School of Animal, Plant and Environmental Sciences (ETDs)
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Item Integrated management of Campuloclinium macrocephalum (pompom weed) (Less.) DC. (Asteraceae) in South Africa(University of the Witwatersrand, Johannesburg, 2024-10) Mudau, Phuluso; Byrne, Marcus J.; Witkowski, Ed T.F.; Goodall, JeremyCampuloclinium macrocephalum (Less.) DC. (Asteraceae) is an invasive perennial forb native to Central and South America and known as pompom weed in South Africa. It has since naturalized and poses a threat to grasslands, wetlands and savannas in many parts of South Africa. The weed is listed as category 1b of NEMBA (National Environmental Management Biodiversity Act), an invasive species which must be controlled and wherever possible, removed and destroyed. It causes significant reduction in grazing capacity of farms and game reserves, as it is unpalatable to livestock and wildlife. The weed has a clustered thick tuber-like root system that enables it to withstand fire and harsh winter conditions such as low rainfall and frost. Pompom has increased its invasion range by 671% between 2006 and 2016. Management strategies to date, such as the application of chemical, fire, mechanical and biological control have not yielded substantial results, hence the increase in invasion range of C. macrocephalum. Application of herbicides alone requires multiple annual applications which may not be feasible, logistically or financially. It is also not ideal to continuously apply herbicides in sensitive environments such as areas that are close to streams, wetlands and dams. Three annual applications of metsulfuron methyl and picloram alone were found to suppress the abundance of C. macrocephalum but failed to control the weed. Mechanical control of C. macrocephalum through hoeing or digging is ineffective as damage to rootstocks by splitting them leads to further vegetative growth resulting in an increase in pompom density. Multiple biological control agents are often released against a single invasive plant to improve the degree of control. There are three biological control agents released against C. macrocephalum in South Africa namely, Liothrips tractabilis Mound and Pereyra (Thysanoptera: Phlaeothripinae), Puccinia eupatorii (Pucciniales: Pucciniaceae) and a flower-feeder, Cochylis campuloclinium Brown (Lepidoptera: Tortricidae). Damage inflicted by L. tractabilis and P. eupatorii is moderate, and the degree of control provided by the two agents has not resulted in sufficient control of the weed. A strategy of combining different control methods such as chemical, mechanical, fire or biological control can improve the impact and effectiveness of any combination of the four methods and improve the degree of control of a particular weed. Integrated management of invasive weeds vary to suit a target plant based on invaded habitat, existing control method and management objectives. The first aim of the study (Chapter 2) was to evaluate how burning alone prior to the growing season of C. macrocephalum and burning alongside herbicide application affects the weed density, regrowth/re-sprouting from rootstocks, flowering density and the seedbank of the weed over two growing seasons at Rietvlei Nature Reserve, Gauteng Province, South Africa. The seedbank was estimated by quantifying the number of newly emerging seedlings on each experimental block. During the first growing season (2020-2021) fire in August significantly reduced the seedbank of pompom by over 85% but failed to reduce the density of mature plants within the invaded areas. Herbicide application in December 2020 post fire of the first growing season resulted in over 98% reduction of the weed density during the first growing season. For the second growing season (2021-2022), there was a 9% regrowth from rootstocks of the weed on experimental blocks previously treated with fire and herbicide, which can be managed by a follow up application of herbicide. Integrating fire and herbicide was found to be a successful management strategy and it is therefore recommended as a management approach for the control of pompom weed in South Africa. The impact of L. tractabilis is variable at different sites invaded by C. macrocephalum. This is because L. tractabilis has established in some open grasslands and failed to establish in more mesic environments particularly seasonal wetlands. A sub-lethal dose of herbicide can be used to suppress the reproductive ability of the weed without killing the plant and sustain the biocontrol population. Therefore, the second aim (Chapter 3) was to identify sub-lethal doses of three herbicides (picloram, impala and metsulfuron methyl) that will not kill but suppress the vegetative growth of C. macrocephalum and sustain the L. tractabilis population. However, the identified sub-lethal doses of the three herbicides were found to be incompatible with the agent L. tractabilis, because of an indirect impact on their feeding sites (young and apical stem sections) which affected the abundance of the agent. Due to lack of feeding sites, L. tractabilis was found to feed on old stems which are the least preferred sites. Consequently, considering the indirect impact of sub-lethal doses on L. tractabilis, the use of such doses is not recommended given the incompatibility. In a study in 2018, early season mowing of surrounding vegetation, led to enhanced effectiveness of L. tractabilis on pompom weed, resulting in increased levels of stem deformation by the agent. Campuloclinium macrocephalum in more sunny vegetation (areas with mown short vegetation) experienced increased light intensity and temperatures compared to areas with unmown long vegetation (more shady sites). However, it remains unclear how the physiology and growth rate of C. macrocephalum were affected by the difference in light intensities and temperature and how subsequent changes in plant growth and ecophysiology affected the biocontrol agents. The third aim of this study (Chapter 4) was to evaluate the influence of two light intensities (full sunlight and reduced sunlight) on chlorophyll content, chlorophyll fluorescence, stomatal conductance, and growth of C. macrocephalum, and to assess the reproduction and feeding impact of L. tractabilis in a laboratory trial. Reduced light intensity (shade plants) resulted in higher chlorophyll content, chlorophyll fluorescence, stomatal conductance, growth rate and chlorophyll fluorescence than in sun plants suggesting increased photosynthetic rates. This resulted in a significant increase in growth rate, with greater height of C. macrocephalum in the shade (108 cm) compared to in the sun (72 cm) over seven weeks. The feeding performance and abundance of L. tractabilis was significantly higher in open sun plants. This suggests that light intensity plays a critical role in the performance and establishment of the thrips. Therefore, mowing or burning the surrounding vegetation prior to and post release of the thrips may aid establishment and improve efficacy of the agent. Liothrips tractabilis is known to prefer young apical shoot stems compared to more mature and old stems. To understand why L. tractabilis preferred young stems and plants in short vegetation, the fourth aim of the study (Chapter 5) was to evaluate and compare the nutritional quality of young apical stems compared with old stems (mid-section) of C. macrocephalum that grew in long and short vegetation by assessing the nitrogen and carbon levels and C:N ratio. Nitrogen content was greater in apical stems than in mid-section stems from short vegetation, suggesting better nutritional quality for L. tractabilis compared to plants from long vegetation. Therefore, the surrounding vegetation has an impact on the nutritional quality of C. macrocephalum which affects the performance and population size of L. tractabilis. In conclusion, neither fire alone nor herbicide alone significantly reduce the population density of pompom weed, but the application of lethal herbicide to C. macrocephalum after fire proved to be the most effective control method.Item Examining intraspecific ploidy variation and functional traits that facilitate the environmental distribution of the Drakensberg near-endemic species, Rhodohypoxis baurii (Baker) Nel. var. platypetala Hilliard & Burtt(University of the Witwatersrand, Johannesburg, 2024-09) Mtileni, Masingitla Promise; Glennon, Kelsey I.Polyploidy is widely acknowledged as a key feature of evolution in flowering plants. Polyploidy often leads to reproductive isolation between polyploids and their diploid progenitors. This can arise via morphological and habitat differentiation, with polyploid plants often exhibiting increased growth, survival, and reproductive output under different environmental conditions. However, whether polyploidy drives general ecological divergence between diploids and polyploids or confers an advantage for plants under different environmental conditions remains an open question. Polyploids are generally thought to have an increased adaptive potential to populate areas that are increasingly environmentally ‘extreme’. These ‘extremes’ can be described as experiencing the extreme end of an environmental variables; either colder or hotter temperatures, drier or wetter habitats, increased UV exposure, or increased/decreased seasonality. The ability of polyploids to acclimate to these ‘extremes’ may be a consequence of the beneficial outcomes of polyploidy, such as intrinsically higher heterozygosity and altered gene expression. My thesis examines how environmental variables may shape the distribution of plants with different ploidies, the association of polyploidy with plant morphotypes, and whether plants with different ploidy levels respond distinctively to different environmental conditions. Using a meta-analysis, I examined the hypothesis that there is consistent segregation between diploid and polyploid plants based on elevation. I found that the perceived trend of polyploids occurring at significantly higher elevations than diploids was not supported for 71% of the sampled 28 studies. In addition, climate variables, soil moisture, and geographic region only explained 0.3% of polyploid presence at the highest elevations across studies. Next, I conducted a cytogeographic study, growth chamber and greenhouse experiments, and reciprocal transplants to examine ploidy level distribution and the association of polyploidy with the responses of plants to different environmental conditions at the population level. I focused on Rhodohypoxis baurii var. platypetala (Hypoxidaceae), a Drakensberg nearendemic taxon. I found evidence for both habitat and morphological differentiation between diploid and tetraploid populations, where tetraploids had larger leaves and larger flowers and generally occurred at lower elevations in warmer and drier habitats with soil that is marginally higher in nitrogen and phosphorus concentration than diploid habitats. Only one mixed-ploidy population (diploids and triploids) was found. My findings suggest that a higher ploidy level was not associated with larger morphological traits or increased reproductive output under greater soil nitrogen, phosphorus, and salinity levels, nor greater survivorship and increased reproductive output under higher salinity, or after being transplanted. Together, findings from this thesis dovetail with collective findings from other work where increased ploidy was not found to confer an advantage or limitation under different environmental conditions, and where the general relationship between environmental variables and polyploid distribution was found to be indirect or negligible. Work at large scales (e.g., broad scale and at a global level) may reveal meaningful polyploid patterns that may not be evident at smaller scales. However, such work may not be accurate when predicting the role of polyploidization in plants generally or outlining the general biogeographic principle of polyploid distribution due to the lacking historical component which prevents us from inferring nascent drivers of observed distributions. Broad comparative work should be complemented with robust experimental studies (e.g., reciprocal transplants and common garden experiments). Comparing niches of diploid and polyploid populations from the same species may also be more useful in identifying unifying trends than comparing niches of polyploid species across the globe.Item Costs and benefits of solitary living in the bush Karoo rat (Otomys unisulcatus)(University of the Witwatersrand, Johannesburg, 2024-10) Makuya, Lindelani; Pillay, Neville; Schradin, CarstenSolitary living has traditionally been regarded as the ancestral as well as most common and most primitive form of social organisation in mammals. However, recent comparative studies indicate that solitary living is not ancestral for all mammalian orders, and that solitary living is an adaptation to the environment. I show that solitary living occurs in only 22% of studied mammalian species and argue that the main benefit of solitary living is to avoid the costs of group-living. Group-living has been explained using socio-ecological models, and I used the same factors of resource distribution and predation risk to develop a socio-ecological model explaining solitary living. To reach a better understating of solitary living, I studied the social system of free-living bush Karoo rats (Otomys unisulcatus) in the Succulent Karoo semi-desert of South Africa. I used trapping and marking, focal animal observations and mini-GPS dataloggers that I fitted simultaneously to neighbouring females. I found that 96% of female bush Karoo rats were solitary living, with social groups of two or three individuals occurring occasionally. Groups always consisted of close kin, typically females. The home ranges of kin neighbours overlapped more than those of non-kin. Neighbours were, however, attracted to the same foraging grounds, irrespective of relatedness. Females tolerated one another at shared foraging grounds, which could be interpreted as byproduct mutualism, a simple form of cooperation. I recorded interactions between neighbouring bush Karoo rats both in a neutral test arena and in the field to investigate whether solitary living was due to aggression and social intolerance. Social interactions between neighbours were rare and aggression was rare in neutral arena tests. However, female bush Karoo rats were more aggressive towards non-kin intruders in the field tests. Finally, the relationship between mother and offspring remained amicable even after the offspring had dispersed from the lodges, indicating that maternal aggression was not the mechanism that led to offspring dispersal and solitary living. In conclusion, I showed that solitary living is not always characterised by aggression and avoidance, but rather that solitary species can have non-random and individualised social interactions that are influenced by kinship.Item Mining company governance and the spectre of environmental prosecutions: Is there any deterrent effect?(University of the Witwatersrand, Johannesburg, 2024-10) Monoke, Kwena Martha; Field, Tracy-LynnSouth Africa has developed good environmental legislation, but compliance with these laws is still a challenge (Linde, 2006; Skosana, 2019). According to (Digby, 2016), the South African mining industry has a notorious legacy of inadequate rehabilitation and partially closed mine sites. Mining company directors are the custodians of the company governance and have a duty to ensure compliance with all relevant mining legislation (Bezuidenhout, 2018). Their failure to comply with the law triggers, in many instances, a criminal infraction. All South African environmental legislation relies on criminal penalties to enforce its prescriptions and to punish its offenders (Murombo and Munyuki, 2019). South Africa has strict criminal sanctions for environmental noncompliance and degradation (Truter, 2014). The awareness of South Africans with regards to environmental crimes has increased due to initiatives such as the annual National Environmental Compliance and Enforcement Report, and online judgment archives such as the South African Freedom of Legal Information Institute (SAFLII) and Juta Law (Department of Forestry, Fisheries and the Environment, 2023a). The State v Blue Platinum Ventures and Mr Maponya case was used as a case study. This study seeks to investigate whether the threat of environmental prosecution influenced the mining company governance and its director and whether it had any deterrent effect on the company’s commission of environmental crimes. A qualitative case study approach was undertaken. Several documentary sources of information were relied on for the analyses of the Blue Platinum case and interviews were conducted to fill in the gaps from the data analyses. It was determined that the rule of law was being put into practice and that the community had received justice because rehabilitation was conducted and it addressed their concerns. The Blue Platinum Ventures and Mr Maponya case has had a deterrent effect on the company itself and Mr Maponya.Item Investigating hybridization among high altitude Rhodohypoxis species in the Drakensberg Alpine Centre(University of the Witwatersrand, Johannesburg, 2024-07) Coetzer, Dewald Janus; Glennon, Kelsey L.Putative hybridization between the alpine Rhodohypoxis taxa (R. baurii var. confecta, R. deflexa, R. rubella, R. incompta, and R. thodiana) as well as Hypoxis parvula var. parvula has been documented in the wild – suggesting that there are few genetic barriers between these taxa that often grow in sympatry. This study aimed to assess patterns of hybridization among the alpine Rhodohypoxis species and between them and H. parvula var. parvula at three different natural study sites and to contribute new data that might help delineate/solidify genus and species boundaries in this group using morphometric analysis, seed surface micromorphological comparisons, microsatellite data, and controlled greenhouse crosses. It was found that although all the methodologies were congruent in their ability to delineate the Rhodohypoxis species from one another and from H. parvula var. parvula (thereby corroborating their current circumscription), substantial admixture was detected at each of the three study sites – and admixed individuals were largely morphologically cryptic. Furthermore, morphometric analysis and seed surface micromorphology could not distinguish between R. thodiana and putative hybrid taxa – suggesting it may be of hybrid origin. The present study also reports the complete self-incompatibility of polyploid H. parvula var. parvula, the facultative self-compatibility of diploid R. baurii var. confecta, the successful crossbreeding of these two taxa from Sentinel Peak with a strong asymmetrical barrier to gene exchange, and a mechanism involving double-reduced polyploid pollen facilitating this interploidy cross. Low germination rate of the resulting hybrid seed is consistent with a decrease in F1 viability. These findings, coupled with the low incidence of polyploid H. parvula var. parvula individuals producing double reduced pollen, and the low levels of admixture detected, suggesting substantial post-pollination reproductive isolation between these two taxa. Nevertheless, caution should be taken when making strong taxonomic inferences from phylogenies that include R. baurii var. confecta and H. parvula var. parvula representatives from the Sentinel Peak study site.Item Critiquing existing criteria for financial provisioning for rehabilitation and closure of coal mines in South Africa(University of the Witwatersrand, Johannesburg, 2024-08) Raine, Keith Ian; Watson, Ingrid; Schwaibold, UteIt's vital for mining companies to allocate sufficient funds for environmental restoration after mining activities. This research explores the adequacy of financial provisions for the rehabilitation and closure of coal mines in South Africa, a critical issue given the country's heavy reliance on coal for energy and the significant environmental impacts associated with mining activities. The purpose of this research is important as it aims to ensure that financial provisions accurately reflect the true costs of environmental rehabilitation, thereby safeguarding ecological integrity and promoting sustainable mining practices. This is especially important in the context of South Africa's transitioning energy landscape and the global shift towards more sustainable energy sources. Employing a mixed-methods approach, the study combines an extensive literature review, analysis of South African mining legislation, and comparison with international standards and best practices. The methodology is further augmented by the researcher's direct engagement with the industry, providing an insider's perspective on the challenges faced in financial provisioning for mine closure. Through interviews with industry the research offers an examination of the current state of financial provisions in the coal mining sector. Key findings reveal gaps in the existing framework for calculating financial provisions in South Africa, including underestimation of costs, lack of comprehensive criteria covering all aspects of mine closure, and the misalignment of legal requirements with actual rehabilitation needs. The study also highlights the disparity between South African regulations and international best practices, underscoring the need for a more robust, transparent, and inclusive approach to financial provisioning. The research proposes a set of detailed themes and criteria to enhance the accuracy and efficacy of financial provisions, advocating for a just transition that balances economic, environmental, and social considerations. However the over-reliance on specialist studies when calculating financial provisions for mine closure poses significant risks and challenges that can compromise the effectiveness and sustainability of closure efforts. The significant costs associated with conducting comprehensive specialist studies can pose a barrier to smaller mining operations, potentially exacerbating the issue of mine abandonment.Item The Impact of the Just Energy Transition on Job Creation in South Africa: A Case of the Wind Energy Sector(University of the Witwatersrand, Johannesburg, 2024-10) Zondi, Nomvula Beryl; Ngubevana, LwaziSouth Africa's ratification of the Paris Agreement, an international accord established during the Conference of the Parties (COP21) in December 2015, underscores its dedication to confronting climate change and enacting measures to counteract human-induced global warming. Aligned with numerous other nations, South Africa is actively promoting a just energy transition that prioritises the Sustainable Development Goals (SDGs) established by the United Nations General Assembly on September 25, 2015. This transition entails a shift from reliance on carbon-intensive fuels like coal towards renewable energy sources. Given South Africa's substantial coal reserves—ranking sixth globally coal mining and processing has historically played a central role in the nation's energy sector, industrialisation, and economy, contributing significantly to its GDP and providing employment for up to 150,000 individuals throughout the coal value chain. However, the imperative for an energy transition to mitigate climate change and fulfil the country's National Determined Contributions necessitates structural changes that will inevitably impact socio-economic dynamics. Notably, disruptions in the coal value chain will have profound repercussions on both direct and indirect employment and the communities and local economies reliant on the coal industry. The Integrated Resource Plan (IRP) 2010-2030 outlines South Africa's energy trajectory of increasing renewable energy sources into the energy mix. This study focused on wind energy deployment, with a targeted capacity of 17,742 MW by 2030. It aims to identify critical considerations essential for facilitating a just energy transition that maximises job creation in South Africa. Applying a qualitative research methodology, semi-structured interviews were conducted to gather data, utilising a deductive approach based on predetermined themes derived from existing literature on factors influencing job creation. Findings underscore the importance of addressing policy implementation gaps related to the socio-economic impact of the transition, establishing clear directives for skills development in the low-carbon economy, and prioritising local manufacturing and assembly of turbine components. Moreover, the study highlights wind energy deployment as a catalyst for fostering the development of a low-carbon ecosystem while advocating for exploring broader low-carbon value chains such as green hydrogen to enable new industries and employment opportunities. Finally, the study underscores the need for focused attention and investment in research and development of clean coal technologies, offering a potential avenue for sustainable coal utilisation devoid of adverse greenhouse gas emissions and environmental impacts.Item Natural resource use and environmental perceptions in different types of rural villages in Bushbuckridge, South Africa(University of the Witwatersrand, Johannesburg, 2024-09) Mbedzi, Mary Emma; Twine, WayneHouseholds in rural communities in developing countries rely on natural resources that contribute to income generation, food, medicine, cooking energy, and act as livelihood safety nets. Levels of dependency vary between households within communities due to factors such as wealth status and household size. However, less is known about differences in household resource use between communities within an area. Environmental awareness, values, and preferences are shaped by various factors including, local context. Thus, perceptions of the environment and natural resources, and changes in these are likely to vary between communities. This study aimed to compare the levels of natural resource use and environmental perceptions across village types and determine if there is any relationship between the level of natural resource use and environmental perceptions across village types in the Bushbuckridge Local Municipality in the Mpumalanga province, South Africa. Village types were defined and categorised based on their size, socio-economic factors, access to basic services, connectedness, and remoteness. The level of natural resource use was analysed using existing data from a survey of 491 households across 12 villages located in the Agincourt Health and Demographic Surveillance System (AHDSS) site. This included data on the use, collection, buying, and selling of a range of natural resources used locally (e.g., wild foods, firewood, and medicinal plants), annual consumptions, ownership of resources made from natural resources, and livestock (cattle) ownership. The survey included questions on respondents’ perception of the change in the supply of natural resources over the past 5 years (2016-2021) before the survey. Focus group discussions were conducted in 10 of the study villages asking participants their perception of the changes in the environment and the causes thereof, the importance of the natural environment, natural resources used for their daily needs, income generation, their culture, as well as the changes in availability of natural resources and impacts on their livelihoods. The study villages were classified according to a village typology that had been developed for the AHDSS study site, based on factors such as connectedness, access to amenities and services, and the proportion of Mozambican refugee households. ANOVA and Kruskal Wallis tests were used for continual data, while the Chi-squared test was used for categorical data to test for significant differences across village types in the quantitative part of the study. For qualitative, responses of participants from each village were recorded and grouped into village types, and an overall picture of the perception of natural resources that participants used was developed using the focus group schedule. Similarities and differences in natural resources between villages were assessed by grouping widely and less used resources by villages and village types. There was no significant difference (p>0.05) in the mean prevalence of use, collection, buying, and selling of natural resources, or annual consumption of natural resources across villages and village types. Households in better-serviced villages owned more products from natural resources and were to greater extent, likely to own livestock than poorly-serviced villages. As to environmental perceptions, more respondents in the poorly serviced village types (refugee settlements (RS) and underdeveloped communities (UC)) perceived a decrease in the supply of natural resources than better-serviced village types (established communities (EC) and central communities (CC)). Participants in focus group discussions also noted a decrease in the supply of natural resources across all villages and village types. There was a relationship between village types, natural resource use, and perceptions of change in natural resource availability. Established communities correlated with a higher number of resources perceived as decreasing and central communities were associated with higher cattle ownership. Underdeveloped communities and refugee settlements were associated with a higher number of resources used/owned, a higher number of resources used often (more than 4 times a month), and a higher number of resources sold, and buying firewood. Natural resources were more highly used in, better-serviced village types (central communities, and established communities), than in poorly-serviced village types (underdeveloped communities, and refugee settlements), which was unexpected. However, there were quite a few proxies such as the collection and selling of resources, which were used that did not help back up these findings which could explain the unexpected results. Most respondents in remote and poorly-serviced village types perceived a change in the supply of natural resources, the greatest decrease being in the supply of natural resources. This is associated with awareness of the value of the environment and high reliance on natural resources for these poorly-serviced village types. This study suggests that differences exist in resource use patterns between villages, even in the same area. However, village characteristics were not a good predictor of all aspects of resource use. Changes in proxies of resource utilization and re-evaluating the existing village typology would be useful for further studies.Item Surface water dependencies and activity patterns of mammalian herbivores in South Africa(University of the Witwatersrand, Johannesburg, 2024-10) Padayachy, Janiel; Hetem, Robyn; Strauss, Willem Maartin; Venter, JanAn increase in aridity in Africa may make water availability more variable, thus understanding how animals respond to these conditions is important for future wildlife management and conservation. However, mammalian herbivores with varying water requirements may respond differently to changes in water availability and predation. Using camera trap data, I analysed the spatial distribution relative to surface water sources and the 24-hour activity of 16 mammalian herbivores across 10 sites in South Africa. As expected, water dependent herbivores were generally closer to water, but only at sites where lions were absent. Herbivores with low water requirements were more nocturnal, potentially reducing water required to cool themselves evaporatively when active during the heat of the day. But that nocturnal activity was reduced when lions were present, likely reducing predation risk, increasing water requirements to dissipate heat and forcing herbivores to remain close to water. Nocturnal activity increased with body size in mixed-feeders and grazers, but decreased with body size in browsers, potentially reflecting more time spent foraging by large browsers. Using a novel approach of multistate diel occupancy models I showed that herbivores were generally active during both the day and night, and that the presence of lions impacted occupancy of preferred prey species (blue wildebeest, gemsbok and zebra). Diel occupancy of water-dependent prey (blue wildebeest) was influenced by an interaction between lion presence and distance to water sources. Thus environmental factors as well as physiological and morphological features affected the timing of activity and spatial distribution of several mammalian herbivore species in South African wildlife areas, which should be considered for future research and management of these species.Item The Gene Catalogue and Functional Analysis of the Gut Microbiome of Lions in Etosha National Park(University of the Witwatersrand, Johannesburg, 2024-09) Belger, Carl Warner; Hetem, Robyn; Hazelhurst, ScottCharacterising the microbiomes of free-living mammals may aid conservation efforts, yet the gut microbiome of carnivores is underrepresented. This study represents the first description of the gut microbiome of free-living African lions (Panthera leo melanochaita). Faecal samples from 20 lions were collected in Etosha National Park, Namibia and microbial DNA was extracted. Samples were then whole genome sequenced, and classified using MetaPhlAn and Genome Taxonomy Database toolkit. The two most abundant bacterial genera in the lions’ gut microbiomes were Bacteroides (16.9%) and Phocaeicola (16.6%). Microbiome diversity was similar between the sexes and across seasons as assessed through Bray-Curtis dissimilarity and Shannon diversity index. The genus Clostridium_AH was more abundant in male lions (P = 0.007; d.f. = 22), while Aphodousia (P = 0.003; d.f. = 22) was more abundant in females. Lions captured in winter had a high abundance of Plesiomonas relative to those captured in summer (P = 0.008), whereas lions captured in summer a high abundance of Dysosmobacter (P = 0.038; d.f. = 22), Pelethomonas (P = 0.021; d.f. = 22), Metalachnospira (P = 0.033; d.f. = 22) and Clostridium Q (P = 0.012; d.f. = 22) compared to those captured in winter. Following various taxonomic classification approaches, a third of the reads (33.6%) present in the lion gut microbiome remained unclassified. We constructed 272 metagenome assembled genomes, from seven bacterial phyla, representing mostly new species which will contribute to understanding of the carnivore gut microbiome.