Japanese macaque
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Japanese or red-faced macaque ( Macaca fuscata ) |
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| Macaca fuscata | ||||||||||||
| ( Blyth , 1875) |
The Japanese macaque , snow monkey or red-faced macaque ( Macaca fuscata ) is a primate species from the genus of macaques ( Macaca ) within the family of vervet monkeys (Cercopithecidae). It lives in Japan and has the northernmost range of all primates (with the exception of humans).
features
Japanese macaques reach a head body length of 52 to 57 centimeters, the tail is a short stub with 8 to 9 centimeters in length. At an average of 11.3 kilograms, males are significantly heavier than females, who weigh 8.4 kilograms. There is also a correlation between climate and weight: animals in the northern, cooler regions are heavier. The coat color varies from yellowish brown to dark brown, in the cooler months the coat can become very thick and long. The hairless, pink or reddish colored face is striking.
distribution and habitat
Japanese macaques are native to three of the four main Japanese islands - Honshū , Shikoku and Kyūshū . They are absent on the northernmost island of Hokkaidō , the northernmost point of their occurrence is the Shimokita peninsula in northern Honshū. In addition to the main islands, they can also be found on several offshore islands. The southernmost point of its occurrence is the island of Yakushima , the population living here is considered a separate subspecies ( Macaca fuscata yakui ). A small, overgrown population also lives near the Texas city of Laredo .
These primates live in forests, but are found in a wide variety of forest types. In the south they can be found in subtropical forests, in the north also in mountainous forests. Here they also live in an extremely cool climate; there can be meters of snow for several months a year. Mainly because of the dense population of Japan, they are rarely found in the lowlands. The highest known occurrences are at 3180 meters.
Way of life
Activity times and movement
Japanese macaques, like all old world monkeys, are diurnal. However, the activity also depends on the habitat and the season. In winter they are generally less active, and the length of the daily forays also decreases significantly. In the north of the distribution area they only cover around 0.5 kilometers a day in winter. In the south they cover an average of 2 kilometers every day in summer and 1.2 kilometers in winter.
These primates are semi-terrestrial, which means they can be found both in the trees and on the ground. In general, females are more common on trees and males more often on the ground. They usually move quadruped (on all fours). In the trees they can also jump distances, but suspensively (with their arms hanging on branches) they do not move.
When they sleep, they tend to retreat to trees, but sometimes they also sleep on the ground, for example on flat rocks and fallen tree trunks. Especially in winter, when they sleep, they cuddle up in groups on the floor; the lower the temperature, the larger the group. You can swim very well and cover distances of 0.5 kilometers. In winter, they like to visit hot springs in cooler regions , which are quite common in volcanic Japan. They sometimes spend hours in these warm waters to regulate their body temperature.
Social behavior
Like all macaques, Japanese macaques live in groups, the size and composition of which are variable. The average group size is 41 animals, but it can range from 10 to over 160. The groups consist of several males and females as well as the young animals, an average of 18% adult males, 32% adult females, 35% adolescent animals and 15% children.
Because female animals remain in their birth group for life, one or more groups of closely related females form the core of a group, the groups are thus organized matrilinearly . Males, on the other hand, have to leave their birth group when they reach sexual maturity. These males either join together to form bachelor groups or initially live solitary. However, it is normal for males to have belonged to more than one group in their lifetime.
The males in a group establish a hierarchy, one animal becomes the dominant " alpha male ". There are several ways for a male to achieve alpha status: the previous leader dies, leaves the group or loses its rank, or a group that is too large splits up, or a male animal from outside displaces the previous leader. However, the support of the dominant females plays an important role, with which an older or weaker male can maintain the leadership function.
The females also develop a hierarchy. This often remains stable and young females often assume the same status that their mother already has. Mutual grooming plays an important role in the hierarchy of females . In addition to the hygienic purpose, this also serves to strengthen the togetherness within the group, especially between unrelated females.
The grazing areas of different groups overlap at the edges, the groups usually avoid each other. If a meeting does take place, the form of the meeting can vary. Aggressive behavior can occur during the mating season or when there is a lack of food.
Communication and learning behavior
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Japanese macaques communicate with one another using a series of sounds, which can be easily divided into six areas: peaceful or soothing, defensive, aggressive, warning, female oestrus and toddler sounds . Peaceful or quiet sounds can often be heard, such as a “coo” sound while moving or eating, which is believed to serve to keep the group together. The alarm calls and the oestrus calls sound very similar. Alarm calls serve to warn the other group members of a danger. The oestrus calls, on the other hand, advertise the fertile status.
In addition to sounds, the animals also communicate by means of facial expressions, such as pointing or putting their ears back, raising their eyebrows and opening their mouths. Ritualized postures are also shown, for example of males who vigorously shake, kick or hop around shortly before the mating season. Females, however, rarely show such behavior.
Japanese macaques are capable of learning and can adopt behavior from other group members. One example of this is "potato washing": On the island of Kōjima , researchers had sprinkled sweet potatoes on the beach to lure a group of monkeys out of the forest. One female in this group started washing the sweet potatoes in the water and after a few years almost all group members had adopted this behavior. Later they also discovered washing in salt water known as "salting". These techniques were later adopted by other groups. This phenomenon is often used as an example of collective consciousness, however, is based on false reproduced scientific sources for collective and learning and is a pseudoscientific myth under the name Hundertster Monkey known principle ( "The Hundredth Monkey Phenomenon"). While the other groups learned the techniques simply by imitating them, it is postulated that they would be conveyed to the common monkey consciousness in a spiritual way when a threshold was crossed.
Another example of learning and tradition building is snowball rolling, which is mainly observed as a game among young animals. In 1979 it was first observed that a female macaque was playing with stones - similar to how children played with building blocks. In 1983 this game with stones was already widespread over half the group. The exact manner in which they groom each other, the supervision of the young or certain eating habits are also passed on from adults to young animals in the sense of (non-human) cultural achievements .
food
Japanese macaques, like all macaques, are omnivorous ; however, they mainly eat plant-based foods. Generally they are not picky, the food varies according to habitat and season. Fruits are often the most important part of their diet, animals also consume nuts, leaves, seeds, herbs and mushrooms. In northern Japan, tree bark plays an important role as food during the winter months. To compensate for their low nutritional value, they eat up a supply of fat in summer. Sometimes they also dig for underground parts of plants, such as roots and tubers. In addition to plant food, they also eat insects, other invertebrates, and fish. In addition, the consumption of earth ( geophagy ) is also observed.
Reproduction
During the mating season, a male and a female form a short-lived pair. They stay together for an average of 1.6 days, mate, eat and rest together. Females can enter into short relationships with several males one after the other, which last longer, the higher the rank of the male. In general, the females prefer a higher-ranking mating partner. They attract him by, for example, looking back over the shoulder or walking backwards towards him. Males also try to steal their partner from lower-ranking males, but the ultimate decision as to whether they will mate is made by the female.
After a gestation period of around 170 days, the births fall in the months of March to September, the time depends on the habitat and climate, but is the same within a group. As a rule, a single young is born.
The birth takes place on the ground, the female withdraws a bit from the group without losing touch. Newborns weigh around 540 grams, they are initially dark brown in color and only reach the color of adult fur at around six months of age. In the first four weeks the young animal clings to the mother's belly, later it rides on her back as well. Males rarely take care of young animals, but sometimes other females, especially those who have not yet given birth themselves. The youngster starts eating solid food at five to six weeks and is finally weaned at around one year. Females become sexually mature at around 3.5 years of age, males around 4.5 to 5 years old, at which point they have to leave their birth group.
Japanese macaques and people
The IUCN classifies the Japanese macaque as "Least Concern", ie not endangered. Currently, an expansion of the distribution area can be observed, whether this is accompanied by an increase in the total population is controversial. It could also be that the animals merely expand their roaming areas, since the forest monocultures created by humans often offer too little food. To a certain extent, the animals have lost their fear of humans in the last few decades; they can sometimes even be found in large cities. But this also means that they often devastate fields and are therefore viewed and hunted as a plague. It is believed that over 10,000 specimens are killed each year. The total population is estimated at around 100,000 animals. The subspecies M. f., Which occurs only on Yakushima . yakui , on the other hand, is endangered.
literature
- Thomas Geissmann : Comparative Primatology. Springer-Verlag, Berlin et al. 2003, ISBN 3-540-43645-6 .
- Don E. Wilson, DeeAnn M. Reeder (Eds.): Mammal Species of the World. A taxonomic and geographic Reference. Johns Hopkins University Press, Baltimore MD 2005, ISBN 0-8018-8221-4 .
Individual evidence
- ↑ Japanese Macaque on blueplanetbiomes.org
- ^ Bijal P. Trivedi: "Hot Tub Monkeys" Offer Eye on Nonhuman "Culture". In: National Geographic Channel, 2004
- ↑ Marvin Harris: Cultural Anthropology - A Textbook. From the American by Sylvia M. Schomburg-Scherff, Campus, Frankfurt / New York 1989, ISBN 3-593-33976-5 . Pp. 35-36.
Web links
- KJ Gron: Primate Factsheets: Japanese macaque ( Macaca fuscata )
- Macaca fuscata the endangered Red List species the IUCN 2006. Posted by: Eudey, A. & Members of the Primate Specialist Group., 2000
- Macaca fuscata videos published by the Institute for Scientific Film . Provided by the Technical Information Library .