Browsing by Author "O'riain, Mannus"

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    An interdisciplinary study on the human-baboon interface in Rooiels, South Africa
    (2024) Mormile, Joselyn Elise; O'riain, Mannus
    The ongoing transformation of natural habitat for urban land use has negatively affected most wildlife, but some species are capable of adapting to novel human-dominated landscapes and even exploit anthropogenic resources. Primates are particularly adept at exploiting resources in human-modified landscapes, and in Africa, chacma baboons (Papio ursinus) are arguably the most successful primate urban exploiters. However, these spaces present novel risks to their health and survival, and baboons can damage urban infrastructure, access food from gardens, vehicles, and houses, and pose health and safety risks to people and pets. Consequently, in the interests of both people and baboons, the latter are typically actively discouraged from entering urban areas through a variety of interventions. There is, however, a notable exception to this exclusionary approach with the small coastal village of Rooiels (Western Cape Province, South Africa) having opted to share their properties and village with the local baboon troop. This provided a unique opportunity to explore the local community's acceptance of baboons, and to investigate how, when given a choice, baboons use urban versus natural habitat. Additionally, the absence of formal deterrents in the urban area allows for a rare opportunity to explore how the use of an urban area may influence the ranging patterns, activity budget, diet, and life history of baboons. I explored the spatial and behavioural ecology of the Rooiels troop using GPS data and behavioural observations, respectively, and used questionnaires to understand the attitudes, emotions, and value orientations of the local community towards the troop. The troop had a small home range of 5.78 km2 with a clear preference for both low-lying land and the village. Within the village, the troop selected for developed properties and roads over undeveloped erven, and amongst the developed erven they preferred those with larger areas of grass, properties where residents did not actively deter them and where food was provisioned. Their diet in urban areas was comprised predominantly of natural fynbos vegetation, with grass from lawns a commonly consumed fallback food. Aside from some deliberate provisioning, which greatly influenced the troop's space use within the village, human-derived foods, including foods from houses, vehicles, and bins, comprised <4% of their overall diet but their access to these foods peaked during the summer holidays when visitors were prevalent. The troop's activity budget more closely mimicked those of provisioned primates, with the least amount of time spent feeding, and considerable time spent resting and socialising. However, fecundity was not greater than troops living in natural habitats and mortality was high with 20 deaths occurring during the research period, of which 75% were due to anthropogenic causes, namely vehicles and dogs. Most residents held a mutualist wildlife-value orientation, had a positive attitude towards baboons, and expressed low levels of fear and stress in response to baboon visits. Consequently, most residents were willing to share the urban space with baboons, and this acceptance increased over time, developing into a culture of community stewardship which encouraged responsible behavior aimed at enabling the existence of the troop in the village. Despite this, the high level of anthropogenic mortality poses a risk to the persistence of the troop and suggests that this, and other urban areas, act as an evolutionary trap for baboons. Thus, the application of this inclusion model to other urban areas is ill-advised, although promoting community education and awareness to promote wildlife responsible behaviour and so reduce the potential for negative interactions associated with occasional urban incursions, is strongly advised. This interdisciplinary study has shown that communities can learn to adjust their behaviour and attitudes to wildlife in a manner that promotes coexistence, but if space sharing has unintended negative impacts on wildlife, it should not be encouraged until those impacts are mitigated.
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    Assessing the sustainability of seal tourism at Duiker Island, Hout Bay
    (2020) Heide, Trygve; O'riain, Mannus; Nattrass, Nicoli
    Pinniped focused tourism has grown rapidly both globally and in South Africa. In a 2002 survey South Africa was identified as having earned the most revenue from seal ecotourism of all the countries that engage in this activity. Seal tourism includes approaching colonies on foot, by kayak, on large and small motorised boats and more recently in the water through snorkelling and scuba diving activities. Like most wildlife tourism seal snorkelling operators can use their tours to educate clients about seal biology and threats, while providing them with a memorable physical experience with minimal impact on the seals. The goal of this research was to explore aspects of the demography, attitudes and values of tourists participating in two different seal viewing activities at the same island. Additionally, I investigated levels of satisfaction with each tour type, differences in the style of education provided by operators and which tour provided tourists and what facts tourists found most interesting. In the second part of the study I quantified the behavioural response of seals to tourists who entered the water to snorkel with seals in an attempt to assess potential impacts of immersive trips on seal behaviour. The study was conducted at Duiker Island, near Hout Bay in the city of Cape Town between November 2019 and January 2020. This period coincides with the breeding season of Cape fur seals (Arctocephalus pusillus pusillus) and the peak tourist season. Questionnaires were distributed to both seal viewing tourists (n = 53) who had viewed seals from a large boat and seal snorkelling participants who had swum with seals at the island (n = 90). More women than men undertook both types of tour, though the proportion of men increased on snorkelling compared to viewing tours. Probit models revealed key behavioural and attitudinal differences between seal viewing and seal snorkelling participants with the latter being more pro-environmental. Seal snorkelling guides used a more interpretive style when educating tourists including the use of visual aids while seal viewing tours announced facts through a loudspeaker on the vessel. Seal snorkelling guides would also include information to awareness about plastic pollution and seal entanglement, with a donation box for a seal disentanglement program run by the Two Oceans Aquarium. Seal snorkelling participants listed an average of two facts they had learnt on the tour compared to a mean of 1.24 facts for seal viewing tours. Both tours were rated very highly for overall levels of satisfaction (seal snorkelling mean score = 9.17/10; seal viewing = 8.58/100). Surface observations of seal behaviour in response to seal snorkelers in the water close to the boat suggested a minimal impact with most seals (88%) behaving neutrally and only 0.2 % engaged in avoidance behaviour. Below water observations revealed that seal numbers declined with increasing number of people in the water and seals adjusted both their position in the water column (more diving) and their activity (more active) in response to snorkeler presence. These findings suggest that both the number of snorkelers and the area over which they spread should be controlled so that seals can choose to avoid snorkelers and behavioural changes are localised to select demarcated areas. The presence of the guides in the water together with the tourists ensured there were no inappropriate interactions between seals and snorkelers (e.g. touching and biting by seals in response). This is the first study on the thriving seal ecotourism industry at Duiker Island and reveals high levels of satisfaction by both seal viewing and seal snorkelling tourists. While there were measurable impacts of seal snorkelers on seals these were highly localised and unlikely to present an adverse impact on seals at the Island more generally. Controlling the number of operators and ensuring snorkelers are always accompanied by guides should ensure that this valuable business continues, potential impacts are minimised and negative interactions (e,g. bites from seals or people touching or feeding seals) are prevented.
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    Characteristics, determinants and management of farmer-predator conflict in a multi-use dryland system, South Africa
    (2019) Drouilly, Marine Justine; O'riain, Mannus; Nattrass Nicoli; Clark, Allan E
    Extensive livestock farming provides an important source of food and fibre for humans and is often the only commercially viable land use in the more arid regions of the globe. Pastoralism can however lead to natural habitat degradation, fragmentation of landscape by fencing and conflict between livestock farmers and predators. Collectively these impacts have been identified as major threats to biodiversity in general and predators in particular. In the semi-arid Central Karoo region of South Africa, extensive small-livestock farming is the primary use of land and provides local predators with a plentiful supply of unguarded, easy-to-catch sheep in addition to permanent artificial water sources. The result is a widespread and pervasive conflict between farmers and predators and amongst diverse stakeholders on how to best manage both livestock and predators to reduce such conflict. A major impediment to understanding human-predator conflict on farmland and its impacts on biodiversity is the paucity of relevant applied research. Most research on mesopredators in South Africa has been conducted in protected areas (PA) or at the level of a single farm, precluding the generalisation of results to broader regions, and therefore limiting our understanding of the conflict on farmlands more generally. In this thesis I sought to better understand farmer-predator conflict in the Karoo region of South Africa with an emphasis on measuring the impacts of livestock farming on wildlife in general and how predators in particular impact livestock. I hypothesized that ecological, environmental and socio-economic factors would all contribute to the negative interactions between predators and small-livestock farmers, and to the persistence of the two most prevalent predators in the region, the black-backed jackal (Canis mesomelas) and the caracal (Caracal caracal), despite sustained lethal control. I addressed this hypothesis by first using camera trapping surveys to compare wildlife species richness on farmland with a nearby and similar-sized PA to assess the impacts of small-livestock farming on wildlife diversity and occupancy, notably predators. I then used scat analysis to compare the diet of jackal and caracal with those of conspecifics living in the PA to understand whether predators on farmland are targeting livestock or simply including them opportunistically in their diet. I also used Global Positioning System (GPS) clusters from collars affixed to mesopredators to determine whether jackal and caracal actively kill versus scavenge on livestock. Finally, I performed spatially-explicit interviews using semistructured questionnaires with farmers to assess the distribution and severity of the conflict with jackal, caracal and chacma baboon (Papio ursinus), to explore the potential environmental and socio-economic drivers of reported livestock losses, the attitudes to predators and the use of lethal methods to control predators. Contrary to predictions, species richness was similar on farmland and the PA while community structure, diversity and composition all differed with land use. Species richness and probability of use both varied with environmental factors but not with human disturbance. Diet differed markedly for jackal and caracal between the two land uses, with micromammals and plants dominating mesopredator diet in the PA and livestock on farmland. By combining the results of the biodiversity surveys with the diet analysis, I was able to assess prey preference by predators on medium and large iv vertebrates. The results revealed that while both jackal and caracal consumed more livestock on farmland than wild prey, only jackal showed a preference for livestock. The results of scat and GPS cluster analyses were consistent reinforcing the findings that mesopredators actively killed livestock on farmland but not from within the PA, even when individuals crossed onto neighbouring farms. Survey results showed that farmers perceive the severity of the conflict with jackal, caracal and baboon to be increasing, especially since the 2000s. There was a positive relationship between perceived livestock losses and both environmental (e.g. terrain ruggedness) and socio-economic (e.g. decrease in farm worker numbers) factors. Surprisingly, negative attitudes towards jackal and caracal were not significantly linked to the percentage of lamb losses but rather to their belief that predators should be confined to PAs. Tolerance was best explained by the perceived aesthetic appeal of both jackal and caracal. Finally, I showed that farmers preferred to use lethal versus non-lethal control methods to manage predation, including poison, because non-lethal methods were considered to be expensive, unpractical, labour intensive and less effective. The use of poison was driven by ecological (e.g. having jackal, caracal and baboon as the top three predators on the farm) and socio-economic (e.g. decrease in farm worker numbers) factors. Together, my results suggest that jackal and caracal, like many other mesocarnivores worldwide, display a remarkable ability to adapt to human-modified landscape, using both rangeland and the PA to feed on a diverse range of prey species. Even if small-livestock farms in the Central Karoo still host important components of indigenous biodiversity, the lack of government support and incentives to protect wildlife, the changes in farming practices, the associated increase in natural habitat from which predators can recolonise commercial farmland, and the reduced labour force may together result in farmers increasing their reliance on non-selective lethal control methods to protect their livestock. Of particular concern is the widespread use of illegal poisoning. If we are to find an appropriate balance between farming and conserving biodiversity on farmland, then a new approach will be required to this very old problem. Resource-constrained conservation authorities will need to be backed by multi-stakeholders’ engagements. Farmers will need to be supported through funds to increase farm worker numbers on farms and through improved livestock husbandry measures based on scientific research conducted at the appropriate temporal and spatial scales. The conflict between predators and farmers in the Karoo is complex and multifactorial, involving environmental, ecological, and socioeconomic factors. Finding solutions to limit its impacts is a societal decision at the crux of the debate between conservation and development and requires better use of available funding and multidisciplinary teams to tackle the issue.
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    Cheetah (Acinonyx jubatus) mortality and survival in fenced reserves as part of a managed metapopulation across South Africa
    (2019) Schroeder, Michelle M.; O'riain, Mannus; van der Merwe, Vincent; Naude,Vincent
    Large carnivores require expansive habitat to meet their life history needs making them vulnerable to the loss and fragmentation of natural habitat. This, in addition to human persecution has led to substantial population and range reductions of most of the world’s large carnivores over the past century. Cheetahs are no exception, occupying only 12% of their historic range in South Africa. Reintroduction programs have attempted to re-establish cheetahs to parts of this historic range, and increasingly the potential exists for their conservation in smaller fenced game reserves. However, this requires managers to maintain demographic and genetic diversity. In 2011, the Endangered Wildlife Trust initiated a project which coordinates movements between reserves using a metapopulation framework. This coordinated management approach is still in its infancy and little data exist on how reintroduction success varies amongst individuals and reserves. This study aims to examine the causes of mortality and the factors influencing cheetah survival on 20 reserves using individual life history records from 1993-2018. We assessed demographic, environmental, and management factors that are predicted to influence cheetah survival using a Cox proportional hazard model. Predation, mostly by lions (Panthera leo) accounted for 39% of known mortalities. However, the presence of spotted hyena (Crucota crucuta) posed the greatest threat to survival. Contrary to my prediction, translocation improved survival when controlling for age. Survival has also improved with time since the coordinated metapopulation approach was initiated in 2011. We created a nomogram which can be used by practitioners to predict cheetah survival within the metapopulation. Our study shows the importance of monitoring reintroduction efforts and encourages similar methods be used for other species of conservation concern that are managed within a metapopulation framework.
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    Heavy metal and organic compound bioaccumulation in bronze whaler sharks (Carcharhinus brachyurus) along the coastline of South Africa
    (2024) Adebowale, Adetola Q; O'riain, Mannus; Naude, Vincent
    Anthropogenic activities may release harmful contaminants into the environment which are subsequently ingested and gradually bioaccumulated up the food-web. As apex predators, sharks are prone to heavy metal and persistent organic pollution, being especially vulnerable to such exposure over long lifespans, making these species indicators of systemic pollution in marine ecosystems. As tons of shark meat is harvested annually for consumption, the risk of human exposure to these harmful bioaccumulated pollutants cannot be over-emphasized. In this study, we examined heavy metal and persistent organic pollutant concentrations in the muscle tissue of 41 bronze whaler sharks (Carcharhinus brachyurus) sampled along the southern and eastern regions of the South African coastline. The concentrations of 10 heavy metals (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Pb, and Zn) and 8 congeners of polychlorinated biphenyls (PCB 28, 52, 101, 118, 138, 153, 180, 194) were analysed with inductively coupled plasma optical emission (ICP-OES) and gas chromatography coupled with low resolution mass spectrometry (GC-LRMS), respectively. Average concentrations of mercury (2.53 ±0.44 mg/kg), arsenic (16.60 ±1.38 mg/kg) and chromium (0.31 ±0.07 mg/kg) exceeded the World Health Organisation and other internationally recognised regulatory maximum limits for human consumption, while lead (0.14 ±0.09 mg/kg) and zinc (13.70 ±1.74 mg/kg) was close to the permissible limit. Aluminium, cadmium, copper, iron, manganese, and zinc were well below these regulatory limits, including those set by the Department of Health in South Africa and all PCB congener concentrations were below detectable limits. There were no significant differences in heavy metal concentration between sexes, except for chromium which was significantly higher in male sharks. We found that heavy metal concentrations varied significantly with shark size and sampling region. Mercury, chromium, and iron concentrations correlated positively and significantly (Hg: r = 0.78; Cr: r = 0.60; Fe: r = 0.47) with shark size (i.e., total length and body weight) while manganese had a strong negative correlation (r = -0.42). Cadmium, chromium, iron, and mercury concentrations were significantly higher in both adult (>230 cm) and sub-adults (130–230 cm) than in juvenile sharks (<130 cm) while manganese and aluminium concentrations were significantly higher in juvenile sharks. Mercury, iron, cadmium, and chromium concentrations were significantly higher in sharks sampled on the eastern coast while aluminium and manganese were higher in sharks from the southern coast of South Africa. Significantly positive and negative correlations were also found between heavy metals, suggesting underlying and systemic interactions between these pollutants. Our results underscore the ecological threat of heavy metal pollution along the South African coastline and the potential toxicity of consuming such shark meat from small-scale fisheries (i.e., high levels of mercury, arsenic and chromium toxicity have lethal effects). Potential sources of these heavy metal and organic pollutants include improper sewage treatment, dysfunctional waste-water treatment plants, and mining activities both inland and along South African coastline. Building on these study findings alongside existing literature and international policy, we suggest several recommendations to reduce such pollution and promote shark health and conservation in South Africa. Furthermore, detailed guidelines on safe shark meat consumption and more stringent environmental policies around waste-water management should be considered by the Departments of Health and Forestry, Fisheries, and the Environment in South Africa.
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    How land use influences wildlife occupancy and species richness in the City of Cape Town
    (2024) Oladimeji, Akinwale; O'riain, Mannus
    Urbanisation is rapidly transforming and fragmenting natural habitat, disrupting ecosystems and negatively impacting biodiversity. The city of Cape Town is situated in a global biodiversity hotspot but sustained anthropogenic activities have resulted in the local extirpation of most medium and large mammals. A recent survey of mammals within urban protected areas of the City of Cape Town revealed that only a few, mostly medium sized generalist species, persist. What is not known is what native mammal species, if any, are living in unprotected green belts and parks in suburban and urban areas of the city. In this study I follow the approach of the Urban Wildlife Information Network by establishing multiple (n=4) transects (ca. 13km long) that extend from natural to suburban and urban land–use in the City of Cape Town (CoCT). A total of 37 camera trap sites were established along these four transects and they captured photographs of both target and non–target species for a period of four weeks between the 31st of January and 31st of May in 2022. Sample coverage was almost complete for the three land–use types and camera traps recorded 3045 independent images across 2,434.5 trap nights, that were used to identify 12 mammal species, nine of which were wild mammal species, but only seven of which are native to the region. Cape porcupine (Hystrix africaeaustralis; n = 222), Water mongoose (Atilax paludinosus; n = 27) and Grey squirrel (Sciurus carolinensis; n = 85) were the most frequently detected species across all three land–use types, with the Cape porcupine the most frequently detected across all transects. Species richness varied significantly between the three types of land–use being higher in natural compared to suburban areas. Both suburban and urban areas had lower evenness and diversity than natural areas. Single season hierarchical multi–species occupancy models revealed that tree cover had a significant positive effect on both community and individual species occupancy. Contrary to my predictions, neither human population density nor the extent of the impervious surface at sites had a significant effect on occupancy. Cape grysbok (Raphicerus melanotis), a shy indigenous antelope, were significantly more likely to occur at sites with a higher proportion of impervious surfaces supporting other recent research which showed this species together with water mongoose and Cape porcupine are one of only a few native mammals that appear to persist and even thrive in human–modified landscapes. My findings are consistent with those around the globe which have shown that urban areas have low biodiversity relative to natural areas. Even natural areas adjacent to the City, in the iconic Table Mountain National Park, have relatively few native mammal species. Rivers originating in the natural areas which run to the sea provide green corridors within the city, but these support relatively few species and pose numerous risks to wildlife health and survival making it unclear as to whether they are an ecological asset or a trap for wildlife.
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    Investigating the conservation value of leopard population indices obtained through camera traps in the greater Kruger region of South Africa
    (2023) Smyth, Lucy; O'riain, Mannus; Balme, Guy A.
    Leopards (Panthera pardus) are one of the most widespread large felids, historically ranging across much of Africa, the middle east and Asia. Their solitary and elusive nature has allowed them to persist in many areas where other members of the large carnivore guild have been extirpated. However, the combined effects of habitat loss, reduced prey abundance, unsustainable trophy hunting, negative interactions with humans and a growing demand for body parts are taking their toll on the species. Leopards now occupy between 25 and 37% of their historic range, and population densities are decreasing across many small reserves in South Africa. Modifications to current management regimes, informed by monitoring programs, are thus crucial to the persistence of the species. Kruger National Park (KNP) is the largest protected area in South Africa and has thus been assumed to be an inviolate refuge for leopards, despite a lack of data on key leopard population parameters. In this thesisI provide crucial density estimates for leopardsin different regions of KNP and adjacent privately managed areas. Additionally, I explore other often neglected data routinely recorded by camera traps that are potentially important to refining population monitoring efforts. Specifically, I investigate temporal leopard activity quantified using time stamps on photographs of individuals and the potential drivers of activity patterns across differentsites as well asthe relationship between phenotypic similarity derived from photographs of known individuals and relatedness estimates from pedigree data. Multisession spatial capture-recapture (SCR) models proved useful in estimating density across sites and looking at drivers of density. Leopard density ranged from 2.6 ± 0.6 to 13.2 ± 2.6 leopards/100km2 across the sites surveyed. Differences in reserve management appear to be having a substantial effect on the density of leopard populations, providing cause for concern that leopards are being negatively affected by anthropogenically driven mortalities and populations are thus failing to reach their carrying capacity. Normalised Difference Vegetation Index (NDVI) was also an important driver of density, showing a strong interaction with Reserve Type. Higher NDVI was more strongly positively correlated with leopard density in better protected reserves. Leopard activity was predominantly nocturnal with crepuscular peaks and diel activity patterns that differed between sites. These differences were driven mainly by seasonal variation in temperatures and not the relative abundance of humans, potential competitors, or prey. Leopard activity also varied on a lunar scale, with leopards showing higher activity levels with greater lunar illumination, possibly in response to decreased hunting success at higher light levels. I quantified phenotypic similarity in leopards from the Sabi Sand Game Reserve (SSGR) by measuring the resemblance of flank rosette patterns using Hotspotter and ImageJ software and manually recording the resemblance of whisker spot markings. I then compared these metrics to relatedness scores obtained from a pedigree derived from known maternal relationships with offspring. Despite six of 15 phenotypic metrics showing significant heritability, this relationship was noisy at the population level and thus phenotypic resemblance measures derived from photographic data could not provide information on the level of relatedness between leopard individuals from within populations. The data collected throughout this study provides a comprehensive baseline of leopard population status in KNP and select adjacent and contiguous private protected areas. Density remains highest in the SSGR which invests heavily in preventing negative anthropogenic impacts, is intermediate in KNP where there is concern over the potential for some human induced mortality and is lowest in Karingani Game Reserve (KGR), a protected area in its infancy where the effects of protection have not yet had time to materialise. This study also provides an indication of the uses and limitations of camera trap data, and how it can be helpful in informing leopard conservation and management.
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    Movement patterns and habitat use by Namib golden moles (Eremitalpa granti namibensis Bauer and Neithammer, 1959)
    (2023) Iipinge, Ndelimona; O'riain, Mannus
    Linnaeus first documented the existence of Golden Moles (Chrysochloridae and Afrosoricida) in 1758 but little is currently known about the biology of most of the species. Namib Golden Moles (Eremitalpa granti namibensis) are small, blind insectivorous mammals that inhabit the Namib Desert dunes. They are a subspecies of Grant's Golden Mole, with the other subspecies, Eremitalpa granti granti, found south of the Orange River. These free-ranging small mammals consume a wide variety of predominantly sand-dwelling invertebrates, with termites (Psammotermes allocercus silvestri) making up more than 95% of the diet by biomass. In this study my primary aim was to investigate habitat use and foraging behaviour of a subpopulation of Namib Golden Moles (E.g. namibensis) within the Namib Sand Sea by following their tracks over a full calendar year at a single site. My secondary aim was to compare mole movement patterns and habitat use at the main study site with two other nearby sites that differ in habitat. I hypothesised that movement and habitat use will be non-random and influenced by the local distribution of prey resources namely, vegetation hummocks and dune slip faces. I further predicted that movement patterns would show seasonal variation linked to changes in ambient and sand surface temperatures. I followed mole tracks in the early morning for 3 to 14 consecutive days each month at the main study site and compared a subset of these data with two other sites in a single season. Along each track, I recorded GPS waypoints where the mole emerged, dipped its head into the sand to listen (head-dip), foraged (sand-swimming), and rested. I recorded both the microhabitat type (dune phase) and broad habitat (hummock or open) for each foraging and resting GPS waypoint. The area of each microhabitat available at each study site and the density of vegetation were calculated from drone images in QGIS using NGRDI and Field calculator respectively. Manly's alpha (αr) index was used to determine microhabitat and hummock preference. Home ranges were estimated using a 95% Kernel Density Estimation and were compared monthly and between the three sites. Key measures of movement and foraging behaviour were estimated for each mole track at all sites and the averages were compared monthly within the main site and for a single season between sites. Significant differences in movement and behaviour were evident both within the main site across months and between sites within summer. The track length was shortest but straightest with the lowest number of head dips at the main site which had the least hummocks and the most open habitat. Moles preferred to both rest and forage on or close to hummocks at all sites and preferred large hummocks. Within dune habitats, moles preferred avalanche bases and slip faces both of which are associated with higher prey density. Moles also preferred to forage and rest in large hummocks and the mean number of hummocks visited each day increased with track length and the number of head dips per track but decreased with track straightness. The best predictors of track length were season and sand surface temperature with track length being highest in summer and increasing with sand surface temperature. The results support previous findings that Namib Golden Moles have larger home ranges (mean = 5.08 ha) and move greater daily distances than other mole species, and furthermore that they both head dip and swim in the sand to first detect and secondly increase their chances of encountering prey. Novel findings include that mole track length is mostly affected by seasonal changes in sand surface temperature, and they resort to shorter, straighter, and mostly under-sand movement in winter. They prefer to forage in detritus trap zones (avalanche base and slip face) and foraging was not always associated with the extant hummocks.
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    Multiscale patterns of mammal diversity and occurrence in the Karoo
    (2022) Woodgate, Zoë Anne; O'riain, Mannus; Distiller, Gregory
    The transformation of natural habitat for urban, industrial, and agricultural activities is the leading driver of terrestrial biodiversity loss. Yet how such land–use changes will impact the global drylands is poorly understood, despite the vulnerability of these once isolated regions. One such region is South Africa's Karoo, which is characterised by low human density, high levels of endemism and extensive pastoralism. Whilst centuries of small–livestock farming have severely impacted the Karoo's biophysical environment it remains relatively intact from an ecological perspective. However, novel threats have emerged, including a proposal for the extraction of natural gas by hydraulic fracturing extensive shale reservoirs. A major impediment to understanding how this, and other land–use changes, may impact indigenous wildlife is the lack of updated, multiscale foundational biodiversity data. To address this knowledge gap, my thesis evaluates the distribution and ecology of the mammalian (>0.5kg) community across the Karoo, with a focus on developing potential methods that can effectively record both common and rare species. My primary aim was to understand how biophysical drivers and intraguild interactions have shaped the distribution of mammals at different spatial scales, relative to existing and proposed land–uses. I had three main objectives: 1) to provide a foundational understanding of the mammalian community present throughout a 171 811km2 area under consideration for shale gas extraction, 2) to compare species occurrence and diversity across different land–use types (i.e., farmland, protected area [PA] and private protected areas [PPA]), and 3) to understand the drivers of the Karoo's rarest mammal species, namely the critically endangered riverine rabbit (Bunolagus monticularis), presence. To accomplish these objectives, I deployed three camera trap surveys at different geographic extents, with differing array designs. At the broadest geographical extent, I utilised an array consisting of 25 sites (125 camera traps total) that were selected using the Latin hypercube method. At the intermediate extent I compared three different land–uses, each sampled using a standardised 2km2 grid of sites (451 camera traps total). Lastly, at the finest scale (223.24km2 ), I deployed a stratified random design (30 clusters of 5 camera traps deployed within 400m) with the explicit goal of detecting riverine rabbits. I found that at the broadest scale wildlife diversity and occupancy was largely influenced by landscape–level abiotic processes, namely longitude and precipitation. None of the wide–ranging large predator (e.g., leopard or brown hyena) or endangered species (i.e., riverine rabbit) known to occur in the region were detected, suggesting the survey design was too coarse, and that protected areas were underrepresented. At the intermediate extent I used a hierarchical multi–species single–season occupancy model that incorporates species–specific responses to management treatments to show that land–use has a significant impact on species richness and occupancy, both of which were highest in the PPA and lowest in commercial small livestock farms. It was only at the finest sampling scale, with numerous camera traps arranged in discrete clusters at independent sites, that I detected all of the rare species present in the region, including the targeted riverine rabbit. Using a multispecies occupancy model that accounts for ≥2 interacting species, I showed that riverine rabbit occurrence was conditional on the absence of close competitors– namely scrub and cape hares– and smooth terrain. These results will better align ongoing conservation efforts for the species, which currently focus exclusively on environmental restoration of assumed preferred habitat. Overall, my findings reveal a diverse community of mostly medium sized generalist species that have persisted throughout the Karoo despite hundreds of years of sustained human impact. Larger predators and herbivores were almost entirely restricted to protected areas, and the PPA provided the only refuge for the critically endangered riverine rabbit. Whilst the predicted impacts of climate change and extractive mining on the mammals of the Karoo remain poorly understood, this thesis provides an important baseline of the extant mammal communities across the three dominant land–uses. Long term monitoring of select sites would provide a better understanding of how local and global anthropogenic impacts may affect the future of mammals in the drylands of South Africa.
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    Scale and impact of the illegal leopard skin trade for traditional use in southern Africa
    (2020) Naude, Vincent Norman; Bishop, Jacqueline; Balme, Guy A; O'riain, Mannus
    While leopards (Panthera pardus) currently occupy the most extensive geographic range of all large felids, they are also suffering the highest rate of current range loss amongst large terrestrial carnivores. This is primarily because most leopards still range outside of formally protected areas where they are exposed to the full suite of anthropogenic threats affecting carnivores including habitat loss, prey depletion, conflict with humans, and commercial harvest for body parts. The extensive use of leopard derivatives among traditional healers, royalty, and culturo-religious groups poses a known but poorly understood threat to leopards. Sociopolitical sensitivities surrounding cultural identity and the illegality of much of this use have impeded an objective assessment of both the drivers and impacts of this threat. Through a multi-disciplinary approach, this thesis describes the drivers of illegal leopard skin trade among a significant portion of traditional users in South Africa, quantifies the extent of this trade across the southern African region and assesses its impact on local leopard populations. Together these findings seek to address the lack of conservation- and policy-relevant data regarding the impact and scale of the trade for traditional use in South Africa. Followers of the recently established ‘Shembe' Church, with its estimated membership of over four million in South Africa, represent the foremost culturo-religious users of illegal leopard skins in the world. Following the introduction of a faux skin alternative, I used longitudinal surveys to explore the drivers of authentic skin desirability and possession amongst faux skin recipients. While demand for authentic skins decreased, and faux alternatives were generally considered satisfactory, 27% still expressed a desire for an authentic skin, and 15% had acquired one in the three years since receiving their faux skin. Both desiring and having obtained an authentic skin were best explained by improved economic status and the perceived weakness of law enforcement. The combined demand of all Shembe followers cannot be sustained by the estimated extant leopard population of South Africa, and it is predicted that traders must be sourcing leopards from surrounding range states to meet local demands. To investigate this, I created a genetic reference database of leopards across southern Africa (1,452 individuals) and using DNA-based assignment tests, inferred the geographic origins of illegally traded skins sourced within southern Africa. Smoothed continuous assignment techniques revealed leopard source ‘hotspots' in southwestern Zimbabwe, southern Mozambique and along the eastern borders of South Africa confirming suspicions that the illegal leopard skin trade for traditional use in South Africa is transnational. A similar distribution of leopard source populations was identified from leopard parts obtained in traditional wildlife markets and a large-scale confiscation from a single trader. Together, this suggests the regional trade in leopard parts has been syndicated with predictable harvesting and trade routes into the South African consumer market. Genotyping across all trade samples (237 individuals) revealed a clear bias towards males despite reported sex-ratios being female-biased for natural free-ranging populations. To understand the ecological cost of this sex-biased exploitation of leopards, I compared the spatial, genetic, and demographic data of two South African leopard populations with markedly different histories of anthropogenic mortality. Home-range overlap, parentage assignment, and spatio-genetic autocorrelation showed that extensive historical exploitation, linked to Shembe and other traditional trade, has reduced subadult male dispersal, thereby facilitating opportunistic male natal philopatry. The resultant kinclustering in males is comparable to that of females in the well-protected reserve and has promoted localised inbreeding. Together these results demonstrate novel evidence linking significant ecological consequences to an underestimated, transnational, and syndicated illegal leopard skin trade driven by demand for traditional and religious use in South Africa. These findings are translatable to all leopard populations threatened by exploitation and emphasise the importance of long-term monitoring of leopard populations within protected areas and improving management interventions to mitigate these effects. Interventions such as anti-poaching can be focussed on the ‘hotspots' identified in this study while protected area management should prioritise the maintenance of dispersal corridors to promote in situ recovery of exploited populations. Lastly, demand reduction strategies such as the continued provisioning of suitable alternatives, together with improved education and increased enforcement, are essential to addressing the growing culturo-religious demand for leopard products contributing to the illegal harvest and trade in this iconic large predator. Success will depend on finding the balance between an improved transnational policy which effectively conserves wild leopard populations and maintaining respect for cultural practices
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    The application of spatial capture-recapture models to investigate leopard ecology and conservation in South Africa
    (2021) Rogan, Matthew S; O'riain, Mannus; Distiller, Gregory
    Population monitoring is essential to wildlife conservation and management. Rare and elusive species are difficult to observe, and hence monitor, in wild populations. Leopards (Panthera pardus) are an iconic and threatened species whose conservation is hampered by a lack of robust population data, in part due to their sparse populations and cryptic nature. I used cameratrap surveys from 27 protected areas in northeastern South Africa to make inferences about the status and conservation needs of leopards. I first evaluated the relationship between leopard density and proportion of area used within protected areas to determine if the latter could serve as a more efficient yet robust proxy for the former. I found that the relationship was too imprecise to be informative, that many populations of varying density used all the space available, and that the scale of individual movement strongly influenced the proportion of area used regardless of density. I then fit multisession spatial capture-recapture models to time series data from seven of these leopard populations to assess their threat level based on the estimated probability of population declines. I found some evidence of decline in six of the seven populations and found that the population at one site has a 75% chance of declining by 80% over three leopard generations. Lastly, I investigated the relative influence of bottom-up ecological factors and top-down anthropogenic factors as possible determinants of leopard density to identify what conditions are most suitable for conserving leopard populations. I found that while habitat and management characteristics of protected areas matter, human impacts around and within protected areas are the primary drivers of variation in leopard density. Based on these analyses, I conclude that South African protected areas are not conferring sufficient protection to leopard populations and that more must be done to mitigate human impacts inside protected areas. I also show that the leopard monitoring program would benefit from longer surveys with more sampling locations to increase the statistical power for detecting changes. This thesis demonstrates the capacity for large-scale monitoring programs to greatly expand our understanding of the conservation needs of a cryptic species.
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    The density of leopards in a mixed-use landscape in the Western Cape, South Africa
    (2023) Hinde, Kyle Cameron; O'riain, Mannus
    Large carnivores face numerous threats, including habitat loss and fragmentation, direct killing, and prey depletion, leading to significant global range and population declines. Despite these threats, leopards (Panthera pardus) persist outside protected areas throughout most of their range, occupying a diverse range of habitat types and land uses, including peri-urban and rural areas. Our understanding of leopard population dynamics in mixed-use landscapes is limited, especially in South Africa, where most research has focused on protected areas. Here I use spatially explicit capture-recapture (SECR) models on camera trap data to estimate how leopard density varies across a mixed-use landscape of protected areas, farmland, and urban areas in the Overberg region of the Western Cape, South Africa. Data were derived from 86 paired camera stations, which collected data for 161 camera trap nights, providing 221 independent leopard captures at 50 camera trap stations. A total of 25 individual leopards were identified, and the best-performing SECR model included the covariate sex on the σ (spatial decay), and a combination of sex, vegetation type and the interaction on λ0 (capture probability), with a density estimate of 0.64 leopards per 100 km2 . Elevation, terrain ruggedness, protected area status and NDVI were all important drivers of leopard density in the region, with leopard density highest on elevated remnants of natural land outside of protected areas. These results are similar to previous research findings in the Western Cape, where high-lying natural vegetation was shown to serve as both a refuge and a corridor for leopard movement in otherwise transformed landscapes. Given the low level of risks to lives and livelihoods posed by leopards in this region, the continued persistence of leopards in this shared landscape is considered high. Education of landowners should still be prioritised to improve tolerance towards leopards in the event of occasional negative impacts (e.g., livestock depredation).
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    The effects of land use change, from small livestock farming to protected area, on vegetation and mammal communities in the SKA region of the Karoo, South Africa
    (2021) Blanckenberg, Michelle Claire; O'riain, Mannus; Bronner, Gary
    Land-use change, particularly agriculture, has been identified as one of the major drivers of biodiversity loss worldwide. Meeting global biodiversity targets requires both the establishment of protected areas (PAs) and learning to coexist with wildlife in human-modified landscapes, particularly extensive rangelands. In the semi-arid regions of the Karoo, South Africa, small livestock production has been the primary land use for more than 350 years. This extensive agricultural activity has allowed much of the native flora and fauna to persist leading to a complex interplay between vegetation, livestock, humans and wildlife. Most farmers strive to optimise livestock production and thus actively seek to reduce or eradicate wild predators and competitors of livestock. It is against this background that the recent establishment of a large (131 000 ha) protected area within a well-established small livestock farming region in the Karoo represents a rather unprecedented event with clear benefits for biodiversity and both real and perceived costs to the farming community. This landscape level shift in land use from farming to protected area provided a unique opportunity to design a Before-After-ControlIntervention (BACI) study investigating how a cessation in farming activity impacts both natural vegetation and wildlife. I hypothesised that this change would positively impact vegetation, and small and medium/large mammals. To test this, I compared biota using standard surveys on farms before and after the cessation of farming (core, n = 3) and compared this to both neighbouring farms (edge, n = 3) that are likely to be impacted by the land use change and farms at least 50 km from the new PA (control, n = 3). I also explored the condition, maintenance levels and success of fences between the core and edge farms at preventing the movement of wildlife onto edge farms. Before the cessation of farming activities on the core, species richness and the abundance of vegetation, small mammals and medium/large mammals were similar across all farm types. After the cessation of farming activities forb cover and grass height increased slightly on core farms, while small and medium/large mammal richness and abundance remained constant. Daily activity patterns for several medium sized mammals shifted on the core farms from almost exclusively nocturnal to more diurnal. Both caracal and black-backed jackal naïve occupancy remained constant on all farm types over the study period. Despite this, edge farmers (as well as control farmers) complained of increased predator numbers and livestock losses and their attitudes to predators and the PA worsened over the study period. These perceived changes may well have been attributed to the extreme drought conditions that prevailed during the study. Most farmers resorted to food provisioning which concentrates livestock at feeding sites and around farm buildings both increasing the detection of livestock by predators and the detection of predators by farmers. Well maintained fences significantly reduced wildlife movement in general and predator movement from the core to edge farms. Poor quality and poorly maintained fences had a higher incidence of mammal movement along the fence line and a higher frequency of hole utilisation, particularly by small and medium sized herbivores. Overall, my results support expert predictions that the recovery of both flora and fauna in the Karoo following cessation of sustained livestock farming will be slow and dependent on rainfall. The drought conditions that prevailed during the study may well have dampened a resurgence in primary productivity on core farms and with that the recovery of small mammals and medium sized herbivores, followed by their predators. It will be important to continue monitoring these farms over the medium/long term to better understand the relative impacts of farmers and livestock on the flora and fauna of the Karoo and the recovery of biota within this newly proclaimed PA especially where abiotic factors such as variability of rainfall may confound these influences. In the interim improving relationships between farmers and managers of the PA is essential and will largely depend on the quality and maintenance of the fence line that separates these different land uses.
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    The spatial ecology and behaviour of the broadnose sevengill shark (Notorynchus cepedianus) in South Africa
    (2024) Engelbrecht, Tamlyn; O'riain, Mannus
    Top predators are an important component of healthy ecosystems, contributing to ecosystem stability and biodiversity through direct and indirect effects. However, significant knowledge gaps exist in our understanding of the occurrence, biology and spatiotemporal dynamics of marine predators, limiting our ability to conserve these species in the face of anthropogenic threats. The broadnose sevengill shark (Notorynchus cepedianus) is a marine top predator with a global distribution in coastal and shelf waters of temperate regions. This species faces exploitation across their range and are classified as “Vulnerable” on the IUCN Red List of Threatened Species. In this thesis, the distribution, growth rates, spatiotemporal dynamics and habitat use of N. cepedianus in the coastal waters of southern Africa were investigated. Firstly, the distribution and growth rate of N. cepedianus in southern Africa were investigated using data from the Oceanographic Research Institute's Cooperative Fish Tagging Project. Broad-scale patterns in coastal presence, movement and population connectivity were then investigated for both sexes and a range of sizes of N. cepedianus in South Africa using acoustic telemetry, and a national scale array of acoustic receivers (the Acoustic Tracking Array Platform). Finally, an array of acoustic receivers in False Bay, Cape Town, were used to investigate patterns in the presence and fine-scale movement patterns of N. cepedianus in False Bay. During data collection, several unexpected predations on N. cepedianus by killer whales (Orcinus orca) occurred in False Bay, providing a unique opportunity to investigate the impacts of a novel apex predator on the behaviour of N. cepedianus. Overall, the results showed that N. cepedianus has a broad distribution in temperate coastal waters of southern Africa, ranging from northern Namibia to the Eastern Cape Province of South Africa. Growth rates for N. cepedianus at reference lengths of 100 cm and 160 cm (PCL) were estimated to be 4.7 cm.year-1 and 4.0 cm.year-1 , respectively, which are slower than previous growth estimates for this species. Population connectivity was established between the west and south coasts of South Africa, but not between South Africa and Namibia. Tag recapture data and acoustic telemetry showed that N. cepedianus of all sizes display site fidelity to certain coastal sites, and most movements had a limited range (<50 km). However, a few individuals of both sexes and a range of sizes made large-scale coastal movements of up to 600 km, highlighting that a portion of the population roams more widely. Acoustic telemetry also confirmed size and sex segregation by N. cepedianus at coastal sites in southern Africa. These findings can be used in stock assessments and to guide spatial management for this species. Within False Bay, most female N. cepedianus showed high site fidelity to Miller's Point, a large, well-known aggregation site for this species, and were observed returning for up to four consecutive years after extended periods of absence. However, following O. orca predation events, tagged N. cepedianus fled the site within 24 hours for up to 290 days. There was a notable decrease in the number of N. cepedianus that returned to Miller's Point following each of the four confirmed predation events by O. orca, until eventually, the sharks abandoned the aggregation site completely. Displacement of a top predator (N. cepedianus) by an even higher-level predator (O. orca) is expected to have cascading effects on ecosystems, highlighting the need to monitor impacts to better understand the ecological role of sharks and the consequences of population declines.
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    Under the skin of a culture: perceptions of fake leopard skin alternatives in the Shembe Baptist Church
    (2024) Mabaso, Xolani X; O'riain, Mannus; Nattrass, Nicoli; Naude, Vincent
    Since prehistoric times, big cats such as leopards have had symbolic importance in human culture. They are prized as symbols of power, nobility, ferocity and very often, masculinity. Religious groups have also been known to wear animal skin as part of their ceremonial regalia, typically for aesthetic, superstitious and spiritual reasons. However, throughout much of their historical distribution, leopards have been actively hunted, poached or killed in retaliation for livestock losses so extensively that many of their populations are now under direct threat. Despite attempts to control illegal harvesting and trade through international conservation organizations such as CITES the use of and trade in leopard products remains commonplace throughout their range. In Southern Africa one of the most widespread and obvious users of leopard skins are members of the Shembe Nazareth Baptist Church. The Shembe church, which has approximately 6 million followers, was founded by Prophet Isaiah Shembe on 1910 in Durban, South Africa. This modern take on Zionist beliefs integrates aspects of Christianity and traditional Zulu beliefs. Followers wear white, full length garments when praying and a diverse array of animal skins when engaging in traditional dance. The most popular and prestigious animal skin is that of a leopard. Given concerns around the increasing demand for leopard skins, Panthera (cat conservation NGO) initiated the Furs for Life project in 2013, introducing synthetic leopard skin alternatives to real skins. These ‘faux' skins were donated to the Shembe church for dissemination among their followers, with the hope that this would ultimately reduce demand for real skins. While approximately 24,000 faux furs have been distributed within the Shembe church to date, little is known about how well these have been received or how effective this conservation intervention has been. In this brief, exploratory study 100 randomly selected recipients of faux furs were surveyed to address concerns pertaining to: faux fur use, demand for real skins, consumer satisfaction, knowledge of conservation and policy perceptions, through a descriptive statistics and basic generalised linear model framework. We found that after a period of three years, at least 90% of the respondents still have their fake furs, have been using them approximately six times a year and were positive about the product they received from Panthera. More than 60% of respondents are aware of leopard population trends, and 66% of respondents believed that the government should intervene in leopard conservation. Faux leopard furs have been very successful, reporting a higher than 50% usage in Shembe gatherings, with most respondents indicating how aesthetic and durable faux furs are as well as how similar they are to real leopard fur. As this was a pilot study with only 100 respondents so statistical power was limited given the number of variables, we suggest a similar study done on a larger scale to understand the efficacy of the intervention.