Monkey 'queen'

In southern Japan, a young female macaque has upended societal norms by seizing control of her 677-member troop through a violent primate coup. Now, her hard-won empire could come crumbling down around her due to one unstoppable force: mating season.

Meet Yakei, a 9-year-old female living in a Japanese macaque reserve called the Takasakiyama Natural Zoological Garden, where she has spent the last year reigning as the first female troop leader in the park's 70-year history. After assaulting her own mother and assuming the role of top female in the troop, Yakei embarked on a violent vendetta against her troop's four highest-ranking males, finally assuming the troop's coveted alpha position after beating up Nanchu — an elderly, 31-year-old male who had ruled the troop for five years.Hostile takeovers by aggressive females are exceptionally rare in Japanese macaque society, with only a handful of recorded cases preceding Yakei's coup, Yu Kaigaishi, a research fellow at the Japan Society for the Promotion of Science, told The New York Times.

Japanese macaques (Macaca fuscata) — also known as snow monkeys for their habit of basking in hot springs when the weather gets snowy — live in strictly hierarchical societies, Kaigaishi explained; higher-ranking monkeys get greater access to food and mates. A male's rank is usually determined by how much time he has spent in a particular troop (males tend to leave the troop they were born into after reaching puberty), while female macaques inherit the rank just below their mother's. Sometimes, macaques can violently seize higher ranks.

These contests for position are almost exclusively between males, Kaigaishi said, which is why Yakei's rise to power was at once shocking and exciting to researchers who followed her case. After toppling the top male, Yakei eventarted to exhibit traditionally male behaviors, such as walking with her tail up and shaking tree branches with her body, experts at the reserve said.

However, after nearly a year in the top spot, Yakei's position may be in jeopardy during the chaos that is mating season — which typically runs from November to March. According to reserve researchers, an 18-year-old male named Luffy has been making unwanted courtship advances on Yakei since this year's breeding season began. Queen Yakei, meanwhile, seems to regard Luffy with fear.Even monkeys know it's right to care for strangers in need. (Or maybe their parents just didn't teach the helpers about "stranger danger.")

In a new paper published in the July issue of the journal Primates, scientists document for the first time Barbary macaques (Macaca sylvanus) fostering an older juvenile macaque — a stranger to them — after finding him lost and hurt on the side of the road days after he had been struck by a car inside a park in Morocco. The monkeys groomed and cared for the injured juvenile, named Pipo and almost 3 years old, and socialized with him until he was healed and ready to return to his own group.

The observation was surprising, study author Liz Campbell, a zoologist at the University of Oxford, wrote in the journal article, because "intergroup encounters at this [national park in Morocco] range from immediate withdrawal by one group to lengthy, sometimes aggressive, contests."That was good news for Pipo. After a car struck him on March 20, 2018, Campbell wrote, he retreated to a nearby tree while other members of his home group looked on.

"Several group members displayed affiliation towards him, and a juvenile sat with him and groomed him as he appeared to be losing consciousness," she wrote. "At approximately 17:35 (1 hour before sunset), his group left for their sleeping trees, but Pipo was left behind in the tree."

The next day, Pipo was nowhere to be found, Campbell wrote, and she and her colleagues assumed he had died. But on March 22, she wrote, "he was found in the same tree, alone and screaming repeatedly. He later left the tree to feed on the ground but continued screaming intermittently, then returned to the trees."