Learned precision tool use in carrion crows.

Area of Science:

• Animal Cognition
• Behavioral Ecology
• Avian Intelligence

Background:

• Tool use is a complex behavior observed in a few animal species, including New Caledonian (NC) crows.
• The specific motor-cognitive skills and learning processes underlying tool use in corvids are not fully understood.

Purpose of the Study:

• To investigate how learning shapes tool-use skills in carrion crows, a species related to NC crows but without specialized tool-use adaptations.
• To determine if reinforcement learning alone can lead to skilled tool use in cognitively flexible corvids.

Main Methods:

• Three tool-naive carrion crows were trained to use a stick to retrieve food from an automated apparatus.
• Computational pose estimation was used to track the development of tool-handling skills over thousands of trials.

Main Results:

• Carrion crows rapidly acquired impressive stick tool skills, achieving dexterity comparable to habitual tool users.
• Crows developed efficient, goal-directed movement patterns and maintained flexibility, swiftly correcting errors.
• Reinforcement learning alone was sufficient to foster skilled tool use.

Conclusions:

• Dexterous generalists like carrion crows can learn skilled tool use through reinforcement learning.
• This suggests that only minor evolutionary adaptations may be necessary for the emergence of habitual tool use in corvids.