Maternal care in capuchin monkeys (Sapajus libidinosus: plasticity or personality?

• Grant number: 24/04046-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: August 01, 2024
• End date: January 31, 2027
• Field of knowledge: Humanities - Psychology - Experimental Psychology
• Principal Investigator: Patrícia Izar Mauro
• Grantee: Julia de Omena Gomes
• Host Institution: Instituto de Psicologia (IP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

Increasing evidence suggests that individuals within the same population differ consistently in the way they behave (animal 'personality') and in their ability to respond to environmental variation (plasticity), but both phenomena can be considered complementary aspects of the individuals' phenotype. In the context of maternal care, investigation into how parental care styles occur and whether they vary according to characteristics of the environment and the mother becomes relevant to understand one of the dimensions of the females' phenotype, which has a direct link with the development of the offspring. By observing the capuchin monkey (Sapajus libidinosus) as a model, the current study aims to analyze whether females have a consistent maternal care style across multiple offspring, and whether this style varies according to variables such as the sex of the infant and experience of the mother, studied through parity and matrilineality. The population of capuchin monkeys studied inhabits Fazenda Boa Vista, Gilbués, PI, and presents groups with adults, juveniles and infants of both sexes. Groups are habituated to researchers and monkeys are individually recognized. Through footage taken using focal animal sampling method, 10 females will be observed in 30 mother-infant dyads, with 3 different offspring per female. The dyads will be watched during the first 12 weeks of the infant's life, using the BORIS software to record the observed behaviors. Using the maternal engagement rate (number of occurrences per hour) in the behavioral categories: investment in survival, social affiliative behaviors, maternal rejection and proximity, the data will be analyzed using generalized linear mixed models (GLMM). Through the R software, GLMMs will be applied to obtain intra-individual and inter-individual variances in the data set, in order to verify whether there is repeatability for mother's identity and matrilineal status and whether there are effects of the infant's sex and mother's parity on the variables.