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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

Screening of banded mongooses (Mungos mungo) for mycobacterial infection in the Kruger National Park, South Africa

Brüns, Angela Caren January 2014 (has links)
Bovine tuberculosis (bTB) was first diagnosed in the Kruger National Park (KNP) in 1990 and research has since focused primarily on the buffalo (Syncerus caffer) as the maintenance host and lion (Panthera leo) as a clinically affected species. However, little is known about the role that small predators might play in the tuberculosis epidemiology. The aim of this pilot study was to screen banded mongoose populations in the bTB high prevalence zone of the KNP for mycobacteria in general and for Mycobacterium bovis and other Mycobacterium tuberculosis complex members in particular to detect presence of infection. Faecal swabs, tracheal swabs and tracheal lavage of 76 banded mongooses caught in cage traps within a two kilometre radius of Skukuza Rest Camp in the KNP were submitted for culture, isolation and speciation of Mycobacterium as the gold standard of bTB diagnosis. Blood was collected and serologically analysed for M. bovis and Mycobacterium tuberculosis antibodies using the ElephantTB STAT-PAK® Assay (STAT-PAK) and the EnferplexTM TB Assay (Enferplex). DPP® VetTB Assay for elephants (DPP) was used on STAT-PAK positive samples. To complement the sample set obtained from live banded mongooses 12 animals were necropsied. Lesions and pooled lymph node samples together with a standard set of organ samples were submitted for culture and histopathology analysis. Two banded mongooses had developed well demarcated, irregularly margined, greyyellow nodules of up to 5 mm diameter located in the caudal lung lobes and/ or tracheo-bronchial, retropharyngeal or superficial cervical lymph nodes. These lesions were characterised by central necrosis in the one and calcification in the other animal. Histopathologically the lesions were described as caseating necrosis associated with epithelioid macrophages and necrogranuloma with calcified centre respectively. No acid fast bacteria were identified with Ziehl-Neelsen stain. M. bovis was isolated from lung, lymph node and liver samples as well as tracheal lavages and tracheal swab from the same two banded mongooses but not from any other study animal. No other Mycobacterium of the M. tuberculosis complex was isolated. However, a variety of environmental mycobacteria, the most frequent from the Mycobacterium avium complex, M. fortuitum group, M. simiae group and M. terrae group, were cultured. M. fortuitum group was only and M. terrae group predominantly isolated from tracheal and faecal samples whereas M. simiae group and M. avium complex were the most frequent species isolated from post mortem samples, including tissue lesions and lymph nodes. Serological analysis revealed 12 banded mongooses with a positive STAT-PAK result, confirmed with DPP. Enferplex was positive for MPB83 in four and MPB70 peptide in one animal. Only two banded mongooses, the ones with the strongest positive reaction on both STAT-PAK and DPP, reacted positively on all three serological assays. These were the same two animals that had developed granulomatous lesions and that M. bovis was cultured from ante and post mortem samples. In conclusion, this study has provided the first evidence of bTB infection in banded mongooses in the KNP and demonstrated their ability to shed M. bovis. This finding has opened the discussion around possible sources of infection and its significance at the human/ wildlife interface in and around Skukuza. / Dissertation (MMedVet)--University of Pretoria, 2014. / tm2015 / Production Animal Studies / MMedVet / Unrestricted
2

Ecological suitability modelling for anthrax in the Kruger National Park, South Africa

Steenkamp, Pieter Johannes 15 January 2013 (has links)
Bacillus anthracis is the causal agent of anthrax which primarily affects ungulates, occasionally carnivores and less frequently humans. The endospores of this soil-borne bacterium are highly resistant to extreme conditions, and under ideal conditions, anthrax spores can survive for many years in the soil. The bacterium is generally found in soil at sites where infected animals have died. When these spores are exposed, they have the potential to be ingested by a mammalian species which could lead to an anthrax outbreak. Anthrax is almost never transmitted directly from host to host, but is rather ingested by herbivores while drinking, grazing or browsing in a contaminated environment, with the exception of scavengers and carnivores consuming infected prey. Anthrax is known to be endemic in the northern part of Kruger National Park (KNP) in South Africa (SA), with occasional epidemics spreading southward into the non-endemic areas. The aim of this study is to identify and map areas that are ecologically suitable for the harbouring of B. anthracis spores within the KNP. Anthrax surveillance data and selected environmental variables were used as inputs to the maximum entropy (Maxent) species distribution modelling method. Five-hundred and ninety-seven anthrax occurrence records, dating from the year 1988 to 2011, were extracted from the Skukuza State Veterinary Office’s database. A total of 40 environmental variables were used and their relative contribution to predicting suitability for anthrax occurrence was evaluated using Maxent software (version 3.3.3k). Variables showing the highest gain were then used for subsequent, refined model iterations until the final model parameters were established. The environmental variables that contributed the most to the occurrence of anthrax were soil type, normalized difference vegetation index (NDVI), land type and precipitation. A map was created using a geographic information system (GIS) that illustrates the sites where anthrax spores are most likely to occur throughout the Park. This included the known endemic Pafuri region as well as the low lying soils along the Shingwedzi-Phugwane-Bubube rivers and the Letaba-Olifants river drainage area. The outputs of this study could guide future targeted surveillance efforts to focus on areas predicted to be highly suitable for anthrax, especially since the KNP uses passive surveillance to detect anthrax outbreaks. Knowing where to look can improve sampling efficiency and lead to increased understanding of the ecology of anthrax within the KNP. / Dissertation (MMedVet)--University of Pretoria, 2013. / Production Animal Studies / unrestricted
3

A study of tetracycline resistant Escherichia coli in impala (Aepyceros melampus) and their water sources

Mariano, Valeria 19 February 2009 (has links)
A case control study was performed in the conservancy area of the Kruger National Park (KNP), South Africa to find out whether the faeces of impala (Aepyceros melampus) were more likely to contain tetracycline resistant Escherichia coli (TREC) when they drank from rivers that contained these bacteria, compared to rivers that were uncontaminated with TREC. Five perennial rivers (Crocodile, Letaba, Olifants, Sabie and Sand) were selected. A total of 11 points in these rivers were sampled on three separate occasions and cultured for E. coli. Impala herds within 5 kilometres of each water collection site were identified and between 5 and 10 fresh faeces were collected for each collection period (n=209 faecal specimens). Selective culturing of E. coli was done and the resulting colonies were screened for tetracycline resistance by using the Lederberg Replica Plating (LRP) method. Resistant colonies were those that grew in the presence of 4 mg/L of tetracycline. Both a resistant and/or a susceptible isolate were then selected from each specimen, and subjected to the minimum inhibitory concentration (MIC) micro-broth dilution test for tetracyclines. The breakpoint for the MIC method was considered ≥ 8 mg/L (which is higher than for the LRP method). Twenty one of the 33 water specimens examined were found to be contaminated by E. coli. Among them (n=21), 76.19% (n=16) were resistant to tetracycline using the LRP method, although using the MIC method only 19.05% (n=4) were resistant. All of the resistant strains originated from the Letaba, Olifants and Crocodile rivers (TRECpos rivers). Among the 209 impala faeces sampled, 191 were positive for the presence of E. coli (91.38%). Within these (n=191), 36.64% (n=70) showed TREC using the RPL method, while using the MIC, 9.95% (n=19) were found to be TREC. The RPL and MIC methods showed a concordance of only 48%. Resistant isolates screened by PCR for tet(A) and tet(B) genes were found to be negative and it was concluded that other resistant genes were responsible. The odds ratios (OR) showed that impala drinking from TRECpos rivers were 19.3 (2. 63-141.68) times more likely to be infected with TREC than unexposed impala / Dissertation (MSc)--University of Pretoria, 2007. / Paraclinical Sciences / unrestricted
4

The long-term effects of fire frequency and season on the woody vegetation in the Pretoriuskop Sourveld of The Kruger National Park

O’Regan, Sean Patrick 01 March 2007 (has links)
Student Number : 9008538J - MSc Dissertation - School of Biology - Faculty of Science / O’Regan SP, 2005. The long-term effects of fire frequency and season on the woody vegetation in the Pretoriuskop sourveld of the Kruger National Park. MSc Dissertation, University of the Witwatersrand, Johannesburg. The role of fire in the management of conservation areas has historically been a contentious issue in which traditional agricultural principles and ever-changing conservation principles tend to collide. The Kruger National Park (KNP) in the early 1950s was no exception where the appropriate use of fire and its ecosystem consequences were hotly debated. The controversy surrounding the management of fire in the KNP highlighted the significant lack of understanding of fire and its role in the ecosystem and because of this controversy, the Experimental Burn Plot (EBP) experiment was established in 1954. The EBP experiment comprised 12 treatments, and a pseudo-randomised block design was used in which the 12 fire treatments were replicated four times each in four of the six major vegetation zones identified at the time. The EBP experiment originally comprised 192 experimental plots approximately 7 Ha in size each and covered approximately 12 km2 in the KNP. The twelve fire treatments were an annual burn in August, biennial and triennial burns in February, April, August, October, and December, and a control on which fire was excluded. Despite having been plagued with negative assessments from internal and external researchers from its inception, the EBP experiment was meticulously maintained, and it has now become a valuable research asset in the KNP. Four replicates of twelve plots each were located in the Pretoriuskop sourveld landscape of the KNP. These replicates were named Fayi, Kambeni, Numbi, and Shabeni after nearby landmarks. The Pretoriuskop region is a moist infertile mesic-savanna, which experiences on average 744mm of rain annually. The dominant tree species in Pretoriuskop are Dichrostachys cinerea and Terminalia sericea and the dominant grass species is Hyperthelia dissoluta. A baseline survey of the woody vegetation was done on all the Pretoriuskop plots in 1954 by HP Van Der Schijff. A second survey of the woody vegetation on all the Pretoriuskop plots was done in 1996 by SP O’Regan. This provided a 42-year period of treatment application over which the effects of fire frequency and season on the woody vegetation of the Pretoriuskop region were studied. The aim of this study was to investigate the long-term effects of the twelve fire treatments on the density, structure, and species composition of the woody vegetation in Pretoriuskop. The objectives of this study were: 1. To carry out a complete re-survey of the trees and shrubs on the Pretoriuskop EBPs using similar methods as those used in the baseline survey in 1954. 2. To capture into a digital format pertinent woody vegetation survey data from surveys that had been conducted on the Pretoriuskop EBPs between 1954 and 1996. 3. To compare the density, structure, and composition of the woody vegetation on the Pretoriuskop EBPs between 1954 and 1996, to determine the effects of fire on the woody vegetation of Pretoriuskop. 4. To investigate the history of the Kruger National Park Experimental Burn Plots experiment. The four replicates in the Pretoriuskop region were found generally to have very similar woody vegetation traits (density, species composition, and structural composition). However, the EBPs were established and surveyed in two distinct phases, the first phase comprised the control, August Annual, and the Biennial plots, and the second phase comprised the Triennial plots. The baseline structural composition of the plots established in the first phase was different from the structural composition of the plots in the second phase. Furthermore, the Pretoriuskop EBPs are located in two distinct vegetation types, namely the open and the closed Terminalia sericea \ Combretum woodlands of the Pretoriuskop region. The Numbi and Shabeni replicates are in the open Terminalia sericea \ Combretum woodlands, and the Kambeni and Fayi replicates are in the closed Terminalia sericea \ Combretum woodlands. It was found that the species composition of the plots was influenced by the location of the plots in the different vegetation types. The exclusion of fire in the Pretoriuskop sourveld results in an increase in the density of the overstorey and understorey woody vegetation, and an increase in the number of species, species diversity, and species evenness. This is because fire sensitive and fire intolerant woody species become more abundant as the period between fires increases. In Pretoriuskop, there is no evidence of relay floristic succession, because fire sensitive and fire intolerant woody species do not replace fire tolerant species. Instead, the floristic succession is accumulative and fire tolerant, fire sensitive, and fire intolerant woody species coexist as the period between fires increases. Woody species tolerant of frequent fires in Pretoriuskop are Albizia versicolor, Catunaregam spinosa, Lonchocarpus capassa, Pavetta schumanniana, Senna petersiana, Strychnos madagascariensis, and Turraea nilotica. Woody species that are sensitive or intolerant of fire in Pretoriuskop are Acacia swazica, Bauhinia galpinii, Combretum mossambicense, Commiphora neglecta, Croton gratissimus, Dalbergia melanoxylon, Diospyros lycioides, Diospyros whyteana, Euclea natalensis, Hyperacanthus amoenus, Kraussia floribunda, Ochna natalitia, Olea europaea, Psydrax locuples, Putterlickia pyracantha, Tarenna supra-axillaris, and Zanthoxylum capense. Dichrostachys cinerea and Terminalia sericea were found to dominate in areas that had been burnt frequently as well as areas where fire has been excluded. The change in the density of the woody vegetation as the inter-fire period increases is not linear but rather J shaped with an initial decrease in the density as the inter-fire period increases from 1 year to 3 years. This initial decrease in density is the result of a loss of very short (<1m tall) woody individuals. In contrast, there is no initial decrease in the number of tree equivalents (phytomass) of the woody vegetation as the inter-fire period increases. After the initial decrease in the density of the woody vegetation, the density increases as the inter-fire period increases beyond 3 years. Generally in Pretoriuskop, post fire age of the vegetation was found to be an important factor affecting the structure of the woody vegetation, and as the inter-fire period increases the number of structural groups, the structural diversity, and the structural evenness of the woody vegetation increases. As the inter-fire period increases the number of single-stem individuals relative to the number of multi-stem individuals increases, and the average height of the woody vegetation increases. The findings regarding the effects of fire frequency on the Pretoriuskop EBPs were similar to the findings on other fire experiments in mesic African savannas. The finding on the Pretoriuskop EBPs differed from the findings in other fire trials that were in arid savannas in Africa. Generally, the exclusion of fire in moist savannas (> 600 mm of rain annually) results in the woody vegetation becoming denser, while the exclusion of fire in arid to semi-arid savannas (< 600mm of rain annually) does not result in the woody vegetation becoming denser. In Pretoriuskop, fires occurring in summer between December and February have a different impact on the density, species composition, and structure of the woody vegetation than fires occurring in winter between August and October. Furthermore, fires occurring in April have a different impact on the density, species composition, and structure of the woody vegetation in Pretoriuskop. Woody vegetation burnt by summer fires is denser than woody vegetation burnt by winter fires. The number of species and species diversity of the woody vegetation is also higher in vegetation burnt by summer fires in comparison with vegetation burnt by winter fires. The density and species composition of woody vegetation in areas that have been burnt in summer fires is more similar to areas where fire has been excluded than to areas that have been burnt in winter fires. The woody species associated with vegetation burnt in summer fires and where fire has been excluded are Euclea natalensis, Antidesma venosum, Diospyros lycioides, Phyllanthus reticulatus, Grewia flavescens, Grewia monticola, Ochna natalitia, Peltophorum africanum, Rhus pyroides, Diospyros mespiliformis, Rhus transvaalensis, Securinega virosa, Putterlickia pyracantha, Rhus pentheri, Commiphora neglecta, Heteropyxis natalensis, and Olea europaea. Structurally the average height of the woody vegetation is taller in areas burnt by winter fires than in areas burnt by summer fires. The woody vegetation in areas burnt in summer fires have more single-stem individuals relative to multi-stem individuals than in areas burnt in winter fires. The structural composition of areas burnt in summer fires is more similar to areas where fire has been excluded than with areas burnt in winter fires. The structure of the woody vegetation in areas burnt in winter fires is generally dominated by multi-stem individuals that are 0-1m tall or 3-5m tall. The structure of the woody vegetation in areas burnt in summer fires or where fire has been excluded is dominated by both single-stem and multi-stem individuals of all heights and basal diameters. Findings regarding the effect of early dry season fires (April) in comparison with late dry season fire (August) on the woody vegetation are consistent with the findings on other fire trails in Africa. However, a comparison of all the fire-timing treatments between the Pretoriuskop and Satara EBPs in the KNP reveals that the timing of fires affects the woody vegetation differently in different areas even when the affects at certain times appear similar. The data collected on the Pretoriuskop EBPs reveals that there have been significant changes in the woody vegetation in Pretoriuskop between 1954 and 1996. The density of the woody vegetation increased between 1954 and 1996 by almost 200%. The number of species and the species diversity of the woody vegetation also increased between 1954 and 1996. In 1954, there were approximately equal numbers of single-stem and multi-stem individuals, while in 1996 there were more multi-stem individuals than single-stem individuals. The increase in atmospheric CO2 levels between 1954 and 1996 is believed to have been a factor that has driven the changes in the woody vegetation of Pretoriuskop between 1954 and 1996.
5

The influence of the 2008/2009 economic recession on travel behaviour of visitors to the Kruger National Park / Marco Scholtz

Scholtz, Marco January 2010 (has links)
During the recession period of 2008/2009, global tourism declined by 8%. This was also evident is South Africa with the domestic travel market shrinking by 8% as well. However, this did not apply to the Kruger National Park (KNP) which experienced a sustained Accommodation Unit Occupancy growth of 1.6% during the same period. Visitors to the KNP thus see it as an attractive holiday destination irrespective of tough economic conditions characterised by less disposable income. To sustain this growth, it is important to be aware of the reasons visitors still visit the KNP during a recession. The aim of this study was to determine the reasons why visitors still travelled to the KNP during the 2008/2009 recession. This can be done by analysing the visitors’ behaviour and the motivational factors (internal feelings of the visitors) and determinants of the demand (income and exchange rates for instance) that influenced visitors’ choice to visit the KNP. To achieve this aim, a survey was conducted at the KNP between 15 and 20 December 2009 (high season). A total of 355 questionnaires were completed, after which a number of analyses were done to determine the effects of the recession on travel behaviour. For the purpose of this study, two articles were written. Article 1 is titled: “Motivations of visitors to the Kruger National Park during the 2008/2009 recession period”. The aim of this article was to determine the motivations of visitors to the KNP during the recession. A factor analysis on the motivations to visit the park was conducted, of which the following factors obtained the highest mean values: Escape, Wildlife experience and Family benefits. Push factors to the KNP were important to such an extent that visitors regarded visiting the park as a primary need or lifestyle. The results furthermore showed that visitors might have adapted their spending behaviour at the park to still afford to visit the park during the recession. This article provides a better understanding of visitors’ feelings towards the KNP, especially amidst recessions which, in turn, will improve niche marketing and a competitive advantage. Article 2 is titled: “Factors that influenced demand to the Kruger National Park during the 2008/2009 economic recession”. The aim of this article was to identify the determinants that influence the demand for visits to the KNP. Due to the homogeneous nature of the park’s market, the results of the stepwise logistic regression analysis revealed a few socio-demographic and behavioural determinants that influenced visitors’ demand to the park. The motives Escape and Souvenirs were the only two behavioural determinants while the provinces Gauteng and Mpumalanga were the only socio-demographic determinants. These two provinces are the two main markets for the KNP. Visitors indicated that visiting the KNP is a great way of escaping their busy metropolitan areas, especially in the Gauteng province. Mpumalanga residents have many tourism attractions in their province thus lowering the chances that they will visit the KNP. The determinant Souvenirs indicates that visitors adapted their spending at the park to still be able to afford visits. It was also found that demand to visit the park was not greatly influenced by the recession, because visitors could adapt their spending at the park. This is the first time the determinants of demand to a national park during a recession period have been conducted. The study indicated that visiting natural areas may have become a primary need or part of a lifestyle, especially during the 2008/2009 recession period. This article gives park management guidelines that will ensure the sustainability of the KNP because this information now allows for well-planned, thorough marketing and management of the park. In the case of KNP, which has a homogeneous market, the number of determinants identified influencing demand for visiting the park is fewer than has been found in other studies done on heterogeneous markets. This study therefore also makes a valuable methodological contribution in relation to analysing demand of homogeneous and heterogeneous markets. / Thesis (M.Com. (Tourism))--North-West University, Potchefstroom Campus, 2011.
6

The influence of the 2008/2009 economic recession on travel behaviour of visitors to the Kruger National Park / Marco Scholtz

Scholtz, Marco January 2010 (has links)
During the recession period of 2008/2009, global tourism declined by 8%. This was also evident is South Africa with the domestic travel market shrinking by 8% as well. However, this did not apply to the Kruger National Park (KNP) which experienced a sustained Accommodation Unit Occupancy growth of 1.6% during the same period. Visitors to the KNP thus see it as an attractive holiday destination irrespective of tough economic conditions characterised by less disposable income. To sustain this growth, it is important to be aware of the reasons visitors still visit the KNP during a recession. The aim of this study was to determine the reasons why visitors still travelled to the KNP during the 2008/2009 recession. This can be done by analysing the visitors’ behaviour and the motivational factors (internal feelings of the visitors) and determinants of the demand (income and exchange rates for instance) that influenced visitors’ choice to visit the KNP. To achieve this aim, a survey was conducted at the KNP between 15 and 20 December 2009 (high season). A total of 355 questionnaires were completed, after which a number of analyses were done to determine the effects of the recession on travel behaviour. For the purpose of this study, two articles were written. Article 1 is titled: “Motivations of visitors to the Kruger National Park during the 2008/2009 recession period”. The aim of this article was to determine the motivations of visitors to the KNP during the recession. A factor analysis on the motivations to visit the park was conducted, of which the following factors obtained the highest mean values: Escape, Wildlife experience and Family benefits. Push factors to the KNP were important to such an extent that visitors regarded visiting the park as a primary need or lifestyle. The results furthermore showed that visitors might have adapted their spending behaviour at the park to still afford to visit the park during the recession. This article provides a better understanding of visitors’ feelings towards the KNP, especially amidst recessions which, in turn, will improve niche marketing and a competitive advantage. Article 2 is titled: “Factors that influenced demand to the Kruger National Park during the 2008/2009 economic recession”. The aim of this article was to identify the determinants that influence the demand for visits to the KNP. Due to the homogeneous nature of the park’s market, the results of the stepwise logistic regression analysis revealed a few socio-demographic and behavioural determinants that influenced visitors’ demand to the park. The motives Escape and Souvenirs were the only two behavioural determinants while the provinces Gauteng and Mpumalanga were the only socio-demographic determinants. These two provinces are the two main markets for the KNP. Visitors indicated that visiting the KNP is a great way of escaping their busy metropolitan areas, especially in the Gauteng province. Mpumalanga residents have many tourism attractions in their province thus lowering the chances that they will visit the KNP. The determinant Souvenirs indicates that visitors adapted their spending at the park to still be able to afford visits. It was also found that demand to visit the park was not greatly influenced by the recession, because visitors could adapt their spending at the park. This is the first time the determinants of demand to a national park during a recession period have been conducted. The study indicated that visiting natural areas may have become a primary need or part of a lifestyle, especially during the 2008/2009 recession period. This article gives park management guidelines that will ensure the sustainability of the KNP because this information now allows for well-planned, thorough marketing and management of the park. In the case of KNP, which has a homogeneous market, the number of determinants identified influencing demand for visiting the park is fewer than has been found in other studies done on heterogeneous markets. This study therefore also makes a valuable methodological contribution in relation to analysing demand of homogeneous and heterogeneous markets. / Thesis (M.Com. (Tourism))--North-West University, Potchefstroom Campus, 2011.

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