Jean-Baptiste Leca, Ph.D.

Assistant Professor
Board of Governors Research Chair (Tier II)
Department of Psychology
University of Lethbridge
Canada

Coconut bashing in Balinese long-tailed macaques


Even though most groups of Balinese long-tailed macaques have coconuts in their environment, the percentage of group members being experts at coconut bashing is extremely low.

We are documenting intragroup and intergroup variation in this complex extractive foraging technique.

We are investigating the development and mechanisms (e.g., kinematics) of coconut bashing.



Fined-tuned sensori-motor coordination is needed in order to produce a first crack in the coconut shell from which the monkey can drink the coconut water before cracking the coconut open and access the white pulp.

[VIDEO 1]


Following the perception-action theory (or affordance learning theory), we hypothesize that playing with coconuts allow immature individuals to acquire some familiarity with the properties of this fruit, which may have functional consequences in the future.

("Play buys you practice")


[VIDEO 2]


Begging and scrounging pieces of food from experts at coconut bashing (as long as the presence of juveniles is tolerated in their vicinity) may also facilitate individual
and social learning.


Thus, the gradual acquisition of this complex extractive foraging technique in Balinese long-tailed macaques is aided jointly by physical growth and experiential processes supporting learning.