Anthropogenic edge effects and aging errors by hunters can affect the sustainability of lion trophy hunting

Many large predator populations are in decline globally with significant implications for ecosystem integrity and function. Understanding the drivers of their decline is required to adequately mitigate threats. Trophy hunting is often cited as a tool to conserve large mammal populations but may also have negative impacts if not well managed. Here we use a spatially implicit, individual based model to investigate the threats posed to African lion populations by poorly managed trophy hunting and additive anthropogenic mortality such as poaching and retaliatory killing. We confirm the results of previous studies that show that lion trophy hunting can be sustainable if only older male lions are hunted, but demonstrate that hunting becomes unsustainable when populations are exposed to additional anthropogenic mortality, as is the case for most free ranging populations. We show that edge effects can be a critical determinant of population viability and populations that encompass well protected source areas are more robust than those without. Finally, errors in aging of hunted lions by professional trophy hunters may undermine the sustainability of the age-based quota setting strategies that are now widely used to manage lion trophy hunting. The effect of aging errors was most detrimental to population persistence in the ≥ 6 and ≥ 7 year-old age thresholds that are frequently used to define suitably aged lions for hunting. Resource managers should limit offtakes to older demographics and additionally take a precautionary approach when setting hunting quotas for large carnivore populations that are affected by other sources of anthropogenic mortality, such as bush-meat poaching, retaliatory killing and problem animal control.

Ten years of coverage of trophy hunting in UK newspapers

Hunting is an increasingly contentious topic. Trophy hunting, whereby people hunt individual animals with desirable characteristics in order to keep body parts (e.g. horns, heads, hides, antlers) as mementos, is especially contested. Political pressure, often in the form of trophy import bans, is being applied in multiple nations, and campaigns to ban trophy hunting, or trophy imports, attract considerable media attention. However, trophy hunting often has conservation value, acting to protect habitat and provide income for local communities. Assuming that media coverage can influence public and political opinion, negative or simplistic media coverage of trophy hunting has the potential to cause adverse outcomes for conservation and local communities. Here, we analyse coverage of trophy hunting from July 2010 - June 2020 (five years before and five years after the death of Cecil the Lion) in the most popular UK media outlets (624 articles in total), assessing the overall sentiment of each article, and the species and countries covered. Ninety percent of all coverage occurred after the death of Cecil the lion, marking this event as a watershed moment in UK mainstream media depiction of trophy hunting. The overall sentiment of articles was largely against trophy hunting (63.1%), and this was more pronounced in tabloids (84.2%) than broadsheets (42.2%). Pro-trophy hunting articles were very uncommon overall (3.5%). Articles that described the complexity of trophy hunting decreased following Cecil and were most common in pre-Cecil broadsheets (35.7%, dropping to 30.6%) and rarest in post-Cecil tabloids (3.1%). Articles focussed mainly on charismatic but rarely hunted species including lion, elephant and rhino, with commonly hunted species (such as impala or Cape buffalo) only rarely being mentioned. When countries were mentioned, southern African nations predominated, with four nations (Zimbabwe, South Africa, Namibia and Botswana) being named in 68% of qualifying articles. We conclude that simplistic media depiction of trophy hunting has the potential to cause negative outcomes for conservation through its impact on public perception and political opinion.

Predation strongly limits demography of a keystone migratory herbivore in a recovering transfrontier ecosystem

Large herbivore migrations are imperiled globally; however the factors limiting a population across its migratory range are typically poorly understood. Zambia's Greater Liuwa Ecosystem (GLE) contains one of the largest remaining blue wildebeest (Connochaetes taurinus taurinus) migrations, yet the population structure, vital rates, and limiting factors are virtually unknown. We conducted a long‐term demographic study of GLE wildebeest from 2012 to 2019 of 107 collared adult females and their calves, 7352 herd observations, 12 aerial population surveys, and concurrent carnivore studies. We applied methods of vital rate estimation and survival analysis within a Bayesian estimation framework. From herd composition observations, we estimated rates of fecundity, first‐year survival, and recruitment as 68%, 56%, and 38% respectively, with pronounced interannual variation. Similar rates were estimated from calf‐detections with collared cows. Adult survival rates declined steadily from 91% at age 2 years to 61% at age 10 years thereafter dropping more sharply to 2% at age 16 years. Predation, particularly by spotted hyena, was the predominant cause of death for all wildebeest ages and focused on older animals. Starvation only accounted for 0.8% of all unbiased known natural causes of death. Mortality risk differed substantially between wet and dry season ranges, reflecting strong spatio‐temporal differences in habitat and predator densities. There was substantial evidence that mortality risk to adults was 27% higher in the wet season, and strong evidence that it was 45% higher in the migratory range where predator density was highest. The estimated vital rates were internally consistent, predicting a stable population trajectory consistent with aerial estimates. From essentially zero knowledge of GLE wildebeest dynamics, this work provides vital rates, age structure, limiting factors, and a plausible mechanism for the migratory tendency, and a robust model‐based foundation to evaluate the effects of potential restrictions in migratory range, climate change, predator–prey dynamics, and poaching.

Low-Cost Forensics Reveal High Rates of Non-lethal Snaring and Shotgun Injuries in Zambia's Large Carnivores

The impact of snaring and human-wildlife conflict (HWC) on large carnivore populations is of growing concern, and yet few empirical data are available. Mortality is the metric most often used, but non-lethal injuries that impact fitness are also important threats. However, because non-lethal injuries to wild carnivores are difficult to detect, they have received little study. Using straightforward forensic examination of the skulls of trophy-hunted lions and leopards from Luangwa Valley (LV) and Greater Kafue Ecosystem (GKE), Zambia, we identified non-lethal injuries consisting of snare damage to teeth and shotgun pellets in skulls. Wire snare entanglement can cause permanent, diagnostic damage to carnivore teeth when individuals bite and pull on the wire. Shotguns are used by poachers, as well as during HWCs to drive off carnivores perceived as threats. Carnivores struck by shotgun pellets can suffer non-lethal, but potentially toxic injuries such as pellets embedded in their skulls. Because poaching and HWC are generally more prevalent near human settlements, we predicted a higher incidence of anthropogenic injuries to carnivores in Luangwa where the human population is larger and more concentrated along protected area edges than Kafue. Contrary to expectation, anthropogenic injuries were more prevalent among lions and leopards in Kafue than Luangwa. Notably, definitive evidence of snare entanglement greatly surpassed previous estimates for these regions. Overall, 37% (41 in 112) of adult male lions (29% in Luangwa, 45% in Kafue) and 22% (10 in 45) of adult male leopards (17% in Luangwa, 26% in Kafue) examined had survived being snared at some point in their lifetime. Among adult male lions, 27% (30 in 112) had old shotgun pellet injuries to their skulls. Our procedure of forensic examination of carnivore skulls and teeth, some of which can be applied to live-captured animals, allows for improved detection of cryptic, non-lethal anthropogenic injuries. Further, our methods represent a consistent and economical way to track changes in the frequency of such injuries over time and between regions, thereby providing a direct measure of the effectiveness of conservation programs that seek to reduce poaching and HWC.

Response of lion demography and dynamics to the loss of preferred larger prey

Large carnivores are experiencing range contraction and population declines globally. Prey depletion due to illegal offtake is considered a major contributor, but the effects of prey depletion on large carnivore demography are rarely tested. We measured African lion density and tested the factors that affect survival using mark-recapture models fit to six years of data from known individuals in Kafue National Park (KNP), Zambia. KNP is affected by prey depletion, particularly for large herbivores that were preferred prey for KNP lions a half-century ago. This provides a unique opportunity to test whether variables that explain local prey density also affect lion survival. Average lion density within our study area was 3.43 individuals/100 km² (95% CI, 2.79-4.23), which was much lower than lion density reported for another miombo ecosystem with similar vegetation structure and rainfall that was less affected by prey depletion. Despite this, comparison to other lion populations showed that age- and sex-specific survival rates for KNP lions were generally good, and factors known to correlate with local prey density had small effects on lion survival. In contrast, recruitment of cubs was poor and average pride size was small. In particular, the proportion of the population comprised of second-year cubs was low, indicating that few cubs are recruited into the subadult age class. Our findings suggest that low recruitment might be a better signal of low prey density than survival. Thus, describing a lion population's age structure in addition to average pride size may be a simple and effective method of initially evaluating whether a lion population is affected by prey depletion. These dynamics should be evaluated for other lion populations and other large carnivore species. Increased resource protection and reducing the underlying drivers of prey depletion are urgent conservation needs for lions and other large carnivores as their conservation is increasingly threatened by range contraction and population declines.

Do protection gradients explain patterns in herbivore densities? An example with ungulates in Zambia's Luangwa Valley

Ungulate populations face declines across the globe, and populations are commonly conserved by using protected areas. However, assessing the effectiveness of protected areas in conserving ungulate populations has remained difficult. Using herd size data from four years of line transect surveys and distance sampling models, we modeled population densities of four important herbivore species across a gradient of protection on the edge of Zambia's South Luangwa National Park (SLNP) while accounting for the role of various ecological and anthropogenic variables. Our goal was to test whether protection was responsible for density dynamics in this protection gradient, and whether a hunting moratorium impacted herbivore densities during the studies. For all four species, we estimated lower densities in partially protected buffer areas adjacent to SLNP (ranging from 4.5-fold to 13.2-fold lower) compared to protected parklands. Density trends through the study period were species-specific, with some species increasing, decreasing, or remaining stable in all or some regions of the protection gradient. Surprisingly, when controlling for other covariates, we found that these observed differences were not always detectably related to the level of protection or year. Our findings highlight the importance of accounting for variables beyond strata of interest in evaluating the effectiveness of a protected area. This study highlights the importance of comprehensively modeling ungulate population density across protection gradients, identifies lands within an important protection gradient for targeted conservation and monitoring, documents prey depletion and expands our understanding on the drivers in a critical buffer area in Zambia.

Quantifying lion (Panthera leo) demographic response following a three-year moratorium on trophy hunting

Factors that limit African lion populations are manifold and well-recognized, but their relative demographic effects remain poorly understood, particularly trophy hunting near protected areas. We identified and monitored 386 individual lions within and around South Luangwa National Park, Zambia, for five years (2008-2012) with trophy hunting and for three additional years (2013-2015) during a hunting moratorium. We used these data with mark-resight models to estimate the effects of hunting on lion survival, recruitment, and abundance. The best survival models, accounting for imperfect detection, revealed strong positive effects of the moratorium, with survival increasing by 17.1 and 14.0 percentage points in subadult and adult males, respectively. Smaller effects on adult female survival and positive effects on cub survival were also detected. The sex-ratio of cubs shifted from unbiased during trophy-hunting to female-biased during the moratorium. Closed mark-recapture models revealed a large increase in lion abundance during the hunting moratorium, from 116 lions in 2012 immediately preceding the moratorium to 209 lions in the last year of the moratorium. More cubs were produced each year of the moratorium than in any year with trophy hunting. Lion demographics shifted from a male-depleted population consisting mostly of adult (≥4 years) females to a younger population with more (>29%) adult males. These data show that the three-year moratorium was effective at growing the Luangwa lion population and increasing the number of adult males. The results suggest that moratoria may be an effective tool for improving the sustainability of lion trophy hunting, particularly where systematic monitoring, conservative quotas, and age-based harvesting are difficult to enforce.

Questionnaire survey of the pan-African trade in lion body parts

The African lion is in decline across its range, and consumptive utilisation and trade of their body parts and skins has been postulated as a cause for concern. We undertook a pan-African questionnaire and literature survey to document informed opinion and evidence for the occurrence of domestic and international trade and consumption in African lion body parts across current and former range states. Sixty-five people from 18 countries participated in the online questionnaire survey (run from July 2014 to May 2015), with information provided for 28 countries (including 20 out of 24 countries believed to have extant populations). Respondents were experts within their professional spheres, and 77% had ≥6 years relevant experience within lion conservation or allied wildlife matters. Their opinions revealed wide sub-regional differences in consumptive use, drivers of trade, and access to lions that impact wild lion populations in different ways. Traditional medicine practices (African and Asian) were perceived to be the main uses to which lion body parts and bones are put domestically and traded internationally, and there is reason for concern about persistent imports from former lion range states (mainly in West Africa) for parts for this purpose. The domestic, rather than international, trade in lion body parts was perceived to be a bigger threat to wild lion populations. Parts such as skin, claws, teeth and bones are thought to be in most demand across the continent. The impact of international trade on wild populations was acknowledged to be largely unknown, but occasionally was judged to be ‘high’, and therefore vigilance is needed to monitor emerging detrimental impacts. Seventeen countries were nominated as priorities for immediate monitoring, including: South Africa, Tanzania, Zimbabwe, Mozambique, Zambia, Botswana, Kenya, Nigeria, and Cameroon. Reasons for their selection include: prevalence of trophy hunting, ‘hot spots’ for poaching, active domestic trade in lion body parts, trade in curios for the tourist market, and histories of legal-illegal wildlife trade. This survey, and increased incident reports since mid-2015 of lion poisoning and poaching in Mozambique, Zimbabwe and South Africa, and sporadic poaching events in Uganda and Tanzania, are signalling an escalating trend in the trade of lion products that is an increasing threat to some national populations. The evidence is sufficient to make more detailed investigation of this trade a conservation priority.

Assessing the sustainability of African lion trophy hunting, with recommendations for policy

While trophy hunting provides revenue for conservation, it must be carefully managed to avoid negative population impacts, particularly for long-lived species with low natural mortality rates. Trophy hunting has had negative effects on lion populations throughout Africa, and the species serves as an important case study to consider the balance of costs and benefits, and to consider the effectiveness of alternative strategies to conserve exploited species. Age-restricted harvesting is widely recommended to mitigate negative effects of lion hunting, but this recommendation was based on a population model parameterized with data from a well-protected and growing lion population. Here, we used demographic data from lions subject to more typical conditions, including source-sink dynamics between a protected National Park and adjacent hunting areas in Zambia's Luangwa Valley, to develop a stochastic population projection model and evaluate alternative harvest scenarios. Hunting resulted in population declines over a 25-yr period for all continuous harvest strategies, with large declines for quotas >1 lion/concession (~0.5 lion/1,000 km² ) and hunting of males younger than seven years. A strategy that combined periods of recovery, an age limit of ≥7 yr, and a maximum quota of ~0.5 lions shot/1,000 km² yielded a risk of extirpation <10%. Our analysis incorporated the effects of human encroachment, poaching, and prey depletion on survival, but assumed that these problems will not increase, which is unlikely. These results suggest conservative management of lion trophy hunting with a combination of regulations. To implement sustainable trophy hunting while maintaining revenue for conservation of hunting areas, our results suggest that hunting fees must increase as a consequence of diminished supply. These findings are broadly applicable to hunted lion populations throughout Africa and to inform global efforts to conserve exploited carnivore populations.

Effects of a protection gradient on carnivore density and survival: an example with leopards in the Luangwa valley, Zambia

Human activities on the periphery of protected areas can limit carnivore populations, but measurements of the strength of such effects are limited, largely due to difficulties of obtaining precise data on population density and survival. We measured how density and survival rates of a previously unstudied leopard population varied across a gradient of protection and evaluated which anthropogenic activities accounted for observed patterns. Insights into this generalist's response to human encroachment are likely to identify limiting factors for other sympatric carnivore species. Motion‐sensitive cameras were deployed systematically in adjacent, similarly sized, and ecologically similar study areas inside and outside Zambia's South Luangwa National Park (SLNP) from 2012 to 2014. The sites differed primarily in the degree of human impacts: SLNP is strictly protected, but the adjacent area was subject to human encroachment and bushmeat poaching throughout the study, and trophy hunting of leopards prior to 2012. We used photographic capture histories with robust design capture–recapture models to estimate population size and sex‐specific survival rates for the two areas. Leopard density within SLNP was 67% greater than in the adjacent area, but annual survival rates and sex ratios did not detectably differ between the sites. Prior research indicated that wire‐snare occurrence was 5.2 times greater in the areas adjacent to the park. These results suggest that the low density of leopards on the periphery of SLNP is better explained by prey depletion, rather than by direct anthropogenic mortality. Long‐term spatial data from concurrent lion studies suggested that interspecific competition did not produce the observed patterns. Large carnivore populations are often limited by human activities, but science‐based management policies depend on methods to rigorously and quantitatively assess threats to populations of concern. Using noninvasive robust design capture–recapture methods, we systematically assessed leopard density and survival across a protection gradient and identified bushmeat poaching as the likely limiting factor. This approach is of broad value to evaluate the impacts of anthropogenic activities on carnivore populations that are distributed across gradients of protection.

Mitochondrial Haplotype Diversity in Zambian Lions: Bridging a Gap in the Biogeography of an Iconic Species

Analysis of DNA sequence diversity at the 12S to 16S mitochondrial genes of 165 African lions (Panthera leo) from five main areas in Zambia has uncovered haplotypes which link Southern Africa with East Africa. Phylogenetic analysis suggests Zambia may serve as a bridge connecting the lion populations in southern Africa to eastern Africa, supporting earlier hypotheses that eastern-southern Africa may represent the evolutionary cradle for the species. Overall gene diversity throughout the Zambian lion population was 0.7319 +/- 0.0174 with eight haplotypes found; three haplotypes previously described and the remaining five novel. The addition of these five novel haplotypes, so far only found within Zambia, nearly doubles the number of haplotypes previously reported for any given geographic location of wild lions. However, based on an AMOVA analysis of these haplotypes, there is little to no matrilineal gene flow (Fst = 0.47) when the eastern and western regions of Zambia are considered as two regional sub-populations. Crossover haplotypes (H9, H11, and Z1) appear in both populations as rare in one but common in the other. This pattern is a possible result of the lion mating system in which predominately males disperse, as all individuals with crossover haplotypes were male. The determination and characterization of lion sub-populations, such as done in this study for Zambia, represent a higher-resolution of knowledge regarding both the genetic health and connectivity of lion populations, which can serve to inform conservation and management of this iconic species.

The Lion King and the Hyaena Queen: large carnivore interactions and coexistence

Interactions among species, which range from competition to facilitation, have profound effects on ecosystem functioning. Large carnivores are of particular importance in shaping community structure since they are at the top of the food chain, and many efforts are made to conserve such keystone species. Despite this, the mechanisms of carnivore interactions are far from understood, yet they are key to enabling or hindering their coexistence and hence are highly relevant for their conservation. The goal of this review is thus to provide detailed information on the extents of competition and facilitation between large carnivores and their impact in shaping their life histories. Here, we use the example of spotted hyaenas (Crocuta crocuta) and lions (Panthera leo) and provide a comprehensive knowledge of their interactions based on meta-analyses from available literature (148 publications). Despite their strong potential for both exploitation and interference competition (range and diet overlap, intraguild predation and kleptoparasitism), we underline some mechanisms facilitating their coexistence (different prey-age selection and scavenging opportunities). We stress the fact that prey abundance is key to their coexistence and that hyaenas forming very large groups in rich ecosystems could have a negative impact on lions. We show that the coexistence of spotted hyaenas and lions is a complex balance between competition and facilitation, and that prey availability within the ecosystem determines which predator is dominant. However, there are still many gaps in our knowledge such as the spatio-temporal dynamics of their interactions. As both species' survival becomes increasingly dependent on protected areas, where their densities can be high, it is critical to understand their interactions to inform both reintroduction programs and protected area management.

Underperformance of African protected area networks and the case for new conservation models: insights from Zambia

Many African protected areas (PAs) are not functioning effectively. We reviewed the performance of Zambia's PA network and provide insights into how their effectiveness might be improved. Zambia's PAs are under-performing in ecological, economic and social terms. Reasons include: a) rapidly expanding human populations, poverty and open-access systems in Game Management Areas (GMAs) resulting in widespread bushmeat poaching and habitat encroachment; b) underfunding of the Zambia Wildlife Authority (ZAWA) resulting in inadequate law enforcement; c) reliance of ZAWA on extracting revenues from GMAs to cover operational costs which has prevented proper devolution of user-rights over wildlife to communities; d) on-going marginalization of communities from legal benefits from wildlife; e) under-development of the photo-tourism industry with the effect that earnings are limited to a fraction of the PA network; f) unfavourable terms and corruption which discourage good practice and adequate investment by hunting operators in GMAs; g) blurred responsibilities regarding anti-poaching in GMAs resulting in under-investment by all stakeholders. The combined effect of these challenges has been a major reduction in wildlife densities in most PAs and the loss of habitat in GMAs. Wildlife fares better in areas with investment from the private and/or NGO sector and where human settlement is absent. There is a need for: elevated government funding for ZAWA; greater international donor investment in protected area management; a shift in the role of ZAWA such that they focus primarily on national parks while facilitating the development of wildlife-based land uses by other stakeholders elsewhere; and new models for the functioning of GMAs based on joint-ventures between communities and the private and/or NGO sector. Such joint-ventures should provide defined communities with ownership of land, user-rights over wildlife and aim to attract long-term private/donor investment. These recommendations are relevant for many of the under-funded PAs occurring in other African countries.

A metapopulation approach to African lion (Panthera leo) conservation

Due to anthropogenic pressures, African lion (Panthera leo) populations in Kenya and Tanzania are increasingly limited to fragmented populations. Lions living on isolated habitat patches exist in a matrix of less-preferred habitat. A framework of habitat patches within a less-suitable matrix describes a metapopulation. Metapopulation analysis can provide insight into the dynamics of each population patch in reference to the system as a whole, and these analyses often guide conservation planning. We present the first metapopulation analysis of African lions. We use a spatially-realistic model to investigate how sex-biased dispersal abilities of lions affect patch occupancy and also examine whether human densities surrounding the remaining lion populations affect the metapopulation as a whole. Our results indicate that male lion dispersal ability strongly contributes to population connectivity while the lesser dispersal ability of females could be a limiting factor. When populations go extinct, recolonization will not occur if distances between patches exceed female dispersal ability or if females are not able to survive moving across the matrix. This has profound implications for the overall metapopulation; the female models showed an intrinsic extinction rate from five-fold to a hundred-fold higher than the male models. Patch isolation is a consideration for even the largest lion populations. As lion populations continue to decline and with local extinctions occurring, female dispersal ability and the proximity to the nearest lion population are serious considerations for the recolonization of individual populations and for broader conservation efforts.

Application of the anthropogenic allee effect model to trophy hunting as a conservation tool

Trophy hunting can provide economic incentives to conserve wild species, but it can also involve risk when rare species are hunted. The anthropogenic Allee effect (AAE) is a conceptual model that seeks to explain how rarity may spread the seeds of further endangerment. The AAE model has increasingly been invoked in the context of trophy hunting, increasing concerns that such hunting may undermine rather than enhance conservation efforts. We question the appropriateness of uncritically applying the AAE model to trophy hunting for 4 reasons. First, the AAE assumes an open-access resource, which is a poor characterization of most trophy-hunting programs and obscures the potential for state, communal, or private-property use rights to generate positive incentives for conservation. Second, study results that show the price of hunting increases as the rarity of the animal increases are insufficient to indicate the presence of AAE. Third, AAE ignores the existence of biological and behavioral factors operating in most trophy-hunting contexts that tend to regulate the effect of hunting. We argue that site-specific data, rather than aggregated hunting statistics, are required to demonstrate that patterns of unsustainable exploitation can be well explained by an AAE model. Instead, we suggest that conservation managers seeking to investigate and identify constraints that limit the potential conservation role of trophy hunting, should focus on the critical governance characteristics that shape the potential conservation role of trophy hunting, such as corruption, insecure property rights, and inadequate sharing of benefits with local people.

The trophy hunting of African lions: scale, current management practices and factors undermining sustainability

The trophy hunting of lions Panthera leo is contentious due to uncertainty concerning conservation impacts and because of highly polarised opinions about the practice. African lions are hunted across at least ~558,000 km(2), which comprises 27-32% of the lion range in countries where trophy hunting of the species is permitted. Consequently, trophy hunting has potential to impart significant positive or negative impacts on lions. Several studies have demonstrated that excessive trophy harvests have driven lion population declines. There have been several attempts by protectionist non-governmental organisations to reduce or preclude trophy hunting via restrictions on the import and export of lion trophies. We document the management of lion hunting in Africa and highlight challenges which need addressing to achieve sustainability. Problems include: unscientific bases for quota setting; excessive quotas and off-takes in some countries; fixed quotas which encourage over-harvest; and lack of restrictions on the age of lions that can be hunted. Key interventions needed to make lion hunting more sustainable, include implementation of: enforced age restrictions; improved trophy monitoring; adaptive management of quotas and a minimum length of lion hunts of at least 21 days. Some range states have made important steps towards implementing such improved management and off-takes have fallen steeply in recent years. For example age restrictions have been introduced in Tanzania and in Niassa in Mozambique, and are being considered for Benin and Zimbabwe, several states have reduced quotas, and Zimbabwe is implementing trophy monitoring. However, further reforms are needed to ensure sustainability and reduce conservation problems associated with the practice while allowing retention of associated financial incentives for conservation.

Rabies, canine distemper, and canine parvovirus exposure in large carnivore communities from two Zambian ecosystems

Disease transmission within and among wild and domestic carnivores can have significant impacts on populations, particularly for threatened and endangered species. We used serology to evaluate potential exposure to rabies virus, canine distemper virus (CDV), and canine parvovirus (CPV) for populations of African lions (Panthera leo), African wild dogs (Lycaon pictus), and spotted hyenas (Crocuta crocuta) in Zambia's South Luangwa National Park (SLNP) and Liuwa Plain National Park (LPNP) as well as community lands bordering these areas. In addition, domestic dogs in the study region were evaluated for exposure to CDV and rabies. We provide the first comprehensive disease exposure data for these species in these ecosystems. Twenty-one lions, 20 hyenas, 13 wild dogs, and 38 domestic dogs were sampled across both regions from 2009 to 2011. Laboratory results show 10.5% of domestic dogs, 5.0% of hyenas, and 7.7% of wild dogs sampled were positive for CDV exposure. All lions were negative. Exposure to CPV was 10.0% and 4.8% for hyenas and lions, respectively. All wild dogs were negative, and domestic dogs were not tested due to insufficient serum samples. All species sampled were negative for rabies virus neutralizing antibodies except lions. Forty percent of lions tested positive for rabies virus neutralizing antibodies. Because these lions appeared clinically healthy, this finding is consistent with seroconversion following exposure to rabies antigen. To our knowledge, this finding represents the first ever documentation of rabies virus neutralizing antibodies consistent with rabies exposure that did not lead to clinical disease in free-ranging African lions from this region. With ever-increasing human pressure on these ecosystems, understanding disease transmission dynamics is essential for proper management and conservation of these carnivore species.

Using pedigree reconstruction to estimate population size: genotypes are more than individually unique marks

Estimates of population size are critical for conservation and management, but accurate estimates are difficult to obtain for many species. Noninvasive genetic methods are increasingly used to estimate population size, particularly in elusive species such as large carnivores, which are difficult to count by most other methods. In most such studies, genotypes are treated simply as unique individual identifiers. Here, we develop a new estimator of population size based on pedigree reconstruction. The estimator accounts for individuals that were directly sampled, individuals that were not sampled but whose genotype could be inferred by pedigree reconstruction, and individuals that were not detected by either of these methods. Monte Carlo simulations show that the population estimate is unbiased and precise if sampling is of sufficient intensity and duration. Simulations also identified sampling conditions that can cause the method to overestimate or underestimate true population size; we present and discuss methods to correct these potential biases. The method detected 2–21% more individuals than were directly sampled across a broad range of simulated sampling schemes. Genotypes are more than unique identifiers, and the information about relationships in a set of genotypes can improve estimates of population size.

Glucocorticoid stress responses of lions in relationship to group composition, human land use, and proximity to people

Large carnivore populations are in global decline, and conflicts between large carnivores and humans or their livestock contribute to low tolerance of large carnivores outside of protected areas. African lions (Panthera leo) are a conflict-prone species, and their continental range has declined by 75% in the face of human pressures. Nonetheless, large carnivore populations persist (or even grow) in some areas that are occupied by humans. Lions attain locally high density in the Olkiramatian and Shompole Group Ranches of Kenya's South Rift region, despite residence by pastoralist Maasai people and their sheep, goats, and cattle. We have previously found that these lions respond to seasonal movements of people by moving away from occupied settlements, shifting into denser habitats when people are nearby, and moving into a protected conservation area when people move into the adjacent buffer zone. Here, we examined lion stress responses to anthropogenic activities, using enzyme-linked immunoassay to measure the concentration of faecal glucocorticoid metabolites in 136 samples collected from five lion groups over 2 years. Faecal glucocorticoid metabolite concentrations were significantly lower for lions in the conservation area than for lions in the human-settled buffer zone, and decreased significantly with increasing distance to the nearest occupied human settlement. Faecal glucocorticoid metabolite concentrations were not detectably related to fine-scaled variation in prey or livestock density, and surprisingly, faecal glucocorticoid metabolite concentrations were higher in the wet season, when regional prey abundance was high. Lions coexist with people and livestock on this landscape by adjusting their movements, but they nonetheless mount an appreciable stress response when conditions do not allow them to maintain adequate separation. Thus, physiological data confirm inferences from prior data on lion movements and habitat use, showing that access to undisturbed and protected areas facilitates human-lion coexistence in a broader landscape that is used by people and livestock.