ABS 2022
Variation in Nut-Cracking Sites of Bearded Capuchin Monkeys in Wet and Dry Areas of Ubajara National Park
Tatiane Valença1,2,3, Giulia Sirianni4,5, Michele P. Verderane2, Beatriz C. Santana1, Tiago Falótico1,2. 1School of Arts, Sciences and Humanities, University of São Paulo, São Paulo, SP, Brazil; 2Neotropical Primates Research Group, São Paulo, SP, Brazil; 3Institute of Psychology, University of São Paulo, São Paulo, SP, Brazil; 4University of Rome “La Sapienza”, Rome, RM, Italy; 5Istituto di Scienze e Tecnologie della Cognizione, CNR, Rome, RM, Italy

Ecological, genetic, and cultural variables can cause behavioral variation in animal populations. Understanding the role played by each factor is essential to determine whether a behavioral variation can be defined as a cultural trait. Macauba (Acrocomia aculeata) is a palm nut consumed by capuchin monkeys (Sapajus spp.). While S. libidinosus, living in drier areas, use stone tools to crack and access the endosperm of this nut, other species do not use tools, consuming just the soft mesocarp of this resource. In this study, we conducted a systematic survey of nut-cracking sites, macauba trees and potential stone tools in Ubajara National Park. Macaubas and stones occur in both upper-humid and lower-dry areas, however the higher availability of both resources was recorded in dry areas. We recorded 201 macauba cracking-sites. Dry areas have higher density of cracking sites than wet areas. Branches are also used as anvils in wet areas. The distribution of resources and cracking sites suggest that ecological conditions may affect the density of the nut-cracking sites, but a potential tradition may explain why this behavior persists in areas of less favorable ecological conditions.

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