White-headed Langur
| White-headed Langur | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
White-headed Langur ( Trachypithecus leucocephalus ), specimen |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Trachypithecus leucocephalus | ||||||||||||
| Tan , 1955 |
The white-headed langur ( Trachypithecus leucocephalus ) is a species of primate from the group of the Schlankaffen (Presbytini). It occurs only in karst regions in southern China in the Guangxi Autonomous Region . The distribution area lies in the districts of Fusui , Longzhou and Ningming and is bounded in the north and northwest by the Zuojiang River, in the south and southwest by the Mingjiang River and in the southeast by the Shiwan Mountains.
features
White-headed langurs reach a head body length of 55 to 62 (males) or 47 to 55 centimeters (females), the tail is with 82 to 89 centimeters significantly longer than the body. Males are larger than females, reaching 8 to 9.5 kilograms, while females weigh around 6.7 to 8 kilograms. They are slender primates with slender hands and feet, the thumbs are greatly reduced in size.
The fur of these primates is dark chocolate brown in the rear area, the head, the shoulders and the upper chest region contrast strongly and are colored white to ivory. There is a white mop of hair on the head, the tip of which can also be brownish. Depending on the individual, there can also be whitish regions on the arms, legs, hands and feet. The third of the tail close to the body is brownish, the rest is whitish. In females, the whitish color on the arms, legs and tail diminishes with age. It is not yet known whether this is also the case with the males. The reason for the differences in coloration may be hybridizations with the Tonkin black langur ( Trachypithecus francoisi ). The pubic area of the females is light yellowish or white. All hairless skin areas, i.e. face, ears, hands and feet, are black.
Newborns have a light yellow-orange coat and acquire the color of the adult coat within the first six months of their life.
.jpg)
habitat
White-headed langurs live in forests that grow on 200 to 300 meter high karst hills . The distribution area is highly fragmented and surrounded by intensively cultivated arable land. The mean annual rainfall is around 1000 mm, the mean annual temperature is 22 ° C, the maximum temperature is 39.5 ° C and the lowest measured temperature is −0.5 ° C.
Way of life
White-headed langurs usually stay on trees but also go to the ground. They are skilled climbers who mainly move around on four legs. They are active during the day and at twilight, when they go to sleep they retreat to karst caves - especially in the cooler seasons and in bad weather. They live in groups of five to eleven animals. These are harem groups that usually consist of a male, one or more females and their offspring. If there are two males in a group, they are likely either brothers or father and son. Young males leave the parent group and roam alone or form their own small groups of up to four members.
White-headed langurs feed mainly on leaves, and fruits, flowers, beetles and bark are also eaten. In a reserve in Fusui they eat around 50 of the 164 species of plants found there, in the Bapen nature reserve parts of 85 different plant species are consumed. In both places, leaves make up about 90% of the food consumed, 60 to 80% are young leaves. The animals rest for about one to two thirds of the day and they eat up to 20% of the time. White-headed langurs also lick water from the leaves in the early morning hours; otherwise they drink rainwater from karst holes. They also regularly lick karst rocks, whether water, insects or lichens are absorbed is not yet known.
Female white-headed langurs become sexually mature at 3.4 to 4 years of age, males at around 5 years of age. The animals get their first young at an age of 57 to 68 months. The gestation period lasts about 214 days. Only one young animal is ever born. Births occur all year round, but around 80% occur from December to March. The young are suckled for 17.5 to 20.5 months, and between two births it usually takes 18 to 28.4 months. About 15% of the young die in the first year of life and the females only have 2.5 young animals on average in their entire life. If your habitat is severely impaired, e.g. If, for example, a dwindling supply of edible plants is exposed, the apes stop reproducing.
Danger
White-headed langurs are among the rarest primates and are listed by the IUCN as Critically Endangered. Their range is highly fragmented and the population has declined by 80% over the past 36 years. Within the approximately 3500 km² distribution area, the species only occurs in 16 different locations, with a total area of about 200 km². In 2002 the number of monkeys was estimated at 580 to 620 individuals. Individual specimens of the Tonkin black langur, whose distribution area is north of the Zuojiang River, were released in the distribution area of the white-headed langur and have mixed with them. The first generation of these hybrids and their offspring are more similar to the Tonkin black langurs. The genetic diversity of the white-headed langurs is extremely low. The big cats, leopards and snow leopards originally found in the distribution area have now disappeared there.
Individual evidence
- ↑ a b c d e f g h D. Zinner, GH Fickenscher & C. Roos: Family Cercopithecidae (Old World monkeys). Pages 749-750 in Russell A. Mittermeier , Anthony B. Rylands & Don E. Wilson : Handbook of the Mammals of the World: Primates: 3rd ISBN 978-8496553897
- ↑ Trachypithecus poliocephalus ssp. leucocephalus in endangered species red list of the IUCN 2006. Posted by: Bleisch, B., Xuan Canh, L. Covert, B. & Yongcheng, L., 2000. Accessed January 20, 2017th
- ↑ Weiran Wang, Yu Qiao, Wenshi Pan, Meng Yao: Low Genetic Diversity and Strong Geographical Structure of the Critically Endangered White-Headed Langur ( Trachypithecus leucocephalus ) Inferred from Mitochondrial DNA Control Region Sequences. PLOS, June, 2015, doi: 10.1371 / journal.pone.0129782
