Sumatran orangutan
| Sumatran orangutan | ||||||||||||
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Male Sumatran orangutan ( Pongo abelii ) |
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| Pongo abelii | ||||||||||||
| Lesson , 1827 |
The Sumatran orangutan ( Pongo abelii ) is a great ape . Together with the Bornean orangutan and the Tapanuli orangutan described in 2017, it forms the genus of orangutans . He lives in the northwestern parts of the island of Sumatra .
The Sumatran orangutan got its scientific name after the British naturalist and botanist Clarke Abel .
features
Sumatran orangutans differ from their Bornean relatives, among other things, in their fur , which is usually lighter and more reddish in color and has a slightly more delicate, lighter build. The cheek bulges, especially in older males, are somewhat smaller, they lie flatter on the head and are often covered with white hair. The beard worn by both sexes is usually a little longer, while the throat pouch of adult males is smaller. With the Bornean orangutans, they share a physique that is adapted to a tree-dwelling way of life: the arms are very long, the hands are hook-shaped, the thumb is short and located close to the wrist, the legs are short and very flexible and the feet are hand-like.
Way of life
Sumatran orangutans are diurnal forest dwellers; when they sleep they build a leaf nest that is usually only used once. They slowly climb with all four limbs or swing on the branches. In contrast to their Bornean relatives, they rarely come to the ground, presumably due to the threat from their main predator, the Sumatran tiger .
They can usually be found alone, but do not lead a strictly solitary lifestyle. Males and females try to establish fixed territories, with the male's territory overlapping that of several females. They are more social than Bornean orangutans, sometimes two females join forces for several days to forage. There are observations of larger group formations and also temporary associations of a male with a female and their young animals. Younger animals in particular cannot establish a territory, but spend their lives as “hikers” who constantly roam around without a territory.
Presumably because of their more social way of life, they use tools much more frequently than their Bornean relatives. Animals have been seen using wooden sticks to dig, fight, or scratch themselves with. They protect themselves from rain and blazing sun with large leaves that they hold over their heads.
Sumatran orangutans are mainly herbivores that feed mainly on fruits (such as figs ), but also on leaves, young shoots and tree bark. To a greater extent than Bornean orangutans, however, they also eat insects and other carnal foods. For example, there is evidence of the looting and consumption of Sunda slow loris .
Threat and protection
The Sumatran orangutan is an endangered species. The main reason for this is the loss of its habitat: the forests are being cleared to a large extent for wood production or for the establishment of agricultural land (e.g. for palm oil ). In addition, there is hunting and the illegal trade in young animals that are kept as pets. These factors are exacerbated by the slow rate of reproduction of the animals: a female gives birth to a young animal only every four to eight years.
The orangutans have become extinct in many regions of Sumatra. Today they only occur in the north of the island. The population is estimated at around 14,600 animals (as of 2015). The IUCN lists the Sumatran orangutan as " critically endangered ".
The largest populations can be found in the Gunung Leuser National Park . Regina Frey and Monica Borner initiated the Bohorok orangutan station there in 1973, supported by the Frankfurt Zoological Society (FZS) and private donations. In 1980 the FZS handed over the administration of the station to the Indonesian government, since then it has been run by the national PHPA (Perlindenan = protection, Hutan = forest, Pengewetan = conservation, Alam = nature). From this point on, however, the station became more and more a destination for tourists. At some point, a coordinated and successful release into the wild was hardly possible. In 1997, the release from this station was finally stopped. (A severe flash flood from the Bohorok River in 2003 severely affected the facility.)
Therefore, the Frankfurt Zoological Society decided in 1998, together with the PanEco Foundation, to set up a new release station on Sumatra. This time, however, this should arise outside the Gunung Leuser National Park. Many researchers have long been of the opinion that when orangutans are released into the wild, they should be avoided if possible in areas already inhabited by orangutans. And since the only significant orangutan population on Sumatra lives in the Gunung Leuser ecosystem, alternatives were sought. These were eventually found in the Bukit Tigapuluh National Park ( Jambi Province ). The area has been assessed as a suitable habitat for orangutans. In addition, no orangutans have lived here since the 19th century. The station was approved in 2001 and is now located in the buffer zone outside the Bukit Tigapuluh National Park and thus provides hope for a second large orangutan population in Sumatra.
literature
- Thomas Geissmann: Comparative Primatology . Springer, Berlin 2003, ISBN 3-540-43645-6 .
- Ronald M. Nowak: Walker's Mammals of the World . 6th edition. Johns Hopkins University Press, Baltimore 1999, ISBN 0-8018-5789-9 (English).
- Don E. Wilson, DeeAnn M. Reeder (Eds.): Mammal Species of the World . A Taxonomic and Geographic Reference . 3. Edition. Johns Hopkins University Press, Baltimore 2005, ISBN 0-8018-8221-4 (English).
Web links
- Primate Factsheets: Orangutan (Pongo) Taxonomy, Morphology, & Ecology
- Sumatran Orangutan Conservation Program
- Sumatra Orangutan Society (English)
- Pongo abelii in the Red List of Threatened Species of the IUCN 2006. Posted by: A. Eudey & Members of the Primate Specialist Group, 2000. Accessed July 17 of 2007.
Individual evidence
- ↑ Bo Beolens, Michael Grayson, Michael Watkins: The Eponym Dictionary of Mammals. Johns Hopkins University Press, 2009; P. 1; ISBN 978-0-8018-9304-9 .
- ↑ Madeleine E. Hardus et al: Behavioral, Ecological, and Evolutionary Aspects of Meat-Eating by Sumatran Orangutans (Pongo abelii). In: International Journal of Primatology. Online pre-publication of January 7, 2012, doi : 10.1007 / s10764-011-9574-z
- ↑ newscientist.com of January 17, 2012: Video document of two orangutans eating a Sunda slow loris
- ↑ Press release of the Max Planck Society : More Sumatran orangutans than previously assumed , March 4, 2016, accessed on October 17, 2016.