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| Author(s): |
Michele Pereira Verderane
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Psicologia (IP/SBD) |
| Defense date: | 2010-06-18 |
| Examining board members: |
Patricia Izar Mauro;
Renata Goncalves Ferreira;
Francisco Dyonisio Cardoso Mendes;
Eduardo Benedicto Ottoni;
Briseida Dogo de Resende
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| Advisor: | Patricia Izar Mauro |
| Abstract | |
Primates exhibit a wide diversity of social systems. Socioecology proposes an approach for studying the evolution of this diversity, by analyzing the relationship between social behavior, ecology and population dynamics. Primates of the genus Cebus exhibit a wide geographic distribution and a related diet and behavioral flexibility, thus are ideal for testing predictions from the socioecological model. In addition, some populations exhibit the spontaneous use of tools for processing food. Although it is recognized that the use of tools may change the characteristics of food resources, the impact of this technique was never incorporated into the predictions of socioecological models. Our aims were (1) to study the social relationships of females of a wild tool using population of Cebus libidinosus, in an area of ecotone Cerrado/Caatinga, in the light of socioecological models, investigating whether the use of tools affects the pattern of females social relationships, and (2) to study the activity budget, diet and substrate use, assessing whether ecological factors affect these behavioural patterns of the animals. This research was conducted at Fazenda Boa Vista (BV), located in the municipality of Gilbués, south of Piauí state. We studied two groups of monkeys (ZA and CH), between May 2006 and April 2008. The results show that the amount of available food did not change in BV during the research period, as well as the activity budget of the animals. Fruits and invertebrates were the main foods eaten by the monkeys, while foods obtained with the aid of tools represented a small proportion of their diet. Sex differences in diet and activity patterns suggest that females have a higher energy demand and/or are less efficient foragers than males, while the differences between age groups indicate that juveniles are less efficient foragers than adults. Fruits, which are a high quality, patchily distributed and usurpable food resource, were the main food for females, and the size of patchy food sources ranged from intermediate to large. The social system of the study population corresponded to the standard Resident-nepotistictolerant (philopatry of females, linear dominance hierarchy and stable relations of grooming and coalition between females), supporting the models predictions for primates that feed on high quality, patchily distributed and usurpable food resources, and are subject to strong direct competition within and between groups for food. The pattern of activities, diet, substrate use and the social structure of C. libidinosus at BV were similar to the pattern found in some populations of Cebus that do not use tools, indicating that the use of these artifacts did not significantly alter the activity period and the diet of animals in the BV or the competitive regimes and the dynamics of relations between females. However, it is possible that the impact of using tools on behavioral aspects is most evident in populations that depend primarily on foods extracted with the aid of tools (AU) | |