Browsing by Author "O'riain, Justin"

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    A camera trap assessment of factors influencing leopard (Panthera pardus) habitat use in the Nouabalé-Ndoki National Park, Republic of Congo
    (2018) Mavinga, Franck Barrel; O'riain, Justin; Mann, Gareth; Breuer,Thomas
    Leopards (Panthera pardus) are faced with increasing levels of anthropogenic pressure resulting in population declines across much of their historical range. While there is relatively limited knowledge of leopards occurring in African rain forests, their abundance and distribution is assumed to be impacted by a combination of several anthropogenic factors, most notably loss of prey and habitat conversion. In this study I used a long-term camera trap array that forms part of the Tropical Ecology, Assessment and Monitoring (TEAM) project - Terrestrial Vertebrate (Camera Trapping) Monitoring Protocol, to estimate the species richness of mammals, the relative abundance of leopard prey species and leopard habitat use in the Nouabalé-Ndoki National Park (NNNP) in the Republic of Congo. I investigated the impact of different environmental and anthropogenic factors on leopard occurrence at two camera trap arrays (a northern and southern cluster) within the NNNP using occupancy modelling. While there were no significant differences in mammalian species richness between the two clusters there was a higher relative abundance of the preferred prey species of leopards in the northern cluster. A total of 106 leopard photographic events were recorded across all camera traps and all survey years. The top occupancy model produced an average probability of site use (ψ) over all sites of 0.52 ± 0.14 (SE). The covariate specific β-coefficient estimate suggests that leopard occurrence and detectability were positively correlated with both the relative abundance of the blue duiker (Philantomba monticola) and the distance to the nearest river (β =0.062 ± SE 0.053 and 6.55 ± SE 10.84, respectively). Therefore there was no support for the prediction that the probability of leopard habitat use increases with a higher relative abundance of all potential prey species, nor was there support for the prediction that leopard habitat use would be higher further away from human settlements (β =3.42 ± SE 2.94). 2 Leopard habitat use was higher in the southern cluster which may be linked to the denser understory that would provide greater cover which is important for improved hunting success in leopards. Together, these results suggest that both the prey species and leopards appear to be thriving within the NNNP with limited evidence of anthropogenic impacts despite an increase in commercial logging and the itinerant bushmeat hunting in the peripheral area. It would be worth expanding the existing camera trap arrays to cover a greater spatial extent within NNNP and hence allow for a more detailed analysis of edge effects and to detect the potential impacts of anthropogenic activities which are predicted to increase in selected villages in the periphery of the park.
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    Behavioural and physiological responses of chacma baboons (Papio ursinus) to wildfire in the Cape Peninsula of South Africa
    (2018) Dubay, Shannon; O'riain, Justin; Lewis, Matthew; Swedell, Larissa; Foerster, Steffen
    In an ecological context, ‘flexibility’ refers to an animal’s ability to respond immediately to environmental stimuli through physiological and behavioural adjustments. Specifically, primates exhibit a high degree of ecological flexibility, which allows them to persist through environmental changes that vary in duration and predictability. To cope with the variability of conditions within their habitats, baboons have evolved flexibility in ranging behaviour, social behaviour, and diet. Natural disasters are predicted to increase across the globe, and many parts of the world are experiencing longer wildfire seasons and higher wildfire frequencies than ever before. The aim of this study is to use an existing data set to assess how baboons responded, behaviourally and physiologically, to an extensive wildfire. I compare home range use, activity budgets, faecal glucocorticoid concentrations, and urinary C-peptide concentrations three months after the fire to the same three months in the previous year for the same 16 adult females. In the months following the fire, the baboons had a larger spatial range compared to the same months in the year prior. The additional area incorporated unburnt areas into their home range, which were preferentially used over burnt areas. Behavioural adjustments included notably less time spent engaging in social behaviours than in the year prior. Perhaps most surprisingly, postfire physiological indicators did not suggest high levels of psychological, energetic, or nutritional stress, as glucocorticoid concentrations were significantly lower post-fire compared to the year prior, while C-peptide concentrations were not significantly different between the two periods. The troop appears to have benefited from a surfeit of exotic pine seeds that were released by pine trees as a result of the fire. This unexpected nutritional windfall, in addition to the inclusion of vineyards within their ranging patterns, may explain why there were no physiological indicators of nutritional stress despite the loss of most above ground biomass. Despite suffering the loss of 12 troop members in the fire and injury to a further 12 individuals, adult females in the Tokai troop were able to adjust to a severe and extensive change to their home range. Although primate ecological flexibility has been widely documented, this is the first study to explore the behavioural and physiological responses of baboons to extensive habitat changes resulting from a wildfire, and the potential implications for the management of wildlife on the urban edge.
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    Environmental predictors of Carcharodon carcharias presence at two popular beaches in False Bay, South Africa using acoustic telemetry
    (2018) Van Beuningen, Dave; O'riain, Justin; Kock, Alison; Irion, Dylan
    By understanding when white sharks (Carcharodon carcharias) are likely to be at certain popular beaches, it is possible to predict when the risk of overlap between water users and white sharks is highest, and to convey this information to the public so they can make informed decisions about using these areas. Previous studies have shown that white shark presence near popular recreational beaches in False Bay, South Africa, is influenced by a range of environmental variables. These studies have relied on land-based observers (shark observers), whose ability to detect sharks is subject to the depth at which the sharks swim and a suite of environmental conditions that influence water visibility, including cloud cover, wind speed and ambient light levels. In this study, I use passive acoustic telemetry on 56 tagged white sharks to determine whether the same or other environmental variables explain variation in white shark presence at the same beaches. A total of 13 803 and 1 481 white shark detections were recorded between April 2005 and December 2007 at Muizenberg and Fish Hoek beaches, respectively. This represented 32 and 16 individual white sharks with a median number of 32.5 (range 5.5 – 57.8) and 7 (range 4 – 14.8) detections per shark at Muizenberg and Fish Hoek beach, respectively. The low number of detections at Fish Hoek resulted in the data being highly zero-inflated with the result that the subsequent modelling of the data with environmental covariates did not converge, and hence I focused solely on Muizenberg beach. The probability of detecting a white shark at Muizenberg beach was modelled using binomial generalised additive mixed models (GAMMs) with water temperature, wind speed, wind direction, cloud cover, lunar phase, tide height, barometric pressure, year, season and time of day as predictor variables. Water temperature was a significant predictor of white sharks at Muizenberg beach during summer, autumn and winter while wind speed, time of day and barometric pressure were significant predictors of shark presence during the summer and autumn months. There was significant inter-annual variability in white shark detections and a strong seasonal relationship, with presence being highest during spring and lowest during winter. Encouragingly, the findings from this study support some of the key findings of previous studies using observational data, including the significant positive effects of increasing temperature, year, season and time of day.
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    Estimating leopard density in a coastal protected area of the Western Cape, South Africa
    (2022) Hargey, Ayesha; O'riain, Justin; Mann, Gareth
    Leopards (Panthera pardus), like many other large carnivores, are facing increasing threats including habitat degradation, illegal hunting, and persecution for perceived or actual livestock depredation. Protected areas remain the cornerstone of conservation efforts throughout the world but they are not a panacea and recent studies have shown declining populations within many protected areas of South Africa. Efforts to improve leopard conservation are hampered by a lack of reliable and repeated estimates of population size across their distribution, which limits an understanding of population dynamics and the potential drivers of declines. Monitoring efforts that produce density estimates are invariably the most informative for reserve managers who work with endangered species and are responsible for regional conservation planning – especially in cases where both predator and prey are of vulnerable populations. A small coastal area within the De Hoop Nature Reserve has been fenced off from the reserve with the goal of establishing a mainland breeding colony for the endangered African penguin (Spheniscus demersus). The fence is designed to reduce the threats posed by terrestrial predators, particularly leopard and caracal (Caracal caracal). Both feline species engage in supernumerary killings of penguins due to their poor predator response and are thus of special relevance to reserve managers and NGOs committed to their conservation. In this study, I conducted a camera trap survey in the De Hoop Nature Reserve, along the south coast of the Western Cape with the primary objective of estimating the density of leopards and the secondary goal of understanding the distribution, abundance, and activity patterns of leopard and caracal relative to the proposed penguin colony. I deployed 40 paired camera trap stations over 2457 trap nights and captured 312 independent images of the target taxa. A sample-based species accumulation curve revealed a clear asymptote indicating adequate sampling effort and a total of 24 medium and large mammal species. Both leopard and caracal had high relative abundance indices at camera stations close to the designated penguin colony. I recorded 111 independent images of leopards, of which six males and one female could be reliably identified. I derived a density estimate of 0.18 ± 0.07 individuals per 100km2 which is lower than estimates for protected areas in the eastern and northern regions of South Africa, and lower too than other estimates obtained from the fold mountains of the Western Cape. Coastal fynbos has low productivity and supports a low prey biomass relative to other biomes in South Africa, and thus the density may be justifiably lower than in other more productive habitat types. Of immediate concern is the heavily skewed sex ratio (6M:1F) and low total population size which — together with a permeable boundary fence and known persecution of leopards on neighbouring farms — makes this population vulnerable to both stochastic events and edge effects. Lethal management of leopards that threaten penguins would not be sustainable and thus it is important that a non-lethal barrier has been implemented as it offers the prospect of coexistence between two endangered and charismatic species.
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    Human safety and shark conservation: an analysis of surfer risk perceptions and attitudes towards shark management
    (2020) Sheridan, Katherine; O'riain, Justin; Needham, Mark; Nattrass, Nicoli
    South Africa has a history of human conflict with sharks and shark safety management. Management of this conflict differs throughout the country, with Cape Town opting for a non-lethal approach in the form of the Shark Spotters programme, and Kwa-Zulu Natal (KZN) opting for a lethal approach using shark nets and drumlines. Lethal management of sharks stems from a belief that without it, people would be too afraid to go in the water, leading to adverse effects on tourism and other associated industries. I assessed surfers' perceptions of risk from sharks, how they value sharks, their knowledge of sharks, and their attitudes towards shark management. I surveyed surfers at Muizenberg Beach in Cape Town, and North Beach and Bay of Plenty Beach in Durban by asking them to answer questions in a questionnaire. A conjoint analysis assessed how likely respondents were to go in the water under various scenarios using situational factor levels related to shark presence, surf/sea and spotting conditions, and whether other people were in the water. The questionnaire results showed no support for lethal shark control and only 8.3% of respondents were aware the nets used in KZN were a lethal form of shark control. Respondents had good knowledge of shark ecology and a positive perception of sharks, both of which have been shown to benefit shark conservation in previous studies. A multiple linear regression model showed a positive correlation between perception of shark risk and perception of other risks, such as car accidents and natural disasters, with respondents perceiving other risks as greater than shark risks. In the conjoint analysis, shark presence was the most influential factor for surfers deciding to go in the water, but respondents were more likely to go in under good surf conditions and spotting/sea conditions even if a shark had been seen recently. Overall, sharks do not deter people from going in the ocean. Implications of these results undermine the longstanding argument that lethal shark management is necessary to protect tourism. Furthermore, the lack of knowledge that lethal shark control is being practised in South Africa coupled with the opposition to lethal management found in this study highlights a clear disconnect between water users and shark managers in KZN.
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    Investigating the hidden costs of livestock guarding dogs and the diet of a sympatric predator in Namaqualand, South Africa
    (2018) Kelly, Caitlin; O'riain, Justin; Drouilly, Marine
    The global decimation of carnivore populations has been called one of mankind’s most pervasive impacts on the natural world. Human-wildlife conflict over the threat (both real and perceived) predators pose to livestock is one of the leading causes of carnivore decline worldwide. Livestock guarding dogs have been widely acclaimed as an environmentally friendly tool for reducing this conflict, yet little is known about the hidden costs of their presence. This study used scat analysis to reconstruct the diet of livestock guarding dogs and local caracals (Caracal caracal) to better understand their impacts on biodiversity and livestock in Namaqualand, South Africa. For livestock guarding dogs, 187 scats revealed the consumption of (from most to least frequent): livestock, wild mammals (including ten native species), vegetation, anthropogenic items, invertebrates, reptiles, fruit and birds. However, the diet of dogs accompanied by a human attendant differed significantly (χ 2 = 94.075, p < 0.001) from dogs guarding sheep independently. While 75% of scats collected from dogs operating independently contained domestic ungulates, less than 5% of scats from dogs with a human attendant contained livestock. For caracals, 185 collected scats were analysed across two land uses: Namaqua National Park and surrounding farms. Eighteen mammalian prey species were identified in their overall diet, with medium sized (1-10 kg) mammals (particularly the rock hyrax, Procavia capensis) accounting for more than half of consumed prey (59.1%). Small mammals (<1 kg) and wild ungulates were consumed more frequently in the protected area than on farmland. Livestock comprised 16% of the mammalian biomass consumed on farms, however no livestock was found in caracal scat within the protected area. These results support a growing body of research that suggests caracals do not prefer livestock, but will consume them when their numbers are considerably higher than that of wild prey, as is the case on many farms. Although this analysis cannot differentiate between predation and scavenging, the results provide novel insight into the potential impacts of livestock guarding dogs on the landscape and their overall effectiveness as a nonlethal predator management tool. This can help inform livestock guarding dog training and predator management while providing key information about the diets of both an indigenous and introduced predator.
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    Landscape utilisation by an introduced pack of African wild dogs (Lycaon pictus) in eastern Botswana
    (2018) Mottram, Phoebe; O'riain, Justin; Mann, Gareth; Snyman, Andrei
    African wild dogs (Lycaon pictus) are one of the most endangered carnivores in southern Africa. Direct persecution, prey decline and habitat loss and fragmentation all contributed to a rapid decline in this species’ population size and distribution during the 20th century. Following a thorough population viability analysis in the late 1990s the decision was taken to manage the South African population as a metapopulation. This involved the reintroduction of packs to small, fenced protected areas and the subsequent transfer of individuals or small groups between reserves to avoid inbreeding. A key component of successful metapopulation management is post-release monitoring to provide data on the determinants of reintroduction success and failure, particularly when establishing new populations. This study aimed to provide information on the post-release behaviour and movements of a pack of eight African wild dogs introduced to the Northern Tuli Game Reserve in eastern Botswana in February 2017. Two individuals from the introduced pack were fitted with GPS collars. A total of 933 GPS locations were recorded between February 2017 and October 2017. Movement data was used to analyse home range, habitat resistance and resource utilisation by this pack across a range of spatial and temporal scales. Monthly 95% kernel density estimations revealed a mean home range of 330.02 km2 . A reduction in home range size to 37% of the average monthly 95% kernel density estimations revealed that the pack commenced denning in May 2017. However, this denning attempt failed, as shown by the home range size increasing only a month after it initially contracted, which is less than the expected contraction period required to produce a successful litter. Habitat resistance analysis revealed that the pack readily crossed fences but not rivers, with the Limpopo river serving as a very hard barrier that consistently deflected pack movement parallel to its course. Resource utilisation functions showed a preference for sites far from riverine areas, with low elevation and rough and rocky terrain. I propose that this may reflect a predator avoidance pattern, with lions (Panthera leo) in particular preferring riverine habitat with a less rough terrain in this area. The persistence of this pack in the landscape nine months post-release indicates that this reintroduction has been a partial success. Large perennial rivers provide important barriers to the movement of this pack and may thus be important for mitigating local human-wild dog conflict. Fences, however, were readily traversed and therefore communities outside of fenced areas are likely to experience conflict with this pack and any future packs re-introduced to this area.
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    Life on the edge: exploring the effects of urbanisation on the foraging ecology and ecotoxicology of caracals
    (2021) Leighton, Gabriella Ruth Michaela; Bishop, Jacqueline; Serieys, Laurel; O'riain, Justin
    The continuing loss of natural habitat to a broad range of human activities is one of the main drivers of biodiversity decline worldwide and a defining feature of the Anthropocene. However, some opportunistic, generalist species may benefit from transformed landscapes through, for example, the absence of apex predators or access to human-subsidised food resources. These benefits may thus offset the higher mortality and health risks typically associated with human-dominated landscapes. To understand the cost-benefit trade-offs of life on the urban edge, I investigated the foraging ecology and ecotoxicology of a highly adaptable medium-sized carnivore, the caracal (Caracal caracal), utilising both natural and transformed landscapes around the rapidly growing city of Cape Town, South Africa. Through a combination of scat analysis (n = 654 scats) and prey remains located at 677 GPS clusters, I quantified dietary resource use of 26 collared individuals, as well as opportunistically sampled caracals. Using a range of gut transit times, I estimated whether scat at cluster sites was from the same or an earlier feeding event, thereby increasing the overall detection of individual-specific feeding events by > 50%. While most feeding events occurred within 200 m of the urban edge of Cape Town, I found that caracals have flexible diets that largely comprise medium- to small-sized wild prey (60%), followed by human-associated species (27%), and introduced or domestic species (13%). Using a subset of the feeding and resting events (n = 326 prey remains, n = 384 scat, n = 177 resting sites) that were associated with known individuals (n = 17), I then investigated caracal resource selection using both anthropogenic and environmental factors. Additionally, I examined the behaviour of caracal at feeding clusters to determine if they respond to spatial and temporal risks associated with anthropogenic factors. I found divergent resource selection patterns based on the level of exposure to urbanisation: caracals living in the urban-dominated region of the Peninsula (n = 14; 548 feeding events) select for the urban edge, while caracals in the wildland-dominated region (n = 3; 162 feeding events) strongly avoid it. I argue that in the more urbanised region, caracals forage on or close to the urban edge because this is where the remaining low-lying wildland habitat is most productive and attractive. Consequently, caracals in heavily transformed areas, which might otherwise tend to avoid human disturbance, have habituated to human presence but reduce their risk of detection by remaining cryptic, prolonging handling time, and maintaining high feeding site fidelity where cover is available. To quantify the consequences of peri-urban foraging, I use an ecotoxicological approach to assess environmental contamination and its potential effects on caracals. It is widely reported that persistent organic pollutants (POPs), including organochlorines (OCs) such as PCBs and DDT and its metabolites, are extremely toxic, causing adverse effects on wildlife and human health. I tested blood and adipose tissues of caracals, with different diets utilising a range of natural and transformed landscapes, for exposure to commonly detected OCs. Despite restrictions on their use, I found extensive OC burdens, with 100% of adipose samples exposed to both DDT and PCBs, and 100% and 83% of blood samples exposed to DDT and PCBs respectively. Caracals using areas with a higher density of people and electrical transformers, and those using areas close to informal settlements, had higher exposure to OCs. Additionally, the use of vineyards and wetlands and a diet with a greater proportion of higher trophic level or exotic prey correlated with a higher risk of exposure to OC pollutants. Full blood analyses revealed that exposure levels to OCs were also associated with higher counts of infection-fighting cells, suggesting these compounds may affect the immune response of individuals. With time, these detrimental effects may have population-level repercussions through impacts on reproductive success and fitness. Together these findings reveal that while caracals and other medium-sized adaptable carnivores may persist within or adjacent to human transformed habitats, they still prefer natural habitat and pay a significant cost for foraging on prey species that have been contaminated by pollutants associated with urban and rural land uses. Urban edges may thus be an ecotoxicological trap, threatening the health and long-term persistence of caracals and other wildlife in this and other biodiversity hotspots. Reducing environmental contamination and limiting habitat loss to urban sprawl would benefit wildlife living on the transformed edges but requires significant improvements to both the legislation governing pollutants and the spatial planning of cities.
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    Lion population status and ecology in a seasonally-flooded wetland, the Okavango Delta
    (2022) Kotze, Christen Robynne; O'riain, Justin; Loveridge, Andrew J
    The Okavango Delta in north-western Botswana, is a population stronghold for the African lion (Panthera leo). As lion populations are declining, there is a pressing need to develop conservation plans that can secure the future for lion populations in natural environments that face increasing anthropogenic pressure. The Okavango Delta is a dynamic wetland that undergoes significant ecological change in response to an annual flood pulse, the extent of which is determined by both short-and long-term climatic variation. The resulting fluctuations in landscape structure and resource availability affect all trophic levels. However, their effects on apex predators are not well understood. In this thesis, I examined which ecological and anthropogenic factors underpin population processes such as population density, home range size and resource selection of lions in the Okavango at various temporal and spatial scales, in order to better inform conservation plans for this population. As lions can be difficult to count, a situation made more challenging by a seasonally flooded environment, I first looked at camera trapping as a potential survey method for lions. With high resolution images, lions could be individually identified from trap images and spatiallyexplicit capture-recapture applied to produce reliable population estimates. Furthermore, spatial variation in density could be linked to environmental and anthropogenic covariates. Lion densities were highest along the floodplains, and were correlated strongly with vegetation productivity, but decreased with proximity to human settlements, suggesting an edge effect along the boundaries of the wildlife management areas. This edge effect may result from retaliatory killing in response to livestock predation by lions in adjacent community areas but could also be the effect of prey depletion from bushmeat harvesting along the Okavango's boundaries. As flooding can induce significant changes in landscape structure, I examined what effect this had on lion home range size at minimum and maximum flood extent. When floods were at their lowest, home range sizes of males were larger than those of females, which is typical of large carnivores. Females appeared to minimize the area used by prioritizing access to prey, and home range was also negatively correlated with habitat heterogeneity and island size and connectivity. Male home range sizes, however, were not affected by prey availability, but instead were negatively correlated with habitat heterogeneity and proportion of woodland, both of which are considered indices of high-quality habitat in this landscape. As higher quality habitat may result in higher female density, males may instead be trying to maximize access to areas which would have a higher density of females. At peak flood, however, males and females had similar range sizes, and home range sizes were positively correlated with dry land fragmentation. During high flood phases, lower availability of dry land, together with the need to increase home range size as land fragments, could exacerbate intraspecific competition for space, and potentially increase conflict with adjacent communities as floods displace lions towards the boundaries of the wildlife management areas. However, in extended phases of low flood, which could result from prolonged drought, rising 2 temperatures or excessive water abstraction for human use, habitat heterogeneity may decline, with potential negative effects on herbivore and lion populations. Consequently, both scenarios are predicted to ultimately reduce the carrying capacity for resident lions. Lastly, I examined seasonal resource use at a finer scale, and focused on how changes in flooding could affect the size of population cores in the Okavango and connectivity between these, and connectivity from the Okavango to surrounding areas. Seasonal habitat selection by lions mimicked shifts exhibited by large herbivores in other studies on the Okavango, and habitat selection was therefore likely driven by seasonal prey availability. After translating resource selection into resistance maps, I found that seasonal permeability of the landscape to movement differed significantly based on the flood levels. During maximum flood, the lion population within the Okavango becomes fragmented - the population cores in the central, southern and western Delta decrease in size and become isolated from the rest of the Okavango Delta. During both seasons, lions avoided areas close to people, and as a result, connectivity from the Okavango moving outwards to the south and west was limited. Connectivity towards Chobe National Park to the east, however, remained intact. Therefore, restoring connectivity with neighbouring sub-populations to the south and to the west of the Okavango, and reducing anthropogenic pressure on lions in these regions during high flood phases, will help build resilience for the Okavango's lion population and should be considered a conservation priority. Ultimately, the consequences of low and high flood scenarios for lions can serve as a proxy for protracted periods of 'dry' and 'wet' environmental conditions that could result from climate change or upstream water extraction. This study shows that both flood extremes, in the long-term, can be detrimental to the Okavango lion population. It also provides a framework for long-term monitoring of lions in this wetland to be able to detect population changes. The future of the Okavango lion population depends largely on compensating for impacts of climate change by minimizing upstream water offtake to maintain natural flood cycles and reducing other anthropogenic pressures. The results of this study may also provide insights into conservation challenges impacting big cat populations in wetlands elsewhere around the world.
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    On the fence: The impact of education on support for electric fencing to mitigate negative human-baboon interactions in Kommetjie, South Africa
    (2021) Walsh, Debbie; O'riain, Justin; Nattrass, Nicoli; Gaynor, David
    There are few studies that empirically test whether education can improve stakeholder support for a particular wildlife management/conservation intervention. Evidence-based decision making is critical for conservation actions, especially when people and wildlife are engaged in negative interactions to the detriment of both. Rising human and baboon numbers in the Cape Peninsula of South Africa is associated with increasing levels of damage to properties, both indirect and direct human-induced injury and mortality to baboons. A possible management intervention to reduce these negative interactions is a baboon-proof electric fence which has already been shown to be very effective in the suburb of Zwaanswyk on the Peninsula but surprisingly has low public acceptance. For this study, I produced a short survey that included an educational video on the welfare, conservation, and lifestyle benefits of a baboon-proof electric fence. Two versions of the same survey were created but with the educational video provided either before or after questions pertaining to the level of support for the fence. Using a randomised controlled trial method, I tested whether the level of support for the fence changed according to the order of viewing the video. I also used a pre- and post-test method to explore whether level of support for the fence changed for those who watched the video at the end and were given a chance to answer the question again about level of support for the fence. The results showed that watching the video before the survey increased the average marginal probability of supporting an electric fence by 15 percentage points and reduced the average marginal probability of not supporting the fence by 17 percentage points. There was also a significant difference in level of support for the fence in the pre- and post-test experiment, and my results show that women were more likely to adjust their response in favour of the fence. Implications of these results are significant as managing a peri-urban species is considerably more effective if there is collaboration, agreement, and support for management measures between and within key stakeholders. This study contributes to the emerging literature on the importance of education in managing human-wildlife conflict.
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    Spatial distribution and intensity of snare poaching in the Boland region of South Africa: implications for optimising anti-poaching efforts
    (2021) Kendon, Tamar A; O'riain, Justin; Wilkinson, Anita; Naude, Vincent N
    The human population of sub-Saharan Africa is growing exponentially, increasing anthropogenic impacts on natural resources, including wildlife, both inside and outside of protected areas. The rising demand for cheap sources of protein is fuelling the harvesting of bushmeat. In South Africa, illegal wire-snares are the most popular method of bushmeat harvesting. However, snare poaching is indiscriminate and inhumane, causing the death of many non-target species and suffering by all animals captured. The impacts of snaring on an ecosystem can be devastating, yet few studies have explored wire-snare poaching trends in southern Africa or on private agricultural lands. This study used data obtained during 210 snare patrols to investigate the intensity of use and spatial distribution of wire-snares across 111 private agricultural properties in the Boland region in the Western Cape province, South Africa. I considered the influence of social and ecological attributes on property-level snare use, including punitive measure enforcement, the employment of seasonal workers, farmer residency, the use of legal lethal control measures, the number of families on the property, property size, the proportion of natural land, and primary agricultural output. I also considered the influence of anthropogenic structures and abiotic variables on snare placement across the landscape, including elevation, fine-scale land-use types, slope, ruggedness, and distance to the nearest street, river, servitude area, farm boundary, and protected area. Wire-snares were largely placed close to the ground, along game trails and fence lines, and anchored to trees and fence posts. My findings reveal that snare use was higher on properties where the farmer lived permanently on the property (P = 0.005) or the primary agricultural output was orchards (P = 0.043). Snares were more likely to be present further from a public street but within roughly 1 km, close to rivers, at an elevation of 300 to 500 m, and in patches of forest plantations, wetlands, bare ground, and natural woody vegetation. There was also a strong interaction (interaction size = 116.56) between distance to street and proximity to a protected area. The predicted snare hotspots are centred around protected areas at mid-elevation (300-500 m) but are not remote in terms of distance to a public street. It is important to use these findings to inform anti-snaring efforts as wire-snare poaching is likely to be a growing threat to local biodiversity. Future studies should use questionnaires or structured interviews in conjunction with field studies to collect data on snare use. This will help to prevent the misleading interpretation of respondent claims, avoid respondent biases and improve targeted snare removal and law enforcement actions. It will also provide insight into the local context, crucial for identifying potential local drivers of snaring, such as food security, and informing the focus of awareness campaigns.
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    Spatial variation in small mammal communities across the Karoo Shale Gas Development Area of South Africa
    (2020) Nadine, Aboul-Hassan; Bronner, Gary; O'riain, Justin
    This study details results of small mammal surveys at 24 sites in four biomes (Nama- and Succulent Karoo, Albany Thicket, Grassland) as part of the Karoo BioGaps project to augment baseline biodiversity information needed to guide proposed fracking activities in the Shale Gas Development Area (SGDA) (Holness et al. 2016). A strategic Environmental Assessment (SEA), commissioned by the South African Government, evaluated the potential to exploit the supposedly substantial reserves of shale gas using hydraulic fracturing (“fracking”) in the Great Karoo Basin of South Africa. Terrestrial micromammals (<500g) were captured using Sherman livetraps (September 2016 to March 2017). Sampling over 6580 trap-nights produced 339 captures of 271 individuals representing 14 taxa. Trapping success was low 5.14% (mean per site 0.37± 0.61%). Most captures (87%) and individuals (83%) were recorded in the Nama-Karoo (294 captures, 226 individuals, 15 sites), whereas only 5 captures were recorded in Albany Thicket (3 sites). Four xerophilous/generalist species (Micaelamys spp. (Rock rats), Gerbilluscus paeba (Hairyfooted Gerbil), Macroscelides proboscideus (Round-eared Sengi), and Elephantulus spp. were numerically dominant at most sites, and within most biomes/bioregions; while five rare species were only ever recorded once. Mean α diversity (observed species richness Sobs) per site (2.88 ±1.99) and Shannon-Wiener diversity (1.70 overall, 1.04 ±0.33 per site) were low, with only 5.47 effective species (mean = 3.04 ±1.08 per site) and low equitability (0.64 overall). Sobs was highest in Nama-Karoo (13 species), and lowest in the Grassland and Albany Thicket biomes (2-5 species). Species accumulation/rarefaction curves did not reach asymptotes, and Sobs values for most sites/biomes/bioregions were significantly lower than Chao1 predicted species richness, suggesting that sampling effort did not accurately estimate species richness. However, trapping efficiency was generally high (56-100%; mean 86.7%) which compares favourably with that of two recent published studies in South Africa. Multiplicative beta diversity (βMt) across the SGDA was 4.56 indicating high species turnover between sites/biomes/bioregions. Species turnover was high across biome boundaries, notably Albany Thicket-Grassland (15), Nama-Karoo-Albany Thicket (14), and Succulent Karoo-Grassland (12). Biomes and bioregions tended to plot apart in ordination analyses with relatively low (40-60%) Sorenson similarity, indicating that most regional small mammal communities were well-differentiated. Despite data limitations, 66 new distribution records for 21 sites are reported for the SGDA. Total species richness (including historical records) was highest in the Nama-Karoo (19), particularly the Upper Karoo bioregion (19, mean 6.45 ±2.16, 11 sites), followed by the Grassland (16), and Albany Thicket (5) biomes. Total species richness records for most sites/regions fell within the iChao2 CI bounds, thus integrating trapping and historical records provided a relatively robust data set for subsequent spatial diversity analyses. However, even the total species richness dataset is likely to underestimate true diversity owing to not sampling arboreal species or detecting some cryptic species. Generalized linear analyses indicated that small mammal diversity indices were significantly associated with certain environmental/climatic parameters (livestock, drought). Despite the west to east increase in precipitation, highest diversity was concentrated in the arid north-west Nama-Karoo where dwarf shrubs and succulents predominate. This suggests that environmental and niche filtering are significant proximate factors shaping small mammal assemblages. No significant effects of biotic interactions (particularly competition following Diamond's (1975) first two rules) or resource-mediated niche limitations were evident for SGDA species assemblages. However, results for the Nama-Karoo (i.e. for a natural phytogeographical rather than geoeconomically-defined area) were significant suggesting that biotic interactions may also be proximate factors shaping local assemblages. Site assemblages were significantly nested, indicating that species at species-poor sites were subsets of those at richer sites; and thus, that site communities may have been structured by either long-term (ultimate) regional biogeographic processes (e.g. immigration and extinction related to distances between sites) or habitat filtering operating at local scales. Data deficiencies notwithstanding, my results present the most comprehensive landscape-level analysis for small mammals, and the only baseline dataset (based on randomized sampling) for the Greater Karoo and SGDA. While my results must be treated with caution, I am confident that the recommendations I make on species, sites and regions potentially vulnerable will be a useful guide to possible impacts of fracking in the study area.