Spider monkeys
| Spider monkeys | ||||||||||||
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Northern spider monkey ( Brachyteles hypoxanthus ) |
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| Brachyteles | ||||||||||||
| Spix , 1823 |
The spider monkey ( Brachyteles ) are a primate genus in the family atelidae (Atelidae). They are among the most endangered American primates. The genus is divided into two types, the northern arachnid ( Brachyteles hypoxanthus ) and the southern arachnoides ( Brachyteles arachnoides ). In English, spider monkeys are called "Woolly Spider Monkeys" or "Muriquis". Muriqui goes back to the corresponding name of the Tupi , a former indigenous population group in Brazil. “Spider Monkeys”, however, refer to another genus of primate, the spider monkeys .
description
Spider monkeys are the largest New World monkeys . They reach a head body length of 45 to 78 centimeters, plus a 65 to 80 centimeter long tail. Males are 12 to 15 kilograms heavier than females, which reach 9.5 to 11 kilograms. Their fur is short and yellow-gray in color, but the color varies according to region and gender and can also be reddish. Your whole body is adapted to the tree-dwelling way of life, arms and legs are noticeably long and slender. The thumb is small in the northern species, but it is present, in the southern species it is completely absent. The tail, which is as long or longer than the body, is used as a prehensile tail. As with the other spider-tailed monkeys, it is hairless at the bottom of the tip, which allows for a better grip.
distribution and habitat
Spider monkeys live in the forests of southeastern Brazil . In the past, its range stretched from the state of Bahia in the north to the state of Paraná in the south, but today its range is greatly reduced and fragmented. The habitat of these animals are the coastal rainforests, where they occur up to 1600 meters above sea level.
Lifestyle and diet
Spider monkeys are diurnal tree inhabitants and prefer to stay in the upper crown area. They are skilful climbers who often move suspensively - swinging by their arms or hanging by their tail - or on all fours. If necessary, they come to the ground too.
Spider monkeys live together in small groups. Unlike other primate species, they have little aggression within the group. Amazingly, the males stay with their family group, while the females have to look for a new group after weaning. The groups often move through the trees in a row. This reduces the risk of falling, as the animal in front has already tested the branches for their load-bearing capacity.
Southern spider monkeys are herbivores that feed on leaves (around 50% of the diet), fruits (30%, especially in the rainy season) and other plant material.
Reproduction
There is very little fighting over the right to mate, males and females mate with as many animals as possible. It has also been observed that the males waited in sequence to be able to mate with the same female. After a gestation period of seven to eight months, a young animal is born. It clings to its mother until the age of six months, after which it begins to explore its surroundings independently. Young animals are weaned at around two years of age, and sexual maturity occurs at around five to seven years of age. The life expectancy of the spider monkeys is unknown.
Danger
Spider monkeys are among the most endangered primate species. They exist in only two percent of the forests of south-east Brazil, and the range of the animals is fragmented into several small populations. The total population of the Northern spider monkeys is estimated at 300 to 800 animals, he is, according to IUCN as "threatened with extinction" ( critically endangered ), the Southern spider monkeys are around 1,000 to 1,500 individuals, he is considered "high risk" ( endangered ). Breeding programs and educational events are intended to draw attention to the severe endangerment of these animals.
Systematics
The genus is divided into two types, the northern arachnid ( Brachyteles hypoxanthus ) and the southern arachnoides ( Brachyteles arachnoides ). The two species are very similar to each other, they differ in the fact that the thumbs are small in the northern species, but present, in the southern species it is completely absent. They are classified in the family of the spotted monkeys (Atelidae), which are all characterized by the prehensile tail. Their closest relatives are the woolly monkeys ( Lagothrix ).
literature
- Thomas Geissmann : Comparative Primatology. Springer-Verlag, Berlin et al. 2003, ISBN 3-540-43645-6 .
- Ronald M. Nowak: Walker's Mammals of the World. 6th edition. Johns Hopkins University Press, Baltimore MD 1999, ISBN 0-8018-5789-9 .
Web links
- Northern spider monkey and southern spider monkey at arkive.org - information, photos and videos