Adult long-tailed wild monkeys have been found to be intelligent enough to know which items have the highest value to visitors, such as an electronic element, and would only release it after receiving food they believe has value.
The authors say the behavior shows “unprecedented economic decision-making processes” among the monkeys observed as part of the study.
Researchers at the University of Lethbridge, Canada and Udayana University in Indonesia have found that in addition to being able to “use objects as symbolic tools to claim specific food rewards,”
The study, published on Monday, was conducted for 273 days from 2015 to 2016, and additional observations were conducted in 2019.
The scientists photographed the monkeys as they stared at a visitor, approached them imperceptibly, picked up an object, and then retreated, waiting for a suitable suggestion.
Adult monkeys have accumulated “several food prizes before returning the symbol” where the item is of high value, and are “more likely” to accept a “less preferred food prize” in exchange for a lower value item. , says the study.
“The token robbery and the exchange of symbols / prizes are cognitively challenging tasks for the Uluwatu macaques, which have revealed unprecedented economic decision-making processes,” the authors say.
“This spontaneous, population-specific, prevalent, intergenerational, learned and socially influenced practice may be the first example of a culturally sustained symbolic economy in free-range animals.”