Academic Wits Research Outputs (All submissions)
Permanent URI for this collectionhttps://hdl.handle.net/10539/36827
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Item Land-cover change in the Kruger to Canyons Biosphere Reserve 1993-2006): A first step towards creating a conservation plan for the subregion.(Academy of Science of South Africa (ASSAf), 2010-07) Coetzer, K.L.; Erasmus, B.F.N.; Witkowski, E.T.F.; Bachoo, A.K.This paper is a first step towards a conservation plan for the Kruger to Canyons Biosphere Reserve K2C) on the South African Central Lowveld, quantifying the historical land-cover trends 1993-2006). During the analysis period, 36% of the biosphere reserve BR) underwent land-cover change. Settlement areas increased by 39.7%, mainly in rural areas, becoming denser, particularly along roadways. Human-Impacted Vegetation increased by 6.8% and Intact Vegetation declined by 7.3%, predominantly around settlement areas, which is testament to the interdependency between rural communities and the local environment. However, settlement expansion exceeded the rate of rangeland growth; in the long term, this may raise questions for sustainable resource extraction. Similarly, the block losses of intact vegetation are of concern; issues of fragmentation arise, with knock-on effects for ecosystem functioning. In the economic sector, agriculture increased by 51.9%, while forestry and mining declined by 7.1% and 6.3%, respectively. The future of these three sectors may also have significant repercussions for land-cover change in the BR. The identification of historical drivers, along with the chance that existing trends may continue, will have important implications for biodiversity protection in this landscape. Applied within a conservation-planning framework, these land-cover data, together with economic and biodiversity data, will help reconcile the spatial requirements of socio-economic development with those of conservation.Item Feeding preferences of Oxpeckers in Kruger National Park, South Africa.(AOSIS OpenJournals Publishing AOSIS (Pty) Ltd, 2015-11) Ndlovu, M.; Combrink, L.Oxpeckers reduce tick loads on ungulate hosts, but they are also known to feed on and exacerbate wounds. An understanding of the feeding behaviours and host preferences of these birds is important since they serve as agents of tick control on both domestic and wild ungulates. We conducted an observational study at two sites within the Kruger National Park in South Africa, exploring the feeding preferences of both Red-billed and Yellow-billed Oxpeckers. Oxpeckers’ host preferences, body-location preferences on different hosts, prevalence of feeding and non-feeding behaviours, and frequency of tolerance versus rejection in different hosts were determined. It was found that Yellow-billed Oxpeckers had a smaller range of hosts – typically larger-sized ungulates – and that Red-billed Oxpeckers diversify to smallersized ungulate hosts when in competition with Yellow-billed Oxpeckers. Body-location preferences were generally consistent across sites and across host species. Tick feeding and other host-feeding behaviours (around the eyes, nose, mouth and ears, and anogenital areas) were fairly common. Only six incidents of wound feeding, from a total of 855 observations, were recorded. Tolerance by an ungulate host species was not related to Oxpeckers’ host preferences, suggesting that other factors such as ungulate body size, tick species and tick stages on the host animal may play a significant role in the feeding preferences of Oxpeckers. Conservation implications: It is important to study Oxpeckers’ behavioural feeding preferences so as to better understand their ecology and present distribution, and to determine where they can be reintroduced in future. Reintroduction not only helps with the proliferation of Oxpeckers, but also benefits ungulate hosts through ectoparasite removal and the subsequent control of tick-borne diseases.Item Elephant movement patterns in relation to human inhabitants in and around the Great Limpopo Transfrontier Park.(AOSIS OpenJournals Publishing AOSIS (Pty) Ltd, 2015-11) Cook, R.M.; Henley, M.D.; Parrini, F.The presence of humans and African elephants (Loxodonta africana) in the Great Limpopo Transfrontier Park can create situations of potential human–elephant conflict. Such conflict will likely be exacerbated as elephant and human populations increase, unless mitigation measures are put in place. In this study we analysed the movement patterns of 13 collared adult African elephants from the northern Kruger National Park over a period of eight years (2006–2014). We compared the occurrence and displacement rates of elephant bulls and cows around villages in the Limpopo National Park and northern border of the Kruger National Park across seasons and at different times of the day. Elephants occurred close to villages more often in the dry season than in the wet season, with bulls occurring more frequently around villages than cows. Both the bulls and the cows preferred to use areas close to villages from early evening to midnight, with the bulls moving closer to villages than the cows. These results suggest that elephants, especially the bulls, are moving through the studied villages in Mozambique and Zimbabwe at night and that these movements are most common during the drier months when resources are known to be scarce. Conservation implications: Elephants from the Kruger National Park are moving in close proximity to villages within the Great Limpopo Transfrontier Park. Resettlement of villages within and around the park should therefore be planned away from elephant seasonal routes to minimise conflict between humans and elephants.Item Spatially nested niche partitioning between syntopic grazers at foraging arena scale within overlapping home ranges.(Ecological Society of America, 2015-09) Owen-Smith, N.; Martin, J.; Yoganand, K.Niche separation among species with similar resource requirements can be expressed at various spatiotemporal scales, from the resource components selected at feeding sites to habitat and home range occupation and ultimately geographic distribution ranges. African large herbivores present a challenge to niche theory because multiple species commonly overlap both spatially and in vegetation components consumed. Aided by GPS telemetry, we investigated the space use patterns of two large grazers that are frequently associated in mixed-species aggregations. Specifically, we compared a generalist grazer with hindgut fermentation (plains zebra) with a similar-sized grazing ruminant (blue wildebeest) in west-central Kruger National Park, South Africa. We found that herds of the two species overlapped substantially in the home ranges that they occupied, but exploited spatially distinct foraging arenas for periods lasting several days or weeks within these ranges. Moreover, wildebeest and zebra differed in duration of settlement, extent of areas occupied during settlement, consequent exploitation intensity per unit area, proportion of time spent within foraging arenas relative to roaming interludes, and movement rates while within these arenas. In particular, wildebeest herds concentrated within small areas for prolonged periods, while zebra herds used more foraging arenas but exploited them for briefer periods. Both species overlapped substantially in habitat use, although wildebeest more strongly favored gabbro uplands and sodic sites presenting short grass lawns while zebra made greater use of areas with a taller grass cover. Hence resource partitioning was expressed mainly through behavioral distinctions in patch exploitation at foraging arena scale rather than in home range or habitat separation. Although zebra may have been partially excluded from the grasslands kept short by wildebeest, these sites formed only a small part of the wider ranges utilized by zebra, thereby restricting the competitive consequences. Hence spatially nested resource partitioning of this form contributes to the coexistence of these two grazers, and may be a mechanism enabling niche separation among other species.