Impact of anthropogenic factors on affiliative behaviors among bonnet macaques

Behaviour, 2019

Time is a valuable but limited resource, and animals’ survival depends on their ability to carefully manage the amount of time they allocate to each daily activity. While existing research has examined the ecological factors affecting animals’ activity budgets, the impact of anthropogenic factors on urban-dwelling animals’ time budgets remains understudied. Here we collected data through focal animal sampling from three groups of rhesus macaques in Northern India to examine whether interactions with humans decrease macaques’ resting and social time (time constraints hypothesis), or whether, by contrast, foraging on anthropogenic food, that is potentially high in calories, leads macaques to spend more time resting and in social interactions (free time hypothesis). We found that macaques who interacted more frequently with people spent significantly less time resting and grooming, supporting the time constraints hypothesis. We argue that these time constraints are likely caused by the...

Provisioning of free-living primate groups usually leads to a significant increase in competition among individuals for the newly available resources. Do such individuals, however, exhibit altered behavioural strategies to alleviate social tension? Changing patterns of social interactions between adult females was studied in a wild group of bonnet macaques (Macaca radiata) in the Mudumalai Wildlife Sanctuary, Tamil Nadu, southern India, under two conditions of foraging. The group spent approximately 66% of the observation time foraging on its natural diet; during the remaining period the group gathered provisioned food from tourists visiting the sanctuary. Provisioning was marked by a sharp increase in aggression and feeding supplants within the group. Dominant females directed contact aggression specifically towards higher-ranked subordinates, while subordinate females increased non-contact aggression towards their dominant counterparts. Allogrooming was, however, much more reciprocated at the group level during provisioning. Subordinate females also initiated relatively more allogrooming towards those dominant individuals who were most aggressive during this period. Social tensions thus increase markedly when bonnet macaques move from natural foraging to competing for provisioned food; individual macaques, however, can adopt appropriate social strategies under such rapidly changing ecological regimes.

Quaternary International, 2020

The sharing of food is an essential component of human societies and has likely played a key role for the evolution of several human traits such as reduced sexual dimorphism, a more flexible maturational pace in relation to environmental variation and an increase in human tolerance and cooperation. For this reason, the investigation of the evolutionary origins of food sharing in humans has been a central topic in biological anthropology. Since behaviour does not fossilize, investigations on food sharing in nonhuman primates are key in providing a window into the evolution of food sharing and cooperation in humans. Among non-human primates, apes and New World monkeys have mostly shown evidence of non-kin food sharing, but in Old World monkeys, it is a very rare phenomenon. Here we provide the first descriptive report of food sharing in wild macaques. We studied two free-ranging groups of Nicobar long-tailed macaques from two different islands (i.e., Great Nicobar and Katchal), that have very different ecological settings and vegetation, for over 168 days. Using focal animal sampling, we observed a total of 18 food sharing events, that revolved around monopolizable food items (coconut and termite log) and mostly involved males. Females, even when present near the food owner, took very little interest in observing the event. The macaques shared food only among the individuals who sat close to the food owner, who, in turn, displayed very little aggression against bystanders. Given that, among Nicobar macaques, males have been previously described as forming strong social relationships, and since harassment was rarely observed in the present study, we argue that our observations could support the reciprocal exchange rather than the harassment hypothesis. While more observations are needed to better clarify the ultimate function of food sharing in this species, our study on Nicobar long-tailed macaques, highlighting some features that might make this species an ideal model to study the evolution of human behavior.

Behaviour, 2020

Access to limited resources may be achieved by dominance as well as by high rates of aggressive and affiliative behaviour. We investigated the relative effectiveness of dominance rank and aggressive and affiliative behaviour in accessing three material and three social resources. Aggressive and affiliative behaviour of 24 female long-tailed macaques was scored along with their success in resource access. Path models revealed that high-ranking individuals have more access to resources than low-ranking ones through their employment of both aggressive and affiliative behaviour. Physical aggression was effective in accessing two material resources (food and enrichment). Affiliative behaviour was effective in accessing one material (co-drinking) and one social (tolerance) resource. In conclusion, since aggressive behaviour was effective in accessing two material resources, while affiliative behaviour increased access to both a material and a social resource, affiliative behaviour is at l...

Primates, 2017

Robbing and bartering (RB) is a behavioral practice anecdotally reported in free-ranging commensal macaques. It usually occurs in two steps: after taking inedible objects (e.g., glasses) from humans, the macaques appear to use them as tokens, returning them to humans in exchange for food. While extensively studied in captivity, our research is the first to investigate the object/food exchange between humans and primates in a natural setting. During a 4-month study in 2010, we used both focal and event sampling to record 201 RB events in a population of long-tailed macaques (Macaca fascicularis), including four neighboring groups ranging freely around Uluwatu Temple, Bali (Indonesia). In each group, we documented the RB frequency, prevalence and outcome, and tested the underpinning anthropogenic and demographic determinants. In line with the environmental opportunity hypothesis, we found a positive qualitative relation at the group level between time spent in tourist zones and RB frequency or prevalence. For two of the four groups, RB events were significantly more frequent when humans were more present in the environment. We also found qualitative partial support for the male-biased sex ratio hypothesis [i.e., RB was more frequent and prevalent in groups with higher ratios of (sub)adult males], whereas the group density hypothesis was not supported. This preliminary study showed that RB is a spontaneous, customary (in some groups), and enduring population-specific practice characterized by intergroup variation in Balinese macaques. As such, RB is a candidate for a new behavioral tradition in this species. Keywords Token exchange Á Anthropogenic influences Á Demographic correlates Á Cultural behavior Á Balinese macaques

American journal of …, 2006

American Journal of Primatology, 1988

Abstract Resource availability or distribution may affect interindividual competition in species such as primates, which forage in social groups, and several field studies suggest that dominance status predicts access to restricted food sources. Increased competition due to ...

Indonesian Journal of Primatology

Non-Human Primates (NHP) have a slow life history compared to other mammals due to their complex brain growth. Brain complexity correlates with behaviour complexity, especially feeding behaviour, which enables primates to have the capability in leaf processing step, tool use, or even food washing. Macaca fascicularis on Tinjil Island is one of the NHP species conducting food-cleaning behaviour. Thus, this study aims to figure out the food-cleaning behaviour differences across the age classes of juvenile and male long-tailed macaques (LTM). The feeding behaviour of two age classes of male LTM through 3 different types of food processing was analysed using focal animal sampling and instantaneous recording methods. Then, the data were statistically analysed using Mann-Whitney and Kruskal-Wallis. We found that both age classes used Step 1 of the processing food type more than other types. Analysis within each age class showed different results that juvenile male LTM had a higher frequen...

Scientific Reports

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 perspec...

Primates and non-primates inhabiting tropical forests may interact with each other since they coexist in the same communities. Primates usually interact with their prey, predators, competitors and neutral species. Using ‘all occurrence’ sampling, we have studied inter-specific interactions of lion-tailed macaques with non-primate species found in their habitat. We observed that the percentage of total time spent on interactions with non-primates was less than 1. Also, the percentage of total time spent in interacting with competitors, predators and neutral species was less than 0.5. The lack of predation pressure and lack of opportunities for mixed-species associations for increasing foraging efficiency appear to be the major reasons for the absence of interactions with nonprimates. By comparing with studies from other primate habitat regions, we observed that primates in South Asia interact much lesser with non-primates than those in South America and Africa. A previous study showed that the interactions of lion-tailed macaques even with other primate species in the Western Ghats are less than expected by chance.