Asia’s Only Tool-Wielding Monkeys Are Abandoning Their Stone Implements

For humans, figuring out how to use tools was a pretty big deal. Once we began smashing things with rocks and sticks, our evolution took a sharp turn, steering us towards developing a more complex brain.

But we’re not the only tool-wielding animals in the jungle. Species like dolphins, crows and elephants use tools, too. Researchers interpret this skill as a sign of intelligence.

But, as usual, humans are messing with animals’ abilities to live their own lives. In this case, expanding farms and roaming dogs in Thailand are slowly obliterating Burmese macaques’ skills at using stones to open up hard-to-crack food, like nuts and shellfish. Rather than spend time perfecting their tool skills, the monkeys are preoccupied with keeping a wary eye out for danger. Humans are also outcompeting the animals for the foods that normally inspire tool use.

The macaques are Asia’s only species of tool-wielding monkey, so researchers think the potential loss will have both ecological and cultural implications. Here’s Past Horizons explaining the situation:

The researchers, who have been studying the Burmese long-tailed macaques living on Piak Nam Yai Island since 2007, found that the island’s macaque population had 192 individuals in nine groups and 88% of all adults there use stone tools. Tool-use is a part of the everyday life of these long-tailed macaques. “They have a fascinating lithic culture,” noted researcher, Dr Gumert.

“Generally, when we think of conservation, we think of species preservation, but I think we must also be concerned with the preservation of rare and interesting behaviour produced by animals’ cultures as well. Many animal species have unique traditions, and these traditions are fragile to disturbance. They require good conservation management of the habitats that foster these traditions,” he added.

If Thailand’s gifted macaques are not sheltered from the corrupting influence of humans, the researchers fear, they will succumb to the fate of so many of their comrades around Asia: cheeky pests who hang around temples and tourist hubs, ready to snatch a child’s ice cream cone as readily as a banana.

More from Smithsonian.com:

Becoming Human: The Origin of Stone Tools
Neanderthals Made Specialized Bone Tools And May Even Have Taught Humans How

Rachel Nuwer | | READ MORE

Rachel Nuwer is a freelance science writer based in Brooklyn.