Feeding ecology, space use and habitat selection of elephants in two enclosed game reserves in the Eastern Cape Province, South Africa
- Authors: Roux, Candice
- Date: 2006
- Subjects: Shamwari Game Reserve (South Africa) , Kwandwe Game Reserve (South Africa) , Elephants -- South Africa -- Eastern Cape , Elephants -- Ecology -- South Africa -- Eastern Cape , Elephants -- Feeding -- South Africa -- Eastern Cape , Elephants -- Nutrition -- South Africa -- Eastern Cape , Elephants -- Behavior -- South Africa -- Eastern Cape , Elephants -- Habitat -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5699 , http://hdl.handle.net/10962/d1005385 , Shamwari Game Reserve (South Africa) , Kwandwe Game Reserve (South Africa) , Elephants -- South Africa -- Eastern Cape , Elephants -- Ecology -- South Africa -- Eastern Cape , Elephants -- Feeding -- South Africa -- Eastern Cape , Elephants -- Nutrition -- South Africa -- Eastern Cape , Elephants -- Behavior -- South Africa -- Eastern Cape , Elephants -- Habitat -- South Africa -- Eastern Cape
- Description: The development of small (<300 km²), private game reserves has become a trend, not only in the Eastern Cape Province, but also elsewhere in South Africa as a result of a shift in land use practise from agriculture to ecotourism. The resultant re-introduction of elephants to many of these reserves has lead to management concerns because of the limited research on small reserves regarding their impact on the vegetation. In this study I assessed the space use, habitat selection, diet and impact of two elephant populations on the vegetation in the Eastern Cape Province between February 2004 and March 2005. Home range sizes were calculated using the kernel utilization distribution method. Home range sizes for elephants on Kwandwe were significantly larger during summer than winter (p<0.05). There was no significant difference between the home range sizes of the herds and males within a season and during summer the elephants utilized about 75 % of the reserve and only 54 % during winter. On Shamwari, the herd utilized about 92 % of the reserve during summer and 83 % during winter; while the males utilized 76 % of the reserve. Core areas for both elephant populations shrank from summer to winter and were concentrated around the permanent water sources on each reserve. Habitat selection was assessed using χ² tests and Bonferroni confidence intervals. On Kwandwe, there was a significant difference between observed and expected use of vegetation types (p<0.05) and karroid shrubland was strongly avoided by both herds during summer and winter. The preferred vegetation types of the males ranged from relatively open (short euphorbia thicket, bushclump karroid thicket and karroid shrubland) to completely open (old lands). On Shamwari, subtropical thicket, bontveld and montane grassland were avoided; while primary and secondary acacia thicket, riverine thicket and cultivated lands were preferred. The predominant vegetation type in the home ranges of herds on Kwandwe and Shamwari was subtropical thicket. The diet was assessed by direct observations over two seasons and dietary preferences were calculated. There was a significant difference in the frequency of occurrence of plants in the diet on the two reserves (p<0.05) and no significant effect of time of day or season (p>0.05). Seventeen woody plant species were utilized on Kwandwe and 23 species were utilized on Shamwari. Grass constituted a significantly greater percentage of the diet in summer than winter (p<0.05). Elephants on Kwandwe showed a selective preference for Ozoroa mucronata, Pappea capensis and Acacia karroo; while on Shamwari, A. karroo was selected. Transects were conducted in two different vegetation types on each reserve so as to assess the impact of elephant on the vegetation and damage scores were then calculated from these data. There was no significant effect of vegetation type or elephant density on mean damage scores in Kwandwe (p>0.05). Five hundred and seventy-eight plants were assessed in the subtropical thicket vegetation type and 225 plants were assessed in the savanna-type vegetation, with more than half the trees showing low levels of damage that could not only be attributed to elephants. Mean damage was highest for Portulacaria afra and Pappea capensis in subtropical thicket and for Rhus spp. in the savanna-type vegetation. On Shamwari, 408 plants were assessed in subtropical thicket and 215 in the savanna-type vegetation, with more than 70 % of trees showing low levels of damage. There was a significant effect of plant species and elephant density on the mean damage scores in subtropical thicket, with Aloe ferox showing more damage than the other plant species (p<0.01). In the savanna-type vegetation, A. karroo was the most severely damaged. Overall, damage was greater in the thicket vegetation type compared to the more open vegetation type on both reserves.
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- Date Issued: 2006
Elephant impacts on plant diversity and structure in the Shamwari Private Game Reserve
- Authors: Halvey, Andrew Lloyd
- Date: 2024-04
- Subjects: Elephants -- Nutrition -- South Africa -- Eastern Cape , Elephants -- Habitat -- South Africa -- Eastern Cape , Shamwari Game Reserve (South Africa)
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/63777 , vital:73597
- Description: Many African landscapes rely on processes such as fire, tree-fall and drought in addition to herbivores to initiate change across the landscape. In the Eastern Cape, elephant have a significant impact on the community structure and diversity of the vegetation they live in. This is most likely the case for the Albany Valley Thicket and azonal riparian vegetation of Shamwari Private Game Reserve, where browsing animals, particularly megaherbivores like the black rhinoceros and elephant, are the main cause of defoliation. The presence of large herbivores creates challenges when it comes to long-term sustainability and biodiversity of the vegetation in Shamwari. Vegetation monitoring provides essential information for effective management of megaherbivores not only in Shamwari but in many other similar reserves. The aim of this study was to design a monitoring plan for the Albany Valley Thicket and riparian vegetation in Shamwari using available vegetation metrics. The vegetation was measured in permanent plots (90 m line intercept analysis per plot) in the Albany Valley Thicket and riparian vegetation of Shamwari. Plot selection was based on thicket structural integrity using NDVI score as a proxy. In all plots, thicket structure was assessed using canopy heights measured every 50 cm along the line. Detrended correspondence analysis of the species abundance data suggested three distinct structural and compositional vegetation states for thicket and riparian vegetation: dense, intermediate and open. Significant relationships between NDVI and vegetation structural metrics across the condition states indicated that NDVI could be used as a proxy for vegetation condition. Vegetation compositional metrics, however, were not always correlated to NDVI and determining species diversity for the vegetation presents additional information useful for monitoring. The monitoring recommended for the reserve is to evaluate vegetation structural integrity annually in summer using NDVI. Areas of change could then be measured for diversity as well as for change in the abundance of selected plant indicator species. This information should be used to initiate management actions if unwanted change has occurred. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2024
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- Date Issued: 2024-04