Please read the abstract in the section 00front of this document / Dissertation (MSc (Wildlife Management))--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted

This study assesses elephant induced damage and mortality of baobab and common star-chestnut trees in the northern Kruger National Park. Comparisons are made between the populations north and south of the Luvuvhu River. The density, population size and age structure are estimated. The population structure of neither species has been shaped by elephant utilisation. While the baobab population has a healthy age distribution, that of the star-chestnut population shows that recruitment has declined in recent decades. Utilisation has been found to be higher in the south as a result of higher elephant densities, although recently damage has been greater in the north. Damage increases with tree size. The mortality of baobabs is lower than in other areas where elephants and baobabs co-exist. Elephants are not playing a significant role in mortality of either tree species and management of factors other than elephant is required to improve regeneration rates of these species. / Dissertation (MSc (Wildlife Management))--University of Pretoria, 2007. / Animal and Wildlife Sciences / unrestricted

The objectives of this study were(1) to analyse a data-set on cheetah home range size, habitat utilisation, prey selection and hunting behaviour in the Kruger National Park (KNP), and (2) conduct a comparative study on the above aspects of cheetah ecology across a variety of African savanna ecosystems. Cheetah home range sizes in the KNP for territorial male cheetahs were 173 km2, 438 km2 for a nomadic male cheetah coalition, and 193 km2 and 179 km2 for two female cheetahs. Cheetahs preferred open savanna habitat, although females used areas with thicker bush such as drainage lines) more than males, probably because this is the preferred habitat of their main prey. Analysis showed that while females were closely associated with drainage lines, males were closely associated with roads. A male cheetah coalition preferred scent marking along roads rather than in the bush. Impala occurred most frequently in the cheetahs’ diet, although males took larger prey than females. Cheetahs hunted and killed more frequently in open savanna, even though impala densities were higher in adjacent habitats. Mean chase distance for successful hunts was 18l9 m and unsuccessful hunts was 96 m. Cheetah hunting success was 20.7%, kleptoparasitism was 11.8%, mean kill retention time was 165 min, kill rated averaged 1 kill per 4.61 days, and consumption rate of a three-male cheetah coalition was 1,4 kg meat/cheetah/day. Across African savanna ecosystems, female cheetah home range size was determined by the dispersion patterns and biomass of medium-sized prey. Female home range size was larger in areas with migratory (833 km2) than sedentary prey (105 km2) and increase as prey biomass decreased in areas with sedentary prey only. Conversely, male cheetah territory size was smaller in areas with migratory (37 km2) than sedentary prey (108 km2). Although it was predicted that male cheetah territory size would be determined by female cheetah density, no relationship was found here. Across a range of African savannas, cheetahs showed distinct preferences for open habitats that provided some woody cover. Adults (40%) and juveniles (20%) of medium-sized prey made up the largest proportion in the cheetahs’ diet. There were, however, significant variations in the size and age groups of prey taken by cheetahs in different areas. Areas with the least amount of cover appeared to have the longest mean chase distance, and the greatest percentage hunting success and incidents of kleptoparasitism (%). A population viability analysis, using VORTEX, found that cheetah population viability was greater in a woodland savanna than a grassland savanna, particularly at small population sizes. While the grassland savanna population was most affected by changes in juvenile mortality the woodland savanna population with exceptionally high cub mortality may be a sink for cheetahs while the woodland population with lower cub mortality and predicted high dispersal rates may be a source. Maximum annual litter size and female mortality rates had large impacts on population persistence. / Dissertation (MSc (Zoology))--University of Pretoria, 2006. / Zoology and Entomology / unrestricted

Please read the abstract (Uittreksel) in the section, 00front of this document. See also 10summary / Dissertation (MSc (Zoology))--University of Pretoria, 2007. / Zoology and Entomology / MSc / unrestricted

Worldwide there is a growing concern of the emergence and evolution of antimicrobial resistance among bacterial pathogens, which poses a threat to human and animal health. The extensive use and misuse of antimicrobials in human and veterinary clinical therapy and agricultural practices have been a major selective force for the emergence, selection, and dissemination of antimicrobial resistant bacteria and resistant genes. Commensal bacteria constitute a reservoir of resistant genes and their level of resistance is considered to be a good indicator for resistance problems to be expected in pathogens. The monitoring of the prevalence of resistance in indicator bacteria such as faecal Escherichia coli and enterococci in different human and animal populations allows the comparison of the prevalence of resistance and to detect transfer between animals and humans and vice versa. Antimicrobial resistance has however, been found in the bacteria of wildlife not exposed to antimicrobials and living in remote areas of this earth. This has implications for resistance control strategies. Previous studies on antimicrobial resistance in wildlife have yielded contrasting results, such as an almost complete absence of resistance in enterobacteria isolated from moose, deer and vole in Finland compared to a high prevalence of resistance in faecal bacteria from wild rodents living in northwest England, which are possibly due to differences in the ecological systems and the proximity to anthropogenic activities. This study further investigates the phenomenon of antimicrobial resistance in wildlife. A previous study conducted in the conservancy area of Kruger National Park (KNP) within South Africa showed that surface water could be a possible source of antimicrobial resistance in unexposed animal populations and that impala (Aepyceros melampus) were good sentinel animals for the documentation of antimicrobial resistance through rivers. This current study followed on this hypothesis and investigated the prevalence of resistance in commensal bacteria isolated from impala and their water sources in KNP. The following four perennial river systems were selected: the Olifants, the Letaba, the Crocodile, the Sabie-Sand Rivers. Samples of river water (n=11) and faeces (n=165) were collected at 11 different sites along these rivers. Samples were directly plated and resistant colonies were selected by means of discs containing antimicrobials (direct plating method). Resistant colonies that grew in the presence of antimicrobials were cultured and identified. Isolates of E. coli (n=12), Enterobacter cloacae (n=49), Pantoea species (n=9), Enterococcus faecalis (n=59), Enterococcus faecium (n=4) and Enterococcus durans (n=64) were tested for susceptibility to a selection of commonly used veterinary antimicrobial drugs. Susceptibility to 18 antimicrobial drugs was determined by means of minimum inhibitory concentrations (MIC) using a commercial MIC test (Sensititre® Bovine/Porcine plate format BOP06F). Our results allow us to give further support to our working hypothesis that antimicrobial resistance, as evidenced in the impala faeces, may have been due to the impala drinking from the polluted rivers, knowing full well that impala are not routinely subjected to any form of antimicrobial treatment. Although the isolates obtained from the water sources were not as many as those obtained from the faecal samples, a degree of resistance was also observed across all the four river systems that we isolated bacteria from, and this was also evident in the faecal samples as well. Our results also further add to the importance of wildlife as sentinels in environmental antimicrobial resistance studies. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Veterinary Tropical Diseases / Unrestricted

Analyzes of bat echolocation calls enable to investigate diverse patterns of bat communities without the need for contact manipulation with individuals. The continuous all-night acoustic recordings provide standardised data open to quantitative comparisons and testing effects of diverse contextual factors upon bat community structure. The multidisciplinary project MOSAIK (Monitoring Savanna Biodiversity in Kruger NP) mapping patterns of variation in savanna communities under different spatial and temporal influences includes bats as one of the model groups. At standardized monitoring points of the project (covering 20 different areas, each containing triplet points differing in access to the water surface: permanent, seasonal and the crests without a water source), all-night acoustic recordings of bats were undertaken over two seasons (using Song Meter recorders SM4BAT). All records were analyzed with aid of Kaleidoscope Pro software and cluster identification technique (with an input database developed by Weier et al. 2018 and Taylor et al. 2020) controlled by manual checking. Multiple comparisons of diverse coenologic variables of the particular samples were performed together with testing effects of associated contextual variables (geographic setting and climatic currents, seasons, vegetation,...

Black rhinoceroses (Diceros bicornis) have been extirpated from most of their historic range with the remaining individuals (ca. 5200) living in geographically isolated populations. Management priorities include creating new populations whilst maintaining genetic diversity and promoting gene flow between existing isolated populations. Such objectives are however currently hindered by a lack of comparative/reference data on levels of diversity, relatedness and inbreeding in a large, free-ranging black rhinoceros population. Here I attempt to address this gap in our knowledge by investigating the genetic diversity of the black rhinoceros Diceros bicornis minor within Kruger National Park (the largest free-ranging population of this subspecies) using nuclear and mitochondrial DNA. I compared the diversity of this founded population with the two source populations (KwaZulu-Natal, South Africa and Zimbabwe) using published studies, and evaluate the relative contribution of source lineages relative to the proportion of original founders. Analysis of the mtDNA control region revealed four haplotypes, with moderate haplotype and nucleotide diversity (h=0.48 (± 0.05 SD); π= 0.29%). Data from 13 microsatellite loci revealed moderate to high levels of genetic variation (number of alleles = 4.92 ± 0.90, effective number of alleles = 2.26 ± 0.25, observed heterozygosity = 0.50 ± 0.04, expected heterozygosity = 0.51 ± 0.04), low mean pairwise relatedness (r = -0.03), a low inbreeding coefficient (Fis = 0.04) and no evidence of genetic structuring. Diversity levels within the Kruger black rhinoceros population were high compared to levels reported in black rhinoceroses originating in KwaZulu-Natal and similar to those reported in individuals originating in Zimbabwe. Results show that 40-60% of the Zimbabwean lineages are represented in the Kruger population which is a noticeable increase in the relative contribution of the Zimbabwe founder population. The data provided by this study can be used to guide management and conservation decisions regarding maximising genetic variability across the subspecies. Furthermore, given the encouraging levels of genetic diversity observed, the Kruger black rhinoceros population would be an ideal source population for supplementation of genetically depauperate populations or creating new populations. Finally, these findings demonstrate a positive outcome in mixing the KwaZulu-Natal and Zimbabwe gene pools, with evidence that the founder Kruger black rhinoceros population has been genetically rescued from the low diversity seen in the KwaZulu-Natal black rhinoceroses in South Africa.

No abstract available Copyright / Dissertation (MSc)--University of Pretoria, 2010. / Plant Science / unrestricted

Theileriosis, babesiosis, heartwater and anaplasmosis are considered to be amongst the most important tick-borne diseases of livestock in sub-Saharan Africa‟s tropical and subtropical regions resulting in extensive economic losses to farmers in endemic areas. It is well-known that the African buffalo (Syncerus caffer) is the natural reservoir host of various tick-borne haemoparasites of veterinary importance. In this study, the occurrence of tick-borne haemoprotozoan parasites (Theileria, Babesia, Anaplasma and Ehrlichia species) in buffalo from two geographically isolated national parks in South Africa (Kruger National Park and Hluhluwe-iMfolozi Park) was determined using the reverse line blot (RLB) hybridization assay. The RLB results revealed the presence of Theileria, Babesia and Anaplasma species either as single or as mixed infections. Although not detected with the RLB assay, 5% of the buffalo blood samples from the KNP tested positive for the presence of Ehrlichia ruminantium using the pCS20 real-time PCR assay. Previous studies on the occurrence of haemoparasites in the South African buffalo population have mainly focussed on the prevalence of Theileria species only. The finding on the presence of Anaplasma, Ehrlichia and Babesia species is therefore a novel contribution. This study has confirmed the findings of previous studies that buffalo is the natural reservoir host of both pathogenic and non-pathogenic Theileria species namely, T. parva, Theileria sp. (buffalo), T. mutans, T. velifera and T. buffe1i.In this study, the most frequently occurring Theileria species detected in the KNP were T. mutans (81%), Theileria sp. (sable) (61%), T. parva (40%), Theileria sp. (buffalo) (13%) and T. velifera (11%). Theileria buffeli was not detected in the KNP. In the Hluhluwe-iMfolozi Park, the most occurring Theileria species were T. mutans (55%), T. velifera (54%), T. parva (53%), Theileria sp. (sable) (53%), Theileria sp. (buffalo) (49%) and T. buffeli, (49%). Theileria sp. (sable) causes fatal clinical disease in roan and sable antelope in South Africa and we can only speculate whether the presence of Theileria sp. (sable) DNA in the buffalo population was a true and/or incidental finding. An interesting finding was the presence of Babesia occultans DNA in 50% of the buffalo from the Hluhluwe-iMfolozi Park. Babesia occultans is the causative agent of a benign form of cattle babesiosis in South Africa and, to date; this organism has not been identified in wildlife in South Africa. The significance of this finding warrents further investigation and confirmation using gene cloning, sequencing and phylogenetic analysis. Ehrlichia ruminantium has been reported to infect not only domesticated ruminants but also wild ruminants, however most wildlife species appear to carry the organism asymptomatically. In this study, we were not able to detect E. ruminantium DNA in any of the buffalo samples tested using the RLB hybridization assay. However, using the quantitative pCS20 real-time PCR assay we detected E. ruminantium DNA in 5% of the KNP samples. None of the Hluhluwe-iMfolozi Park samples tested positive for E. ruminantium using the real-time PCR assay. These results suggest that buffalo is not the natural reservoir host of E. ruminantium. However, a subclinical carrier state in buffalo has been experimentally shown to occur after tick transmission from carrier animals and further studies will have to be conducted to confirm whether this finding holds any potential risk to domestic animals. In Southern Africa, two Anaplasma species are known to infect cattle, A. marginale and A. centrale. Clinical bovine anaplasmosis is usually caused by A. marginale; whilst A. centrale generally results in mild disease. Because there is partial cross immunity between the two species, A. centrale is used as a live vaccine for cattle in Israel, South Africa, South America and Australia. Apart from cattle, Anaplasma marginale has been described in wild ruminants which can become persistently infected serving as reservoirs for infection of susceptible hosts; it has been recovered from 10 wild ruminants. Subclinical occurrence of A. marginale, either natural or after artificial infection has been confirmed in the African buffalo and various other wildlife species. In this study, the Anaplasma species detected from HluhluweiMfolozi Park buffalo samples were A. centrale (75%), A. marginale (42%) and Anaplasma (formerly Ehrlichia) sp. Omatjenne (28%). DNA of these species was also detected in buffalo from KNP; A. centrale (49%), A. marginale (24%) and Anaplasma (Ehrlichia) sp. Omatjenne (5%). The presence of A. marginale in the buffalo population suggests that buffalo may be a factor in the epidemiology and spread of bovine anaplasmosis because, as reservoir hosts of A. marginale, they could serve as a source of infective blood for mechanical spread by various routes and biological transmission by ticks. Factors such as climate, host abundance, tick host diversity, and topography have, however, all been shown to also impact on the epidemiology of A. marginale. Subsequently 64 samples were selected that either tested (i) positive for a specific Anaplasma spp. (A. centrale, A. marginale and/or Anaplasma (Ehrlichia) sp. Omatjenne) using the RLB assay, or (ii) in which the PCR products hybridized only with the Anaplasma/Ehrlichia genus-specific probes for molecular characterization by cloning and sequencing of the 16S rRNA gene. Aplification of the full-length and/or partial parasite 16S rRNA gene of any of the selected samples that previously tested positive for the presence of Anaplasma (Ehrlichia)sp. Omatjenne (using the RLB assay) or E. ruminantium (using the pCS20 real-time PCR assay) was unsuccessful. This was most probably due to low rickettsaemia. However, amplification of either the near full-length parasite 16S rRNA gene or a partial 16S rRNA gene from seven samples from the KNP and three from Hluhluwe-iMfolozi Park was successful. Results indicated that the obtained sequences of 12 of the 18 clones were highly similar to published A. centrale 16S rRNA gene sequences, four of the clones were highly similar to the published A. marginale sequences and the sequences of the remaining two clones were closely similar to Anaplasma (Ehrlichia) sp. strain Omatjenne. The observed sequence similarities were confirmed by phylogenetic analyses. An interesting finding was the presence of one full-length parasite 16S rDNA sequence that was 100% identical to that of the published A. centrale vaccine strain sequences. It is well known that A. centrale is widely used as live vaccine for the control of bovine anaplasmosis. The occurrence of A. centrale vaccine strain DNA in the South African buffalo population is therefore of great interest. It can only be speculated whether A. centrale has evolved in the African buffalo, and/or if buffalo act as natural reservoir hosts, or if is it merely being maintained in the buffalo population by in utero transmission. This also serves as the first report of Anaplasma (Ehrlichia) sp. Omatjenne DNA in the African buffalo which warrents further investigation. In conclusion, the findings suggest that buffalo is a natural reservoir of Anaplasma spp. infection and could play an important role in the epidemiology and spread of anaplasmosis and may represent a serious threat to the livestock industry. / Dissertation (MSc)--University of Pretoria, 2012. / Veterinary Tropical Diseases / unrestricted

Methods used to estimate the prey consumption by large carnivores include direct continuous observation, stomach content analysis, carcass observations and scat analysis. Continual observations are widely considered the best approach to estimate large carnivore diets, with lions (Panthera leo) being no exception. Continual observation allows the recording of all prey encounters and biases inherent in the other approaches are minimised. However, continuous observations are not always feasible, and in situations where animals cannot be observed at all times, diets are often estimated from observed carcasses. This often leads to an over-estimation of large kills in the estimated diet. Alternative methods that are free of the constraints placed on continuous observations are needed to provide data of a similar quality to that obtained using these continuous observation bouts. I employed a cluster follow up technique to locate lion kills from remotely accessed Global Positioning System (GPS) data from lions in the Kruger National Park (KNP). I develop Generalized Linear Models (GLMs) that increase the probability of locating kills at GPS cluster events. By increasing the predictive ability of detecting kills I show that this technique can be used to locate kills in a more efficient manner than random searching of GPS clusters, with further advantages in that multiple groups of lions can be monitored simultaneously. By incorporating this technique into an adaptive research framework, the diet of lions (and that of other large carnivores) can be estimated. In addition, I show that the spatial association between lions at kill sites, while feeding on carcasses, provides a further increase in the predictive ability of kill site models. Lionesses were found to be considerably closer together at the start of clusters associated with kills in comparison to clusters where no kill was found. This pattern remained consistent for both small and large kills. This proximity approach could therefore be incorporated into the GLMs that are developed to predict kill sites of large social carnivores. To further reduce the bias (where small kills are often missed) inherent in carcass observations, I combined scats and carcasses collected from known times, locations and lion groups to construct a temporal kill record for each group of lions. By combining scats and carcasses I estimate that at least 50% of the small prey items, namely impala (Aepyceros melampus) and warthog (Phacochoerus africanus) were missed when GPS clusters were investigated for carcasses. Ultimately, I show that a combination of GPS cluster investigations based on models developed using GPS movement data in combination with lion proximity data, augmented with scats collected at GPS clusters, could provide estimates of large carnivore diets that begin to approach estimated diets obtained through continuous monitoring. The resulting diet, estimated from the GPS cluster approach in combination with scat collection, indicated that the dominant prey item in the region was zebra (Equus quagga) followed by wildebeest (Connochaetes taurinus), impala and buffalo (Syncerus caffer). Selection indices for the eight dominant prey items were calculated using prey availability measures obtained from the aerial census data and ground counts of groups. It has been suggested that group level selection is a better approach to calculating predator-prey interactions, and that stability in predator-prey systems is improved if group metrics of prey are used as apposed to individual measures of availability. I show that there is a considerable shift in selection indices, as well as in the order that prey is selected, when using different measures of prey availability. In selection studies, more effort needs to be paid to the assessment and definition of prey availability to ensure results accurately reflect selection patterns in the field, especially when data are used for the development of management practices. Combining buffalo predation data collected from GPS cluster investigations with buffalo mortality data collected over five years prior to the commencement of the GPS cluster investigations, allowed an investigation into patterns of lion predation on buffalo between 2000 and 2007. Buffalo of both sexes were more vulnerable to predation in habitats that gave lions an ambush advantage (i.e. increased grass height and tree density). Despite this similarity in landscape risk, different processes lead to similar fates in dangerous habitats for buffalo of both sexes. Predation pressure by lions on buffalo increased following periods of reduced rainfall; with more buffalo predated on following drier six month periods. Predation on males constituted a significant proportion of all predation and was focused predominantly into the late dry season. The resulting method of locating kills by using GPS clusters and correcting carcass data with scats collected along the movement path represents a robust technique to estimate large carnivore diets. In the concluding chapter I present avenues where future research can build on the current thesis and present a framework that can be employed when attempting to estimate large carnivore diets. / Thesis (PhD)--University of Pretoria, 2010. / Zoology and Entomology / unrestricted