrestricted

The aim of this study was to determine the species composition of questing ixodid ticks on the vegetation in intensive breeding enclosures for sable antelopes (Hippotragus niger), on which strategic tick control is practiced, and to compare it with that of questing ixodid ticks in a multi-species herbivore enclosure surrounding the breeding enclosures, and where no tick control is practiced. A total of eight ixodid tick species were collected namely, Amblyomma hebraeum, Amblyomma marmoreum, Haemaphysalis elliptica, Rhipicephalus appendiculatus, Rhipicephalus decoloratus, Rhipicephalus evertsi evertsi, Rhipicephalus simus and Rhipicephalus zambeziensis. A. marmoreum was only collected in the intensive breeding enclosures and H. elliptica only in the multiple herbivore species enclosure, whilst the remaining tick species were collected in both enclosures. The study was also designed to determine the abundance, seasonal abundance and proportion of ixodid tick larvae collected in the sable antelope breeding enclosures as well as in the multi-species herbivore enclosure and to compare the population dynamics of tick species in the respective enclosures with particular emphasis on R. decoloratus. R. decoloratus accounted for 65.4% of the total number ticks collected in the sable enclosures, whilst it represented only 24.3% of the total number of ticks collected in the multi-species herbivore camp. R. decoloratus was more abundant than A. hebraeum and R. appendiculatus in the woodlands of the sable antelope enclosures whilst R. decoloratus and R. evertsi evertsi were more abundant in grassland habitats of the sable antelope enclosures than both A. hebraeum and R. appendiculatus. R. decoloratus larvae were collected throughout the year with peak collections in November 2012 and between October and December 2013 in the sable breeding enclosures, and in April and May 2012 and February and April 2013 in the multi-species herbivore enclosure. The numbers of R. decoloratus larvae collected in the sable breeding enclosures increased significantly during the study period (p≤0.020). / Dissertation (MSc)--University of Pretoria, 2014. / gm2014 / Veterinary Tropical Diseases / unrestricted

This study focused on how changes in food availability during the dry season, influenced various aspects of sable (Hippotragus niger niger) foraging and social ecology. The main purpose of this was to determine whether differences in their foraging ecology explained the reduction in population size compared to other more abundant herbivores (e.g. zebra, buffalos, hartebeest). Contrary to expectation, sable did not limit their foraging to woodlands, but also fed in open grasslands, provided these retained green grass during the dry season. Wetlands were key resource areas during the dry season, but sable did not limit their feeding to these bottomland areas. They also fed on hill slopes and upper plateaus that had been burnt. During the study, sable were attracted to burnt areas despite the reduced grass availability. My study highlights how these burnt areas were important in alleviating nutritional deficiencies during the dry season. At lower spatial levels, I looked at the factors that influenced the selection of feeding areas and plant species. Like other grazers, sable were attracted to green leaves but did not avoid brown leaves or stems. Grass species eaten were the same as those preferred by most domestic and wild grazers. Surprisingly, adult males stayed with the breeding herds despite their different activity budgets. Unlike most other African grazers, sub adult sable males did not form bachelor groups. Instead, they stayed within the breeding herds the whole time and had a similar activity budget to females. As adult males moved with the breeding herds, I was able to examine the costs and benefits involved with such a social structure. From this, I was able to relate my results to the bigger picture of factors influencing sexual segregation in ungulates. In conclusion, sable utilised a wide variety of habitat types and adjusted their foraging behaviour to accommodate different seasonal situations. I was unable to find anything in their feeding ecology that could explain the continued decline in population size. Therefore, I suggest that future research needs to focus on other potential causes such as a higher susceptibility to predation and disease as compared to more abundant herbivore species.