The Japanese Macaque - Facts, Information, And Places To See Them

At the mention of the word “Japan”, the first image that often comes to one’s mind is a crowded city bustling with lively people. This is true for many tourist destinations of the country but is not the only thing that foreign travelers can expect for their trip. Japan is also home to a variety of natural scenic beauty such as mountain ranges, forests, hot springs, and parks. Furthermore, given the country’s wide geographical scope, it is not surprising that a diverse wildlife continues to abundantly grow in several of these places.

The animals of Japan are just as interesting as the humans, with their quirky and interesting behaviors. Nara Park has bowing sika deer, Minami Minowa Village has luminous fireflies, and Higashikawa has the flying squirrel. If none of these are enough to make for a unique experience, several islands of Japan are inhabited by an intelligent species known as the Japanese Macaque that can be seen bathing in hot springs, making snowballs, or even riding deer.

Japanese Macaque – The Snow Monkey of Japan

The Japanese Macaque, better known as Snow Monkey, is a native species to Japan. As implied by its name, the monkey can be found living in areas frequently showered with snow throughout the year. It is among the few non-human primates that prefer cold, northern habitats. Its binomial name is Macaca Fuscata.

Members of the Japanese community know the species as Nihonzaru, which comes from the terms nihon meaning Japan and saru meaning monkey. The name is sometimes shortened to just Saru, given the species’ popularity in the country.

Facts about the Japanese Macaque – Physical Characteristics (Weight, Tail, Posterior), Behavior, Ecology, Diet, and Lifespan

Physical Characteristics

Male and female Japanese macaques both exhibit red faces, short tails, and brown-gray fur but differ in size. The males are typically bigger, averaging at 11.3 kg in weight, 22.44 inches in height, and 3.642 inches in tail length. Females, on the other hand, have a weight of 8.4 kg, height of 20.58 inches, and a tail length of 3.113 inches on average. Japanese macaques living in warmer areas such as Yakushima often weigh less, regardless of gender.

Other than its face and posterior, the snow monkey’s body is entirely covered with grayish brown fur. This coat adapts well to the environment, increasing in thickness as the temperature decreases. As such, the snow monkey can handle low temperatures up to -20 degrees Celsius.

Like many other monkeys, the Japanese macaque uses all fours to move from place to place. Female snow monkeys can often be found spending their time in the trees, while male monkeys on the ground. They are known to be great swimmers, reportedly able to swim over 500 meters. On land, the Japanese macaque displays an equally notable skill in leaping.


Group Hierarchy

Snow monkeys follow a matrilineal system in which the females live with the same groups from the first and last days of their lives while the males leave before reaching sexual maturity. Each group of the Japanese macaque often has several male and female adults but there are also temporary groups consisting of males that have just moved out of their natal groups and are in the process of transferring to another.

Furthermore, several matrilineal groups also exist within a single troop that follows a dominance hierarchy. This ranking system is applicable to both sexes, whereby the status of a male individual is dictated by how long he has been a part of the troop and the status of a female individual is dictated by her mother.

The hygiene and relationships of social groups within the society of Japanese macaques are maintained by the females. These are done through the practice of grooming, which mothers pass on to their offspring over time. Females that share matrilineal bonds groom each other more often than those who are unrelated. 

Grooming between unrelated females is done for the purpose of maintaining a sense of unity. Male Japanese macaques are also groomed by the females either for hygienic purposes or for attracting dominant ones to join their group. 

Mating and Parenting Practices

Male and female Japanese macaques will mate and live together for an average of 16 days throughout the mating season. Every season, a female will have about four male partners. Males with higher dominance in the group often have longer partnerships with the females than those under them. Furthermore, dominant males will often try to disturb the bonds of lower-ranking males.

However, the rank of males within the group does not directly dictate their success of mating with a female. The decision ultimately lies on the female macaques, who are not particularly impressed by the male’s hierarchy system. As such, females may choose to mate with males from other troops.

The faces and anogenital regions of Japanese macaques, regardless of gender, redden during the mating season. In addition, the male’s tail stands erect. Snow monkeys have several signals to inform their partner that they are ready to mate such as staying still, walking backward towards them, or looking back over their shoulder.

Copulation may occur in the trees or on the ground. Female Japanese macaques are often vocal during the process while the males are comparatively silent.

Female monkeys expecting to give birth move to the outskirts of their troops, usually to secluded areas. During the first four weeks, the mother keeps her baby close by carrying it on her belly. Afterward, she will start carrying her baby on her back. During this period, the mother and infant will avoid other members of the troop and take as much time as they want before entering the social groups.

There are also instances wherein females who have not had a baby of their own take care of other infants. In some troops, there are also several males that act as mothers to younger Japanese macaques, grooming, protecting, and carrying them as a female would.

Male babies have been observed to be more playful in larger groups than the females. However, in terms of social interaction, the females are more active. More often than not, males will only socialize with other males of the same year while females will associate with all macaques, regardless of gender and age.


Japanese macaques have several sounds that they emit for different purposes. When moving or feeding, “coos” can be heard from the female snow monkeys. This is their way of strengthening and maintaining bonds within the troop.

These coos, along with girneys, are also made by the Japanese macaques before grooming. Girneys are done in various ways, depending on the situation. For example, they may be emitted by Japanese macaques during aggressive encounters as a way to appease current circumstances.

Snow monkeys also have calls meant for alerting groups about danger or threats, which may also be heard during fights within the group from supporters of the involved parties.


Japanese macaques are diurnal, meaning they have different activities during the day and sleep or become inactive throughout the night. The activities and feeding schedules of snow monkeys differ per season and per region.

Those living in colder areas often feed between their daily arrangements from the autumn season up until early winter. The activities decrease by mid-Winter and feeding sessions occur two to four times a day.

For Japanese macaques living in warmer areas, there is a great irregularity observed when it comes to the schedule of activities. Nonetheless, they exhibit the same practices such as grooming others, grooming themselves, feeding, and traveling throughout the day.

Snow monkeys usually sleep in the trees but may also be seen sleeping on the ground or on rocks. However, come the winter season, they often huddle and sleep together on the ground to keep warm.


The diet of Japanese macaques includes more than 200 kinds of plants as well as bark, soil, and insects. They also consume several kinds of fruits and nuts that help in storing fat to prepare for winter. When food is unobtainable, snow monkeys will often settle for plant roots and soil. If available, they will also eat fish.


The lifespan of snow monkeys averages at 6 years. However, they are known to be able to live for much longer than that. According to records, the oldest male Japanese macaque lived up to 28 years, while the oldest female up to 32 years.

The Distribution and Habitat of the Japanese Macaque

As previously mentioned, Japanese macaques prefer to live in areas located up north. They can be found on Japan’s main islands, Kyushu, Honshu, and Shikoku, as well as in other smaller islands. At present, the snow monkey’s population is at an estimated total of 114,000. They live in various habitats including subtropical forests and subarctic forests.

Jigokudani Monkey Park – The Best Place to See Adult and Baby Japanese Macaque Soak in Hot Springs and Enjoy Snowball Fights

It is one thing to read about the Japanese macaque’s lifestyle, but another to actually see it in person. The Jigokudani Monkey Park provides visitors with a once in a lifetime experience of closely observing snow monkeys go about their day amidst their natural habitat.

The park is situated in a forest of Yamanouchi, specifically in the Jigokudani valley. There is a man-made pool meant for the snow monkeys located a few meters from the entrance of the park. Visitors will most likely come across several Japanese macaques along their way to the pool. As these monkeys have grown used to the presence of humans, they often just ignore visitors of the park.

Foreign travelers can make a trip to the park any day of the year. The area is particularly spectacular from the month of December to the month of March when the region is frequently showered with snow. Tourists are recommended to visit the Jigokudani Monkey Park from January to February, as the site is covered in snow during this period and the snow monkeys spend more time soaking in the hot bath. On rare occasions, several of the Japanese macaques also engage in snowball fights.

The Jigokudani Monkey Park is open from 8:30 AM to 5:00 PM during April – October and from 9:00 AM to 4:00 PM during November – March. Admission is priced at ¥800 per person. There is an information center within the park that showcases several explanations and details about the societal system of the Japanese macaques. Also, for those who want to check out the monkey pool from the comfort of their homes, a live camera situated beside it can be accessed online.

There are also several onsen (hot spring) towns and ryokans (traditional Japanese inns) nearby, where visitors can avail of various lodging options. These places often provide free shuttle services to and from the park.

Other Interesting Behaviors of the Japanese Macaque – Riding Deer and Washing Potatoes

Yakushima Island

The island of Yakushima located in the south is also home to several Japanese macaques that live alongside sika deer. Just like the ones in Yamanouchi that bathe in hot springs and make snowballs, the snow monkeys here exhibit interesting behaviors.

This is the only place that both animals seem to have a symbiotic relationship, wherein the deer follows the monkeys to the forests in order to eat any food dropped by the latter. Similarly, the Japanese macaques groom the deer in order to obtain protein-rich parasites. Both behaviors are already quite odd but do not compare to a particular site visitors may chance upon – a monkey riding a deer.

From time to time, Japanese macaques will hop onto the back of sika deer and use them as a means of transportation. Of course, they do not ride them for long distances as a human would with a horse, but there is an uncanny similarity.

Kojima Island

The Japanese macaques of the Kojima island in the Miyazaki Prefecture also have peculiar practices. Kojima is known to house a study site dedicated to primate research about snow monkeys living in wild conditions. Over the years, they have found that many of the skills developed within Japanese macaque troops are spread by imitation.

Researchers left out several sweet potatoes on the beach for the monkeys to eat. A certain female Japanese macaque washed her food with the water from the river instead of just brushing off the dirt. Soon after, the other monkeys started copying her which eventually led to the whole troop, excluding the oldest members, doing the practice. There is still much to learn about the Japanese macaque, but it is clear that they have a great sense of intelligence.