The black-and-white snub-nosed monkey (''Rhinopithecus bieti''), also known as the Yunnan snub-nosed monkey, is a large black and white primate that lives only in the southern Chinese province of

Yunnan Yunnan; is an inland Provinces of China, province in Southwestern China. The province spans approximately and has a population of 47.2 million (as of 2020). The capital of the province is Kunming. The province borders the Chinese provinces ...

, where it is known to the locals as the Yunnan golden hair monkey () and the black-and-white snub-nosed monkey (). The common name, black snub-nosed monkey, is issued to '' Rhinopithecus strykeri'', inhabiting the Northern Sino-Myanmar border. Coniferous and deciduous forests in the mountainous regions of Yunnan are the ideal terrain for these primates. It is threatened by

habitat loss Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...

, and is considered an

endangered species An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

. With their unique adaptations to their environment, these monkeys thrive at extreme altitudes despite the below freezing temperatures and thin air. This primate's diet is mainly made up of the large amounts of

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

s available in their region.

Anatomy and physiology

Male and female black-and-white snub-nosed monkeys have no colorization differences, but do differ in sizes. Females weigh 20 lbs, while males are around 30 lbs. Adult black-and-white snub-nosed monkeys are identifiable by their gray/black and white fur. The underbelly and central facial zone are all white, while the rest of the body is a grayish black color. Their fur is extremely thick to protect them against below freezing temperatures. They are born with white fur that darkens with age. Another distinctive feature shared by both adults and babies, is their hairless and vibrant pink lips. These primates get the "snub-nosed" part of their name from the absence of nasal bones. This is considered their most distinctive feature.

Behavior

Diet

Unlike many primates, the black-and-white snub-nosed monkey's diet consists mainly of

found on trees. Lichens grow in abundance in mountainous regions, and make for a reliable, year-round food supply. These primates will also eat

bamboo Bamboos are a diverse group of mostly evergreen perennial plant, perennial flowering plants making up the subfamily (biology), subfamily Bambusoideae of the grass family Poaceae. Giant bamboos are the largest members of the grass family, in th ...

leaves and other, more seasonal plants if the opportunity presents itself. Many food items vary depending on the geographical location of each troop including

rhododendron ''Rhododendron'' (; : ''rhododendra'') is a very large genus of about 1,024 species of woody plants in the Ericaceae, heath family (Ericaceae). They can be either evergreen or deciduous. Most species are native to eastern Asia and the Himalayan ...

flower's

nectar Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ...

in the spring. Lichens are toxic to most animals, but the black-and-white snub-nosed monkey has specialized

digestive enzyme Digestive enzymes take part in the chemical process of digestion, which follows the mechanical process of digestion. Food consists of macromolecules of proteins, carbohydrates, and fats that need to be broken down chemically by digestive enzymes ...

s similar to those of a cow that remove the harmful bacteria.

Reproduction

The reproduction cycles of black-and-white snub-nosed monkeys are generally similar to those of

golden snub-nosed monkey The golden snub-nosed monkey (''Rhinopithecus roxellana'') is an Old World monkey in the subfamily Colobinae. It is endemic to a small area in temperate, mountainous forests of central and Southwest China. They inhabit these mountainous forests ...

s, except the time of birth is often two to three months later due to a colder climate. Like most primates, the snub-nosed monkey gives birth at night, making it difficult for researchers to observe. A rare observation of a daytime birth found a

multiparous In biology and medicine, gravidity and parity are the number of times a female has been pregnant (gravidity) and carried the pregnancies to a viable gestational age (parity). These two terms are usually coupled, sometimes with additional terms, t ...

female assisting another female in the birthing process, similar to human

midwifery Midwifery is the health science and health profession that deals with pregnancy, childbirth, and the postpartum period (including care of the newborn), in addition to the sexual and reproductive health of women throughout their lives. In many cou ...

practice.

Evolution

The black-and-white snub-nosed monkey lives at the highest altitude of any known non-human primate. The highest recorded altitude of a group of this species is 4700 m. Surviving in such extreme conditions is only made possible by a mutation in the primate's

genomic DNA Genomic deoxyribonucleic acid (abbreviated as gDNA) is chromosomal DNA, in contrast to extra-chromosomal DNAs like plasmids. Most organisms have the same genomic DNA in every cell; however, only certain genes are active in each cell to allow for c ...

sequence that allows increased resistance to oxygen deprivation ( hypoxia). Other mutations in the DNA sequence have been found to be harmful to the monkeys, as there is evidence of inbreeding and low genetic diversity among populations.

Geographical range and habitat

This species has a highly restricted distribution in the bio-diverse

Nujiang Langcang Gorge alpine conifer and mixed forests The Nujiang Lancang Gorge alpine conifer and mixed forests are a temperate coniferous forests ecoregion in Southwest China and northeastern Myanmar. The forests cover mountains and valleys in the western Hengduan Mountains and because of the extr ...

of the

Yun Range The Yun Range () are a mountain range running north–south in northwestern Yunnan province, China. They were formerly romanized as the Yun Ling and tautologically as the Yun-ling Mountains. The Yun Range runs between the Lancang River (Mekong ...

, which is part of the greater

Hengduan Mountains The Hengduan Mountains () are a group of mountain ranges in southwest China, southwest China that connect the southeast portions of the Tibetan Plateau with the Yunnan–Guizhou Plateau. The Hengduan Mountains are primarily large north-south ...

. Only 17 groups with a total population of less than 1,700 animals survive in northwest

and neighboring regions in the Autonomous Prefecture of

Tibet Tibet (; ''Böd''; ), or Greater Tibet, is a region in the western part of East Asia, covering much of the Tibetan Plateau and spanning about . It is the homeland of the Tibetan people. Also resident on the plateau are other ethnic groups s ...

. The territory of each group varies from 20 to 135 square km. Deciduous and coniferous forests are their preferred habitat, where lichen grows in abundance year-round.

History

The black-and-white snub-nosed monkey was almost completely unknown until the 1990s. The fact that no zoo outside of China has ever kept the black-and-white snub-nosed monkey in captivity has contributed to the enigmatic status of this species.

References

External links

* ARKive
images and movies of the Yunnan snub-nosed monkey ''(Rhinopithecus bieti)''
{{Taxonbar, from=Q1204873

black snub-nosed monkey The black-and-white snub-nosed monkey (''Rhinopithecus bieti''), also known as the Yunnan snub-nosed monkey, is a large black and white primate that lives only in the southern Chinese province of Yunnan, where it is known to the locals as the Yu ...

Endemic fauna of China Mammals of China Primates of East Asia Fauna of Yunnan Endangered fauna of Asia

Taxonomy articles created by Polbot Taxa named by Alphonse Milne-Edwards Endangered Fauna of China