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Pietermaritzburg, South Africa

Grobler J.P.,University of the Free State | Rushworth I.,Ezemvelo KwaZulu Natal Wildlife | Brink J.S.,Florisbad Quaternary Research | Brink J.S.,University of the Free State | And 4 more authors.
European Journal of Wildlife Research | Year: 2011

Hybridization between introduced and endemic ungulates, resulting from anthropogenic actions, has been reported for several species. Several studies of such events contain the common themes of extralimital movements, problematic phenotypic and genetic detection, and imperfect management. In southern Africa, the endemic black wildebeest (Connochaetes gnou) currently faces a serious threat of hybridization and introgression. This species survived near extinction and consequent genetic bottlenecks in the late 1800s and in the 1930s. Initiatives by private farmers followed by conservation authorities led to a dramatic recovery in numbers of this species. However, in an ironic twist, the very same advances in conservation and commercial utilisation which led to the recovery of numbers are now themselves threatening the species. Injudicious translocation has brought the species into contact with its congener, the blue wildebeest (Connochaetes taurinus), and in recent times, hybridization between the species has occurred at numerous localities in South Africa. Consequently, a significant proportion of the national black wildebeest population potentially carries a proportion of introgressed blue wildebeest genetic material. We discuss completed and ongoing attempts to find molecular markers to detect hybrids and highlight the difficulty of detecting advanced backcrosses. Additional avenues of research, such as work on morphology (cranial and postcranial elements), estimating of the probability of introgression and modelling of diffusion rates are also introduced. In addition to the difficulty in detecting hybrid animals or herds, the lack of consensus on the fate of hybrid herds is discussed. Finally, in an environment of imperfect information, we caution against implementation of management responses that will potentially induce a new genetic bottleneck in C. gnou. © 2011 Springer-Verlag. Source

Stone O.M.L.,University of New South Wales | Laffan S.W.,University of New South Wales | Curnoe D.,University of New South Wales | Rushworth I.,Ezemvelo KwaZulu Natal Wildlife | Herries A.I.R.,La Trobe University
Primates | Year: 2012

We report the current species distribution and population estimate for the chacma baboon (Papio ursinus) in KwaZulu-Natal Province (KZN), South Africa, based on an analysis of estimated area of occupancy and estimated home range size. This estimate suggests a total population size of approximately 11,000 individuals for KZN. Much of the province is uninhabited, with a density in occupied areas of approximately 1. 8 animals per km2. The current population size may be more than an order of magnitude smaller than historical population size. Chacma baboons now exhibit a highly fragmented and discontinuous distribution in KZN, with 58% of the population residing within protected areas, and more than half of these troops reside in areas >1,500 m above average sea level. The small population and highly fragmented distribution of chacma baboons in KZN, combined with rapidly increasing human population size and transformation of natural habitat, suggest this species requires greater conservation attention. © 2012 Japan Monkey Centre and Springer. Source

Di Minin E.,University of Kent | Di Minin E.,University of Helsinki | Hunter L.T.B.,Panthera | Hunter L.T.B.,University of KwaZulu - Natal | And 5 more authors.
PLoS ONE | Year: 2013

The ideal conservation planning approach would enable decision-makers to use population viability analysis to assess the effects of management strategies and threats on all species at the landscape level. However, the lack of high-quality data derived from long-term studies, and uncertainty in model parameters and/or structure, often limit the use of population models to only a few species of conservation concern. We used spatially explicit metapopulation models in conjunction with multi-criteria decision analysis to assess how species-specific threats and management interventions would affect the persistence of African wild dog, black rhino, cheetah, elephant, leopard and lion, under six reserve scenarios, thereby providing the basis for deciding on a best course of conservation action in the South African province of KwaZulu-Natal, which forms the central component of the Maputaland-Pondoland-Albany biodiversity hotspot. Overall, the results suggest that current strategies of managing populations within individual, small, fenced reserves are unlikely to enhance metapopulation persistence should catastrophic events affect populations in the future. Creating larger and better-connected protected areas would ensure that threats can be better mitigated in the future for both African wild dog and leopard, which can disperse naturally, and black rhino, cheetah, elephant, and lion, which are constrained by electric fences but can be managed using translocation. The importance of both size and connectivity should inform endangered megafauna conservation and management, especially in the context of restoration efforts in increasingly human-dominated landscapes. © 2013 Di Minin et al. Source

Traynor C.H.,Wildlife and Environment Society of South Africa | Kotze D.C.,University of KwaZulu - Natal | Mckean S.G.,Ezemvelo KwaZulu Natal Wildlife
Bothalia | Year: 2010

In South Africa, wetland plants have been used for centuries and they continue to be harvested for subsistence and commercial purposes. Fibres for crafts are collected by cutting the aboveground parts. KwaZulu-Natal is one of the major basket-producing regions in southern Africa and at least twenty-two species of wetland plants are harvested for crafts. A literature review of the harvested species revealed that the impacts of cutting have only been extensively investigated for Phragmites australis (Cav.) Steud. and Juncus kraussii Hochst. The review suggested that, where plants display strong seasonal aboveground productivity patterns, cutting should take place after shoot senescence and before new shoot emergence to minimize damage to plants. Cutting in the short term could increase the density of green stems. However, in the long term in Phragmites australis, it may deplete the rhizome reserves and reduce the density of useable (longer and thicker) culms. The opportunity for sustainable harvests was investigated by considering the geographic distribution, whether species are habitat specific or not, and local population sizes of the craft plants. Juncus kraussii is of the greatest conservation concern. Ecologically sustainable wetland plant harvesting could contribute to the wise use of wetlands, an approach promoted nationally and internationally. Source

Kyle R.,Ezemvelo KwaZulu Natal Wildlife
African Journal of Marine Science | Year: 2013

The catches of the traditional fish traps in the Kosi Bay estuarine lakes were monitored over a 30-year period from 1981 to 2010. Monitoring data were used to provide estimates of, and insights into, catch size and species composition as well as seasonal and annual cycles of catch abundance. Over 1.2 million fish, comprising 43 species and 23 families, were estimated to have been caught during the study period. Tag-and-release data were used to estimate the impact of trap fishing on fish stocks and comparisons were made with recreational fishing to indicate overall fishing pressure and the sustainability of the fishing. Trap numbers remained fairly similar from the first year of monitoring (1981) until 1994, but thereafter they more than trebled by 2001; although numbers decreased after this, they remained well above earlier levels. During this period, recreational angling was an important factor, and gillnetting - both legal and illegal - added to the fishing pressure. Information from the fish trap monitoring, together with results from fish mark and recapture studies, suggest a very high, and possibly unsustainable, catch rate that requires management intervention to return them back to historical and sustainable levels. © 2013 Copyright NISC (Pty) Ltd. Source

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