In a First, a Female Monkey Has Become the Alpha Leader in a Japanese Zoo


Aug 4, 2021


Image Credit: Mainichi/Nao Ishii

In a rare first, Yakei, a nine-year-old female, is now the leader of a 677-strong troop of Japanese macaque monkeys at a nature reserve on Japan’s Kyushu island.

The macaque reside in the Takasakiyama Natural Zoological Garden since the 1950s. The reserve is home to around 1,500 macaques, divided into two troops — “A” and “B.” This is the first time in the reserve’s 70-year history that a troop has a female monkey boss; as one publication noted, Yakei has shattered the monkey “glass ceiling” when it comes to leadership.

In April, Yakei beat her mother Bikei to become the alpha female of the troop. But she didn’t just stop there; in June, she went after Sanchu, a 31-year-old male, who had been leading the troop for seven years. After challenging, and subsequently “roughing” him up, she took over his role.  

To confirm her alpha status in the troop, the wardens of the reserve conducted a “peanut test” — putting out nuts for the troop, and keeping a watch to find out which member eats it first. Yakei called dibs on the first bite and Sanchu backed off — establishing her supremacy in the troop’s hierarchy.

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“Since then, Yakei has been climbing trees and shaking them, which is an expression of power and a very rare behavior in females,” Satoshi Kimoto, a guide at Takasakiyama, where the troop dwells, told the Guardian. “She has been walking around with her tail up, which is also very unusual for a female,” Kimoto added.

There are estimated to be around 100,000 Japanese macaques in the wild, living across three islands in Japan: Kyushu, Honshu, and Shikoku. Interestingly, all macaque social groups are believed to be matrilineal — with dominant females holding positions of power — but are led by a dominant male called the “alpha.” He is followed by male sub-leaders, then by the females of the group, and lastly, by other males.

Research has shown how macaque monkeys have striking similarities to humans — in terms of their “behavioral capacities, sensory processing abilities, and brain architecture.”

Last month, the park held a ceremony to formally recognize Yakei’s alpha status over troop “B.” She was encouraged to pull a length of cord to unveil a sign announcing her assumption of the leadership position, and was then rewarded with a banana.


Written By Devrupa Rakshit

Devrupa Rakshit is an Associate Editor at The Swaddle. She is a lawyer by education, a poet by accident, a painter by shaukh, and autistic by birth. You can find her on Instagram @devruparakshit.


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