Boesch: Tool Use in Wild Chimpanzees

Question 1

Tool Use in Chimps

Answer 1

Tool use is rare in animals, and the chimpanzee stands out as the most proficient tool users besides humans

Nut-cracking techniques are fully acquired only at adulthood (13-15 years) for chimpanzees

(1) The only tool use by chimps requiring 3 objects to be assembled before starting the task: an anvil, a hammer, & the nuts
(2) Chimps do not see any result from hitting a nut until it opens
(3) Only known tool use in chimps where 2 types of tools are often used to gain access to the same food (stone hammer/ stick)

A chimp cracking at a tree w/ no available hammer would choose the nearest stone to that tree by comparing distances to the target tree for several possible stones

These operations compares with the Euclidean mental map observed for spatial representation abilities in 9 year old children

Question 2

Nut-Cracking, Males v Females

Answer 2

Nut-cracking techniques are used more frequently and at a more superior level in females

This is due to social factors in that males favor social contact whenever there is a conflict between cracking more nuts or remaining w/ other group members

Question 3

Teaching Tool Use

Answer 3

When offspring are 4-5 years, the mothers start to share less but while out collecting nuts, would leave behind on anvils, intact nuts and their tool

No chimpanzee without offspring ever does so.

Usually, the offspring would use this opportunity and start using the tools

This is the beginning of the true apprenticeship – when the offspring start assembling the 3 necessary objects for this activity and use them correctly

Mothers have a direct interest in accelerating their offspring’s performance and helping them get access to a highly important food source