A female Japanese macaque has become the first ever female alpha at Takasakiyama Natural Zoological Garden, an incredibly rare occurrence for the species.
The nine-year-old female named Yakei bested Nanchu, the alpha male of her troop, in combat after he tried to break up a fight involving her child. The 31-year-old male had been the alpha of troop B, made up of 677 macaques, for five years at this point.
Despite being dethroned, Nanchu doesn't seem too upset. "He doesn’t eat in front of Yakei, but other than that, he acts normally as before," said Toshiyuki Sakurai of Oita City Mt. Takasaki Public Corporation to IFLScience.
On July 30, a ceremony was held to welcome the new female boss. A staff member in a monkey suit accepted a plaque, then Yakei pulled a string to reveal a dazzling shower of confetti and a sign commemorating her achievement.
In April, Yakei battled her own mother to take her position as the alpha female of the group.
“Yakei was privileged to be raised by such a strong female leader. We think this influence helped her achieve that title,” Tadamori Fujita, a caretaker at the facility, told Vice.
At the reserve in Ōita city, on the Japanese island of Kyushu, macaques roam freely in the forested mountains and come down for food. On June 30, wardens left out peanuts for troop B as a test to determine who was in charge. The defeated male allowed Yakei to feast first, cementing her position at the top of the troop hierarchy.
"Among the Japanese macaque monkeys at Takasakiyama, it is how long they stayed at a troop to become the top, which is not the case of Yakei," explained Sakurai to IFLScience. "She defeated high-ranked males. Those males do not eat in front of Yakei, and they run away from her. That is how we certify her as a alpha female."
“The only other example I’ve heard is a female monkey in Tokyo’s Ueno Zoo. Other than that, you just never hear this happening,” explained Fujita to Vice. “It’s very rare”
“Normally, female monkeys do not stand up against males,” Tadatoshi Shimomura, a zoo official told the Telegraph. “I have no idea why she became number one. The world of macaques may be changing”.
Since her unexpected jump in status, Yakei has been (deservedly) throwing her weight around. “Yakei has been climbing trees and shaking them, which is an expression of power and a very rare behavior in females,” said Satoshi Kimoto, a guide at Takasakiyama, to the Guardian.
“She has been walking around with her tail up, which is also very unusual for a female.”
So how long will Yakei likely reign as alpha? "We do not have the answer at this point. This is the first case for us," says Sakurai to IFLScience.
"Usually an alpha male can reign as long as he stays at the same troop, but we do not know it will be the case for an alpha female. We will see what happens and how long she will be able to reign," he explains.
This article was amended to include quotes and images from Toshiyuki Sakurai of Oita City Mt. Takasaki Public Corporation