Japanese monkeys in Nagano Prefecture’s Jigokudani valley appear to have lower levels of a stress hormone than usual when they bath in natural hot springs
KYOTO – Japanese monkeys in Nagano Prefecture’s Jigokudani valley appear to have lower levels of a stress hormone than usual when they bath in natural hot springs during winter to warm up, a study has said.
A team including Rafaela Sayuri Takeshita, a researcher at Kyoto University’s Primate Research Institute, made the finding through analyzing the excrement of the monkeys, which are famous for bathing in the hot springs at Jigokudani Yaen-Koen, a monkey park in the Nagano town of Yamanouchi.
A paper on the team’s finding was published in an edition of the international journal Primates on Tuesday by the Japan Monkey Centre in Inuyama, Aichi Prefecture.
Japanese macaques are the world’s northernmost-living monkeys and are also known as snow monkeys. As they regularly soak in hot springs in the winter, it had been assumed they do so to warm themselves up.
In their analysis, the researchers said the results indicate that the snow monkeys bathe in the hot springs to reduce stress from the winter cold and improve their chances at reproducing and surviving.
