More allogrooming is followed by higher physiological stress in wild female baboons.

Social bonds increase fitness in a range of mammals. One pathway by which social bonds may increase fitness is by reducing the exposure to physiological stress, i.e. glucocorticoid (GC) hormones, that can be detrimental to health and survival. This is achieved through downregulating hypothalamic-pituitary-adrenal (HPA)-axis activity. Indeed, long-term measures of social (grooming) bonds are often negatively correlated with HPA-axis activity. However, the proximate role of physical touch through allogrooming remains an open question in the sociality-health-fitness debate. Demonstrating the potential anxiolytic benefits of grooming in the wild is hindered by methodological limitations. Here, we match accelerometer-identified grooming in wild female chacma baboons (Papio ursinus) to non-invasive faecal GC metabolite concentrations (fGCs). Consistent with previous work, we found a negative (but statistically non-significant) overall relationship between individual averaged fGCs and grooming rates. However, when time-matching grooming to fGCs, we found that both more giving and receiving grooming were followed by higher fGCs. This upregulation of HPA-axis activity suggests that maintaining social bonds (and its ultimate fitness benefits) may come at a shorter-term physiological cost. This finding sheds new light on a ubiquitous social behaviour typically considered 'relaxing' and suggests that sociopositive contact can trigger physiological stress.

Effects of accelerometry-derived physical activity energy expenditure on urinary C-peptide levels in a wild primate (Papio ursinus).

Animals have finite energy reserves for growth, survival, and reproduction and must maintain a stable energy balance. Measuring energy balance in the wild, however, is beset with methodological challenges. Quantification of urinary C-peptide (uCP), a proxy for insulin secretion, has enabled researchers to non-invasively estimate energy balance, and positive relationships between uCP levels and energy intake have been documented in numerous non-human primates. Comparatively few studies show that, consistent with insulin physiology, energy expenditure also alters levels of uCP. The timescale and extent of this relationship, however, remains unclear given the reliance on crude measures of activity and inferred energy expenditure. Here, for the first time, we test for effects of accelerometer-derived Vectorial Dynamic Body Acceleration (VeDBA) - a continuous measure of physical activity energy expenditure - on urinary C-peptide (uCP) levels in n = 12 wild chacma baboons (Papio ursinus). Applying a model selection approach, we show that VeDBA summed over short timescales (30 min to 1 h) prior to urine collection was negatively associated with uCP levels. Using the acceleration-based time individuals spent 'non-stationary' (i.e. locomoting) prior to urine collection as a predictor - instead of summed VeDBA - revealed similar but less clear results. Overall, the negative relationship between VeDBA and uCP levels highlights the importance of quantifying physical activity energy expenditure when using uCP measures to estimate energy balance and has potential implications for the field of energetics accelerometry.

Flexible group cohesion and coordination, but robust leader-follower roles, in a wild social primate using urban space.

Collective behaviour has a critical influence on group social structure and organization, individual fitness and social evolution, but we know little about whether and how it changes in anthropogenic environments. Here, we show multiple and varying effects of urban space-use upon group-level processes in a primate generalist-the chacma baboon (Papio ursinus)-within a managed wild population living at the urban edge in the City of Cape Town, South Africa. In natural space, we observe baboon-typical patterns of collective behaviour. By contrast, in urban space (where there are increased risks, but increased potential for high-quality food rewards), baboons show extreme flexibility in collective behaviour, with changes in spatial cohesion and association networks, travel speeds and group coordination. However, leader-follower roles remain robust across natural and urban space, with adult males having a disproportionate influence on the movement of group members. Their important role in the group's collective behaviour complements existing research and supports the management tactic employed by field rangers of curbing the movements of adult males, which indirectly deters the majority of the group from urban space. Our findings highlight both flexibility and robustness in collective behaviour when groups are presented with novel resources and heightened risks.

Troubled spots: Human impacts constrain the density of an apex predator inside protected areas.

Effective conservation requires understanding the processes that determine population outcomes. Too often, we assume that protected areas conserve wild populations despite evidence that they frequently fail to do so. Without large-scale studies, however, we cannot determine what relationships are the product of localized conditions versus general patterns that inform conservation more broadly. Leopards' (Panthera pardus) basic ecology is well studied but little research has investigated anthropogenic effects on leopard density at broad scales. We investigated the drivers of leopard density among 27 diverse protected areas in northeastern South Africa to understand what conditions facilitate abundant populations. We formulated 10 working hypotheses that considered the relative influence of bottom-up biological factors and top-down anthropogenic factors on leopard density. Using camera-trap survey data, we fit a multi-session spatial capture-recapture model with inhomogenous density for each hypothesis and evaluated support using an information theoretic approach. The four supported hypotheses indicated that leopard density is primarily limited by human impacts, but that habitat suitability and management conditions also matter. The proportion of camera stations that recorded domestic animals, a proxy for the extent of human impacts and protected area effectiveness, was the only predictor variable present in all four supported models. Protected areas are the cornerstone of large felid conservation, but only when the human-wildlife interface is well managed and protected areas shelter wildlife populations from anthropogenic impacts. To ensure the long-term abundance of large carnivore populations, reserve managers should recognize the ineffectiveness of "paper parks" and promote contiguous networks of protected areas that offer leopards and other large mammal populations greater space and reduced human impacts.

Behavioral Causes, Ecological Consequences, and Management Challenges Associated with Wildlife Foraging in Human-Modified Landscapes.

Humans have altered up to half of the world's land surface. Wildlife living within or close to these human-modified landscapes are presented with opportunities and risks associated with feeding on human-derived foods (e.g., agricultural crops and food waste). Understanding whether and how wildlife adapts to these landscapes is a major challenge, with thousands of studies published on the topic over the past 10 years. In the present article, we build on established theoretical frameworks to understand the behavioral causes of crop and urban foraging by wildlife. We then develop and extend this framework to describe the multifaceted ecological consequences of crop and urban foraging for the individuals and populations in which they arise, with emphasis on social species for which interactions with people are, on balance, negative (commonly referred to as raiding species). Finally, we discuss the management challenges faced by urban and rural land managers, businesses, and government organizations in mitigating human-wildlife conflicts and propose ways to improve the lives of both wildlife and humans living in human-modified landscapes and to promote coexistence.

Energetics at the urban edge: Environmental and individual predictors of urinary C-peptide levels in wild chacma baboons (Papio ursinus).

As human-modified landscapes encroach into natural habitats, wildlife face a reduction in natural food sources but also gain access to calorie-rich, human-derived foods. However, research into the energetics of wildlife living within and adjacent to urban and rural landscapes is lacking. C-peptide - a proxy for insulin production and a diagnostic tool for assessing pancreatic function in humans and domestic animals - can be quantified non-invasively from urine (uCP) and may provide a way to investigate the energetic correlates of living in human-altered landscapes. UCP is increasingly used in studies of primate energetics, and here we examine predictors of variation in uCP levels in n = 17 wild chacma baboons (Papio ursinus) living at the urban edge on the Cape Peninsula, South Africa. We find that uCP was positively associated with food provisioning and negatively with night fasting. UCP levels were comparable between winter and summer but significantly lower during spring, possibly driven by consumption of energy-rich seeds during summer and more human-derived foods during winter. UCP was elevated in pregnant females and similar for lactating and cycling females. We find no effect of dominance rank on uCP. Samples collected with synthetic Salivettes had significantly lower uCP levels than directly pipetted samples. Overall, our results indicate that uCP is a reliable, non-invasive measure of energy balance and intake in baboons, and suggest potential energetic benefits of living at the urban edge. More broadly, studies of uCP may offer unique insight into the environmental control of hormone-behaviour relationships in species crossing natural and urban environments.

Isotopic assessment of marine food consumption by natural-foraging chacma baboons on the Cape Peninsula, South Africa.

OBJECTIVES: Stable isotope analysis has been used to investigate consumption of marine resources in a variety of terrestrial mammals, including humans, but not yet in extant nonhuman primates. We sought to test the efficacy of stable isotope analysis as a tool for such studies by comparing isotope- and observation-based estimates of marine food consumption by a troop of noncommensal, free-ranging chacma baboons. MATERIALS AND METHODS: We determined δ13 C and δ15 N values of baboon hair (n = 9) and fecal samples (n = 144), and principal food items (n = 362). These values were used as input for diet models, the outputs of which were compared to observation-based estimates of marine food consumption. RESULTS: Fecal δ13 C values ranged from -29.3‰ to -25.6‰. δ15 N values ranged from 0.9‰ to 6.3‰ and were positively correlated with a measure of marine foraging during the dietary integration period. Mean (± SD) δ13 C values of adult male and female baboon hairs were -21.6‰ (± 0.1) and -21.8‰ (± 0.3) respectively, and corresponding δ15 N values were 5.0‰ (± 0.3) and 3.9‰ (± 0.2). Models indicated that marine contributions were ≤10% of baboon diet within any season, and contributed ≤17% of dietary protein through the year. DISCUSSION: Model output and observational data were in agreement, both indicating that despite their abundance in the intertidal region, marine foods comprised only a small proportion of baboon diet. This suggests that stable isotope analysis is a viable tool for investigating marine food consumption by natural-foraging primates in temperate regions.

Small-livestock farmers' perceived effectiveness of predation control methods and the correlates of reported illegal poison use in the South African Karoo.

The use of poison against predators is pervasive and negatively impacts biodiversity and ecosystem health globally. Little is known about the correlates of poison use as a lethal control method on small-livestock farmland. We used a mixed-methods approach to investigate commercial farmers' experience with and perceived effectiveness of predation control methods, reported poison use and its correlates in the Central Karoo. Farmers perceived lethal methods to be cheaper and more effective than non-lethal methods in protecting their livestock from predation. They reported more experience with lethal methods, and over half reported having used poison. This is higher than other estimates in southern Africa and consistent with other survey-based evidence from the Karoo. Reported poison use was positively related to perceived efficacy, declining on-farm employment and perceived threats of predators. It was negatively related to terrain ruggedness. Our findings provide an understanding of the context and motivations shaping this illegal behavior.

On the Fence: The Impact of Education on Support for Electric Fencing to Prevent Conflict between Humans and Baboons in Kommetjie, South Africa.

Few studies test whether education can help increase support for wildlife management interventions. This mixed methods study sought to test the importance of educating a community on the use of a baboon-proof electric fence to mitigate negative interactions between humans and Chacma baboons (Papio ursinus) in a residential suburb of the City of Cape Town, South Africa. An educational video on the welfare, conservation and lifestyle benefits of a baboon-proof electric fence was included in a short online survey. The positioning of the video within the survey was randomised either to fall before or after questions probing the level of support for an electric fence. The results showed that watching the video before most survey questions increased the average marginal probability of supporting an electric fence by 15 percentage points. The study also explored whether the educational video could change people's minds. Those who saw the video towards the end of the survey were questioned again about the electric fence. Many changed their minds after watching the video, with support for the fence increasing from 36% to 50%. Of these respondents, the results show that being female raised the average marginal probability of someone changing their mind in favour of supporting the fence by 19%. Qualitative analysis revealed that support for or against the fence was multi-layered and that costs and concern for baboons were not the only relevant factors influencing people's choices. Conservation often needs to change people's behaviours. We need to know what interventions are effective. We show in the real world that an educational video can be effective and can moderately change people's opinions and that women are more likely to change their position in light of the facts than men. This study contributes to the emerging literature on the importance of education in managing conservation conflicts and the need for evidence-based interventions.

Leopard density and the ecological and anthropogenic factors influencing density in a mixed-use landscape in the Western Cape, South Africa.

Large carnivores face numerous threats, including habitat loss and fragmentation, direct killing, and prey depletion, leading to significant global range and population declines. Despite such threats, leopards (Panthera pardus) persist outside protected areas throughout most of their range, occupying diverse habitat types and land uses, including peri-urban and rural areas. Understanding of leopard population dynamics in mixed-use landscapes is limited, especially in South Africa, where the majority of leopard research has focused on protected areas. We use spatially explicit capture-recapture models to estimate leopard density across a mixed-use landscape of protected areas, farmland, and urban areas in the Overberg region of the Western Cape, South Africa. Data from 86 paired camera stations provided 221 independent captures of 25 leopards at 50 camera trap stations with a population density estimate of 0.64 leopards per 100 km2 (95% CI: 0.55-0.73). Elevation, terrain ruggedness, and vegetation productivity were important drivers of leopard density in the landscape, being highest on elevated remnants of natural land outside of protected areas. These results are similar to previous research findings in other parts of the Western Cape, where high-lying natural vegetation was shown to serve as both a refuge and a corridor for leopard movement in otherwise transformed landscapes. Given the low leopard density and the prevalence of transformed land intermixed with patches of more suitable leopard habitat, prioritising and preserving connectivity for leopards is vital in this shared landscape. Ecological corridors should be developed in partnership with private landowners through an inclusive and multifaceted conservation strategy which also incorporates monitoring of and rapid mitigation of emerging threats to leopards.

Postpartum cessation of urban space use by a female baboon living at the edge of the City of Cape Town.

Species with slow life history strategies that invest in few offspring with extended parental care need to adapt their behavior to cope with anthropogenic changes that occur within their lifetime. Here we show that a female chacma baboon (Papio ursinus) that commonly ranges within urban space in the City of Cape Town, South Africa, stops using urban space after giving birth. This change of space use occurs without any significant change in daily distance traveled or social interactions that would be expected with general risk-sensitive behavior after birth. Instead, we suggest this change occurs because of the specific and greater risks the baboons experience within the urban space compared to natural space, and because leaving the troop (to enter urban space) may increase infanticide risk. This case study can inform methods used to manage the baboons' urban space use in Cape Town and provides insight into how life history events alter individuals' use of anthropogenic environments.

Quantifying allo-grooming in wild chacma baboons (Papio ursinus) using tri-axial acceleration data and machine learning.

Quantification of activity budgets is pivotal for understanding how animals respond to changes in their environment. Social grooming is a key activity that underpins various social processes with consequences for health and fitness. Traditional methods use direct (focal) observations to calculate grooming rates, providing systematic but sparse data. Accelerometers, in contrast, can quantify activity budgets continuously but have not been used to quantify social grooming. We test whether grooming can be accurately identified using machine learning (random forest model) trained on labelled acceleration data from wild chacma baboons (Papio ursinus). We successfully identified giving and receiving grooming with high precision (81% and 91%) and recall (87% and 79%). Giving grooming was associated with a distinct rhythmical signal along the surge axis. Receiving grooming had similar acceleration signals to resting, and thus was more difficult to assign. We applied our machine learning model to n = 680 collar data days from n = 12 baboons and found that grooming rates obtained from accelerometers were significantly and positively correlated with direct observation rates for giving but not receiving grooming. The ability to collect continuous grooming data in wild populations will allow researchers to re-examine and expand upon long-standing questions regarding the formation and function of grooming bonds.

Seasonal Movement Patterns of Urban Domestic Cats Living on the Edge in an African City.

Domestic cats (Felis catus) are amongst the most destructive invasive vertebrates globally, depredating billions of native animals annually. The size and seasonal variation of their geographical "footprint" is key to understanding their effects on wildlife, particularly if they live near conservation areas. Here we report the first GPS-tracking studies of free-roaming owned cats in the city of Cape Town, South Africa. A total of 23 cats was tracked (14 cats in summer, 9 in winter) using miniature (22 g) GPS locators in 2010-2011. In summer, all cats living on the urban-edge (UE: n = 7) made extensive use of protected areas, while only one of seven urban (U) cats (>150 m from the edge) did so. In winter two of four UE and two of five U cats entered protected areas. Home ranges (95% kernel density estimates) were significantly larger in summer (3.00 ± 1.23 ha) than winter (0.87 ± 0.25 ha) and cats ventured further from their homes in summer (maximum 849 m) than in winter (max 298 m). The predation risk posed by caracal (Caracal caracal) may limit the time cats spend in protected areas, but our results suggest that cat buffers around conservation areas should be at least ~600 m wide to reduce impacts to native fauna.

Anthropogenic activities and age class mediate carnivore habitat selection in a human-dominated landscape.

Human activities increasingly challenge wild animal populations by disrupting ecological connectivity and population persistence. Yet, human-modified habitats can provide resources, resulting in selection of disturbed areas by generalist species. To investigate spatial and temporal responses of a generalist carnivore to human disturbance, we investigated habitat selection and diel activity patterns in caracals (Caracal caracal). We GPS-collared 25 adults and subadults in urban and wildland-dominated subregions in Cape Town, South Africa. Selection responses for landscape variables were dependent on subregion, animal age class, and diel period. Contrary to expectations, caracals did not become more nocturnal in urban areas. Caracals increased their selection for proximity to urban areas as the proportion of urban area increased. Differences in habitat selection between urban and wildland caracals suggest that individuals of this generalist species exhibit high behavioral flexibility in response to anthropogenic disturbances that emerge as a function of habitat context.

Why humans kill animals and why we cannot avoid it.

Killing animals has been a ubiquitous human behaviour throughout history, yet it is becoming increasingly controversial and criticised in some parts of contemporary human society. Here we review 10 primary reasons why humans kill animals, discuss the necessity (or not) of these forms of killing, and describe the global ecological context for human killing of animals. Humans historically and currently kill animals either directly or indirectly for the following reasons: (1) wild harvest or food acquisition, (2) human health and safety, (3) agriculture and aquaculture, (4) urbanisation and industrialisation, (5) invasive, overabundant or nuisance wildlife control, (6) threatened species conservation, (7) recreation, sport or entertainment, (8) mercy or compassion, (9) cultural and religious practice, and (10) research, education and testing. While the necessity of some forms of animal killing is debatable and further depends on individual values, we emphasise that several of these forms of animal killing are a necessary component of our inescapable involvement in a single, functioning, finite, global food web. We conclude that humans (and all other animals) cannot live in a way that does not require animal killing either directly or indirectly, but humans can modify some of these killing behaviours in ways that improve the welfare of animals while they are alive, or to reduce animal suffering whenever they must be killed. We encourage a constructive dialogue that (1) accepts and permits human participation in one enormous global food web dependent on animal killing and (2) focuses on animal welfare and environmental sustainability. Doing so will improve the lives of both wild and domestic animals to a greater extent than efforts to avoid, prohibit or vilify human animal-killing behaviour.

Survey of infections transmissible between baboons and humans, Cape Town, South Africa.

Baboons on South Africa's Cape Peninsula come in frequent contact with humans. To determine potential health risks for both species, we screened 27 baboons from 5 troops for 10 infections. Most (56%) baboons had antibodies reactive or cross-reactive to human viruses. Spatial overlap between these species poses low but potential health risks.

Landscape requirements of a primate population in a human-dominated environment.

INTRODUCTION: As urban and rural land development become widespread features of the global landscape so an understanding of the landscape requirements of displaced and isolated wildlife species becomes increasingly important for conservation planning. In the Cape Peninsula, South Africa, rapid human population growth, and the associated urban and rural land transformation, threatens the sustainability of the local chacma baboon population. Here we analyse spatial data collected from nine of the 12 extant troops to determine their population-level landscape requirements. We use hurdle models to ascertain the key landscape features influencing baboon occurrence and abundance patterns on two hierarchical spatial scales. RESULTS: Both spatial scales produced similar results that were ecologically reliable and interpretable. The models indicated that baboons were more likely to occur, and be more abundant, at low altitudes, on steep slopes and in human-modified habitats. The combination of these landscape variables provides baboons with access to the best quality natural and anthropogenic food sources in close proximity to one another and suitable sleeping sites. Surface water did not emerge as an influential landscape feature presumably as the area is not water stressed. CONCLUSIONS: The model results indicate that land development in the Cape Peninsula has pushed baboons into increasingly marginal natural habitat while simultaneously providing them with predictable and easily accessible food sources in human-modified habitats. The resultant spatial competition between humans and baboons explains the high levels of human-baboon conflict and further erosion of the remaining land fragments is predicted to exacerbate competition. This study demonstrates how the quantification of animal landscape requirements can provide a mechanism for identifying priority conservation areas at the human-wildlife interface.

Troop size and human-modified habitat affect the ranging patterns of a chacma baboon population in the cape peninsula, South Africa.

Differences in group size and habitat use are frequently used to explain the extensive variability in ranging patterns found across the primate order. However, with few exceptions, our understanding of primate ranging patterns stems from studies of single groups and both intra- and inter-specific meta-analyses. Studies with many groups and those that incorporate whole populations are rare but important for testing socioecological theory in primates. We quantify the ranging patterns of nine chacma baboon troops in a single population and use Spearman rank correlations and generalized linear mixed models to analyze the effects of troop size and human-modified habitat (a proxy for good quality habitat) on home range size, density (individuals/km(2) ), and daily path length. Intrapopulation variation in home range sizes (1.5-37.7 km(2) ), densities (1.3-12.1 baboons/km(2) ), and daily path lengths (1.80-6.61 km) was so vast that values were comparable to those of baboons inhabiting the climatic extremes of their current distribution. Both troop size and human-modified habitat had an effect on ranging patterns. Larger troops had larger home ranges and longer daily path lengths, while troops that spent more time in human-modified habitat had shorter daily path lengths. We found no effect of human-modified habitat on home range size or density. These results held when we controlled for the effects of both a single large outlier troop living exclusively in human-modified habitat and baboon monitors on our spatial variables. Our findings confirm the ability of baboons, as behaviorally adaptable dietary generalists, to not only survive but also to thrive in human-modified habitats with adjustments to their ranging patterns in accordance with current theory. Our findings also caution that studies focused on only a small sample of groups within a population of adaptable and generalist primate species may underestimate the variability in their respective localities.

Poisoned chalice: Use of transformed landscapes associated with increased persistent organic pollutant concentrations and potential immune effects for an adaptable carnivore.

Wildlife around cities bioaccumulate multiple harmful environmental pollutants associated with human activities. Exposure severity can vary based on foraging behaviour and habitat use, which can be examined to elucidate exposure pathways. Carnivores can play vital roles in ecosystem stability but are particularly vulnerable to bioaccumulation of pollutants. Understanding the spatial and dietary predictors of these contaminants can inform pollutant control, and carnivores, at the top of food webs, can act as useful indicator species. We test for exposure to toxic organochlorines (OCs), including dichloro-diphenyl-trichloroethane (DDT) and polychlorinated biphenyls (PCBs), in a medium-sized felid, the caracal (Caracal caracal), across the peri-urban and agricultural landscapes of the city of Cape Town, South Africa. Concentrations in both blood (n = 69) and adipose tissue (n = 25) were analysed along with detailed spatial, dietary, demographic, and physiological data to assess OC sources and exposure risk. The analysis revealed widespread exposure of Cape Town's caracals to organochlorines: detection rate was 100% for PCBs and 83% for DDTs in blood, and 100% for both compounds in adipose. Caracals using human-transformed areas, such as vineyards and areas with higher human population and electrical transformer density, as well as wetland areas, had higher organochlorine burdens. These landscapes were also highly selected foraging areas, suggesting caracals are drawn into areas that co-incidentally increase their risk of exposure to these pollutants. Further, biomagnification potential was higher in individuals feeding on higher trophic level prey and on exotic prey. These findings point to bioaccumulation of OC toxicants and widespread exposure across local food webs. Additionally, we report possible physiological effects of exposure, including elevated white blood cell and platelet count, suggesting a degree of immunological response that may increase disease susceptibility. Cape Town's urban fringes likely represent a source of toxic chemicals for wildlife and require focused attention and action to ensure persistence of this adaptable mesocarnivore.

The naked truth: a comprehensive clarification and classification of current 'myths' in naked mole-rat biology.

The naked mole-rat (Heterocephalus glaber) has fascinated zoologists for at least half a century. It has also generated considerable biomedical interest not only because of its extraordinary longevity, but also because of unusual protective features (e.g. its tolerance of variable oxygen availability), which may be pertinent to several human disease states, including ischemia/reperfusion injury and neurodegeneration. A recent article entitled 'Surprisingly long survival of premature conclusions about naked mole-rat biology' described 28 'myths' which, those authors claimed, are a 'perpetuation of beautiful, but falsified, hypotheses' and impede our understanding of this enigmatic mammal. Here, we re-examine each of these 'myths' based on evidence published in the scientific literature. Following Braude et al., we argue that these 'myths' fall into four main categories: (i) 'myths' that would be better described as oversimplifications, some of which persist solely in the popular press; (ii) 'myths' that are based on incomplete understanding, where more evidence is clearly needed; (iii) 'myths' where the accumulation of evidence over the years has led to a revision in interpretation, but where there is no significant disagreement among scientists currently working in the field; (iv) 'myths' where there is a genuine difference in opinion among active researchers, based on alternative interpretations of the available evidence. The term 'myth' is particularly inappropriate when applied to competing, evidence-based hypotheses, which form part of the normal evolution of scientific knowledge. Here, we provide a comprehensive critical review of naked mole-rat biology and attempt to clarify some of these misconceptions.