JAPANESE MACAQUES - Macaca fuscata are also known as Snow Monkeys or Japanese “Apes”. They live in Japan (except Hokkaido). Generally they have long mournful pink faces; shaggy brown to metallic grey pelts; ultramarine faces and naked red hind parts. Adult females have a limited mating period, but no menstrual swelling. Their gestation period lasts about 173 days, after which a single young is born. Infants are generally born between April and September, but the peak birth period is in June and July. The infant coat is much darker than its mothers at birth, but it gets lighter as the offspring matures. Offspring are weaned at 6 to 12 months. Females reach sexual maturity after three and a half years, and males after five years. Mother and child bonds are strong and may last for life. The young mimic the mating, fighting and grooming acts of their elders play is a key part of monkey education. The total Japanese Macaque population is estimated at about 35,000 to 50,000 individuals. Troops average about 80 to 190 individuals, but anything up to 570 in a single troop is known. And at Takasakiyama, near Oita, in Japan there is a troop containing about 1,000 individuals. This is at present the largest troop of primates known anywhere in the world. During the afternoon crèches containing up to 50 youngsters gather to play.
Japanese Macaques eat fruits, berries, nuts, young leaves, grasses, greens, bark, buds, insects, spiders, snails, crayfish, bird’s eggs, and mushrooms. They also eat barnacles and limpets, by wrenching them off the rocks with their teeth at low tide.
If a monkey uses its intelligence to solve a problem, it can demonstrate its solution to others. In one well-studied group of Japanese Macaques. For example, the scientists would put sweet potatoes on the beach as a way of gaining the monkeys’ trust and getting them out in the open. In 1953 an eighteen month old female named Imo was seen to wash the sweet potatoes to remove the mud before eating them. Ten years later the idea had spread throughout the troop, and was being transferred to the next generation. Today, the sweet potatoes the monkeys are given are cleaned first. But the monkeys still wash them. Perhaps they like to wash them because the saltwater improves the taste by seasoning it. Naturally such a trait will only spread through the originator’s sphere of influence, and as a result monkey behaviour is very variable. So one group may spend much of its time foraging in the trees for fruit while another group of the same species devotes hours to searching for nuts on the forest floor. Some Japanese Macaques have taken to feeding on dead fish. Fish either left by fishermen or stranded after typhoons. Others even eat live octopus, given the chance.
At Jikokudani in Shiga Heights, Japan there are troops of Japanese Macaques commonly named “Snow monkeys”. Jikokudani means Valley of Hell. It derived this name from its steaming volcanic hot springs. Today most of the monkeys, except the immigrating adult males (immigrating males never learn), bath in the hot springs. Monkeys started entering the local hotel’s hot baths about 30 years ago. A separate monkey pool was then build into the valley, but some of the monkeys still return to the hotel pool. Tourists visit to see the bathing monkeys and to take baths themselves.
Other Japanese Macaques troops of Miyajima, near Hiroshima, have started some bizarre monkey behaviour. What makes them so strange is that they groom deer. The monkeys groom the brown backs of the deer and pick and eat bits of scurf or lice eggs in the same way they groom eachother.
Subspecies of the Japanese Macaque include: Macaca fuscata speciosa and Macaca fuscata yakui.
As well as being the most northerly-living non-human primate, Japanese macaques are also famous for washing their food. They are often the subject of Buddhist myths, and are thought to be the inspiration behind the saying "see no evil, hear no evil, speak no evil."
Distribution They are native to Japan, but an introduced free-ranging population has been living in Texas since 1972.
Habitat Japanese macaques live in a variety of forest-types, including subtropical to subalpine, deciduous, broadleaf and evergreen forests, below 1500m.
Behaviour
Japanese macaques live in multi-male, multi-female groups, and on average, females outnumber males by 3.4 to 1. The females have a rigid hierarchy with infants inheriting their mother`s rank. The males tend to be transient within the troop. Japanese macaques are diurnal and spend the majority of their time in the trees.
Notes
When researchers studying these monkeys left sweet potatoes out on the beach for them to feed on, they witnessed one female taking the food down to the sea to wash the sand away. After a while, other macaques started to copy her behaviour. This trait was then passed on from generation to generation, until eventually, all except the very old members of the troop were washing their food in the sea.
Records Japanese macaques are the most northerly-living non-human primate, living in mountainous areas of Honshu, Japan. They survive winter temperatures below -15 degrees Centigrade, and keep warm in naturally heated volcanic springs.
