Abstract: This study examined the sociality of two phylogenetically closely related otomyine, murid rodent species that display differences in social behaviour in the wild. A fundamental characteristic of sociality in mammals is the ability to recognise conspecifics and discriminate between familiar and unfamiliar animals. In rodents, olfactory cues serve as the main source of such recognition and has been linked to dopaminergic reward centres in the brain, structures and regions responsible...
Abstract: To improve the efficacy of protected areas in conserving ecological processes, initiatives such as the megaparks for metapopulations strive to increase connectivity between small and often isolated protected areas. Increasing connectivity between protected areas may mediate the apparent impact of elephants on vegetation and promote regional population stability through the spatial structuring of their populations. This relies on asynchronous population dynamics between interconnect...
Abstract: This thesis investigated the use of a static acoustic data logger known as a Cetacean and Porpoise Detection (C-POD) device for monitoring two species of dolphins that occur in Mossel Bay, South Africa: the Indo-Pacific bottlenose dolphin, Tursiops aduncus, and the Indian Ocean humpback dolphin, Sousa plumbea. These two species have a near shore distribution which brings them into frequent contact with human activities such as boating, fishing, desalination plants and the onshore c...
Abstract: As a result of climate change, environmental temperatures across southern Africa are predicted to rise by up to 5˚C by 2070. Elephants may be particularly vulnerable to these changes. Their small surface area to mass ratio and lack of sweat glands may impair heat loss. However, it is not known how elephants respond to high environmental temperatures (above 35˚C), limiting our ability to predict the responses of elephants to climate change. My study assessed these responses for th...
Abstract: Reproduction is the process whereby an animal ensures the continuous existence of their genes in the population by procreation. Reproduction presents a series of obstacles for both males and females. Males have to ensure they are in peak physical condition in order to establish dominance and compete for the attention of the opposite sex. Females need enough energy to support their bodily needs whilst supplying energy to the growing foetuses and suckling young. The current thesis in...
Abstract: Savanna elephants currently inhabit some of the hottest environments in Africa. Because of climate change, these environments are likely to get hotter. Due to their large body size and small body surface area to volume ratio, elephants may face difficulties in dissipating heat. Despite this suggestion, we do not understand how elephants in their natural environment respond to present day climatic extremes, which limits our ability to predict how elephants may respond to climate cha...
Description: Thesis (PhD)--University of Pretoria, 2014.
Abstract: Mating systems are classifications of the outcome of individual strategies aimed at maximising reproductive success. These systems have two components; one describes how individuals socially relate and bond to mating partners and the other describes the genetic outcome of actual mating activities. Reproductive activity is under strong endocrine and behavioural regulation where inter-sexual discrepancies in the regulation of reproductive success have resulted in the majority of mamm...
Abstract: Aspects of the ecology of B. monticularis were studied with a view to the species' conservation. This investigation indicates that the present distribution is half that of the past distribution and that only one third of the original habitat remains uncultivated. It is estimated that this area could, theoretically, support 1435 rabbits. The shrubs, Pteronia erythrocaetha and Kochia pubescens constitute the bulk of the species' diet; grasses are included in the diet whenever rainfal...
Abstract: In most tropical river systems there has been a lack of integrated ecological research to investigate the dynamics and impacts of invasive species on recipient river systems. This is in sharp contrast to temperate river systems. This thesis investigated the nature, extent, and impact of Nile tilapia, Oreochromis niloticus (Linnaeus, 1758), on indigenous congenerics within the Limpopo River basin in northern South Africa. An integrated approach was adopted to gain a better understan...
Abstract: The migration of Southern Hemisphere humpback whales Megaptera novaeangliae between their feeding and breeding areas is considered a highly predictable and seasonal event. The west coast of Africa is host to Breeding Stock (BS) B, which has been divided into sub-stocks B1 and B2 based on different catch histories observed between Gabon in the north, and other stations to the south – a notion supported by recent regional genetic analysis, some samples of which were collected durin...
Abstract: Nectar-feeding birds must ingest copious amounts of water due to their liquid diet. Large volumes of preformed water in the dilute diet mean that birds feeding on these diets risk the loss of solutes in order to excrete this water. Previous studies have found that on dilute diets (
Abstract: Dyer Island is thought to host one of the most abundant populations of white sharks on the planet; this is often credited to the large (55 – 60,000) Cape fur seal colony at Geyser Rock. Yet relatively little work has ever been produced from the area. This may be attributed to the harshness in its location as a study site, exposed to wind and swell from west to east which limits research periods. This study accounts for over 220 hrs of manual tracking at Dyer Island with a further...
Abstract: African swine fever (ASF) is a highly contagious transboundary viral infection of domestic pigs that has serious socio-economic implications on people’s livelihood, international trade and food security. It is still a major limitation to profitable pig production and presently, it is threatening the pig industry internationally with current outbreaks in the Russian federation and the Caucasus. Since 1996, the disease has made major incursions into the West African sub-region. In ...
Abstract: The broad objective of the study is to examine mass change as related to other life history parameters of southern elephant seals Mirounga leonina at Marion Island. It has been argued that mass plays a fundamental role in their annual life cycle. This study investigates the reproductive investment and strategies of female southern elephant seals over a temporal scale using innovative sampling methods. Long term population studies are of great interest to life history studies as the...