Greater tool use diversity is associated with increased terrestriality in wild capuchin monkeys

Author(s)

Falotico, Tiago ; Ottoni, Eduardo B.

• Document type: Journal article
• Source: AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY; v. N/A, p. 6-pg., 2023-04-17.

Abstract

Terrestriality was an essential factor in human evolution. Hominins' extensive use of the ground allowed exploring a new range of environments and their objects, including new resources and potential tool raw materials. Capuchin monkeys are primarily arboreal primates but are also the most prolific tool users among platyrrhines, customarily using stone tools on the ground due to physical limitations and material availability.Objectives: Our goals were to (1) measure the terrestriality levels of a group of capuchin monkeys and (2) test the hypothesis that terrestriality has a positive effect on the stone tool use variability because the increased time on the ground would offer more opportunities to interact with the available stones, leading to more innovations of tool use behaviors. We predict a more diversified use of stone tools in the population with a higher degree of terrestriality.Materials and Methods: This study was on a group of capuchin monkeys (Sapajus libidinosus) at Serra da Capivara National Park (SCNP), Brazil. Scan sampling was done for 23 months, recording the behavior and substrate used by the individuals.Results: The ground use rate was 41%, with no sex difference but an age difference: infants were less terrestrial than juveniles and adults.Discussion: Compared to a population with a more limited tool use repertoire (Fazenda Boa Vista), SCNP adult capuchins are more terrestrial (43% v. 27%). Stone tool use diversity and terrestriality in capuchins appear to be positively correlated. Our results support this hypothesis and provide terrestriality measurements of the wild capuchin population with the most complex stone tool kit. (AU)

• FAPESP's process: 18/01292-9 - Cultural variation in robust capuchin monkeys (Sapajus spp.)
• Grantee: Tiago Falótico
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 06/07187-5 - Tools used by capuchin monkeys (Cebus libidinosus) of Serra da Capivara National Park - PI
• Grantee: Tiago Falótico
• Support Opportunities: Scholarships in Brazil - Doctorate