Development of hand use in a wild tool using primate (Sapajus libidinosus)

• Grant number: 20/13930-0
• Support Opportunities: Scholarships in Brazil - Master
• Start date: August 01, 2021
• End date: July 31, 2022
• Field of knowledge: Biological Sciences - Zoology - Animal Behavior
• Principal Investigator: Patrícia Izar Mauro
• Grantee: Guilbert Rodrigues de Araujo
• Host Institution: Instituto de Psicologia (IP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

The coordinated use of the hands to explore the environment and manipulate objects with dexterity is a milestone in the evolution of primates. The features of the primate hand allow the execution of skilled uni and bimanual actions, which has raised scientific interest since the last century. How primates use their hands when manipulating objects and food can be a window to investigate motor and cognitive features of different species. Bimanual coordination, however, is still an understudied topic, especially with wild individuals. Using this perspective, in this study we will investigate, by means of a longitudinal approach, the emergence, development, and coordination of the use of hands in infants of a wild population of capuchin monkeys (Sapajus libidinosus), a platyrrine primate that uses stones as hammers to open hard fruits. Specifically, we will investigate the hypotheses (1) that the acquisition of postural control and the consequent release of the anterior limbs for exploration favors the rapid increase of unimanual and bimanual actions, and (2) the rate of manual activities will be inversely proportional to the dependence on maternal care. To this end, we will record the manual behavior of infants of capuchin monkeys that inhabit Fazenda Boa Vista, an area within the Caatinga / Cerrado ecotone, in northeastern Brazil. These animals have been followed for eight years through weekly filming throughout the first 36 months of life. The data on the use of hands will be obtained by transcribing these videos using a specific ethogram. Eight infants from this population will be analyzed. For each individual, the rate of display (frequency / time of video) of uni and bimanual behaviors from birth to the period of three years of life will be computed. This rate will be used to characterize the trajectory of manual development over time. This will be the first work to explore the longitudinal development of hand use since birth in wild capuchin monkeys (Sapajus libidinosus). Our results will be potentially important to clarify how bimanual coordination develops in these primates and to elucidate issues of motor and cognitive development around manual coordination in primates that use tools in feeding. (AU)

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

ARAUJO, Guilbert Rodrigues de. One hand helps the other: development of bimanual coordination in wild Sapajus libidinosus. 2023. Master's Dissertation - Universidade de São Paulo (USP). Instituto de Psicologia (IP/SBD) São Paulo.