Habitual stone-tool-aided extractive foraging in white-faced capuchins,

Area of Science:

• Primate behavior
• Animal cognition
• Evolutionary anthropology

Background:

• Tool use varies significantly between robust (Sapajus) and gracile (Cebus) capuchin monkeys.
• Gracile capuchins (Cebus) rarely use tools, with no prior observations of stone tool use.
• Robust capuchins (Sapajus) exhibit widespread and habitual tool use.

Purpose of the Study:

• To investigate the factors contributing to differing tool use patterns between Cebus and Sapajus capuchins.
• To document the first instance of habitual stone tool use in a gracile capuchin species.
• To explore the ecological drivers and evolutionary basis of stone tool use in white-faced capuchins.

Main Methods:

• Review of existing theories on primate tool use.
• Observation and camera trapping of white-faced capuchins (Cebus capucinus imitator) in Coiba National Park, Panama.
• Analysis of tool use patterns, including sex bias and seasonality.

Main Results:

• A population of white-faced capuchins in Coiba National Park habitually uses hammerstone and anvil tools.
• Stone tool use primarily targets coastal food resources like seeds and crabs.
• Tool use was strongly male-biased, with females never observed using stone tools.
• Behavior has been ongoing since at least 2004 and occurs year-round.

Conclusions:

• This finding represents the first documented case of habitual stone tool use in gracile capuchins.
• The Coiba population's terrestrial habits, reduced predation, and potential resource limitation may drive stone tool evolution.
• This unique case provides opportunities for comparative studies on the evolution of tool use.