Black Snub-nosed Monkey

The black snub-nosed monkey (Rhinopithecus bieti), also known as the Yunnan snub-nosed monkey, is an endangered species of primate in the Cercopithecidae family. It is endemic to China, where it is known to the locals as the Yunnan golden hair monkey (滇金丝猴) and the black golden hair monkey (黑金丝猴). It is threatened by habitat loss. It was named after Bishop Félix Biet who collected it.

The black snub-nosed monkey is a large, stocky and well-furred primate belonging to the leaf-monkey Colobinae subfamily. Despite its morphological distinctiveness and noteworthy biology this is one of the lesser known primate species. In recent years, however, knowledge about the behavior and ecology of the black snub-nosed monkey has grown. Lack of information is mainly a result of difficult research conditions due to the monkey's semi-nomadic lifestyle, elusive nature and inhospitable habitat with extremely steep hillsides, impenetrable bamboo thickets, freezing winter climate with snow as well as damp and foggy summers with minimum visibility.

This species has a highly restricted distribution in the biodiversity hotspot of the Hengduan Mountains which borders the Himalaya range. The actual distribution range is limited to the Yun Ridge (云岭) portion of the Hengduan Mountains. Only 17 groups with a total population of less than 1,700 animals have survived in northwest Yunnan and neighboring regions in the Autonomous Prefecture of Tibet. Group size is small, typically only 20 to 60; groups of over 100 have never been observed. The territory of each group varies from 20 to 135 square km.

The black snub-nosed monkey was almost completely unknown until the 1990s. The fact that no single zoo outside China has ever kept the black snub-nosed monkey in captivity has contributed to the enigmatic status of this species. The black snub-nosed monkey lives in one of the most extreme environments of any nonhuman primate. Its habitat is either pure temperate coniferous forest or deciduous/evergreen broadleaf and coniferous forest. The highest recorded altitude of a group of this species is 4700 m. The black snub-nosed monkey lives in very large super-groups which are made up of single-male core families or harems. The monkey moves fast and far in a cohesive group and covers vast areas in search of lichens and other seasonally available food items.

The reproduction cycles of black snub-nosed monkey is generally similar to that of golden snub-nosed monkeys, except the time of birth is often two to three months later due to colder climate. Like most primates, the snub-nosed monkey gives birth at night, making it difficult for researchers to observe. A rare daytime birth observed a multiparous female assisting another female in the birthing process, similar to the human midwifery practice.

The average size of adult male black snub-nosed monkey is between 74 – 83 cm, excluding the tail, which averages 51 – 72 cm. Females are smaller than males.