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| Francesca Parrini (Francesca.Parrini@wits.ac.za) |
| School off Animal, Plant and Environmental Sciences, University of the Witwatersrand |
| November, 2006 |
| Full text (external site) |
| Francesca Parrini obtained her Masters from the University of Florence, Italy, with a study on habitat use of Alpine ibex ( Capra ibex ibex ) in the Italian Alps. She then moved to South Africa to do a PhD at the University of the Witwatersrand, on sable antelope foraging behaviour. Francesca is currently a post-doctoral fellow at the University of the Witwatersrand working on ways to link large scale remote sensing derived vegetation patterns to small scale field measured patterns. |
Abstract |
| 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. |
| Other AOSIS OpenJournals publications include: |