In a rarely seen phenomenon in the simian world, a nine-year-old female known as Yakei has become the boss of a 677-strong troop of Japanese macaque monkeys at a nature reserve on the island of Kyushu in Japan.

Yakei’s path to the top began in April when she beat up her own mother to become the alpha female of the troop at the Takasakiyama natural zoological garden in Oita city. While that would have been the pinnacle for most female monkeys, Yakei decided to throw her 10kg weight around among the males.

In late June, she challenged and roughed up Sanchu, the 31-year-old alpha male who had been leader of “troop B” at the reserve for five years.