We report the spontaneous modification and use of sticks to fish for termites, above the ground, in wild blonde capuchins (
Cebus flavius
). These critically endangered Neotropical primates inhabit remnants of the Atlantic Forest. They used two previously undescribed techniques to enhance their termite capture success: nest tapping and stick rotation. The current ecologically based explanation for tool use in wild capuchins (i.e. terrestrial habits and bipedalism) must be viewed cautiously. Instead, remarkable manual skills linked to a varied diet seem important in promoting tool use in different contexts. The repertoire of tool-using techniques employed by wild capuchins has been expanded, highlighting the behavioural versatility in this genus.
Despite advances in the study of capuchin monkeys (Cebus and Sapajus), there is fairly limited information on their vocal communication systems. The present study focused on investigating the structure and use of vocalizations by wild blonde capuchin monkeys, Sapajus flavius. The study subjects produced 29 different call types, which we grouped into 10 categories according to their behavioral context. The number of call types per context varied from one to six. Some of the call types in the vocal repertoire were only produced by individuals of specific age classes. The "nhan" call, for instance, was only emitted by infants, whereas the "ghrr" call was specific to adults. Other call types had no age-specificity and were produced by animals of two or more age categories. Discriminant Function Analysis correctly classified 77.4% of calls to type (n = 14 types). The "huh" and "huh-1var" calls, which are food-associated calls, were most commonly used, together representing approximately 52% of recorded vocalizations. Information on the vocal repertoire of blonde capuchins increases our knowledge of this very little known and Critically Endangered species. Ultimately, it may be used as a tool to help survey these animals in the wild and to assess welfare in captivity.
The variation in ecological traits in pitheciids allow investigation of vocal communication across a range of social and acoustic circumstances. In this review, we present a summary of the history of pitheciid vocal studies, and review i) the status of current knowledge of pitheciid vocal repertoire sizes, ii) how much we understand about the context of different acoustic signals, and iii) how can we potentially use our knowledge of vocalizations in animal welfare practices. The repertoires described for titi monkeys and sakis have the expected sizes for these genera, considering their relatively small social group sizes. However, uacari groups can contain over 100 individuals, and a larger vocal repertoire than the ones described would be expected, which could be a consequence of the fissionfusion social system where the large group divides into smaller subgroups. Nevertheless, vocal repertoires exist for only about 12% of the pitheciid species and nothing is known, for example, concerning call ontogeny. We hope that this study will act as a reference point for researchers interested in investigating vocal behaviour in pitheciids, thus, optimising both funding focus and, researcher's time and effort. Also, we hope to help defining methodologies and strategies for the conservation and management of pitheciid monkeys. 2014; SilvaJunior et al. 2013. Pitheciids show considerable variation in social traits and range sizes -for example, while all titi monkeys and many sakis form small groups in small territories, groups of uacaris and cuxius in some areas can be very large and range over extensive areas (Barnett et al. 2005; Bowler et al.
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