Browsing by Author "Balme, Guy A"

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    The conservation status and dynamics of a protected African lion Panthera leo population in Kafue National Park, Zambia
    (2014) Midlane, Neil; O'Riain, Justin; Hunter, Luke T B; Balme, Guy A
    The abundance of African lions Panthera leo has declined rapidly in recent decades, largely due to competition for space with growing human populations. The future persistence of the species in the wild therefore depends heavily on viable populations in large protected areas, where lions play key ecological and economic roles. Zambia is one of nine countries estimated to have over 1000 wild lions, and Kafue, its largest national park, is a key refuge for the species. In this thesis I aimed to address the paucity of management and conservation relevant data on Kafue's lion population. I first used a track-based occupancy survey to determine the broad-scale drivers of lion distribution in the park. My results did not support my a priori expectations of anthropogenic edge effects driving lion occupancy; instead favourable habitat emerged as the best predictor of dry season lion distribution. The lack of edge effects is likely a result of the uniform suppressive effect on prey biomass of ubiquitous illegal bushmeat hunting in Kafue. After using my occupancy results to stratify my study area, I tested the effectiveness and efficiency of two well-established survey methods, track counts and call-up surveys, by comparing the resulting density estimates with that of a reference sample of GPS-collared lions in the study area. Accuracy of the two results was comparable, but the call-up estimate was more precise. However, call-up surveys are subject to variation in response rates that is difficult to quantify. I thus recommend that track count surveys are more suitable for monitoring lion population trends in Kafue. I further provide the first robust density estimate for northern Kafue of 1.83 lions (>1yr old) per 100 km2. Understanding how animals use space is fundamental to their conservation. I therefore used GPS collars to investigate lion spatial ecology at a finer scale, and the effects thereon of the seasonal flooding of large parts of Kafue. Home range sizes were comparable to those of other lion populations in the region. However, seasonal inundation caused lions to expand home ranges, travel greater distances and shift away from favourable habitat in the wet season, potentially contributing to apparent high cub mortality rates. The combination of these factors may limit the resilience of the population in the face of identified local anthropogenic threats (i.e. illegal hunting of ungulates and lions, legal trophy hunting of lions and frequent, uncontrolled bushfires). I provide both direct and indirect evidence of such threats, and conclude that lion abundance in Kafue is limited primarily by the suppressed prey population, while the extent and regularity of bushfires may also have adverse effects. I recommend stronger enforcement of existing regulations pertaining to illegal hunting and fires, and the implementation of recently developed monitoring software to improve the efficiency and effectiveness of limited law enforcement resources. I further conclude that lion hunting quotas were excessive prior to the 2013 ban on hunting in Zambia, and suggest that the ban remain in place for at least three years to enable adequate recovery of the population. If the Zambian government elects to lift the ban, I propose a total combined quota of 5.25 lions per annum for the hunting concessions surrounding Kafue. I further recommend the implementation of strict age-based regulations within a robust adaptive management framework, based on the best available scientific data, to ensure the sustainability of harvest. To evaluate the effectiveness of such management interventions I propose long-term monitoring of lion abundance and distribution in Kafue using annual track count surveys. This study highlights that even the largest of Africa's national parks cannot ensure the survival of flagship apex carnivores. My findings and recommendations may be applicable to other wild lion populations in large protected areas where data paucity limits management effectiveness. Understanding and managing threats to these protected areas at the appropriate scale is critical if they are to meet their conservation objectives and ultimately ensure the persistence of wild lion populations.
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    Creating larger and better connected protected areas enhances the persistence of big game species in the Maputaland-Pondoland-Albany biodiversity hotspot
    (Public Library of Science, 2013) Minin, Enrico Di; Hunter, Luke T B; Balme, Guy A; Smith, Robert J; Goodman, Peter S; Slotow, Rob
    The ideal conservation planning approach would enable decision-makers to use population viability analysis to assess the effects of management strategies and threats on all species at the landscape level. However, the lack of high-quality data derived from long-term studies, and uncertainty in model parameters and/or structure, often limit the use of population models to only a few species of conservation concern. We used spatially explicit metapopulation models in conjunction with multi-criteria decision analysis to assess how species-specific threats and management interventions would affect the persistence of African wild dog, black rhino, cheetah, elephant, leopard and lion, under six reserve scenarios, thereby providing the basis for deciding on a best course of conservation action in the South African province of KwaZulu-Natal, which forms the central component of the Maputaland-Pondoland-Albany biodiversity hotspot. Overall, the results suggest that current strategies of managing populations within individual, small, fenced reserves are unlikely to enhance metapopulation persistence should catastrophic events affect populations in the future. Creating larger and better-connected protected areas would ensure that threats can be better mitigated in the future for both African wild dog and leopard, which can disperse naturally, and black rhino, cheetah, elephant, and lion, which are constrained by electric fences but can be managed using translocation. The importance of both size and connectivity should inform endangered megafauna conservation and management, especially in the context of restoration efforts in increasingly human-dominated landscapes.
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    Determinants of predator abundance in northern KwaZulu-Natal: top-down or bottom-up?
    (2014) Woodgate, Zoe Anne; Balme, Guy A; O'Riain, Justin
    As protected areas ultimately aim to successfully conserve natural predator populations, an understanding of the non-anthropogenic drivers of their population change is critical. Both bottom-up (e.g. food limitation, competition) and top-down (e.g. predation, interference) processes play an important role in structuring predator guilds, yet there is a poor understanding of their relative importance. Here, I investigated whether the relative abundance of mesopredators, facultative scavengers, and an apex predator were affected primarily by bottom-up processes (prey abundance) or by top-down processes (predator abundance), or a combination of the two. Central to this study was elucidating the complex relationship between mesopredators and apex predators. Caracal (Caracal caracal), blackbacked jackal (Canis mesomelas), sidestriped jackal (Canis adustus), honey badger (Mellivora capensis) and serval (Leptailurus serval) were classed together as Mesopredators. Facultative scavengers included two hyaena species (spotted Crocuta crocuta and brownhyaena Hyaena brunnea). Leopards (Panthera pardus) were included as an example of an apex predator. Data was obtained from camera-trap surveys conducted in four protected areas located in northern KwaZulu-Natal (South Africa). Results of both a nested analysis of variance and generalised linear mixed models revealed that there was no mesopredator suppression present in protected areas with complete predator guild. In addition, prey and similarly sized predator relative abundance indices (RAIs) had a significant positive effect on mesopredator, hyaena and leopard RAI. The findings suggest that bottom-up drivers are more important than top-down processes in determining the relative abundance of mammalian predators in these protected areas. My study highlights the importance of monitoring prey populations in a protected area when attempting to successfully manage mammalian predator trophic guilds.
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    Estimating spotted hyaena (Crocuta crocuta) population density using camera trap data in a spatially-explicit capture-recapture framework
    (2014) De Blocq , Andrew Dirk; O'Riain, Justin; Balme, Guy A
    Species-specific population data are important for the effective management and conservation of wildlife populations within protected areas. However such data are often logistically difficult and expensive to attain for species that are rare and have large ranges. Camera trap surveys provide a non-invasive, inexpensive and effective method for obtaining population level data on wildlife species. Provided that species can be individually identified, a photographic capture-recapture framework can be used to provide density estimates. Spatially-explicit capture-recapture (SECR) models have recently been developed, and are currently considered the most robust method for analysing capture-recapture data. Camera trap data sourced from a leopard survey performed in uMkhuze Game Reserve, KwaZulu-Natal, South Africa, was analysed using SPACECAP, a Bayesian inference-based SECR modelling program. Overall hyaena density for the reserve was estimated at 10.59 (sd=2.10) hyaenas/100 km2, which is comparable to estimates obtained using other methods for this reserve and some other protected areas in southern Africa. SECR methods are typically conservative in comparison to other methods of measuring large carnivore populations, which is somewhat supported by higher estimates in other nearby reserves. However, large gaps in time between studies and the variety of historical methods used confound comparisons between estimates. The findings from this study provide support for both camera trap surveys and SECR models in terms of deriving robust population data for spotted hyaenas and other individually recognisable species. Such data allows for studies on the drivers of population and distribution changes for such species in addition to temporal and spatial activity patterns and habitat preference for select species. The generation of accurate population data for ecologically important predators provides reserve managers with robust data upon which to make informed management decisions. This study shows that estimates for spotted hyaenas can be produced from an existing survey of leopards, which makes photographic capture-recapture methods a sensible and cost-effective option for the less charismatic species. The implementation of standardized and scientifically robust population estimation methods such as SECR using camera trap data would contribute appreciably to the conservation of important wildlife species and the ecological processes they support.
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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