Uses of nonhuman primates by humans in northeastern Brazil.

Humans have used non-human primates (hereafter referred to as primates) as food source, medicine, parts of rituals, pets, and models for various studies worldwide. Here we investigated the extent of the use of primates by humans in three areas in northeastern Brazil, the country's most impoverished region. We carried out our study in three biomes (Caatinga, Cerrado, and Atlantic Forest). The results showed that humans exploited all five primate species occurring in the study sites: Callithrix jacchus, Sapajus flavius, Sapajus libidinosus, Alouatta belzebul, and Alouatta ululata. They used the primates as a food source, as pets and medicines, and for leisure. Despite socioeconomic differences in the study areas, we found similarities in the use of primates. Larger primates were targeted for meat, whereas the small common marmosets were targeted as pets. We found conflicting interactions between humans and bearded capuchins due to crop raiding, but no such conflict was found between humans and blonde capuchins, reflecting the differences in crop type, pattern, and tradition in the sites. A. ululata was used as medicine. We suggest that environmental education actions in the study areas should focus on (i) raising awareness among local people of the ecological importance of primates, (ii) providing alternative activities to hunting whenever possible, and (iii) minimising conflicts.

Bearded capuchin (Sapajus libidinosus) predation on a rock cavy (Kerodon rupestris) followed by prey sharing.

We describe predation on an adult rodent rock cavy and sharing of the carcass by a group of male bearded capuchins. Despite many studies, such an interaction has never been observed in bearded capuchins. Rock cavies are large rodents weighing around 25% of the weight of an adult male bearded capuchin. The capuchins chased, caught, and shared the adult rock cavy. We observed no strong evidence of communication or division of roles in the successful capture, suggesting that the social hunting episode was not necessarily coordinated or collaborative. Instead, the individuals apparently tried to achieve the same goal of capturing the prey simultaneously (i.e., individuals synchronously performed similar actions to achieve the task), with the strongest individual emerging victorious and tolerating prey sharing afterwards. Our observations add to the understanding of cooperative behaviours such as social hunting and food sharing in bearded capuchins.

Wild Blonde Capuchins (Sapajus flavius) Perform Anointing Behaviour Using Toxic Secretions of a Millipede (Spirobolida: Rhinocricidae).

Defensive secretions of millipedes are remarkable for containing toxic quinones known to efficiently repell hematophagous arthropods. Here we show that Endangered blonde capuchin monkeys make use of such secretions. We (i) describe the anointing behavior performed by the monkeys (ii) identify the millipede species used in the process (iii) describe the volatile chemical composition of its secretion. The blonde capuchin monkeys selectively searched for millipedes hidden under the ground. We observed three bouts of anointing behavior, performed by 13 individuals of all age classes (from adults to independent infants), both solitarily (1 event) and socially (10 events). The only millipede species used by the monkeys is an undescribed species of the genus Poecilocricus (Spirobolida, Rhinocricidae). The volatile chemical composition of the secretions was predominantly comprised of a mixture of benzoquinones and hydroquinones. The social nature of the behavior and time of the observations (mosquito season), suggest that social bonding and mosquito avoidance is linked to the anointing behavior of the monkeys.