Crested gibbons

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Crested gibbons
Northern white-cheeked crested gibbon (Nomascus leucogenys)

Northern white-cheeked crested gibbon
( Nomascus leucogenys )

Systematics
Subordination : Dry- nosed primates (Haplorrhini)
Partial order : Monkey (anthropoidea)
without rank: Old World Monkey (Catarrhini)
Superfamily : Human (Hominoidea)
Family : Gibbons (Hylobatidae)
Genre : Crested gibbons
Scientific name
Nomascus
Miller , 1933
In the crested gibbons, the females (left) are yellow-brown and the males (right) are black.

The crested gibbons ( Nomascus ) are a genus of primate from the family of gibbons (Hylobatidae). They include seven types .

features

The crested gibbons have the typical physique of all gibbons with their slim body, strongly elongated arms and the missing tail. The sexes are approximately equal, differ but mostly in terms of their fur color. Males have a clearly recognizable head of hair on their head and are predominantly black in color, with some species having white or yellow cheek areas. Females, on the other hand, usually have a yellowish-brown fur with a dark spot on the head, sometimes the chest, fingers and toes and other parts of the body can be darker in color. They are the largest gibbons after Siamang ; they reach a head body length of around 60 centimeters and a weight of 7 to 8 kilograms.

distribution and habitat

The crested gibbons have the northeasternmost distribution area of ​​all gibbons. It includes southern China (now only Yunnan and the island of Hainan ), Vietnam , Laos and eastern Cambodia . The Mekong forms (with the exception of Yunnan) the western limit of its range. Like all gibbons, they live in tropical rainforests .

Way of life

Like all gibbons, these animals are diurnal and live in family groups consisting of a male, a female and one to three young animals. They are tree dwellers who move forward in the branches by means of rocking arms (brachiation). The groups inhabit fixed territories between 30 and 40 hectares in size. Like almost all gibbon species, these animals produce duet songs, which serve to mark the territory and to establish contact with the other family members. However, these chants are relatively simple and uniform compared to other gibbon species.

The diet of these animals consists mainly of fruits, they also eat leaves, flowers and sometimes insects.

Reproduction

After a seven-month gestation period, a single young is born. This is - regardless of gender - colored golden yellow at birth and turns black after about six months. They reach sexual maturity at around 5 to 8 years of age. While the females acquire their light color at this age, the males remain black.

Young crested gibbons are colored like males, but their songs are similar to those of females. So you are giving off conflicting information about your gender; the reasons for this are not yet known. This may reduce their sexual attractiveness, which reduces the risk of incest.

threat

All types of crested gibbons are endangered. Around 1000 years ago gibbons were widespread across a large part of China (up to the Yellow River ) - but it is unclear whether they were crested or white- browed gibbons . Today they are pushed back to the extreme south and the stocks are also limited in the other countries in their area of ​​distribution. The main reason for this is the destruction of their habitat , plus hunting. The eastern black crested gibbon , whose population is estimated at fewer than 50 animals, is particularly threatened . But the other species are also listed as critically endangered or endangered by the IUCN .

Systematics

The distribution areas of the seven crested gibbon species (N. sp. =  N. annamensis )

The crested gibbons form the sister group of all other gibbons. In the past they were listed in the genus Hylobates , but today mostly as a separate genus Nomascus . The number of species has also been corrected upwards through more detailed investigations, today seven types are distinguished:

literature

Web links

Commons : Nomascus  - collection of images, videos and audio files