Animal Behavior | Nature | Education

Monkey Ransom Negotiators, Head Bobbing Frogs, and Wonder Woman Snakes

Recent research reports spotlight the quirky and the odd from across the animal kingdom.

Ed Ergenzinger, JD, PhD
Published in
5 min readJan 21, 2021
Image by Olga Ozik from Pixabay

From wild pandas that love to roll around in horse manure to moonwalking birds in the Amazon, the natural world never ceases to provide examples of fascinating and peculiar animal behavior. A few recently published scientific papers add to this list with reports about unique behaviors observed in Balinese monkeys, Guamanian brown tree snakes, and Ecuadorian glass frogs.

“Give Me the Fruit or the Camera Gets It!”

In a paper published January 11 in Philosophical Transactions of the Royal Society B: Biological Sciences, researchers described monkeys at the Uluwatu Temple in Bali, Indonesia, who have learned the finer points of negotiating for the best ransom payments.

Wild long-tailed macaques (Macaca fascicularis) at the temple have learned which high-value items to steal from humans in order to negotiate for the best offerings of food. They knew when they had taken something expensive, like an electronics item, and held out for more and/or better food rewards before giving it back. For lower-value items like empty camera bags or keyrings, the monkeys would accept a lesser reward.

Image by Nico Boersen from Pixabay

The monkeys would stare at a visitor, approach them inconspicuously, snatch the object, then step aside waiting for an offering they deemed suitable to the value of the item. Lower value items included empty containers and accessories like hairpins. Higher value items included mobile phones, tablets, wallets, and prescription glasses.

The longest time before an item was returned was 25 minutes, including 17 minutes of negotiation.

The older monkeys were better at the robbing/ransom negotiation process, which was indicative of experiential learning.

The researchers noted that the behavior was an example of “unprecedented economic



Ed Ergenzinger, JD, PhD

Patent attorney, neuroscientist, adjunct professor, mental health advocate. 5X Top Writer: Mental Health, Health, Science, Food, & Humor.