Japan’s monkeys wash their potatoes and ride deer like horses

Primatologists want the public to know more about Japanese macaques, so they’re writing a book to show off the monkeys’ sometimes quirky behavior.

Conducting research in Japan, French primatologists Cédric Sueur and Marie Pelé were surprised that, in a country where monkeys and humans live side-by-side, there were few resources from which the general public could learn about Japanese macaques and their fascinating social behaviors. The solution: they teamed up with illustrator and photographer Alexandre Bonnefoy to write a book themselves. We asked them to share some of their favorite macaque behaviors.

You can follow the project’s progress on ResearchGate.

ResearchGate: Can you tell us a bit about your own research and personal history with Japanese macaques?

Cédric Sueur and Marie Pelé: We are both primatologists. We spent nearly a year in Japan studying the social networks of Japanese macaques at Kyoto University’s Primate Research Institute. Japan is the cradle of primatology—it was Japanese primatologists who first described the existence of traditions in a species other than humans, and it was a real opportunity to meet some of these researchers and learn more about the cultural diversity of Japanese macaques. Last year, we celebrated 50 years of collaboration between French and Japanese primatologists with a special issue in the journal Primates, in which we published a paper detailing our experience with collaboration in Japan.

Alexandre Bonnefoy: I am an illustrator and lived in Japan from 2010 to 2012. During my time there, I started off doing urban street photography in Tokyo and elsewhere. However, after a visit to the Jigokudani Snow Monkey Park, I became fascinated with Japanese macaques and started doing wildlife photography as well.

Researchers in the field. Credit: Cedric Sueur.
Researchers in the field. Credit: Cédric Sueur.

RG: How much contact do humans and wild macaques have with one another in Japan?

Sueur: Japan has several “monkey parks,” where it is really easy to observe Japanese macaques that are acclimated to humans. However, it is more difficult to meet a truly “wild” monkey. Japanese macaques stay close to human dwellings, because it’s easy to find food there. This results in a surprising cohabitation that can be rewarding—many people have stories about snow monkeys or white monkeys—but also problematic, due to the human-wildlife conflicts it generates.

RG: What problems does this pose and how might public education mitigate them?

Pelé: Japanese macaques frequently raid farms to eat the crops and even enter shops to steal food. The Japanese government tried to decrease this human-macaque conflict by creating monkey parks, where macaques are fed. But each year 20,000 macaques are still killed to keep their population down. However, the cognitive similarities between monkeys and humans made us wonder whether we couldn’t find another solution. Japanese macaques display many different behaviors that vary by location. Some groups make and play with snowballs, others take hot-spring baths, handle stones, or wash their food. The general public, however, appears to be largely unaware of these behaviors. We hope this project will give them a better understanding of the monkeys’ lives.

Japanese snow monkey. Credit: Alexandre Bonnefoy. Japanese macaque forming a snow ball. Credit: Alexandre Bonnefoy.

RG: What gave you the idea for a book aimed at the public?

Bonnefoy: Considering the number of monkeys I encountered while hiking, I was very surprised by how few books on Japanese macaques available in Japan! The few I found focused exclusively on Jigokudani Park and monkeys taking hot baths. We wanted to go further and offer a broader view of the lives of Japan’s snow monkeys across multiple geographic areas and seasons.

Pelé: Exactly—our project aims to resolve the lack of literature for a wider audience about this species. The book will contain around 200 pictures of Japanese macaques from different areas all over the Japan. Japanese macaques display amazing behaviors that resemble culture and traditions. The photographs will be accompanied by texts and illustrations to better explain these behaviors and the ecological and social lives of the monkeys. The publication of the book will be followed by a photographic exhibition and conferences. I will also give a talk about a newly discovered behavior: interspecies sexual relations between a Japanese macaque and a Sika deer.

Macaque mother with potato in hand. Credit: Alexandre Bonnefoy.Macaque mother with potato in hand. Credit: Alexandre Bonnefoy.

RG: What aspects of macaque behavior covered in the book do you personally find most interesting?

Pelé: The macaques washing potatoes at Koshima island. It reminded me my primatology courses, and it was fantastic to observe the behavior having learned about it some years ago. I also enjoyed observing macaques looking for and eating shells on the rocks of the beach of Koshima.

Sueur:  My favorite behavior is that of a macaque riding on the backs of Sika deer. There is a close cooperation between macaques and deer on Yakushima island. The deer eat seeds dropped by macaques on the ground, as well as their feces. Macaques may groom the deer for parasites such as lice, which are rich in proteins. At times, macaques will climb on the back of a deer for transportation. They don’t travel the kinds of distances humans do on horseback, but the similarity is there.

Bonnefoy: During my last trip, I had difficulties finding monkeys to observe. I tried to simulate a contact call in order to find them, and some monkeys answered me. It was awesome. This call is used between macaques to stay in contact with each other, but I succeed in communicating with them too.

Macaque riding a deer. Credit: Alexandre Bonnefoy.
Macaque riding a deer. Credit: Alexandre Bonnefoy.

RG: What can humans learn from macaque behavior?

Sueur: Macaques’ society is very similar to that of humans, with hierarchies, kin clans, and games of seduction and deception. By observing monkeys, from one generation to another, we can learn a lot about ourselves. The maxim of the three wise monkeys "see no evil, hear no evil, speak no evil” originates in Japan. It appears in a 17th-century carving over a door of the famous Tōshō-gū shrine in Nikkō to illustrate Confucius’s Code of Conduct, and uses the monkey as a way to depict man’s life cycle. Observing Japanese macaques might also teach us how to live in harmony with our natural environment.

RG: How will the book be distributed?

Bonnefoy: The book will first be published in French in October and distributed in traditional and online bookshops in French-speaking countries, as well as the Issekinicho editions website. After that, we hope to find foreign publishers interested in translating and publishing the book in other languages.

Additional videos are available on the Saru Project’s website and YouTube channel.

The researchers featured in this interview would like to thank everyone who helped with the project, particularly the Japan-based researchers Andrew JJ Macintosh, Hanya Goro, Hideki Sugiura, Shimada Masaki, and Takafumi Suzumura. This project is funded by the “Investissement d’avenir” mission at the University of Strasbourg, by the CNRS (French National Center for Scientific Research), by Ethobiosciences, and by Issekinicho Editions.

Feature image: bryan...