Black-handed gibbon
| Black-handed gibbon | ||||||||||||
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Male Black-Handed Gibbon |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Hylobates agilis | ||||||||||||
| F. Cuvier , 1821 |
The agile gibbon or Un (g) ka ( Hylobates agilis ) is a primate species from the family of the Gibbons (Hylobatidae). The population in south-western Borneo , the systematic status of which is disputed, is listed here as a whiskered gibbon as a separate species .
features
Although no exact body measurements are known, the weight of the black-handed gibbon is 4 to 7 kg. The species got its name because of its hands and feet, which are usually the same color as the fur or a little darker than it. The coat color is extremely variable, but there is no gender dimorphism . The coat is either black (or maroon) or pale (tan, gray, or cream with a darker belly), and both sexes have a white band of eyebrows. Only males and young animals have white or red-brown-white cheeks and a beard, some of which are also colored. The females lose these traits with sexual maturity. The hair on the head is directed backwards like a fan and a little longer on the ears.
distribution and habitat
The black-handed gibbon occurs in southern Thailand on the Malaysian border and on almost all of Sumatra .
Most blackhand gibbons occur in mixed monsoon forests and tropical rainforests at an altitude of up to 1400 m. However, some also live in swamp and mountain forests.
Way of life and reproduction
Black-handed gibbons are diurnal tree dwellers who are primarily concerned with foraging and eating at the beginning of the day. However, both activities decrease as the day progresses until they go to sleep before dusk.
The average size of an area is 29 ha. In a territory of this size the animals cover up to 1339 m per day. Males are responsible for defending the territory while females lead the groups and chase away other females to prevent males from having more than one partner.
The black-handed gibbon is a fruit eater that prefers fruits with a high sugar content (60%), but also eats young leaves (39%) and insects (1%).
Parental care is mostly provided by the mother, although the male and older kittens also help. The young animal is suckled until it is 18 months old. A black-handed gibbon is fully grown at the age of six, but only reaches sexual maturity at around 8 to 9 years of age. Life expectancy is more than 30 years.
Hybrids between black-handed gibbons and white-handed gibbons ( Hylobates lar ) on the upper reaches of the Muda River are known. However, the hybrid zone was almost completely destroyed by deforestation, so that hybridizations are less common today than before. Hybrids have also been detected with the gray gibbon ( H. muelleri ). A female hybrid, whose parents Pileated ( H. pileatus were) and an agile gibbon, lived for 35 years and her singing combined with the elements of Schhwarzhandgibbons and other gibbon species (but not the cap Gibbons). At least nine hybrids were also born in the Zurich Zoo. A further hybridization between the white-browed gibbon ( hoolock hoolock ) and the black-hand gibbon has not been confirmed. The hybrid's father was described as a cap gibbon (then Hylobates lar pileatus ), but the animal's features indicated a white-browed gibbon. However, it was later found out that the father was really a cap gibbon. The hybrid resembled a dark gray gibbon ( H. muelleri ).
threat
The black-handed gibbon is classified by the IUCN as "endangered" (highly endangered). It is protected in Indonesia, Malaysia and Thailand. The main threats are deforestation, fires, the spread of plantations (e.g. coffee, rubber) and the illegal pet trade. The population on Sumatra in particular is extremely endangered and is falling rapidly. On the Malay Peninsula, populations seem stable, but they are becoming more and more crowded. The species is restricted to closed forests and habitat transformation and fragmentation and road building are increasing threats. Black-handed gibbons can be found in twelve nature reserves. Unfortunately, many of these nature reserves are only suggestions and further development is uncertain. Most of the protected areas on Sumatra are also in mountainous regions, where the animals have only a low population density. In Bukit Barisan Selatan National Park in Southwest Sumatra, the population is currently safe and healthy, but survival depends on the Indonesian government to control illegal logging in this and other parks. How many black-handed gibbons actually live in the wild is not known, but in 2002 there were 4,479 individuals in Bukit Barisan Selatan National Park. On the Malay Peninsula, Belum-Temenggor and Ulu Mudah are the strongholds of the black-handed gibbon. Only a few 1000 specimens live in Thailand, divided into three forest areas or nature reserves.
Individual evidence
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↑ International Zoo Yearbook 1966, p. 391;
- International Zoo Yearbook 1972, p. 320. -
↑ International Zoo Yearbook 1984/1985, p. 524;
- International Zoo Yearbook 1986, p. 480;
- International Zoo Yearbook 1989, p. 320;
- International Zoo Yearbook 1991, p. 344. - ↑ International Zoo Yearbook 1962, p. 225.
literature
- Thomas Geissmann: Comparative Primatology . Springer, Berlin 2003. ISBN 3-540-43645-6
- DE Wilson & DM Reeder: Mammal Species of the World . Johns Hopkins University Press, 2005. ISBN 0-8018-8221-4
- Russell A. Mittermeier, Anthony B. Rylands, Don E. Wilson: Handbook of the Mammals of the World. Volume 3: Primates. Lynx Edition, Barcelona 2013, ISBN 978-84-96553-89-7 , p. 780.
Web links
- Information from the Gibbons Research Lab. (English)
- Hylobates agilis in the endangered Red List species the IUCN 2006. Posted by: Eudey et al , 2000. Retrieved on 11 May, 2006.