The queen lies on the high wall, buttocks to the audience. Satoshi Kimoto, macaque expert from Takasakiyama Natural Zoo in Oita, points across the sand court and past the log jungle gym to the ledge on the paved slope. So here is Yakei, Japan’s most famous monkey, the first female group leader in the zoo’s 70-year history, a biological sensation. She has made herself comfortable between two other macaques. On the left is Yakei’s daughter, says Kimoto, on the right an older admirer. The two carefully search the boss’s fur for dirt, while she seems to be relaxing as if she were being massaged.
Is that a sign of Yakei’s power? Grooming as a privilege of the successful rebel? Satoshi Kimoto has to disappoint the viewer. When it comes to grooming, all Japanese macaques are the same. “There are scenes like that with the others, too,” he says.
Yakei (centre) with attendant Satoshi Kimoto
(Photo: Thomas Hahn)
Yakei, the nine-year-old primate of the species Macaca fuscata, captures people’s imaginations with her story. In her group of 669 animals, she has overturned traditional hierarchies over the past year by ousting the alpha males from the top. And she didn’t lose the lead even in the mating season from November to March. Aren’t these clear signs? emancipation in the animal kingdom. Rebellion against male rule. A monkey in a leadership position. Has social progress reached the wilderness?
Yakei’s behavior is so unusual that it raises questions of principle
One should not draw too bold comparisons between humans and animals. In the open-air zoo of Oita on Japan’s southernmost main island of Kyushu, there are no gender equality debates or discussions about monkey rights. The zoo is located across the main road that runs along Beppu Bay and connects the resort towns of the area. A shady path and stairs lead from the entrance to the playground, where hundreds of Japanese macaques come together every day for feeding times before disappearing back into the mountain forest in the evening. Indifferently, they walk past the onlookers and do what Japanese macaques do. Eating, resting, climbing, being together – apparently nothing productive.
But in fact, Yakei’s behavior is so unusual that it raises fundamental questions about animal behavior. It’s as if she made conscious choices beyond her instincts to get to the position she holds today. So, in the midst of the unsuspecting Japanese macaque crowd, has Yakei developed some kind of career awareness? Ambition? striving for power?
For Satoshi Kimoto and the others at Takasakiyama Zoo, the story began in spring 2021. Until then, Yakei was a monkey like any other: mother of a daughter since 2019, neither aggressive nor in any other way conspicuous. But then something happened. “On March 15, Yakei had a fight with her mother,” says Kimoto, “she bit her mother and she won.” That changed their relationship, Yakei was now the dominant. Kimoto believes that was a pivotal moment for Yakei.
There are clear hierarchies in Japanese macaque societies. But basically only among the males, who are larger and stronger than the females. They determine the ranking among themselves. Whoever has been in the group the longest has an advantage. The females don’t usually interfere. But that’s exactly what Yakei did after winning the argument with her mother. It was as if she had enough of the encrusted structures, because the first four of the group were not only male, but also very old, all older than 28. According to the current research On average, Japanese macaques do not live to be older than 25.
“First she fought Hajime, number four,” says Kimoto, “then on June 26, she fought number one, Nanchu.” The grizzled Eminences stood no chance against the agile Yakei. After defeating Nanchu as well, Kimoto and the others watched her for a while. Yakei behaved like a male showing signs of superiority. Spreading her tail, she climbed the trees and shook branches. In the so-called peanut test, in which the animal keepers observe who gets the first access to the special treat, everyone else let her go first. There were no more doubts. On July 30, the zoo introduced yakei as the number one of its macaque group B.
“Yakei is very special,” says Yu Kaigaishi of Kyoto University. In the winter, the biologist was able to see for himself how typically masculine they behave. “I hadn’t seen anything like it before.” And that’s saying something, because basically the Japanese macaque research should have seen almost everything. “Japanese macaques are among the best-studied mammals in the world,” says Kaigaishi. No other species of monkey lives so far north, no other in a prosperous country like Japan, which has a high density of universities and zoos. And once the Japanese macaques have gotten used to humans, they allow themselves to be patiently observed. Since it was founded in 1952, the Takasakiyama Zoo alone has captured every generation of monkeys that have visited the playground, with all their family relationships.
During the mating season, she wanted to have a particularly large number of partners
So we know a lot about the complex coexistence of the Japanese macaques. For example, that they know their mothers and grandmothers, but not their fathers and grandfathers, because females always mate with several males during the mating season. Kaigaishi himself has found that group cohesion can vary from region to region.
From his point of view, Yakei’s behavior shows a new quality of group dynamics. Most notably the fact that she has maintained her dominion over the mating season even though a male could have easily ousted her. “This means that the society of the Japanese macaques is not only ruled by physical violence,” says Yu Kaigaishi, “I assume that Yakei had support from others. Physically she may have been weaker. But socially she was stronger.” It is also clear to him that Yakei does not only follow instincts: “Japanese macaques can make flexible decisions.”
No one knows exactly what went through Yakei’s mind as she reached for power. “I’d like to ask her that,” says Satoshi Kimoto. Can’t, of course. One can only observe how the group has changed since their battles against Nanchu and Hajime. Most of the group keep a respectful distance from Yakei. Her facial expression seems stricter than that of the others. Sometimes it seems like she looks down on others. Nanchu has no problem with her, says Kimoto. “He can stay close to them when they are eating. But Hajime is afraid of her.” And during mating season, Yakei wanted to have a particularly large number of mates.
Japanese television at times reported on her love triangle with male macaques Luffy and Goro. She had a kind of on-off partnership with Goro, Luffy wooed her in vain. Nobody knows what happened in the depths of the forest. What is clear is that Yakei tried to win the favor of at least five males and in any case mated with one. With said Goro, number five in the ranking.
This has not harmed their supremacy. “Just the fact that she beat number one was enough to earn her respect,” says Satoshi Kimoto. And maybe she has also achieved what many women in the human world have already managed to do: namely to convince with their leadership qualities.