- Title
- The demographic-specific prey preferences of lions and cheetahs, and potential impacts on prey populations
- Creator
- Dreyer, Nicola Bondi
- Subject
- Predation (Biology)
- Subject
- Animal populations
- Subject
- Animal ecology
- Date Issued
- 2024-04
- Date
- 2024-04
- Type
- Master's theses
- Type
- text
- Identifier
- http://hdl.handle.net/10948/63733
- Identifier
- vital:73593
- Description
- Understanding prey selection offers predictive insights into predator-prey interactions, which can be extended to explore the impacts of predators on prey populations. Prey availability and vulnerability vary across species, demographic classes, body sizes, and seasons. Traditional prey selection models for large carnivores, based on estimates of prey body size, assume uniform vulnerability across prey demographic classes and seasons, failing to account for these variations. This study aims to contrast seasonal shifts in demographic-specific prey preferences between lions and cheetahs and examine the potential impact of their demographic-specific predation patterns on a range of prey species across a body size spectrum. It was predicted that cheetahs would shift their selection from adults and juveniles of smaller prey species in the dry season to neonates and juveniles of both smaller and larger prey species in the wet season, while lions would select adults irrespective of the season. Additionally, predation focusing on adults would have a greater impact on prey populations compared to predation focusing on non-adults. Furthermore, it was predicted that prey populations experiencing demographic-specific selection from both lions and cheetahs would be impacted more than species selected by only one predator. Degrees of preference (DOP) were estimated based on prey availability (camera traps) and prey use (GPS clusters) for lion and cheetah populations in Lapalala Wilderness Reserve. Generalized Additive Models for Location, Scale, and Shape (GAMLSS) were used to determine seasonal shifts in demographic-specific prey preferences. The seasonal-demographic specific predation patterns of lion and cheetah, along with prey vital rates extracted from the literature, were then used to model potential predation impacts on prey populations using both Leslie-Usher and Lefkovitch matrix models. Lions preferred larger adult prey such as blue wildebeest, eland, and buffalo, while cheetahs preferred smaller prey, particularly juveniles of small to intermediate-sized species like impala, kudu, blue wildebeest, and zebra. Both predators showed seasonal shifts in demographic-specific prey preferences, with lions selecting adult buffalo during the dry season and juvenile buffalo in the wet season, and cheetahs selecting juveniles in the dry season and neonates and juveniles during the wet season. Lions and cheetahs exerted the highest degree of top-down limitations on their preferred prey. Predation on adult prey had a greater effect on prey population growth rates than predation on non-adults, especially in the dry season. Intermediate-sized prey species experienced the highest predation pressures, while larger prey species were more affected than smaller ones, contrary to the size-nested predation hypothesis. My study represents a first effort in the southern hemisphere to model the demographic impacts of multiple predators on diverse prey species, incorporating seasonal and demographic-specific prey preferences. The findings emphasise the importance of incorporating prey demographics and seasonality in predator-prey studies as these refined studies have implications for the management and conservation of both predator and prey populations.
- Description
- Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
- Format
- computer
- Format
- online resource
- Format
- application/pdf
- Format
- 1 online resource (vi, 89 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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NMU School of Environmental Sciences
| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | SOURCE1 | Dreyer, NB.pdf | 2 MB | Adobe Acrobat PDF | View Details Download |