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Includes abstract. / Includes bibliographical references. / Declines and losses of amphibian populations are a global problem involving a complexity of interacting causes. Regardless of the fact that amphibians in Africa are among those predicted to be hit the hardest by anthropogenic global change, many species remain poorly studied. Capensibufo rosei, Rose's Mountain Toad, is a restricted range species that survives in a few small, isolated montane populations in the extreme south-western Cape of South Africa. A recent study of the genus revealed that C. rosei may in fact comprise several cryptic species, with a distinctive lineage potentially being confined to the Cape Peninsula. I test the hypothesis that breeding sites on the Peninsula form a single genetic lineage, but are distinct at a population level due to limited dispersal abilities and little if any gene flow.

Includes bibliographical references (leaves 87-101).

Golden moles are subterranean mammals endemic to sub-Saharan Africa and threatened by anthropogenic habitat loss. At present, little is known about the biology, taxonomy, distribution and severity of threats faced by many of these taxa. In an attempt to raise awareness of these elusive grassland flagship taxa, the Endangered Wildlife Trust's Threatened Grassland Species Programme (EWT-TGSP) identified the need for more information on the distributions and conservation status of four poorly-known golden mole taxa (Amblysomus hottentotus longiceps, A. h. meesteri, A. robustus, A. septentrionalis) that are endemic to the Grassland Biome, and which may be heavily impacted by anthropogenic habitat alteration in the Highveld regions of Mpumalanga Province. This study employed species distribution modelling to predict the distributional ranges of these taxa, and involved four main processes: (i) creating initial models trained on sparse museum data records; (ii) ground-truthing field surveys during austral spring/summer to gather additional specimens at additional localities; (iii) genetic analyses (using cytochrome-b) to determine the species identities of the newly-acquired specimens, as these taxa are morphologically indistinguishable; and (iv) refining the models and determining the conservation status of these Highveld golden moles. Initial species distribution models were developed using occurrence records for 38 specimens, based on interpolated data for 19 bioclimatic variables, continuous altitude data, as well as categorical spatial data for landtypes, WWF ecoregions and vegetation types. These initial models helped to effectively focus survey efforts within a vast study area, with surveying during the austral spring-summer of 2013-4 resulting in the acquisition of 25 specimens from across Mpumalanga, nine individuals of which (A. h. meesteri n = 2; A. septentrionalis n = 5; unknown n = 2) were captured in five new quarter-degree-squares (QDSs) where no previous golden moles have been recorded. Additionally, observed activity was also recorded in nine new QDSs (see Appendix 3), showing that the model refinement methods used (variable selection, auto-correlation, non-repeated versus cross-validated models, jackknife of variable importance and localities, independent data testing) were effective in locating golden mole populations. By using genetically-identified historical golden mole records, predictive distribution models were calibrated in maximum entropy (MaxEnt) software to focus ground-truthing efforts.

In this study, fish community structure as sampled by shore angling, trawling, boat-based line-fishing and seine netting was compared across the EEZ of South Africa, including sites in designated MPAs. Multivariate statistics were used to assess the extent to which MPAs represent the full range of fish communities in South African waters. Results show there is an increase in fish diversity from west to east along the South African coast.

Biofouling on recreational yachts is an important vector for marine invasive alien species (MIAS) in many countries. There are various characteristics of a vessel that make it more susceptible to hull fouling. Yachts in three Western Cape marinas were surveyed to assess extent of fouling, hull maintenance patterns, travel history and yacht-owner awareness of MIAS issues.

The Argentine Ant, Linepithema humile (Hymenoptera: Formicidae), is one of the world's most successful invasive species and invades undisturbed Fynbos habitats in South Africa, displacing native arthropod species and affecting interspecific associations. In order to assess the impact of Li. humile on native ant assemblages and associations between ants and myrmecophilous butterflies (Lepidoptera: Lycaenidae) on the western slopes of Table Mountain (Cape Town, South Africa), adult butterfly density was scored and distribution of food plants were assessed at two sites.

Includes bibliographical references. / The Northern Rockhopper Penguin Eudyptes moseleyi is listed as Endangered due to an estimated 57% decrease in breeding numbers over the past 37 years. Approximately 85% of the global population breeds at the Tristan da Cunha archipelago (Tristan, Inaccessible and Nightingale Islands) and nearby Gough Island in the central South Atlantic Ocean. The population on Gough Island declined by 50-60% between 1982 and 2005, but in the Tristan da Cunha archipelago the population trend over the last few decades is believed to be stable despite long-term human exploitation (particularly egg collection on Nightingale Island in recent years).This study compares aspects of the breeding biology on Gough Island (where population numbers are decreasing) and Nightingale Island (where numbers are thought to be stable) based on data gathered from five colonies in the 2012/13 and 2013/4 breeding seasons. On Nightingale Island, breeding success was 6.5% lower and 40-day old chick mass 47% less(implying poor juvenile recruitment)compared to on Gough Island. Poor foraging conditions for birds on Nightingale Island is the most probable explanation for these results, and future studies should focus on the foraging locations used by birds on both islands. Additionally, egg collection practices on Nightingale Island may have had a negative impact on the population, and I recommend that the temporary ban on egg-collection at Nightingale Island is made permanent. It is also possible that the population on Gough Island is no longer in decline, or is declining for reasons unrelated to breeding success; to verify this and confirm the findings of this study, future population trends and chick fledging mass on both islands should be monitored over the long-term.

The 75,000 ha area of Riemvasmaak, located north of the Orange River within the Northern Cape Province, is an important case study with regard to land restitution and livestock impacts upon arid rangelands hypothesized to be at disequilibrium. As part of a 'black spot' removal program during apartheid, about 1,500 people from Riemvasmaak were forcibly moved off their land in 1974. With many returning to the area in January 1995, Riemvasmaak represented the first successful land restitution case in post-apartheid South Africa. This study follows up on a long-term environmental monitoring project set up in 1995 and revisited in 2005 and early 2015 to determine the impact of the returnees on the vegetation and ecology of the region. It builds upon the repeat photography methodology utilized by Hoffman et al. (1995) and Hoffman and Todd (2010) in order to provide a robust and accessible measure of change in the herbaceous and woody components of the vegetation. The percentage cover of herbaceous and woody vegetation was visually estimated in repeat photographs from 27 photo stations for the years 1995, 2005, and 2015. The results of a linear mixed-effects model suggest that herbaceous vegetation decreased significantly from 1995 to 2005 (p< 0.001) and increased significantly from 2005 to 2015 (p< 0.001) while woody cover did not change significantly from 1995-2015. There was no difference in these trends between the three landform units assessed (rivers, sandy pediments and rocky slopes). Linear regressions utilizing size class and density of individuals for Acacia erioloba (Vachellia erioloba) indicated that there had been little recruitment over the period 1995-2015 in comparison to the period prior to the initial survey in 1995. Fifteen face-to-face interviews with livestock owners, herders, and the local Agricultural Collective in 2015 outlined the socioeconomic and cultural changes that had occurred in Riemvasmaak since 1995. One such change, a directive issued by the Riemvasmaak Municipality in 2009, that ownership of livestock would no longer be allowed within Municipality boundaries, resulted in the removal of livestock from Riemvasmaak in the years directly before 2015 and corresponded temporally with the rise in herbaceous cover seen in 2015.

Climate change is now considered to be one of the greatest threats to the persistence of biodiversity. Much work has focused on the potential for climatic shifts to alter species' ranges, phenology, physiology, and behaviour, addressing higher level units of biodiversity from populations to biomes. However, the potential effects of climate change on the most fundamental unit of biodiversity, intraspecific genetic diversity, has only recently received research attention. Studies to date suggest that the accelerated climatic changes we currently face could cause a loss of intraspecific diversity, hampering the ability of populations to respond to further environmental change. Amphibians are considered to be one of the most vulnerable taxa to climate change. The amphibians of the Western Cape of South Africa provide a powerful opportunity to study the impact of climate change on genetic diversity, as many are endemic, threatened, and generally considered to be poor dispersers, limiting their ability to respond to climatic changes through range shifts. This project had two aims: first, to explore the potential impact of climatic shifts on the genetic landscape of the endemic and Endangered western leopard toad, Sclerophrys pantherina, a species with a disjunct distribution on either side of the Cape Flats. Second, I aimed to test the hypothesis that climatic fluctuations drive genetic divergence, a mechanism which may explain the potential overlap of high diversity areas with areas of high climatic instability. Population genetic analyses supported the findings of previous genetic work on S. pantherina, that populations in the Cape Metropole and the Overstrand Municipality (to the west and east of the Cape Flats, respectively) are genetically distinct, and thus should be treated as separate conservation units. Higher haplotype diversity was identified in the populations in the Cape Metropole when compared with the Overstrand, highlighting the importance of urban habitat patches in harbouring diversity in the species. Distinct pockets of low haplotype diversity were identified at Observatory and Hout Bay, suggesting a lack of connectivity between these and adjacent breeding sites, likely due to urban-associated habitat fragmentation. Species distribution modelling revealed that the species could lose a substantial amount of climatically suitable space in its current area of occurrence by 2070. Furthermore, the degree of loss was not uniform across the species' distribution. The populations of the Cape Metropole were predicted to experience greater losses in climatically suitable space than populations in the Overstrand. Additionally, the change in climatic suitability between the mid-Holocene (6,000 years ago) and present as well as the change in suitability between future (2050 and 2070) and present were significant predictors of genetic diversity, where areas of the greatest change in suitability between time periods were associated with the highest genetic diversity. Future efforts to conserve the species should focus on establishing connectivity between breeding sites to allow for the rescue of genetically depauperate sites. Efforts to mitigate the drastic negative effects of climate change predicted by the species distribution models should prioritise the breeding sites in the Cape Metropole, which are both higher in diversity and at greater risk from climate change. Mitigation efforts will likely require the application of engineered solutions to promote the maintenance of suitable wetland habitat for the species.