The Relationship Between Humans and Capuchins (Sapajus sp.) in an Urban Green Area in Brazil

Diet and seed dispersal of bearded capuchin monkeys (Sapajus libidinosus) in Brasilia National Park

The dietary ecology of a species can provide information on habitat requirements, food resources, and trophic interactions, important to guide conservation efforts of wildlife populations in endangered habitats. In this study, we investigated the dietary ecology of bearded capuchin monkeys (Sapajus libidinosus) in Brasilia National Park, in the endangered Cerrado biome of central Brazil. To obtain diet composition and evaluate the role of these primates as seed dispersers of local tree species, fecal sample collections and feeding observations were performed for a 7-month period. To determine whether seeds germinated better after passing through a primate gut, we conducted germination trials with (i) pulped seeds from trees, (ii) depulped seeds from trees, (iii) seeds from feces planted with feces, and (iv) seeds from feces planted without feces. During experimental procedures, 7308 seeds from 8 families and 10 species were planted. We found that S. libidinosus spent more time feeding on fruits than on any other food item and the diet consisted of 33 plant species from 21 families. However, 20% of their diet consisted of anthropic food. Most seeds planted with feces germinated faster compared to seeds in other experimental treatments, suggesting that passing through the gut and being deposited with fecal material is advantageous. The bearded capuchins also defecated many medium- (5 species) and large-sized (2 species) seeds that may be inaccessible to smaller arboreal frugivores. The results obtained emphasize the important role of bearded capuchins as seed dispersers for the maintenance and conservation of the endangered Cerrado biome.

Interactions with humans reduce the success of foraging for anthropogenic food by capuchin monkeys (Sapajus libidinosus) in Brasília National Park, Brazil

The progressive growth of urban environments has increasingly forced populations of nonhuman primates to coexist with humans in many cities, which has resulted in problems such as behavioral alterations, conflicts with humans, and threats to the health of the monkeys, due to their consumption of anthropogenic foodstuffs. These anthropogenic foods, which are rich in calories, are the principal driver of the proximity between humans and primates, even though the acquisition of these foods tends to be risky for the monkeys and involve a variety of challenges derived from specific features of the urban environment. The present study evaluated the success/risk relationship of foraging for anthropogenic food by tufted capuchins (Sapajus libidinosus) in Brasília National Park. The data were analyzed using a binary logistic regression, with the backward-stepwise Wald method, to investigate the factors related to the foraging success of the capuchins, considering variables such as their sex and age, the type of approach and its context, and interactions with humans. The capuchins were influenced by the anthropogenic context, which affected their foraging strategies and diet. Interactions with humans reduced the success of foraging for anthropogenic foods. Conflicts between humans and the capuchins were common, especially in the context of access to food. The capuchins thus preferred to access feeding resources directly, probably due to the reduced human interference, which resulted in greater foraging success for unattended food brought by park visitors and the raiding of trash cans. Based on the observed behavior patterns, a number of measures can be proposed to mitigate these conflicts. These recommendations include not bringing food into areas frequented by the capuchins, not reacting to approaching animals, and removing all trash generated during a visit. A cleaning team dedicated to the maintenance of the visitation area free of anthropogenic waste is also be recommended.

Capuchin monkey (Sapajus spp.) diet: current knowledge, gaps, and future directions

Knowledge of the feeding habits of primate species is important for an understanding of their natural history and ecological interactions between their groups, and their interactions with their environments. Capuchin monkeys (Sapajus spp.) present significant diet flexibility and are a good model for investigating diet diversity between species. We undertook a systematic literature review of publications on the diet of free-living Sapajus spp. groups by using the Web of Science platform. We performed scientometric analyses of the objectives and hypotheses of the reviewed works, identified knowledge gaps, and evaluated the composition of each group's diet. Our results indicate geographic and taxonomic biases among the 59 published studies that we examined. The studies were focused on Sapajus nigritus, Sapajus libidinosus, and Sapajus apella, and undertaken in long-term study sites. Foraging and behavioral aspects of how food is processed were recurring themes. Capuchin monkeys increase their consumption of anthropogenic food according to its supply. Despite the similar objectives of these studies, standardized data collection protocols were not employed. Although Sapajus spp. are widely distributed and are used for cognitive studies, basic aspects of their natural history, such as their diet, remain unknown. We emphasize the importance of undertaking studies on this genus to fill the identified knowledge gaps, and propose that investigations should be carried out on the effects of dietary changes on individuals and groups. We stress that, as the Neotropical region is one of those most affected by anthropogenic impacts, opportunities to study these primates in their natural environments are diminishing daily.

Diet diversity and seasonality of robust capuchins (Sapajus sp.) in a tiny urban forest

Capuchins are omnivorous neotropical primates that can survive in urban forests by supplementing their diet with human foods. However, few studies have analyzed the impact of these resources on their diet diversity and feeding seasonality. We aimed to assess the patterns of foraging, feeding, and diet diversity of urban capuchins (Sapajus sp.) that live in a tiny urban forest in Foz do Iguaçu, Brazil, where humans frequently feed them. We predicted that forest degradation and human foods could decrease diet diversity, though capuchins may, conversely, reduce their selectivity and expand their food repertoire. We followed the animals from dawn to dusk between May 2018 and April 2019 to list and quantify the species and items consumed. We used diversity indexes and cluster analysis to understand similarities and differences in the diet composition over the study period. We recorded 58 plant species (being 14 exotics) consumed by the monkeys, and nonconventional items, with low diet diversity overall. The diet consisted mainly of plants (69.8%), animal matter (20.6%), and processed foods (9.5%). Capuchins consumed more food from the anthropic environment (57.5%) than from the forest (42.4%), while their food from the forest included more invertebrates (47.8%) than fruits (40%). The cluster analysis showed two main groups of feeding months, in accordance with the seasons of high and low food production in local forests. Monkeys did not vary the frequencies of foraging or feeding between seasons, probably due to the omnipresent availability of human foods. Despite the high consumption of human foods, capuchins responded to the seasonality of the forest, expanding their feeding diversity in the drier period. Future studies should analyze the correspondence between food consumption and local phenology, as well as the potential role of capuchins as seed dispersers in this depauperate community.

Urine washing in urban robust capuchin monkeys (Sapajus sp.): The relation with visitors

In primates, urine washing (UW) is a behavior in which individuals intentionally deposit urine on their bodies. Social and nonsocial hypotheses have been proposed to explain the adaptive function of this behavior. For capuchins, different functions have been assigned for UW, suggesting it as a flexible behavior, but studies have been mainly in captivity. However, no investigations have been performed in urban environments, where these animals can modify their behavior. Our goal was to study UW in a semi-provisioned group of an introduced unknown robust capuchin species (Sapajus sp.) living in a tiny urban fragment in Foz do Iguaçu, Brazil, where they have contact with humans. We assessed the influence of social (sexual, agonistic, and anointing behaviors) and environmental (temperature, relative air humidity, height of the monkeys in the trees, number of people present in the fragment, and human-monkey interactions) variables, the influence of behavior before and after UW, and the influence of sex-age classes, on the frequency of UW. We observed 75 records of UW in 300 h of observations, where urine was mostly deposited on hands and passed on to feet (95%). There were no significant differences in the frequency of the behavior between sex-age classes nor in the behaviors before and after UW. Around 50% of UW took place in the late morning and we found no correlation between UW and temperature, relative air humidity, nor the heights of the monkeys in the trees. However, we found a significant association between UW and the daily number of people in the fragment, but not between UW and human-monkey interactions, anointing, agonisms, and sexual behavior. Our study increases the scope of UW flexibility by identifying the presence of visitors affecting the occurrence of this behavior. We discussed different possibilities through which people could influence the capuchins to display UW.

Supplemented howler monkeys eat less wild fruits, but do not change their activity budgets

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.

Activity budget and social behavior of urban capuchin monkeys, Sapajus sp. (Primates: Cebidae)

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.