Obtaining raw material: plants as tool sources for Nigerian chimpanzees

Area of Science:

• Primate behavior
• Ethnobotany
• Tool use in animals

Background:

• Chimpanzees exhibit complex tool-making behaviors for resource acquisition.
• Understanding plant selection provides insights into primate cognition and ecological interactions.

Purpose of the Study:

• To investigate the plant species and characteristics used by Nigerian chimpanzees for tool manufacture.
• To explore potential reasons for plant selection, including material properties and possible medicinal benefits.

Main Methods:

• Field observation of chimpanzee tool-making and use for harvesting insects and honey.
• Identification of plant species used for tool construction.
• Analysis of tool material properties and spatial distribution at tool-use sites.

Main Results:

• Chimpanzees primarily use slender trunks of young trees and branches for tool manufacture, favoring sturdier materials over flexible vines.
• Tool sources are often spaced apart, suggesting resource depletion effects.
• Identified tool sources comprise 27 species from 13 families, with some exhibiting antibacterial properties also favored by humans as chewing sticks.
• A significant proportion of tools are sourced from plants located considerable distances from the extraction site, indicating potential forward planning.

Conclusions:

• Chimpanzee tool manufacture for resource extraction involves specific plant material selection.
• The use of plants with potential medicinal properties by chimpanzees warrants further investigation.
• Tool acquisition strategies may reflect an understanding of resource availability and planning.