Human-wildlife conflict: proximate predictors of aggression between humans and rhesus macaques in India

Current wildlife crime (Indian scenario): major challenges and prevention approaches

The constant depletion of wild flora and fauna in India due to uncontrolled human activities, natural habitat destruction and covert poaching activities is threatening the ecological balance. The poaching and trafficking of wild species in the lure of money as well as fashion has wiped out a range of wildlife species that call for critical attention to tackle this menace. There are many transit routes through the states of Uttar Pradesh, Karnataka, West Bengal, Rajasthan, Madhya Pradesh, and Assam, which are major hubs for wildlife trafficking in India, in both domestic and international markets. The poaching of wild animals and plants slowly erases biodiversity, which in turn affects the survival of humans and other living species. Therefore, there is an urgent need to check ongoing wildlife crimes, raise the number of endangered species, rehabilitate exotic/extinct species and restore natural ecosystems. In this article, we collected wildlife crime data from web portals of various stakeholders, government agencies and authentic news sources, and discuss the current crime trends, challenges, and prevention approaches required to control and restore wildlife biodiversity in India.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10531-023-02577-z.

Rhesus Macaque Macaca mulatta (Mammalia: Primates: Cercopithecidae) in a human-modified landscape: population, activity budget, and societal perceptions in Bangladesh

Rhesus Macaques are widely distributed and ecologically diverse primate species that attract special focus from the research and conservation approaches. We studied population, activity budget, and societal perceptions of Rhesus Macaque at Old Dhaka City, Bangladesh from March 2015 to February 2016. Total count was used to determine the group size and composition. Daily activity budgets of Rhesus Macaques were studied using scan sampling method. Questionnaire survey was conducted to know the attitudes of local people towards monkey conservation in the area. Seven groups with a total of 169 individuals were recorded. The population density was 15.5 individuals/ km² and group size ranged from 8 to 63 individuals.  Rhesus Macaque spent most of their time in resting (38.5%) followed by feeding (25.7%), moving (18.4%), grooming (12.8%), and playing or object manipulation (4.6%). There was a significant variation in each behavioral activity among the age-sex classes. Questionnaire survey revealed that property damage was the main problem created by the monkeys. A significant majority of people (83.4%) held a positive outlook toward conservation of this species. Variables such as religion, education, and occupation of the respondents significantly influenced their opinion about conservation. These findings have implications for not only conservation and management interventions of Rhesus Macaque but also helpful for minimizing human-monkey interactions in urban areas. 

The costs and benefits of coexistence: What determines people's willingness to live near nonhuman primates?

Living near primate species has positive and negative outcomes for human communities. While most studies focus on understanding people's perceptions regarding the adverse consequences of interacting with primates, less is known about people's willingness to coexist with primates or reasons that may promote human-primate coexistence. We surveyed 794 people co-living with four different primate species-rhesus macaque Macaca mulatta, bonnet macaque Macaca radiata, lion-tailed macaque Macaca silenus, and Hanuman langur Semnopithecus dussumieri-in southern and western India to understand how people perceived the costs and benefits of coexistence. The results of our semi-structured interview study revealed that although tangible costs (i.e., financial losses from primate depredation) primarily drive people's stated tolerance for primate presence, intangible benefits from primates (i.e., their ecological, existence, sentience, and religious values) also critically affect attitudes towards coexistence. Amongst the four species, people associated rhesus macaques with the greatest costs and fewest benefits, lion-tailed macaques with the lowest costs, and bonnet macaques with the highest benefits. People preferred lion-tailed macaques and Hanuman langurs more than bonnet and rhesus macaques, and affection for a species shaped how people viewed costs accruing from the species. People's preferences for species were influenced by their existence, ecological, and sentience values more than their religious value. We suggest that intangible benefits influence people's fondness for a primate species and this, in turn, shapes how people perceive costs resulting from the species. Hence strengthening people's perceptions of the intangible benefits they receive from primate species will improve human tolerance for living near primates. We argue that there is a need to understand the context of human-primate conflicts beyond the cost aspects and focus on the benefits to improve human-primate coexistence.

The evolutionary consequences of human-wildlife conflict in cities

Human-wildlife interactions, including human-wildlife conflict, are increasingly common as expanding urbanization worldwide creates more opportunities for people to encounter wildlife. Wildlife-vehicle collisions, zoonotic disease transmission, property damage, and physical attacks to people or their pets have negative consequences for both people and wildlife, underscoring the need for comprehensive strategies that mitigate and prevent conflict altogether. Management techniques often aim to deter, relocate, or remove individual organisms, all of which may present a significant selective force in both urban and nonurban systems. Management-induced selection may significantly affect the adaptive or nonadaptive evolutionary processes of urban populations, yet few studies explicate the links among conflict, wildlife management, and urban evolution. Moreover, the intensity of conflict management can vary considerably by taxon, public perception, policy, religious and cultural beliefs, and geographic region, which underscores the complexity of developing flexible tools to reduce conflict. Here, we present a cross-disciplinary perspective that integrates human-wildlife conflict, wildlife management, and urban evolution to address how social-ecological processes drive wildlife adaptation in cities. We emphasize that variance in implemented management actions shapes the strength and rate of phenotypic and evolutionary change. We also consider how specific management strategies either promote genetic or plastic changes, and how leveraging those biological inferences could help optimize management actions while minimizing conflict. Investigating human-wildlife conflict as an evolutionary phenomenon may provide insights into how conflict arises and how management plays a critical role in shaping urban wildlife phenotypes.

Injuries and deaths caused by non-human primate attacks: Paediatric vulnerability

A six-month-old girl was taken from her mother's lap by a macaque monkey (Macaca) that had entered the room through an open door. The monkey escaped with the infant but subsequently dropped her from a rooftop terrace. Death occurred soon after impact with the ground, and was found at autopsy to be due to blunt cranio-cerebral trauma with skull fractures and intracranial haemorrhage. Monkeys and apes may cause a variety of serious and potentially life-threatening injuries and may manifest quite unpredictable and aggressive behaviour around humans. The very young are particularly vulnerable to primate attacks, and 'baby theft' by apes and monkeys is an event that has now been reported, albeit rarely, in a number of different countries around the world. The fatally injured infants have died from bites, falls and drowning. Chimpanzees in the wild may also specifically hunt human infants for food.

Impact of individual demographic and social factors on human-wildlife interactions: a comparative study of three macaque species

Despite increasing conflict at human–wildlife interfaces, there exists little research on how the attributes and behavior of individual wild animals may influence human–wildlife interactions. Adopting a comparative approach, we examined the impact of animals’ life-history and social attributes on interactions between humans and (peri)urban macaques in Asia. For 10 groups of rhesus, long-tailed, and bonnet macaques, we collected social behavior, spatial data, and human–interaction data for 11–20 months on pre-identified individuals. Mixed-model analysis revealed that, across all species, males and spatially peripheral individuals interacted with humans the most, and that high-ranking individuals initiated more interactions with humans than low-rankers. Among bonnet macaques, but not rhesus or long-tailed macaques, individuals who were more well-connected in their grooming network interacted more frequently with humans than less well-connected individuals. From an evolutionary perspective, our results suggest that individuals incurring lower costs related to their life-history (males) and resource-access (high rank; strong social connections within a socially tolerant macaque species), but also higher costs on account of compromising the advantages of being in the core of their group (spatial periphery), are the most likely to take risks by interacting with humans in anthropogenic environments. From a conservation perspective, evaluating individual behavior will better inform efforts to minimize conflict-related costs and zoonotic-risk.

Using environmental niche modelling to investigate abiotic predictors of crocodilian attacks on people

Crocodilians are distributed widely through the tropics and subtropics, and several species pose a substantial threat to human life. This has important implications for human safety and crocodilian conservation. Understanding the drivers of crocodilian attacks on people could help minimize future attacks and inform conflict management. Crocodilian attacks follow a seasonal pattern in many regions, but there has been limited analysis of the relationship between attack occurrence and fine-scale contemporaneous environmental conditions. We use methods from environmental niche modelling to explore the relationships between attacks on people and abiotic predictors at a daily temporal resolution for the Nile crocodile Crocodylus niloticus in South Africa and Eswatini (formerly Swaziland), and the American alligator Alligator mississippiensis in Florida, USA. Our results indicate that ambient daily temperature is the most important abiotic temporal predictor of attack occurrence for both species, with attack likelihood increasing markedly when mean daily temperatures exceed 18 °C and peaking at 28 °C. It is likely that this relationship is explained partially by human propensity to spend time in and around water in warmer weather but also by the effect of temperature on crocodilian hunting behaviour and physiology, especially the ability to digest food. We discuss the potential of our findings to contribute to the management of crocodilians, with benefits for both human safety and conservation, and the application of environmental niche modelling for understanding human–wildlife conflicts involving both ectotherms and endotherms.

Impact of anthropogenic factors on affiliative behaviors among bonnet macaques

OBJECTIVES

In primates, allogrooming and other affiliative behaviors confer many benefits and may be influenced by many socioecological factors. Of these, the impact of anthropogenic factors remain relatively understudied. Here we ask whether interactions with humans decreased macaques' affiliative behaviors by imposing time-constraints, or increased these behaviors on account of more free-/available-time due to macaques' consumption of high-energy human foods.

MATERIALS AND METHODS

In Southern India, we collected data on human-macaque and macaque-macaque interactions using focal-animal sampling on two groups of semi-urban bonnet macaques for 11 months. For each macaque within each climatic season, we calculated frequencies of human-macaque interactions, rates of monitoring human activity and foraging on anthropogenic food, dominance ranks, grooming duration, number of unique grooming partners, and frequencies of other affiliative interactions.

RESULTS

We found strong evidence for time-constraints on grooming. Macaques that monitored humans more groomed for shorter durations and groomed fewer partners, independent of their group membership, sex, dominance rank, and season. However, monitoring humans had no impact on other affiliative interactions. We found no evidence for the free-time hypothesis: foraging on anthropogenic food was unrelated to grooming and other affiliation.

DISCUSSION

Our results are consistent with recent findings on other urban-dwelling species/populations. Macaques in such environments may be especially reliant on other forms of affiliation that are of short duration (e.g., coalitionary support, lip-smacking) and unaffected by time-constraints. We stress on the importance of evaluating human impact on inter-individual differences in primate/wildlife behavior for conservation efforts.

Anthropogenic effects on the physiology and behaviour of chacma baboons in the Cape Peninsula of South Africa

As animals increasingly occupy habitats in proximity to humans, with home ranges a mosaic of natural and anthropogenic landscapes, it becomes imperative from a conservation perspective to understand the impacts of human activities on wildlife. Many non-human primates share habitats with humans, an ability stemming largely from shared ecological needs due to our close evolutionary relationship. Such proximity, however, is often accompanied by direct conflict between humans and wildlife, leading to higher stress levels, injuries, mortality and behavioural changes, with detrimental effects on long-term health and fitness. Glucocorticoid (GC) hormones, which are released in response to ecological and social challenges, are increasingly employed to understand responses to anthropogenic disturbance. Here we investigate physiological and behavioural responses of female chacma baboons (Papio ursinus) to variation in spatial overlap and conflict with humans in their natural home range. The baboons resided in the Tokai Section of Table Mountain National Park in the Cape Peninsula of South Africa, where their home range included four types of habitats: protected, suburban, agricultural and mosaic areas. We studied the largest group of baboons in Tokai (70 individuals) and examined the effects of ranging in these different habitats on the faecal GCs and behaviour of all adult females in the troop (N = 16). We found time spent ranging in more anthropogenic habitats to be associated with higher levels of GCs, more aggression, less time socializing and shorter grooming bouts. Self-directed behaviour, however, varied and did not necessarily reflect physiological measures of stress. Taken together, the results of this study highlight the risks associated with ranging in anthropogenic environments and point to the need for a multifaceted approach to studying the negative impacts of human activities on animals so as to better inform conservation practices.

Interactions with humans are jointly influenced by life history stage and social network factors and reduce group cohesion in moor macaques (Macaca maura)

Human-wildlife encounters are becoming increasingly frequent across the globe, often leading people to interact with and feed wild animals and impacting animal behaviour and ecology. Although the nature of human-wildlife interactions has been well documented across a number of species, we still have limited understanding as to why some individual animals interact more frequently with humans than others. Additionally, we lack a comprehensive understanding of how these interactions influence animal social networks. Using behavioural data from a group of moor macaque monkeys (Macaca maura), we used permutation-based linear regression analyses to understand how life history and social network factors jointly explain interindividual variation in tendency to interact with humans along a provincial road in South Sulawesi, Indonesia. As our study group spent only a portion of their time in proximity to humans, we also examined how social network structure changes in response to human presence by comparing social networks in the forest to those along the road. We found that sex, individual network position, and associate network position interact in complex ways to influence individual behaviour. Individual variation in tendency to be along the road caused social networks to become less cohesive when in proximity to humans. This study demonstrates that nuanced intragroup analyses are necessary to fully understand and address conservation issues relating to human-wildlife interactions.

Experience-based human perception of facial expressions in Barbary macaques (Macaca sylvanus)

BACKGROUND

Facial expressions convey key cues of human emotions, and may also be important for interspecies interactions. The universality hypothesis suggests that six basic emotions (anger, disgust, fear, happiness, sadness, and surprise) should be expressed by similar facial expressions in close phylogenetic species such as humans and nonhuman primates. However, some facial expressions have been shown to differ in meaning between humans and nonhuman primates like macaques. This ambiguity in signalling emotion can lead to an increased risk of aggression and injuries for both humans and animals. This raises serious concerns for activities such as wildlife tourism where humans closely interact with wild animals. Understanding what factors (i.e., experience and type of emotion) affect ability to recognise emotional state of nonhuman primates, based on their facial expressions, can enable us to test the validity of the universality hypothesis, as well as reduce the risk of aggression and potential injuries in wildlife tourism.

METHODS

The present study investigated whether different levels of experience of Barbary macaques, Macaca sylvanus, affect the ability to correctly assess different facial expressions related to aggressive, distressed, friendly or neutral states, using an online questionnaire. Participants' level of experience was defined as either: (1) naïve: never worked with nonhuman primates and never or rarely encountered live Barbary macaques; (2) exposed: shown pictures of the different Barbary macaques' facial expressions along with the description and the corresponding emotion prior to undertaking the questionnaire; (3) expert: worked with Barbary macaques for at least two months.

RESULTS

Experience with Barbary macaques was associated with better performance in judging their emotional state. Simple exposure to pictures of macaques' facial expressions improved the ability of inexperienced participants to better discriminate neutral and distressed faces, and a trend was found for aggressive faces. However, these participants, even when previously exposed to pictures, had difficulties in recognising aggressive, distressed and friendly faces above chance level.

DISCUSSION

These results do not support the universality hypothesis as exposed and naïve participants had difficulties in correctly identifying aggressive, distressed and friendly faces. Exposure to facial expressions improved their correct recognition. In addition, the findings suggest that providing simple exposure to 2D pictures (for example, information signs explaining animals' facial signalling in zoos or animal parks) is not a sufficient educational tool to reduce tourists' misinterpretations of macaque emotion. Additional measures, such as keeping a safe distance between tourists and wild animals, as well as reinforcing learning via videos or supervised visits led by expert guides, could reduce such issues and improve both animal welfare and tourist experience.

Prevalence of enteric bacterial parasites with respect to anthropogenic factors among commensal rhesus macaques in Dehradun, India

There has been a recent surge in research on primate infectious disease ecology. Two major areas remain relatively unaddressed to date-the prevalence of enteric bacterial parasites and the role of anthropogenic environmental factors in parasite acquisition in commensally living primate populations. In this preliminary assessment, we address both these gaps by assessing the prevalence, and the role of anthropogenic factors in shaping this prevalence, of three enteric bacterial parasites-E . coli O157:H7, Salmonella sp., Shigella sp.-across populations of rhesus macaques (M. mulatta) that live commensally with humans in Dehradun, northern India. Across 10-week study period, we collected data on (1) human-macaque behavioral interactions, (2) macaque and human demographic and activity scans, and (3) macaque fecal samples from the environment at four different locations in Dehradun. Biochemical tests and morphology-based confirmations clearly established the presence of all three enteric bacterial parasites in rhesus macaques. Overall prevalence ranged from 2 to 5 %, with Shigella sp. being the most prevalent. Regression analyses linking anthropogenic factors to bacterial prevalence showed a positive association between rates of macaques eating human garbage and E. coli O157:H7 (β = 0.23, p = 0.083), but a negative association with Salmonella sp. (β = -0.17, p = 0.026). Rather, the prevalence of Salmonella sp. was positively linked to rates of macaque eating provisioned food (β = 0.0012, p = 0.058). Finally, we found no relationship between anthropogenic factors and the prevalence of Shigella sp. Our findings establish the prevalence of enteric bacterial parasites in commensal populations of primates and suggest that although anthropogenic factors are linked to bacterial prevalence, the nature of the relationships may depend on the socioecological/foraging strategies of macaques and the food sources that facilitate the environmental survival of particular types of enteric bacteria over others.