Abstract: Amphibians have long been recognized as excellent indicators of both biological and ecological health of ecosystems, as they occupy many habitats and environments and have a diverse range of impacts on their immediate environments. It is thus important to investigate the critical habitat requirements, as well as the preferred environmental variables that are associated with different amphibian species in order to provide insight into conservation and management plans, and to predic...
Abstract: Conservation management approaches for elephants in southern Africa, and particularly in the Kruger National Park, have changed. Recently, Kruger’s managers adapted their approach from artificially manipulating elephant numbers to reinstating and embracing densitydependent processes that could limit or regulate the elephant population. However, few studies have evaluated whether changes in Kruger’s elephant management approach were effective in achieving the desired outcomes. T...
Abstract: Global climate change is expected to increase average surface temperatures by 1.5 to 4.5 °C by the end of the 21st century. Major variation in climatic conditions is predicted to occur, including more frequent droughts and heat waves as well as higher mid-summer temperatures. Water-deficit stress may lead to increased nitrogen levels in plants, which in turn may increase their suitability for insect herbivores. In addition, the higher nutritional quality of the insect herbivore di...
Abstract: The current study is about the evolution and the morphology of dung beetles, subfamily Scarabaeinae. The study includes the systematics of the tribe Canthonini and an exhaustive analysis of the morphological variation of male genitalia including species from the 11 tribes of the subfamily, mainly Canthonini, Ateuchini, Scarabaeini and Coprini. With the aim to go deep in the phylogenetic relationships of the tribe Canthonini, the largest of the subfamily Scarabaeinae, with 91 genera...
Abstract: The ecology and life history of the vlei rat, Otomys irroratus (Brants, 1827), were studied in a population on the Van Riebeeck Nature Reserve near Pretoria. Two main procedures were used to collect the basic information and material for the project. First, a permanent live-trapping grid was established where 333 animals were captured, marked, released, and recaptured over a period of 26 months, Second, snap-trapping and live-trapping were conducted elsewhere in the study area for ...
Abstract: Ground pangolins Smutsia temminckii are inconspicuous, mainly nocturnal mammals that occur at low population densities. As a result, there is scant information available on the ecology and physiology of this species. To date the handful of studies focussing on this species were centred in the mesic eastern regions of its range, with no attention being given to ecological and biological traits in arid environments. To address these data shortfalls, a study was undertaken in the Kala...
Abstract: The giant bullfrog, Pyxicephalus adspersus, is a large, explosive-breeding anuran from southern Africa, which spends most of the year buried in a state of torpor. In South Africa this species is considered to be Near-Threatened by habitat loss and other factors, especially in the densely human populated Gauteng Province. The aim of this thesis was to obtain essential outstanding information about the ecology of P. adspersus to contribute towards improved conservation management of ...
Description: Dissertation (MSc)--University of Pretoria, 2012.
Abstract: The status of honeybee pathogens and parasites in the Gauteng region of South Africa was examined by collecting adult honeybee and worker brood samples from 13 Apis mellifera scutellata apiaries. The prevalence of pathogens and parasites were compared per season between sedentary (permanently stationed colonies) and migratory (transportation of colonies for pollination purposes) apiaries. Honeybee pathogens (Acute bee paralysis virus (ABPV), Black queen cell virus (BQCV), Chronic b...
Abstract: Tropical forests are shrinking worldwide. This is mainly because human beings, in a bid to obtain a livelihood, have overexploited their timber and non-timber products. At Arabuko Sokoke Forest (ASF), Kenya, community-driven conservation projects have been initiated, to ensure that the people can draw a livelihood from this vital ecosystem without destroying it. Among the projects involved is apiculture in the vicinity of the forest. Although some studies have been carried out on v...
Abstract: Please read the abstract in the section 00front of this document
Abstract: Ungulate browsing and its ecological effects at plant, population, community, and ecosystem levels were addressed in a eutrophic southern African savanna. This was to test predictions of prevailing hypotheses, which are based on research in boreal and temperate forests. Changes in plant morpho-functional traits and population structure of a staple palatable species, Acacia nigrescens Miller were addressed over a two-year survey among vegetation stands with very different histories ...
Abstract: The pouched mouse, Saccostomus campestris Peters, 1846 from southern Africa shows a high degree of karyotypic variation where up to 16 variants (2n = 30–50) have been reported. This has led to a systematic uncertainty that the present study attempts to assess using: 1) cytochrome b (cyt b; 1077 bp) and 16S rRNA (528 bp) partial sequences; 2) G-banding cytogenetic data; and 3)geometric morphometric data of various views of the cranium and mandible. The results from these multidisc...
Abstract: Simulium chutteri is considered a major pest in South Africa and it has been estimated that it can potentially cause stock losses amounting to more than R88 million per annum. Although a larval control programme has been launched to control the pest, major outbreaks still occur, since major fitness traits such as longevity are ignored in the planning of control actions. To improve the control programme, the aim of this study was to study the longevity of S. chutteri females under v...
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...