Living in the crowd: Influence of density and social factors on cortisol levels in captive capuchin monkeys (Sapajus libidinosus)
cortisol, stress, crowding, visitor effect, rank, social grooming
Captive animals must cope with chronic stressors in their lives, from reduced and altered space to lack of scape areas. Capuchin monkeys (Sapajus spp.) are detached models to study effects of life in captivity, not only due to their prevalence in Brazilian rescue centers and Zoos, but also because of their detached behavioural flexibility, which made it possible for them to adapt to different natural environments such as the Atlantic forest and the Caatinga. This thesis uses behavioural and physiological (fecal glucocorticoid metabolics - FMG) measures in capuchin monkeys (Sapajus libidinosus) from different captive environments (CETAS at Natal/RN and Cabedelo/PB, and zoo at João Pessoa/PB) to test the hypotheses that social crowding, visitor presence and high hierarchical position are factors that increase stress levels, while social grooming and sexual behaviour decreases stress levels. In the first chapter, we explain the concept of stress, allostatic load and how it is affected by the environmental and social factors we will to analyze. Selecting regression models based on Akaike Information Criteria, our analyses corroborated the hypotheses that social crowding is a strong stressor to capuchins as revealed by increased mean, median and maximum FMG levels, however, presence of visitor was not a strong predictor of cortisol levels. As expected, dominant individuals were more stressed than subordinates. Contrary to expected grooming was not a strong predictor of decreased cortisol levels, but "sexual behaviour", "retreat", "proximity", "self-grooming" were. In conjunct these results indicate that despite increased vigilance in zoos, crowding is a stronger stressor to captive capuchin monkeys, and animals use an avoidance strategy, proximity and sex to cope with challenges of social life in captivity.