These rivers, which originate in caves, are the source of water for the survival of karst landforms in southwest China. In the steep gorge of the MayangHe Nature Reserve in Guizhou Province, there is a wildlife colony. It is home to one of the world's rarest primates, the black langur.
The black langur is a primate endemic to Asia, with a unique face and unique environment. They are a group of rock dwellers who live in the dense karst rocky mountains of tropical and subtropical jungles, using the steep mountains as a natural refuge, developing superb climbing skills and moving between the rocks of the steep mountains.
Adult black langurs are slender and have a long tail that is very conspicuous. They are black all over, with only two white hairs on their cheeks, resembling two whiskers, most notably the crown of hair that stands tall on the top of their heads, and they are born with a Mohican hairstyle. The newborn little black langur is golden yellow, has a common name "yellow cub", and the body color of the three-week-old cub gradually turns black from the tail to the adult color when it is one year old.
Like many primates, the black langur is a social animal. The group is a family unit, usually contains a few to a dozen individuals, there is only one adult male in the group, and all the adult females in the group are its "harem beauties", and scientists also call this group composition form "harem type". The black langur colony is a matrilineal society, and when the monkey colony migrates, the female assumes the role of leader. The cubs in the group are cared for by the entire extended family, and the female cubs remain in the group after adulthood, so all the females in the group are closely related to each other. This also sets the tone within the black langur community – friendly cooperation is more than threatening conflict.
Male pups, however, are seen as a potential threat to adult males and are expelled before they mature. Males who leave the group either wander alone or join a group of males. These "stragglers" often wander around the family monkey colony, looking for opportunities to leave their offspring behind, which can often be achieved in two ways. One is to challenge the male in the monkey group, defeat it and take its place, gaining the right to mate with all the females in the group. This translocation often brings the calamity of killing the cubs in the group, and this "infanticide" behavior is common among non-human primates. The most popular explanation for why this behavior occurs is that the reproductive competition between males is very fierce, and each male's tenure in the breeding group may be very short, so the male always wants to mate with the female in the group as soon as possible. However, lactating females do not make estrus, and only when the cubs die, they will begin to mate again.
Therefore, killing a cub that is not related to oneself is conducive to the reproduction of new males. Another way to reproduce male monkeys outside the group to continue their genes is to sneak up on the males and females in the group. And the female monkeys are by no means "virtuous and spirited", they also have their own calculations. The monkey kings take turns to sit, but the "children" are all their own, and most of them "marry" with foreign males, which can reduce the probability of their cubs being killed. It is the presence of these behaviors that guarantees the genetic diversity of the offspring of the black langur monkey.
The black langur has two white hairs on its cheeks
A female black langur with cubs, the small black langur has golden fur, commonly known as "yellow boy".
The word "leaf" in the name of the black langur monkey indicates their feeding habits, and the black langur monkey is a leaf eater. Plants are their main food, and leaves, stems, flowers, fruit seeds, and even bark are all in their diets. During the rainy season, black langurs are very easy to obtain fresh stems and flowers, and a small range of activity can meet their needs; in the dry season, fruits become their main food source, and they need to expand their search range. These natural climbers can climb and feed among the most rugged rocks. Experienced adult monkeys know what season and where to find enough food. In order to adapt to the life of plant food, the black langur monkey evolved a specialized stomach, their stomach has a separation, functioning similar to the compound stomach of even-hoofed animals such as cattle, and some stomach chambers have bacteria that can break down cellulose to help digest the plants that are eaten.
Black langurs are leaf-eating experts, and plants are their main food
Monkeys forage and move during the day, and at night, to avoid predators, they climb into burrows that are difficult for other animals to enter for the night. In winter, they go deeper into the cave, where the temperature is relatively high. Every morning when the cave comes out and the night returns to the cave, the male monkey leader will probe at the front to make sure that there is no danger, and the whole monkey group will follow. The black langur develops this habit of vigilance during its long-term relationship with natural enemies. Once upon a time, leopards, pythons and tigers used to roam the forests inhabited by black langurs, but now, few beasts of prey can threaten black langurs.
Morning and afternoon are the time for the black langurs to feed, and the monkeys that forage between the branches rarely get off the tree, and the young monkeys will climb on the mother monkeys. Monkeys often take turns drinking water from nearby rivers, and in some places monkeys have a habit of licking rocks, often guessing that this is to obtain minerals from them. At noon, it is the "lunch break" time of the monkeys, the young monkeys rest on the mother monkeys, and the sub-adult monkeys play and fight with each other. Grooming each other is an essential part, and the monkeys will comb their own hair, but when combing each other's hair, they will be more concentrated on the head, back and perimeter of their own combing. This act of combing each other's hair is prevalent among non-human primates, both for hygiene needs and as a glue in group life.
The thumb of the black langur degenerates into a wart, a common feature of the subfamily colobus monkey to which the black langur belongs
Wild black langurs are mainly distributed in China and Vietnam, and the number is very rare, no more than two thousand. In China, the black langur is distributed in Guangxi, Guizhou, Sichuan, Chongqing and other provinces, and about 500 black langurs inhabit the Mayanghe Nature Reserve in Guizhou, which is the largest group of black langurs in the world. In Chinese history, the black langur was once considered to have medicinal properties, but was hunted in large numbers to make "black ape wine", which has become rare with the popularization of animal protection concepts.
Although the black langur is much more widely distributed than its close relative, the white-headed langur, both are divided into isolated habitats due to human activity and the disappearance of forests. This situation, known as habitat fragmentation, is also the main threat facing the black langur monkey today, and the large areas of habitat that were originally connected are cut off by farmland reclamation and artificial construction, which blocks the migration of the black langur monkey when food is insufficient, and also greatly reduces the possibility of genetic exchange between different groups of black langur monkeys. Fragmented habitats, with more edges that border areas of human activity, both bring more human interference and increase the likelihood of conflict between wildlife and humans. Although problems such as overexploitation, habitat destruction, and human-monkey conflict remain to be resolved, efforts to protect wild black langurs have not stopped.
The black langur is listed as a national first-class protected animal, and there are currently more than 20 protected areas inhabiting the black langur, which is well protected. The Wuzhou Black Langur Rare Animal Breeding Center has more than 300 individual artificially bred black langurs, some of which are hybrid offspring of black langurs from different habitats. At the end of 2017, a family group of five black langur monkeys was released into the wild in the Damingshan Nature Reserve in Guangxi, and their survival in the wild will be continuously tracked. This high-profile family carries a new hope for the protection of the black langur monkey.
Black langurs are social animals with rich social behaviors among group members
The black langur is a typical arboreal primate that climbs and jumps flexibly between branches and has a long tail that helps it maintain balance.