Making connections : conserving landscapes for wide-ranging species

Habitat loss and fragmentation are among the greatest threats to global biodiversity. Such threats are greatest in human-dominated landscapes, which comprise an increasing proportion of the Earth’s surface. Wide-ranging species at higher trophic levels are particularly threatened by these pressures, as they need access to large areas of wildlife-friendly habitat to persist. In this thesis, the impacts of anthropogenic change to landscapes are investigated, using as case studies two extremely wide-ranging large carnivores, the cheetah and the African wild dog. Anthropogenic habitat change affected habitat selection and movement patterns for both species. Wild dog habitat selection varied across life stages, with selection for rugged areas away from areas of high human populations densities most pronounced during reproductive stages. Dispersers showed the least aversion to areas of high human population densities, suggesting that they may be more willing to use areas of suboptimal habitat. Connectivity levels between wild dog populations across Kenya were modelled using parameters from resident packs and dispersers. Modelled connectivity was higher for dispersing animals, suggesting that wild dogs may be more able to cross the matrix between wildlife areas than appears when using parameters from resident packs. Nevertheless, the development of a major transport corridor is likely to have substantial impacts on landscape connectivity for wild dogs, and hence on population persistence. Physical barriers impacted movement behaviour for both species. While a deliberately permeable fence had no detectable effects, fences intended to restrict wildlife movement were in fact semi-permeable. Analyses showed that crossing such fences increased cheetah travel distance, imposing an energetic cost projected to rise if fencing of properties continues to increase. Fencing also impacted wild dog movement and demography. Wild dogs crossed more robust fences mainly through purpose-built gaps, which channelled wild dogs into particular parts of the landscape. Away from such gaps, impermeable fencing repeatedly split pack members and trapped individuals in unsuitable habitat, causing human-wildlife conflict and contributing to pack extinction. Overall, results showed that anthropogenic landscape change had substantial impacts on wildlife populations. Future developments are likely to imperil population persistence of endangered species unless they incorporate effective, well-planned mitigation measures.