Interactions with humans impose time constraints on urban-dwelling rhesus macaques (Macaca mulatta)

Abstract

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 unpredictability of human behaviour.

Impact of anthropogenic factors on affiliative behaviors among bonnet macaques

“…We collected data for a total duration of 11 months spread across all three seasons described above. We used data collection protocols and ethograms that we had previously standardized and implemented on urban‐dwelling rhesus macaque in Northern India, and long‐tailed macaques in Malaysia (Kaburu et al, , b; Marty, Beisner, et al, ). MA and five field assistants collected data for 2–3 days per week per macaque group, using 10‐min focal animal sampling (Altmann, , ).…”

“…In each focal session, we recorded all human‐macaque and macaque‐macaque interactions that involved the focal subject in a continuous manner, capturing both the time of occurrence of each interaction and the sequence. We recorded both more frequently occurring human‐macaque interactions such as (a) mutual contact and noncontact aggression, (b) avoidance, and (c) human provisioning of macaques, as well as less frequently occurring interactions initiated by humans towards macaques such as (d) attention, (e) lure, (f) taunt, (g) stare, and (h) touch (see Kaburu et al, , b for detailed definitions). Among the macaque‐macaque interactions, we recorded (a) agonistic behavior which included contact and noncontact aggression that elicited a clear submissive response from the recipient, (b) submissive behavior outside of aggressive contexts, and (c) grooming (including an end‐time in addition to the start‐time to capture bout‐durations) (see Kaburu et al, , b for detailed definitions).…”

“…Urban landscapes have the potential to impose such extreme constraints, since primates that interact more frequently with humans may also be more vigilant (Kaburu, Marty, et al, ), or spend more time monitoring human activity in order to access anthropogenic food or to avoid antagonistic interactions with humans (Kaburu et al, ; Marty, Beisner, et al, ). Several studies have shown that primates living in human‐impacted areas change their activity budgets (Bryson‐Morrison, Tzanopoulos, Matsuzawa, & Humle, ; Jaman & Huffman, ; Ruppert, Holzner, See, Gisbrecht, & Beck, ; Saj, Sicotte, & Paterson, ; Singh & Vinathe, ), but the impact on inter‐individual differences in social behavior remain less clear.…”

“…Several studies have shown that primates living in human‐impacted areas change their activity budgets (Bryson‐Morrison, Tzanopoulos, Matsuzawa, & Humle, ; Jaman & Huffman, ; Ruppert, Holzner, See, Gisbrecht, & Beck, ; Saj, Sicotte, & Paterson, ; Singh & Vinathe, ), but the impact on inter‐individual differences in social behavior remain less clear. More recently, however, our research has revealed how interactions with humans may break up the grooming bout‐durations of rhesus macaques ( Macaca mulatta ) (Kaburu, Marty, et al, ), and reduce the grooming effort (both durations and diversity of partners) of rhesus macaques (Kaburu, Beisner, et al, ) and longtailed macaques ( M. fascicularis ) (Marty, Beisner, et al, ).…”

“…Previous studies on primate populations that thrive in anthropogenic landscapes have revealed that such animals also spend more time resting and socializing than populations in less perturbed landscapes, likely due to the high caloric value of anthropogenic foods leading to less time spent consuming or in search of natural food (El Alami, Lavieren, Rachida, & Chait, ; Hockings, Anderson, & Matsuzawa, ; Jaman & Huffman, ; Koirala et al, ; Saj et al, ; Thatcher, Downs, & Koyama, ). By the logic of this free‐time hypothesis, individuals that forage more on anthropogenic food may also have more time (rather than less time, as in time‐constraints) or energy to invest in grooming and/or other affiliative interactions (Kaburu, Beisner, et al, ).…”