Southern white-cheeked crested gibbon
| Southern white-cheeked crested gibbon | ||||||||||||
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female (left) and male (right) southern white-cheeked crested gibbon ( Nomascus siki ) |
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| Nomascus siki | ||||||||||||
| ( Delacour , 1951) |
The Southern White-cheeked ( Nomascus siki ) is a primate of the family of gibbons (Hylobatidae). It was considered a subspecies of the (northern) white-cheeked crested gibbon until 1983 cytogenetic studies showed that it was a separate species .
features
Exact body measurements are not available. Southern white-cheeked crested gibbons can weigh up to 6 kg (males) or 7 kg (females).
As with all crested gibbons , the sexes differ significantly in the color of their fur. The males and juveniles are black in color and have white cheek patches, but they are half as long as those of the northern white-cheeked crested gibbon. These have a pointed upper end and reach to the upper lip and the sides of the chin, but are not directed outwards as in the northern yellow-cheeked gibbon ( Nomascus annamensis ) or the southern yellow-cheeked gibbon ( N. gabriellae ). The crested is clearly visible, but not as strong as in the northern white-cheeked crested gibbon ( N. leucogenys ). Females are pale yellow to orange-yellow in color, with a black vertex and a white ring around the face and are largely indistinguishable from the females of the northern white-cheeked gibbon.
distribution and habitat
Southern white-cheeked gibbons live in southern Laos and central Vietnam , the Mekong forms the western border of their range. In the south their distribution area overlaps with that of the yellow-cheeked crested gibbons . They are also found in China.
High, mainly tropical, evergreen deciduous forests and steep karst forests at an altitude of 30 to 1800 m represent the habitat . The species is probably also found at higher altitudes.
Way of life and reproduction
Southern white-cheeked gibbons are diurnal tree dwellers and presumably live in monogamous pairs who mark their territory with duet songs.
They mainly eat fruit and supplement the menu with leaves and flowers. Although little else is known about the species, its way of life and reproduction are likely to be largely the same as other species of the genus Nomascus .
Hybrids between the southern white-cheeked crested gibbon and the southern yellow-cheeked crested gibbon are known in the wild in southern Laos and southern Vietnam . However, the frequency of these hybridizations is unknown.
threat
The southern white-cheeked crested gibbon is classified by the IUCN as "endangered" (highly endangered). It is found in six nature reserves, but its frequency is nowhere well documented. The main threat is hunting, be it for food, for traditional Asian medicine or for the pet market (especially young animals). This is exacerbated by habitat degradation and sometimes urbanization. Habitat loss is a bigger problem in Vietnam than in Laos, as the population here is growing rapidly and wood and space are required for usable land. Reducing these threats is key to protecting the Southern White-cheeked Crested Gibbon.
Individual evidence
- ↑ a b J. Couturier, J.-M. Lernould: Karyotypic study of four gibbon forms provisionally considered as subspecies of Hylobates (Nomascus) concolor (Primates, Hylobatidae). In: Folia Primatologica 56, No. 2, 1991, pp. 95-104, doi: 10.1159 / 000156533 .
- ↑ a b Julia C. Ruppell: Vocal diversity and taxonomy of Nomascus in Central Vietnam and Southern Laos. In: International Journal of Primatology 31, No. 1, 2010, pp. 73-94.
- ↑ Chan Bosco Pui Lok, Tan Xue-feng, Tan Wu-jing: Rediscovery of the critically endangered eastern black crested gibbon Nomascus nasutus (Hylobatidae) in China, with preliminary notes on population size, ecology and conservation status. ( Page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF) In: Asian Primates Journal 1, No. 1, 2008, pp. 17-25.
- ↑ Tanja Haus, Martina Vogt, Bernhard Forster, Ngoc Thanh Vu, Thomas Ziegler: Distribution and population densities of diurnal primates in the karst forests of Phong Nha – Ke Bang National Park, Quang Binh province, Central Vietnam. In: International Journal of Primatology 30, No. 2, 2009, pp. 301-312, doi: 10.1007 / s10764-009-9343-4 .
- ^ Russell A. Mittermeier, Anthony B. Rylands, Don E. Wilson: Handbook of the Mammals of the World. Volume 3: Primates. Pp. 779-780.
- ↑ Thomas Geissmann: Status reassessment of the gibbons: results of the Asian primate red list workshop 2006. ( Memento of the original from March 28, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. (PDF) In: Gibbon Journal 3, 2007, pp. 5–15.
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. 790.
Web links
- Information from the Gibbons Research Lab. (English)
- Nomascus siki in the endangered Red List species the IUCN 2006. Posted by: A. Eudey & Members of the Primate Specialist Group, 2000. Accessed July 26 of 2007.