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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The conservation and management of freshwater fishes in the Greater Addo Elephant National Park /

Traas, Graham Ronald Louis. January 2009 (has links)
Thesis (M.Sc. (Ichthyology & Fisheries Science)) - Rhodes University, 2009.
2

Vulnerability, irreplaceability and reserve selection for the elephant-impacted flora of the Addo National Elephant Park, Eastern Cape, South Africa

Johnson, Catherine Fiona January 1998 (has links)
The Addo Elephant National Park (AENP) is the only existing national park situated in succulent thicket. This unique veld type is endemic to the Eastern Cape, and forms an important centre of endemism for small succulents and geophytes which comprise the subdominant component of the vegetation. It is regarded as the most threatened vegetation type in the Eastern Cape, as much of it has been severely degraded by farming activities and its rate of regeneration is very low. Thus the AENP represents an important sanctuary for certain species. However, large herbivores, particularly elephants, pose a further threat to the vegetation, and areas from which elephants have been excluded in the park (botanical reserves) have been shown to be more speciesrich than the surrounding vegetation. Most elephant-impact studies have focussed on the large shrub component of the vegetation, and only preliminary studies have been done in AENP to date. As the elephant population continues to grow, there is pressure to utilise the botanical reserves to increase the amount of available grazing. It is thus important that the botanical reserve system be highly effective and efficient in terms of area. Existing botanical reserves were established ad hoc and are therefore not necessarily optimal in this regard. An iterative reserve-selection algorithm was used to maximise plant species conservation in the most efficient area.
3

Factors Influencing Travel Order as Proxy for Leadership and Trade-offs in Activity Budgets in Lactating and Nonlactating African Savanna Elephants

Wisniewska, Malgorzata 01 December 2011 (has links)
Nutritional and energetic needs of female mammals depend upon size or reproductive investment and shape individual activity budgets and behavioral patterns. To maximize nutritional and energetic intake females may increase time allocated to foraging or access resources through risk-prone behaviors, represented as aggression or leadership. Conversely, to minimize nutritional and energetic spending females may engage in risk-averse activities such as resting or nonaggressive social interactions. Females with the highest needs should exhibit activities and behaviors that facilitate the greatest nutritional and energetic returns or highest metabolic savings. The propensity for risk-prone behaviors may be greater among older as well as lactating females. Older individuals tend to be larger and more experienced than younger conspecifics. Moreover, lactating females are under substantially greater energetic, nutritional and water stresses than nonlactating individuals. Therefore, to fulfill greater nutritional and energetic needs, older and lactating females may allocate more time to foraging or rest or be more assertive during search for and defense of resources. I assessed the relative effects of age, reproductive condition and sex of nursing offspring on activity budgets, the frequency of risk-prone and risk-averse behaviors such as leadership propensity, and chemosensory inspection of the surroundings in female African savanna elephants (Loxodonta africana africana). To quantify activities and behavioral patterns I used focal animal sampling with continuous recording. I determined leadership by the position in a mobile herd, where the first and last positions were considered as ends, and the center was considered as a middle position. I discovered that older females stood more, were more aggressive, socialized less and traveled closer to the end of a traveling group than younger females. Females that were lactating spent more time foraging, were more aggressive and engaged in nonaggressive social interactions less frequently than their nonlactating conspecifics. Finally, females nursing female calves spent more time foraging than females nursing male calves, but the latter spent more time nursing and standing. These results elucidate how individual nutritional and energetic needs influence the activity budgets as well as the propensity to exhibit risk-prone and riskaverse behaviors in female elephants and thus add to a body of work examining mammalian female activity budgets shaped by individual differences such as age and reproductive condition.
4

Changes in diet resource use by elephants, Loxodonta Africana, due to changes in resource availability in the Addo National Park

Du Toit, Jana January 2015 (has links)
Animals are restricted in their diets by several factors, most notably the availability and quality of resources. Variation in resource availability causes herbivores to shift their diets seasonally and spatially. Elephants (Loxodonta africana), are known to have extensive impacts on plant communities, altering ecosystem functioning and causing a decline in biodiversity. In enclosed areas, these impacts are increased leading to a decline in resource availability and presumably resource quality. In the Addo Elephant National Park, the Main Camp section has a history of high elephant impacts and therefore reduced resource availability. Whereas, the recently added Colchester section has greater resource availability, due to the absence of elephants in this section since the fencing of the Park. This study investigated the changes in diet (diet breadth, preference and diet quality) of elephants due to an increase in resource availability. Three alternative hypotheses were contrasted: 1) elephants as generalist foragers, 2) elephants as optimal foragers, or 3) elephants learning foraging behaviour. Using microhistological analysis, the diets of elephants were described over five sampling periods (August 2010 – February 2014) in both sections. Forage availability was estimated using a modified line-intercept method, and was used to determine changes in preference by relating forage availability to use. In the Colchester section the diet breadth of elephants increased, and was coupled with a high initial variation between the diets of elephants, which decreased in subsequent sampling periods. This supported the elephants learning foraging behaviour hypothesis. However, there was no increase in diet preference by elephants in the Colchester section, which supported the elephants as generalist foragers hypothesis. There was also no difference in the diet quality of elephants in the Main Camp and Colchester sections, which did not support any of the three hypotheses. The elephants learning foraging behaviour hypothesis is proposed to be the link between the alternate two hypotheses, and given enough time, either of the two could be supported. The lack of difference in preference and diet quality between elephants in the Main Camp and Colchester sections is hypothesised to be due to the population level (not measured for individuals) at which these were measured. Microhistological analysis of faeces was used to describe the diet of elephants, which was compared to the diet described by DNA metabarcoding. Microhistological analysis is a traditional, favoured technique used in describing the diet of wild herbivores, whereas DNA metabarcoding is a relatively new and untested technique. These two techniques have not yet been compared in the diet of megaherbivores. Results indicated that microhistological analysis identified significantly more grass in the diet of elephants, than DNA metabarcoding did, which was expected as previous studies also found overestimation of grasses. Microhistological analysis identified more plant families in the diet of elephants, than DNA metabarcoding. Most of the differences between the two techniques can be attributed to the difference in taxonomic resolution, which was due to the lack of a complete reference collection for DNA metabarcoding. Although either of the two techniques can be used to describe the diet of elephants, the most reliable results would be obtained when using both techniques. The findings of this study suggest that due to the high initial variation between the diets of elephants, with an increase in resource availability, the impacts will also initially be highly varied. This suggests that identifying plant species to monitor elephants impacts initially will be difficult. However, important plant species, or those known to be vulnerable to elephants impacts should be carefully monitored initially and monitoring should not only occur annually, but also seasonally.
5

Elephant feeding behaviour and forage offtake implications in the Addo Elephant National Park

Lessing, Joan Susanna January 2007 (has links)
Elephants, as megaherbivores and keystone species have major impacts, both positive and negative, on ecosystems such as the Subtropical Thicket of the Eastern Cape. The feeding behaviour of elephants was quantified so as to firstly determine the preferred feeding heights of elephants, and secondly to determine if feeding behaviour and impact varies with size and sex. The preferred feeding height was determined with experimental feeding trials. Feeding height, pluck size, foraging rate and the proportion of plant material discarded were used to test for differences between elephants of different sizes and sexes in the Addo Elephant National Park. The influence of plant growth form on sex-specific feeding was also considered. Elephants preferred to feed at the lowest heights. The preferred feeding height was not related to body size. A wide range of feeding heights was recorded including and extending beyond, both the preferred and maximum feeding height of co-existing indigenous browsers. There was no difference in feeding height between the sizes and sexes. In free ranging conditions, all elephants fed at levels above the preferred foraging height when browsing. There was no difference in feeding behaviour between the different sized elephants, or between males and females. Adult elephants however exhibited larger ranges of feeding heights, pluck sizes, foraging rates and intake rates, including the maximum and minimum values. Growth form influenced the feeding of male and female elephants differently. Elephant feeding behaviour appears to limit opportunities for resource partitioning by way of feeding height segregation. Elephants are also capable of dominating the browse resources available to co-existing browsers by removing large amounts of forage at lower heights. The extent of elephant impact seems to be comparable between sizes and sexes, although adults and especially larger males are often able to use foraging opportunities that other elephants can not effectively utilize. Findings suggest that the feeding heights of elephants are determined by forage availability and reflect the diet in terms of browse or grass. The findings can be used, together with browse inventory methods, to determine browse resources available to elephants, and can also be used to develop monitoring tools to assess the impacts of elephants on plants.
6

A critical analysis of the socioeconomic impact assessments of the Addo Elephant National Park

Rose, Matthew Calvin January 2011 (has links)
Impact assessment is a requirement for development in many countries across the globe, seeking to inform the decision-maker as to the environmental, social and economic impact of an ongoing or proposed project. Socioeconomic impact assessment (SEIA) is a means of informing decision-makers as to the socioeconomic effects a project could have, or is having, thus contributing to informing adaptive management practices. However, the tendency of socioeconomic impact assessment to highly quantitative economic methods of analysis raises the question of whether the desired results are achieved by the process. The purpose of the research was to determine whether highly quantitative forms of economic analysis are suitable for measurement of impacts in a social context where distributive as well as net impact is important; to critically analyze the method utilized in achieving highly quantitative economic impact assessment results; and lastly to draw conclusions and make recommendations regarding the efficacy of monitoring processes used to inform adaptive management practices. The research was conducted by means of a case study focusing on three SEIAs carried out on the same entity, namely the Addo Elephant National Park. Managed by South African National Parks (SANP), it began expanding its borders in the early 2000s. Funded by the World Bank, SANP was required to carry out a comprehensive Strategic Environmental Assessment (SEA) in 2003 to ensure the expansion did not have negative environmental, social and economic repercussions, and where such consequences were unavoidable, to ensure that mitigation and management thereof was informed by useful monitoring exercises. Given the need for resettlement and issues of economic distributive concern raised in the 2003 SEA, the three socioeconomic impact assessments conducted from 2005 – 2010 as part of the ongoing monitoring exercises formed an ideal framework for answering the primary research questions. The findings indicate that despite consistent terms of reference, different assessors interpret mandates from the commissioning body in different ways, leading to varied applications of the same theory, some methodologically better than others. Economic multiplier analysis was found to be inadequate as a measure of the distributive effects of economic impact. Moreover, a lack of consistency, accountability and transparency in the monitoring process led to three sets of results that were incomparable over time and thus inadequate as a means to inform adaptive management practices. Asymmetries of and between power and expertise in the commissioning body and the assessors led to breakdowns of the assessment process in terms of accountability and integrity and resulted in a failure to properly define the scope of the study and measure the relevant indicators. The following recommendations were made: that the economic multiplier method be complemented by additional methods of analysis when utilized in disparate social contexts where distribution of economic benefit is important; that monitoring practices be systematized at an early stage of the process to ensure comparable results useful in informing ongoing management practices; and that what an assessment measures and how it measures it be clarified with reference to an objective source. Finally, the number of factors for consideration in any impact assessment means that measurement of the full picture suffers resource constraints, emphasizing the need for impact assessment oversight to recognize the deficiencies of the process whilst still acknowledging that ‘some number is better than no number’.
7

Opportunity and constraint : historicity, hybridity and notions of cultural identity among farm workers in the Sundays River Valley

Connor, Teresa Kathleen January 2007 (has links)
This thesis focuses on relationships of opportunity and constraint among farm workers in the Sundays River Valley (SRV), Eastern Cape Province. Relationships of 'constraint' include those experiences of displacement and forced removal and war, including forced removals by the apartheid state in 1960 and 1970. Relationships of 'opportunity' include the ways in which residents in the SRV have contested their experiences of upheaval and domination, and the formation of a regional sense of place and belonging/ investigate how farm workers actually draw elements of locality and identity from their experiences of upheaval, and how displacement bolsters feelings of belonging and place. Instead of viewing displacement as a once-off experience, this thesis investigates displacement in historical terms, as a long-term, 'serial' experience of human movement, which is continued in the present- specifically through the creation of the Greater Addo Elephant National Park. I concentrate on developing a spatialised and cultural notion of movemenUplacement. 'Place' is investigated as a term that refers to rather indeterminate feelings of nostalgia, memory and identity, which depend on a particular connection to territory (ie: 'space'). I emphasise that elements of place in the SRV are drawn from and expressed along dualistic lines, which juxtapose situations of opportunity and constraint. In this way, farm workers' sense of connection to farms and ancestral territory in the SRV depends on their experiences of stable residency and work on farms, as well as their memories of removal from land in the area. I emphasise that those elements of conservatism (expressed as 'tradition' and Redness) among Xhosa-speaking farm workers are indications of a certain hybridity of identity in the region, which depend on differentiation from other groups (such as so-called 'coloured' farm workers and 'white' farmers), as well as associations between these groups. This thesis lays emphasis upon those less visible and definable 'identities' in the Eastern Cape Province, specifically by shifting focus away from the exhomeland states of the Ciskei and Transkei, to more marginal expressions of identity and change (among farm workers) in the Province. I point out that labourers cannot solely be defined by their positions as farm workers, but by their place and sense of cultural belonging in the area. In this sense, I use the idea of work as a loaded concept that can comment on a range of cultural attitudes towards belonging and place, and which is firmly embedded in the private lives of labourers - beyond their simple socio-economic conditions of farm work. I use Bourdieu's conception of habitus and doxa to define work as a set of dispositions that have been historicised and internalised by workers to such an extent, that relationships of domination are sometimes inadvertently obscured through their apparent 'naturalness'. Moreover, I point out that work can be related to ritualised action in the SRV through the use of performance and practice-based anthropological theory. Both work and ritual are symbolic actions, and are sites of struggle within which workers express themselves dualistically. Rituals, specifically, are dramatic events that combine disharmonious and harmonious social processes - juxtaposing the powerlessness of workers (on farms), and the deep sense of belonging and place in the SRV. I argue that the deep historical connections in the SRV have largely been ignored by conservationists in the drive to establish new protected zones (such as the Greater Addo Elephant National Park), and that a new model of shared conservation management is needed for this Park.
8

The conservation and management of freshwater fishes in the Greater Addo Elephant National Park

Traas, Graham Ronald Louis January 2009 (has links)
Freshwater fish are the most imperilled vertebrate group with a high projected extinction rate. In general, the world's freshwater ichthyofauna is in a poor state and is threatened by habitat destruction, pollution, the effects of alien species, damming, water extraction and overfishing. Within South Africa, legislation supporting the conservation of aquatic habitats and its associated fauna is strong, but there is a lack of capacity and poor co-ordination between agencies responsible for the conservation and management. The Greater Addo Elephant National Park (GAENP) includes the upper catchments of five of the Sundays River tributaries. Since the optimal method of conserving freshwater aquatic biota is to conserve the headwaters of either the river or its tributaries, there is an opportunity to conserve the native ichthyofauna of the Sundays River system. The principal objective of this thesis was, therefore, to provide information pertinent to the conservation and management of the fishes in the Sundays River system. Sixteen species of freshwater and estuarine fish were sampled, of which eight were alien. Species composition in each of the rivers, with the exception of the Kabouga River, had changed significantly from previous studies. The distribution ranges of several indigenous species had reduced, while those of some alien species was increased. Two species not previously recorded, Labeo capensis and Gambusia affinis, were sampled. Alien species were sampled from all the tributaries. Diversity indices and community assemblage models were identified as approaches for monitoring the ichthyofauna in this species depauperate system. Diversity indices were not recommended for use as a monitoring tool, as they provided insufficient detail on community composition and structure. A modified depletion estimator was applied to multiple pass electrofishing data to determine the effects of various physico-chemical variables on the absolute abundance of Pseudobarbus afer, an endangered species. Pseudobarbus afer density was found to be positively correlated to the presence of boulders. Where P. afer were present, they were abundant. Of the total sampled catch, 21.8% was comprised of alien fishes. Clarias gariepinus was the most successful invader having penetrated all but one of the tributaries. Micropterus salmoides changed the species composition of the Wit River significantly through predation, and is potentially the most dangerous of the alien species in the Sundays River system, capable of extirpating a population of P. afer in as little as three days. Only one man-made barrier to the upstream migration of alien fishes was present on the tributaries, and several addition barriers are required to safeguard the populations of indigenous fish in the headwaters of these tributaries. Several management and conservation tools are presented and discussed, including river rehabilitation, translocation, eradication of alien species, erection of barrier weirs and captive breeding programmes. Public awareness and education is stressed because without support from the communities surrounding the GAENP, management plans for conservation of the indigenous ichthyofauna will, in all likelihood, fail.
9

The effect of elephants (Loxodonta africana, Blumenbach, 1797) on Xeric Succulent Thicket

Knott, Edward Joseph January 2007 (has links)
This study looks at the impact of elephant feeding on the Xeric Succulent Thicket component of Eastern Cape Subtropical Thicket (ECST) in Addo Elephant National Park (AENP). Observations of elephant feeding were carried out and vegetation transects were surveyed for impact of elephant feeding. The results indicated that the Nyati elephants spent the majority of their time grazing (nearly 90%), particularly the cow-young herds, and especially when the herd gathered in larger numbers. Browsing events were concentrated on Acacia karroo (81%) and there was no significant difference between the sexes in their preference for this species. Despite being subjected to most of the browsing, the majority of A. karroo trees were undamaged and the effect of elephants was generally light. It appears unlikely that, three years after re-introduction to Nyati, the elephants have had an effect on community structure of the vegetation. Surveys were conducted on stands of the alien invasive weed prickly pear Opuntia ficus-indica, and it was recorded that elephants in Nyati have had a dramatic effect on prickly pear, utilising all adult plants assessed and destroying 70% of them. This level of destruction in such a short period of time suggests that prickly pear is a highly favoured species. The results from the present study suggest that elephants can play a role in the control of prickly pear. Results are discussed in terms of elephants as both megaherbivores and keystone species, and as agents of intermediate disturbance.

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