Japanese Macaque (Macaca fuscata)

Japanese Macaque overview

The Japanese macaque, or snow monkey, is a stocky, short-tailed monkey found only in Japan. It lives farther north than any other non-human primate, surviving winters in the mountains of Honshu where snow lies for months and temperatures drop to around minus 15 degrees Celsius. It has thick gray-brown fur, a bare pinkish-red face and rump, and a stumpy tail. Troops are organized around lines of related females, with strict dominance ranks that daughters inherit from their mothers. The species is famous for bathing in hot springs and for learned habits, such as washing food, that spread through troops.

How Long Do Japanese Macaques Live?

Japanese macaques typically live 22–27 years, with recorded maximums of about 28 years for males and 32 for females. Those figures come largely from long-studied free-ranging troops, many of them fed by people. Females generally outlive males, and harsh winters are the main natural cause of death.

How Much Does a Japanese Macaque Weigh?

Adult Japanese macaques weigh 8–11 kg (18–24 lb) on average, with males at about 11.3 kg and females about 8.4 kg. Monkeys from cold northern areas are heavier than those from the south, and large males can reach 14 kg or more. The Yakushima subspecies is the smallest.

How Long Is a Japanese Macaque?

A Japanese macaque's head and body measure 50–60 cm (20–24 in), averaging about 57 cm in males and 52 cm in females. The tail is a stub of only 7–10 cm. The winter coat is dense enough to make the animals look considerably bulkier than they are.

How Long Is a Japanese Macaque Pregnant?

A Japanese macaque is pregnant for about 173 days, a little under six months. Mating takes place in fall and winter, and single infants are born between April and July. Females first give birth at about five or six years old and then usually breed every other year.

What Do Japanese Macaques Eat?

Japanese macaques are omnivores that eat more than 200 kinds of plants along with insects, fungi and soil. They feed on fruit, seeds and leaves in the warm months and build up fat for winter, when they survive largely on tree bark and buds. Some island troops eat shellfish and fish.

Diet type: omnivore. Fruit, seeds, young leaves, flowers and fungi for most of the year, with bark and winter buds in the snowy months; also insects, soil, and in some coastal troops fish and shellfish.

Where Do Japanese Macaques Live?

Japanese macaques live in forests on three of Japan's four main islands, from subtropical evergreen forest on Yakushima to snowy subalpine forest in the Japanese Alps and northern Honshu. They range from sea level to above 3,000 m and spend time both in trees and on the ground.

Are Japanese Macaques Endangered?

The Japanese macaque is listed as Least Concern on the IUCN Red List, with a stable population. It is widespread and has expanded in recent decades. The main conflict is crop raiding: thousands of macaques are culled every year in Japan to limit damage to farms and orchards.

Least Concern

Japanese Macaque fun facts

• No other wild primate apart from humans lives as far north or in as cold a climate as the Japanese macaque.
• The hot spring habit at Jigokudani in Nagano began in the early 1960s, when young monkeys started copying each other and entering an inn's outdoor bath.
• In 1953 a young female named Imo on Koshima island began washing sweet potatoes in water, and the habit spread through her troop over the following years.
• Studies at Jigokudani found that bathing in hot springs lowers the monkeys' stress hormone levels in winter.
• Young Japanese macaques have been seen rolling and carrying snowballs, apparently just for play.

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Japanese Macaque FAQ

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