Abstract: Southern Africa contains 58% of the world’s savannah elephant population, yet 72% of their range occurs outside of protected areas. It is, therefore, important to develop management guidelines that satisfy the needs of both elephants and people while maintaining environmental heterogeneity and ecosystem processes. Managing elephants as a metapopulation may provide the solution. The goal of this thesis was then to use a habitat-based approach to identify landscape characteristics ...
Abstract: No abstract available
Abstract: Killer whales are the oceans’ apex predator and are known to have important effects on ecosystems. At Subantarctic Marion Island, southern Indian Ocean, they have only been studied opportunistically, resulting in limited knowledge of their ecosystem impact here. This dissertation describes the prey and seasonal abundance, estimates the population size and assesses the predatory impact of killer whales on seals and penguins at Marion Island, using dedicated and opportunistic shore...
Abstract: This study provides the first quantitative analysis of the littoral and supralittoral arthropod assemblages of sub-Antarctic Marion Island. Seventeen mite species (126 203 individuals) from 11 families were found on the shore at Macaroni Bay. Three families dominated the assemblages in both abundance and diversity: the Hyadesiidae, Ameronothridae and Halacaridae. Six insect species from three orders were found on the shore. Species richness increased from one in the littoral, to fo...
Abstract: The conservation of biotic diversity is a growing challenge within southern Africa at the beginning of the 21st century. Growing populations and trends toward a questionable Western development model place demands on the use of land for food, fiber, and fuel production. The traditional establishment and use of formal conservation areas is being challenged against the needs of humans and the past unbalances created by colonial rule. Conservation areas, as isolated islands in a sea o...
Abstract: The inter- and intraspecific taxonomy of the genus Lepus is highly controversial. Since these animals play an important ecological role as prey species, their conservation is of high priority. A prerequisite for adequate management strategies is the precise knowledge of taxonomic borders and geographic distributions of the taxa in question. Especially in African hares the clear delimitations of the species and subspecies are still unresolved. In an attempt to obtain a clearer under...
Abstract: Please read the abstract in the section, 00front, of this document
Abstract: Please read the abstract in the 00front part of this document
Abstract: The micro frog, Microbatrachella capensis (Boulenger, 1910), is a Critically Endangered anuran found in fragmented marshland habitats along the southern coast of the Western Cape Province of South Africa. The genetic diversity between and within the remaining populations (Kenilworth, Grootwitvlei, Kleinmond, Lamloch, Hagelkraal, and Buffeljacht/Ratelrivier) of Microbatrachella capensis in the Western Cape Province of South Africa was assessed, sampling 12 specimens from each popula...
Abstract: Field-based mesocosm studies may be used as conceptual experiments to examine theoretical questions using the generated empirical data. A field-based Drosophilidae-nectarine mesocosm, comprising sun and shaded microclimate treatments arranged in a checkerboard design, was used in this thesis to examine four theoretical objectives. First, the efficacy of spatial analysis for detecting empirical pattern was examined. Natural variation weakened spatial structuring. However, hypothesis...
Abstract: Small populations of animals are vulnerable to the consequences of breeding within a closed group – inbreeding depression and genetic drift lead to reductions in genetic variability, which in turn can give rise to the amplification of deleterious traits. Traditionally, managers attempt to minimise these effects by controlling the genetic structure via a manipulation of the paternal line, in the case of rhinos usually by translocation of breeding and sub-adult bulls. This strategy...
Abstract: African honeybee workers, Apis mellifera scutellata can activate their ovaries under queenless conditions to produce male (haploid) offspring. In contrast, laying workers of the Cape honeybee, Apis mellifera capensis, produce female (diploid) offspring via thelytokous parthenogenesis. In the early 1990’s colonies of A. m. capensis were transported into the distribution area of A. m. scutellata (corresponding to the summer rainfall region of South Africa), leading to the “capens...
Abstract: The ant Pachycondyla analis (formerly Megaponera foetens, commonly known as the Matabele ant) is a widespread ponerine in sub-Saharan Africa. It feeds solely on termites of economic importance belonging to the sub-family Macrotermitinae. These termites are captured during organised raids on their nests and galleries. Previous studies mostly concentrated on certain aspects of the raiding behaviour and trail laying pheromones in this species. Thus the detailed raiding behaviour and c...
Abstract: The woodwasp Sirex noctilio is one of the most serious invasive pests of Pinus plantations in the southern hemisphere. Extensive control programs have been developed to manage this pest, of which biological control has been a major component. This thesis examined the factors that could influence the control of S. noctilio in South Africa. A critical comparison of S. noctilio infestations and control efforts throughout the southern hemisphere revealed that control has not been unifo...
This study explores the threats of climate change on agriculture and food security globally, focusing on Nigeria. Nigeria, as the most populous country in Africa, is highly vulnerable to the impacts of climate change on its agricultural sector. The research conducts a comprehensive literature review and synthetic analysis to identify the key factors that make Nigeria's food production systems susceptible to climate change. Nigeria's diverse climate, influenced by latitude, topography, win...