Incorporating prey demographics and predator social structure into prey selection and carrying capacity estimates for cheetah

There is a need for a refined understanding of large carnivore prey preference and carrying capacity (K). To date, K estimates for large carnivores have been developed from predictions of carnivore diet at a prey and predator species-level. These predictions therefore assume that all social classes within a carnivore species display similar prey preferences and that all demographic classes within a prey species are equally preferred or avoided. The objective of this study was to investigate the importance of including prey demographics and carnivore social class in carnivore diet descriptions and thereby K estimates, using cheetah Acinonyx jubatus as a study species. It was predicted that prey sex, prey age and cheetah social class influence cheetah prey preferences, when they influence the risk and ease of prey capture, and that their inclusion in a K model would improve its predictive strength. Based on an analysis of 1290 kills from South Africa, male coalition cheetah were found to prefer a broader weight range of prey than solitary cheetah. Prey demographics further influenced cheetah prey preference, when it corresponded to differences in prey size and the presence of horns. The current species-level K regression model for cheetah is based on preferred prey and thus omits highly abundant antelope that often comprise the majority of the diet, an artefact of the way in which preferences are calculated. A refinement of the species-level K regression model, to account for prey demographic- and cheetah social class-level differences in diet and the biomass of accessible prey (defined in this study as all non-avoided prey) instead of just preferred prey, doubled the predictive strength of the K model. Because group-hunting enabled predation on a broader weight range of prey, cheetah K was influenced by the ratio of male coalition cheetah to solitary cheetah in the population. The refined K regression model is derived from ecosystems supporting an intact carnivore guild. A mechanistic approach to estimating K, based on Caughley‟s (1977) maximum sustainable yield model, therefore better predicted cheetah K in systems devoid of lion Panthera leo and African wild dog Lycaon pictus, which were found to suppress cheetah density. This study improves our understanding of the relationships between prey demographics, cheetah social classes and intra-guild competition in determining cheetah prey preferences and K. This study therefore paves the way for similar work on other large carnivores

Multi-scale, social-ecological influences on private land conservation in South Africa

In understanding the behaviour of social-ecological systems, much focus has been placed on the role of institutions that govern how natural resources should be managed, and the biophysical processes affected by this management. Somewhat less attention has been given to the role played by the natural resource managers themselves. Novel insight into social-ecological systems can be gained from understanding why managers act as they do and how management actions become reinforced into (un)sustainable management regimes. In this thesis I applied a social-ecological systems perspective to the phenomenon of private land conservation. With increasing interest in the role that the private sector can play in global conservation efforts, a pertinent but largely unexplored question is whether private land conservation areas (PLCAs) can conserve biodiversity over sufficiently long time scales. This thesis contributes to social-ecological systems theory through an in-depth analysis of the multi-scale interactions among natural resources, managers and socioeconomic processes, which affect PLCA management practices and their sustainability. The potential ability for commercially operated PLCAs to generate the funds necessary for their maintenance makes them an attractive conservation strategy in an economically-orientated world. There are concerns, however, that (a) their long-term sustainability may be dependent on their ability to become and remain financially viable; and (b) they may be tempted to prioritize profit over biodiversity protection in their management practices, thereby jeopardizing their ecological sustainability. The objectives of this thesis were to investigate if, how and why commercial PLCA managers (a) meet their financial objectives and (b) adopt unsustainable ecological management practices. During 2014 and 2015 I interviewed the managers of 72 commercial PLCAs in the Western and Eastern Cape Provinces of South Africa, a region that supports a rapidly growing yet poorly understood PLCA industry. I applied theories from organizational ecology to understand patterns in the income-generating strategies adopted by PLCA managers. Distinct business models were evident, differentiated by incompatibilities in the biophysical (size, fauna) and socioeconomic (activities, affordability) characteristics of these conservation areas. PLCAs characterized by financial objectives but unprofitable business models suggest that these incompatibilities constrain the ability of managers to effectively adapt to their economic environment, a concept known as "structural inertia" in organizational ecology. Profitability was highest on PLCAs that supported megaherbivores and large predators, reflecting international tourist preferences for charismatic game. Managers' financial objectives influenced the strategies that they employed to manage these mammals. When managers used revenue-generation to inform their management decisions, they undertook management actions that enabled them to maximize and stabilize game populations. While this intensive management resulted in higher revenues, it corresponded in many cases with a lack of ecological monitoring and an increased risk of overstocking game. Regional policy guidelines for large predator management both mitigated and exacerbated the mismatch between financially-desirable and ecologically-sustainable management, depending on whether species-specific guidelines were ecologically appropriate or not. Simulations of a mechanistic PLCA model were used to test whether adopted management strategies influenced the observed constraints on business model adaptation. If the income-generating potential of an adopted business model was low, managers were unable to accumulate the capital necessary to overcome the biophysical and socioeconomic incompatibilities that separated business models, constraining their adaptive capacity. Intensively managed PLCAs were able to generate a more stable annual income, accumulate more capital and overcome constraints on adaptation faster than PLCAs managed according to ecological monitoring. This unique, large-sample assessment of the social-ecological mechanisms underlying PLCA sustainability emphasizes the significant role that managers can play in promoting resilient social-ecological systems. When financial viability is an important consideration, broad-scale socioeconomic factors can influence fine-scale management decisions. Through constraints on adaptation, and the presence or absence of corrective feedbacks between management actions and ecological monitoring, these management decisions can become reinforced into management regimes on a trajectory towards, or away from, sustainability. This study therefore provides a novel contribution to our understanding of how the interactions between managers and ecosystems influence the behaviour of social-ecological systems

Importance of private and communal lands to sustainable conservation of Africa's rhinoceroses

A new path for rhinoceros (rhino) conservation is needed. Recent data signal the alarming impact of poaching on populations in Africa's rhino stronghold, the state-run Kruger National Park (South Africa), which today supports one quarter the rhinos than a decade ago. We aggregated African rhino population data, highlighting the growing role of private and community rhino custodians, who likely now conserve >50% of Africa's rhinos. Their contribution has been enabled by a supportive policy and economic environment, but this arrangement is becoming more difficult to sustain as costs associated with protecting rhinos skyrocket and revenue-generating options become insufficient. Some privately held rhino populations are small or intensively managed, raising questions about their conservation value. As the role of private and community custodianship becomes increasingly central to the protection of Africa's remaining rhinos, its resilience must be strengthened through implementation of adaptive policies that incentivize rhino conservation. We outline policy pathways to provide an enabling environment for rhino conservation beyond state parks.Peer reviewe

Predators on private land: broad-scale socioeconomic interactions influence large predator management

The proliferation of private land conservation areas (PLCAs) is placing increasing pressure on conservation authorities to effectively regulate their ecological management. Many PLCAs depend on tourism for income, and charismatic large mammal species are considered important for attracting international visitors. Broad-scale socioeconomic factors therefore have the potential to drive fine-scale ecological management, creating a systemic scale mismatch that can reduce long-term sustainability in cases where economic and conservation objectives are not perfectly aligned. We assessed the socioeconomic drivers and outcomes of large predator management on 71 PLCAs in South Africa. Owners of PLCAs that are stocking free-roaming large predators identified revenue generation as influencing most or all of their management decisions, and rated profit generation as a more important objective than did the owners of PLCAs that did not stock large predators. Ecotourism revenue increased with increasing lion (Panthera leo) density, which created a potential economic incentive for stocking lion at high densities. Despite this potential mismatch between economic and ecological objectives, lion densities were sustainable relative to available prey. Regional-scale policy guidelines for free-roaming lion management were ecologically sound. By contrast, policy guidelines underestimated the area required to sustain cheetah (Acinonyx jubatus), which occurred at unsustainable densities relative to available prey. Evidence of predator overstocking included predator diet supplementation and frequent reintroduction of game. We conclude that effective facilitation of conservation on private land requires consideration of the strong and not necessarily beneficial multiscale socioeconomic factors that influence private land management

Impacts of a trophy hunting ban on private land conservation in South African biodiversity hotspots

Private land conservation areas (PLCAs) have become critical for achieving global conservation goals, but we lack understanding of how and when these areas respond to global pressures and opportunities. In southern Africa, where many PLCAs rely on trophy hunting as an income-generating strategy, a potential ban on trophy hunting locally or abroad holds unknown consequences for the future conservation of these lands. In this study, we investigate the consequences of a potential trophy hunting ban in PLCAs in two biodiversity hotspots in South Africa's Eastern and Western Cape provinces. We used semistructured interviews with PLCA managers and owners to elicit perceived impacts of an internationally imposed trophy hunting ban on conservation activities in PLCAs, and to probe alternative viable land uses. The majority of interviewees believed that both the economic viability of their PLCA and biodiversity would be lost following a hunting ban. Owners would primarily consider transitioning to ecotourism or livestock farming, but these options were constrained by the social-ecological context of their PLCA (e.g., competition with other PLCAs, ecological viability of farming). Our results suggest that a trophy hunting ban may have many unintended consequences for biodiversity conservation, national economies, and the livelihoods of PLCA owners and employees. Along with similar social-ecological studies in other areas and contexts, our work can inform policy decisions around global trophy hunting regulation.Peer reviewe

The influence of biophysical and socio-economic factors on the effectiveness of private land conservation areas in preventing natural land cover loss across South Africa

There is increasing interest in the potential of private land conservation areas (PLCAs) as a complementary biodiversity conservation strategy to state-owned protected areas. However, there is limited understanding of how the diverse social-ecological contexts of PLCAs influence their effectiveness in conserving biodiversity. Here, we investigated how the effectiveness of South African PLCAs in conserving biodiversity varied across social-ecological contexts, using natural land cover as a proxy. Social-ecological contexts were represented by biophysical and legal factors (distance to towns and roads, elevation, slope, terrain ruggedness, rainfall, PLCA size, distance to state-owned national parks, and presence of legal protection) and, for a subset of commercially-operated PLCAs, management factors (adopted business model, and profitability). Biophysical and legal contextual factors had low explanatory power in the best model for the nationwide analysis (n = 5121 PLCAs). For a subset of PLCAs (n = 72) we found that effectiveness depended on the strategy they adopted to generate an income, as opposed to the amount of income itself. PLCAs that attracted high volumes of visitors to small properties to view charismatic "Big 5" wildlife were less effective in conserving natural land cover than larger, more exclusive "Big 5" PLCAs and those focused on hunting. Overall, site-specific management factors were better at explaining the effectiveness of PLCAs than biophysical factors. Our findings indicate that conservation practitioners and policy makers need to recognise the diverse goals, motivations and management models of PLCAs when considering how to support them in conserving biodiversity. Future studies could explore whether these trends hold for other proxies of biodiversity conservation, beyond land cover change.Peer reviewe

Effectiveness of private land conservation areas in maintaining natural land cover and biodiversity intactness

CITATION: Shumba, T. et al. 2020. Effectiveness of private land conservation areas in maintaining natural land cover and biodiversity intactness. Global Ecology and Conservation, 22:e00935, doi:10.1016/j.gecco.2020.e00935.The original publication is available at https://www.journals.elsevier.com/global-ecology-and-conservationPrivate land conservation areas (PLCAs) are increasingly looked to for meeting the deficit left by state-owned protected areas in reaching global conservation targets. However, despite the increasing extent and recognition of PLCAs as a complementary conservation strategy, little research has been done to quantify their effectiveness; a critical consideration if they are to be counted towards international biodiversity conservation targets. The long history of PLCAs in South Africa provides an interesting case study to address this knowledge gap. Here, we quantified the effectiveness of South African PLCAs by comparing losses in natural land cover and biodiversity intactness within PLCAs with different levels of protection to that of unprotected control points. Points within PLCAs were matched with unprotected control points to test the prediction that if PLCAs offer effective protection, losses in natural land cover and biodiversity intactness would be significantly lower within their boundaries in comparison to unprotected controls exposed to similar conditions. Consequences of natural land cover loss on biodiversity intactness were thus assessed, thus advancing standard approaches for quantifying effectiveness. Between 1990 and 2013, PLCAs lost significantly less natural land cover (3%) and biodiversity intactness (2%) than matched unprotected areas (6% and 4%, respectively). Of the natural land cover lost within PLCAs, most was converted to cultivated land. Farms can support more species than other land uses (e.g. mines), a likely explanation for why losses in biodiversity intactness were less than losses in natural land cover. Contrary to the predicted pattern, effectiveness did not increase with level of protection; informal PLCAs with no legal protection had comparable natural land cover and biodiversity intactness retention to strictly protected PLCAs, with most losses recorded among PLCAs with moderate protection. This study provides the first national-scale evidence that PLCAs can be an effective mechanism for conserving natural land cover and biodiversity intactness, which is highly relevant given current discussions around their likely long-term biodiversity conservation capacity.Publisher's versio

Changes in total and functional bacterial genera following biochar application to planted soil

Biochar has the recognized potential to sequester carbon, facilitate contaminant amelioration and enhance agricul-tural crop yield. Different types of biochar have different impacts on ecosystems, and those that are produced locally, relative to where they will be used, are considered more sustainable. It is important, therefore, to determine how the locally produced biochars affect total and functional microbial communities, especially in agronomic contexts. In this study we tested the hypotheses that biochar augmentation would: (1) increase plant yield; and (2) differentially affect total and functional microbial community composition and structure in bulk vs. rhizosphere (Trifolium pratense) soils. Triplicate randomised seedling cells of a 5% (w/w) mixture of sandy clay loam soil (26% clay, 21% silt and 53% sand), with/without locally-produced mixed broadleaf forestry biochar, and with/without 0.1 g clover seeds, were sampled destructively at 2-week intervals for 8 weeks post clover germination. Microbial DNA of bulk and T. pratense rhizos-phere soils were analysed with next-generation sequencing of the 16S rRNA gene. The results showed a statistically significant increase in plant biomass in response to biochar addition correlating to increased abundances of Armati-monadetes and Bacteroidetes specifically in the rhizosphere. Although no significant change in overall alpha diversity was observed, significant changes in abundance at the genus level were recorded particularly in the presence of biochar for a number of recognised nitrogen-fixing and plant growth-promoting bacteria, including those capable of indole acetic acid (IAA) production, plant disease suppression and degradation of toxic compounds. We conclude that although overall soil diversity may not be affected by biochar addition, key genera associated with soil health and nitrogen fixation, such as Pseudoxanthomonas, Variovorax, Pseudonocardia, Devosia, Lysobacter and Hydrogeno-phaga, increased and facilitated plant growth

The dynamics of proclaimed privately protected areas in South Africa over 83 years

Views that protected area (PA) expansion relies predominantly on land purchased by government are increasingly being challenged. The inclusion of privately owned PAs (PPAs) in national conservation strategies is now commonplace, but little is known about their long-term persistence and how it compares to that of state-owned PAs. We undertook the first long-term assessment of the dynamics of a national system of terrestrial PPAs, assessing its growth, as well as its resilience to downgrading, downsizing, and degazettement (PADDD). Between 1926 and 2018, 6.2% of all private nature reserves established in South Africa were degazetted, compared to 2.2% of state-owned nature reserves. Privately owned PA growth exceeded that of state-owned PAs. Trends in PA establishment differed between privately owned and state-owned PAs, reflecting different legislative, political, and economic events. Our findings highlight the value of enabling legislative environments to facilitate PPA establishment, and demonstrate the potential of PPAs as a long-term conservation strategy

Impacts of a trophy hunting ban on private land conservation in South African biodiversity hotspots

CITATION: Parker, K. et al. 2020. Impacts of a trophy hunting ban on private land conservation in South African biodiversity hotspots. Conservation Science and Practice, 2:e214, doi:10.1111/csp2.214.The original publication is available at https://conbio.onlinelibrary.wiley.comPrivate land conservation areas (PLCAs) have become critical for achieving global conservation goals, but we lack understanding of how and when these areas respond to global pressures and opportunities. In southern Africa, where many PLCAs rely on trophy hunting as an income-generating strategy, a potential ban on trophy hunting locally or abroad holds unknown consequences for the future conservation of these lands. In this study, we investigate the consequences of a potential trophy hunting ban in PLCAs in two biodiversity hotspots in South Africa's Eastern and Western Cape provinces. We used semistructured interviews with PLCA managers and owners to elicit perceived impacts of an internationally imposed trophy hunting ban on conservation activities in PLCAs, and to probe alternative viable land uses. The majority of interviewees believed that both the economic viability of their PLCA and biodiversity would be lost following a hunting ban. Owners would primarily consider transitioning to ecotourism or livestock farming, but these options were constrained by the social-ecological context of their PLCA (e.g., competition with other PLCAs, ecological viability of farming). Our results suggest that a trophy hunting ban may have many unintended consequences for biodiversity conservation, national economies, and the livelihoods of PLCA owners and employees. Along with similar social-ecological studies in other areas and contexts, our work can inform policy decisions around global trophy hunting regulation.Publisher's versio