- Title
- Large mammalian fauna of the Palaeo-Agulhas Plain: predicting habitat use and range distribution
- Creator
- Brooke, Christopher F
- Subject
- Gqeberha (South Africa)
- Subject
- Eastern Cape (South Africa)
- Subject
- Herbivores
- Date Issued
- 2021-04
- Date
- 2021-04
- Type
- Doctoral theses
- Type
- text
- Identifier
- http://hdl.handle.net/10948/52332
- Identifier
- vital:43590
- Description
- Understanding the variations in structure and abundance of animals and what leads to their distribution within the landscape has captured the attention of ecologists for centuries. Importantly, knowledge of current behaviour of large mammals can be used to inform historic population dynamics and is essential to understanding how early humans used large mammals as a foraging resource. Central to this thesis and improving our understanding of large herbivores is the Palaeo-Agulhas Plain (PAP) where large mammalian herbivores formed a key food resource for early humans. The PAP, now submerged off the southern Cape of South Africa, formed a novel ecosystem during lower sea levels. Characterised by large expanses of nutrient rich grasslands and large grazing herbivores, the PAP stands in stark contrast to the nutrient poor fynbos ecosystems that is in the southern Cape today. In this thesis I focus on the Last Glacial Maximum (LGM; ~20 ka) when the PAP was last fully exposed to answer questions relating to the habitat use and range distribution of large herbivores. Importantly, through the Paleoscape Project, modelled climate, soil and vegetation have made these recreations of large mammals possible. Using modelled climate and vegetation this thesis aims to model the large herbivore communities and understand the influence of early humans on the PAP during the LGM for successful integration into the PaleoscapeABM (the PAP agent-based model). To improve our understanding of large mammals on the PAP I identified five large herbivores that became extinct on the PAP since the LGM and modelled their behavioural and physical traits using k-Nearest Neighbour imputation. I predicted the biomass of large herbivores across the PAP using actual biomass of large herbivores from 39 protected areas across South Africa (spanning five functional groups to include the extinct species) across a rainfall gradient and different biomes. The distribution of large herbivores would likely have been driven by similar top-down and bottom-up drivers we see in large herbivore ecology today. Knowing this, I created a predictive model for large mammals by predicting the probability of occurrence of functional groups of large herbivores in relation to environmental drivers and humans. Results showed that all species (except Antidorcas australis) were adapted to the grassy environment of the PAP and these specialisations likely contributed to their extinction along with changing climates and intensified hunting from humans. When predicting herbivore viii biomass, biome was the most important factor influencing the relationship between herbivores and rainfall. In general, large herbivore biomass increased with rainfall across biomes, except for grassland. Finally, I showed the probability of occurrence of large herbivores was influenced by early humans, water availability and a landscape of fear on the PAP. Through this thesis I have successfully provided detailed accounts of the biomass and probability of occurrence of large herbivores on the PAP. Importantly, this information can be seamlessly integrated into the PaleoscapeABM. Finally, I highlight the importance of this knowledge in understanding early humans, the potential shortcomings of this study and resulting areas where research needs to be focused.
- Description
- Thesis (PhD) -- Faculty of Science, School of Natural Resource Management, 2021
- Format
- computer
- Format
- online resource
- Format
- application/pdf
- Format
- 1 online resource (xxii, 214 pages)
- Format
- Publisher
- Nelson Mandela University
- Publisher
- Faculty of Science
- Language
- English
- Rights
- Nelson Mandela University
- Rights
- All Rights Reserved
- Rights
- Open Access
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