Ecology of African Vultures in Southern Tanzania

Vulture populations are one of the fastest declining bird groups and have suffered sharp population declines across their range, including in east Africa. Currently, three of the eleven African vulture species are listed as endangered and four are listed as critically endangered. Poisoning due to human-wildlife conflict is the current greatest threat to vultures in Tanzania. In this study I define vulture foraging and feeding, behaviours where vultures may encounter poison and thus most important to conservation, and identify resource selection and high-risk areas associated with these. I also investigate the ecosystem services vultures may provide by assessing the impact scavengers have on anthrax disease ecology. When compared to other behaviours, vultures prefer areas with low tree cover, close to rivers, and less protected areas like game reserves over strictly protected National Parks for foraging. Feeding preferences were not a subset of foraging locations, suggesting that vultures are successful in areas where they spend little time foraging and that risk of encountering poison could occur outside their foraging area. Highest risk of encountering poison occurred within and on the border of protected areas, where high human-use overlaps with areas vultures find a high proportion of carcasses in. The identified high-risk areas were much smaller than traditional buffer zones. In modelling anthrax dynamics, I found that highly efficient scavengers like vultures may play an important role in preventing anthrax outbreaks and lessening their severity when they occur. The ability and rate of anthrax cells transition to spores and spore persistence were also important in determining outbreaks. If infected carcasses were not scavenged or removed, outbreaks became continuous. Vultures provide important services in the ecosystems the inhabit, and to conserve them there must be a focus on preventing and mitigating human-wildlife conflict in the areas identified in this thesis.