Book Description

Abstract Wilderness areas across the globe are under rising threat from increasing anthropogenic activities, the effects of which are likely to be exacerbated by climate change. The Okavango Delta is a relatively pristine wetland system that supports abundant wildlife and provides livelihoods for many local communities. This ecosystem is governed by an unusual dual moisture regime, which is responsible for seasonal changes in resource availabilities, and corresponding shifts in herbivore spatial patterns and population demographics. African buffalo form an important part of the system, so understanding their ecological requirements is essential 'for the conservation of this unique area. My results showed that the extent and location of buffalo home ranges depended on the availability of water and forage, as did their habitat use. Forage abundance and palatability were the main characteristics sought by grazing buffalo, whereas shade and sparse grass were preferred for resting; these trends were apparent at multiple spatial scales, both within and between habitat types. Buffalo displayed an unusual social system: highly dynamic herds occupied shared ranges and, within my study area, formed two sub-populations with divergent migratory strategies; these were probably driven by differing resource availabilities and levels of anthropogenically-induced spatial restriction. The sub-populations shared similar critical seasonal habitats, and showed comparable population demographics and body condition; neither appeared to be under nutritional stress, and their seasonal ranges provided access to forage with similar characteristics. High levels of heterogeneity at several spatial scales appeared to be the most important ecological factor for a sustainable buffalo population. My results highlighted the importance of identifying and protecting critical seasonal resources, and the movement routes linking them, for the conservation of highly mobile large herbivores and the ecosystems that support them, particularly in the light of unpredictable future environmental changes.