Stone tools improve diet quality in wild monkeys

Author(s)

Izar, Patricia ; Peternelli-dos-Santos, Lucas ; Rothman, Jessica M. ; Raubenheimer, David ; Presotto, Andrea ; Gort, Gerrit ; Visalberghi, Elisabetta M. ; Fragaszy, Dorothy M.

• Document type: Journal article
• Source: Current Biology; v. 32, n. 18, p. 9-pg., 2022-09-26.

Abstract

Tool use is a fundamental feature of human evolution. Stone tools are in the archaeological record from 3.4 Ma, even before Homo,1 and the use of stone tools probably predated the split between hominins and pan-ins.2 Using tools (hereafter, tooling cf Fragaszy and Mangalam3) is hypothesized to have improved hominins' foraging efficiency or access to high-quality foods.4-7 This hypothesis is supported if feeding with tools posi-tively contributes to diet quality in extant non-human primates or if foraging efficiency is increased by tooling. However, the contribution of tooling to non-human primates' foraging success has never been investigated through a direct analysis of nutritional ecology.8,9 We used multi-dimensional nutritional geometry to analyze energy and macronutrients (nonstructural carbohydrates, lipids, and protein) in the diets of wild capuchin monkeys (Sapajus libidinous) that routinely crack palm nuts with stone hammers.10,11 We show that eating nuts obtained through tooling helps monkeys to achieve more consistent dietary intakes. Tooling increased the net energy gain by 50% and decreased the proportion of fiber ingested by 7%. Tooling also increased the daily non-protein energy intake. By contrast, protein intake remained constant across foraging days, sug-gesting a pattern of macronutrient regulation called protein prioritization, which is also found in contempo-rary humans.8,9 In addition, tooling reduced dispersion in the ratio of protein to non-protein energy, suggest-ing a role in macronutrient balancing. Our findings suggest that tooling prior to tool making could have substantially increased the nutritional security of ancestral hominins, sowing the seeds for cultural develop-ment.5,7 (AU)

• FAPESP's process: 11/21032-2 - Nutritional parameters of the diet of two populations of capuchin monkeys: comparison between the Atlantic Forest (Cebus nigritus) and Cerrado /Caatinga ecotone (Cebus libidinosus)
• Grantee: Patrícia Izar Mauro
• Support Opportunities: Regular Research Grants
• FAPESP's process: 11/11504-4 - Nutritional parameters of the diet of two capuchin monkey populations: a comparison between the Atlantic Forest (Cebus nigritus) and the Cerrado-Caatinga ecotone (Cebus libidinosus)
• Grantee: Lucas Peternelli Corrêa dos Santos
• Support Opportunities: Scholarships in Brazil - Doctorate