The Biogeography and Palaeobiogeography of the Chacma Baboon (Papio ursinus)

Abstract

Biogeographic knowledge of the chacma baboon (Papio ursinus) is generalised and imprecise. Published distributions are qualitative and actual population counts and location data are few and spatially limited. This research attempts to provide quantitative data to allow repeatable biogeographic assessments of the chacma baboon. Where actual data counts are unknown and impractical to assess, this research provides estimates that, unlike the qualitative data of the past, can be easily updated, validated and remeasured with higher precision. These issues are first addressed by modelling the distribution of chacma baboon habitat and, by association, the potential distribution of the species prior to anthropogenic influence. This is the first quantitative detailed distribution estimate available at a continental scale. Next, anthropogenic influence is explored by assessing the human impact on areas predicted to be the most conducive to species survival. Findings suggest much of the land designated as central niche habitat (land most buffered from the environmental extremes experienced by the population) is impacted by human occupation. The majority of this habitat is within South Africa and the status of baboons in Lesotho appears to be unknown. A case study from the province of KwaZulu-Natal, South Africa, assesses the current population and distribution, finding the population dependent on protected areas and likely in decline. To better understand the species history, the central niche was then investigated through a glacial-interglacial cycle. This indicated a reciprocal relationship of expansion and contraction between the chacma clades. It also identified key areas with stable moderate environmental conditions that would have been central niche habitat regardless of the stage of the glacial-interglacial cycle. Finally, this research explored an association between this ancient habitat prediction and fossil hominins. Although potentially coincidental, it appears there may be a biogeographic bias to the fossil hominin locations. A model of potential hominin core habitat was developed to explore this. My research has provided essential baseline data and knowledge which was a necessary step towards accumulating quality data for future scientific, conservation or management efforts.