Oral tool use by captive orangutans (Pongo pygmaeus).

Area of Science:

• Primate behavior
• Animal cognition
• Tool use in animals

Background:

• Tool use is a significant cognitive ability observed in primates.
• Orangutans (Pongo pygmaeus) are known for their complex behaviors and problem-solving skills.
• Manual laterality studies investigate handedness and its neurological basis in animals.

Purpose of the Study:

• To investigate manual laterality in captive orangutans during a tool-making task.
• To document the frequency and methods of tool use, specifically oral versus manual.
• To explore factors influencing tool use preferences in orangutans.

Main Methods:

• Eight captive orangutans were provided with wooden blocks and bamboo for tool creation.
• Raisins were embedded in blocks to incentivize tool use for extraction.
• Tool manipulation (oral vs. manual) was observed and recorded during raisin extraction bouts.

Main Results:

• Orangutans utilized oral tool use in approximately 75% of raisin extraction attempts.
• A significant subset of individuals displayed a strong preference for oral tool use (>92%).
• Oral tool users typically fashioned short tools held by the lips and tongue.

Conclusions:

• Captive orangutans exhibit customary oral tool use, a behavior previously observed in wild populations.
• Individual preference, potentially linked to hand size, appears to be a key factor in tool use strategy.
• This study provides novel insights into the flexibility and variation of tool use in Pongo pygmaeus.