Constant changes in natural environments impose challenges to wild animal populations, especially those that depend on social life. We gathered data on the activity budget and social interactions of a capuchin monkey (Sapajussp.) group of 17 individuals confined to an urban green area receiving human food supplementation. We observed the capuchins between 7:00 am and 5:00 pm, three days a month, between January 2012 and June 2013 (total of 530 hours of direct observations). We collected 15,208 behavioral records through instantaneous scan sampling and 2,538 events of social interaction in an adapted version of the “all occurrences” method. Activity budget of capuchins was dominated by traveling (42%) and foraging (38%), followed by feeding (10%), social interactions (5%), resting (4%), and others (2%). Except for feeding, the time spent on other activities varied across sex-age classes. Social interactions of capuchins were dominated by affiliative interactions (80%), mainly social play, followed by agonistic (11%) and cooperative (10%) interactions. Sexual interactions were rare (0.4%) and often involved juveniles (45% of the events). Juveniles performed most of the social interactions, followed by the alpha male, and were the main receptors of grooming, food sharing, and agonism. On the other hand, they were the main group involved in allocarrying of infants. Grooming between females and from them to alpha male was infrequent. However, grooming of the alpha male towards the adult females was frequent. We interpreted the deviations in the activity budget and social interactions of the urban capuchins as effects of human food supplementation and restriction on dispersal, illustrating the behavioral ability of capuchin monkeys to adjust their activity in human-altered environments.
Research on the influence of food supplementation on primate behavior has focused on terrestrial and semiterrestrial species. Its effects on highly arboreal species are poorly known. We assessed the influence of food supplementation on the feeding behavior and activity budget of four adult female and two adult male brown howler monkeys (Alouatta guariba clamitans) belonging to two groups (JA and RO) that inhabited periurban forest fragments in southern Brazil. We used the "focal-animal" method during 6-8 full days per month from March to August 2017 (916 h of observation) to record the behavior of the study subjects. The feeding events of the focal individual were recorded using the "all occurrences" method. The supplementation was unevenly distributed during the day and accounted for 5-6% of all feeding events of male and female howlers, respectively. JA always received fruit in a platform, whereas RO had access to fruits and processed foods on roofs and directly from humans. The mean biomass of wild foods ingested by each adult per day was >300% higher than the ingested biomass of supplemented foods (females: 395 vs. 109 g/day; males: 377 vs. 120 g/day), but the ingestion rate of supplemented foods was ca. 400% higher than that of wild foods (females: 17 vs. 4 g/min; males: 19 vs. 5 g/ min). The activity budgets of females and males were dominated by resting (66-72%) followed by feeding (18-14%), moving (12-11%), and socializing (2%). We found that food supplementation reduced the ingestion of wild fruits, but it did not affect the howlers' need to ingest a given amount of leaves per day and the time spent resting, feeding, moving, and socializing.
K E Y W O R D SAlouatta guariba clamitans, anthropic food, behavioral flexibility, diet, human-wildlife interaction, provisioning
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