Trachypithecus francoisi

The black leaf monkey, with a black body, upright crest on the top of the head, and only white cheeks and tail tip, is a national first-class protected animal. There are only about 2,000 black leaf monkeys in the world. Among them, there are 76 groups of about 730 black leaf monkeys in the Mayang River National Nature Reserve in Guizhou Province. It is currently the most densely distributed and largest area of black leaf monkeys in my country. It is also the largest distribution area of black leaf monkeys in the world, accounting for one-third of the total number of black leaf monkeys in the world. It is known as the "kingdom of black leaf monkeys".

The black leaf monkey mainly feeds on plants. Some people think that it only feeds on tender leaves, so it is called a leaf monkey. In fact, it not only eats tender leaves, but also eats tender shoots, stems, flowers, fruits and seeds. The plants it likes to eat include more than 20 kinds of plants such as kapok, rootless vines, lettuce shoots, privet, sand pear, litchi, etc. The most favorite species are species of Rosaceae, Vitaceae, Actinidia, etc.

The black leaf monkey is a very smart animal. They always leave one or two monkeys sitting on the high treetops to keep watch, while the other individuals sneak into the fields, hold sweet potatoes or carrots in their hands and rub and shake them constantly. They will soon get the fruits of victory, and when they are full, they will run over to replace the monkeys standing guard. Some of them sneak into the village, steal food from the villagers' homes, and even climb up the roof to remove tiles. Although the black leaf monkey is naughty in front of people, it is very serious in its own system.

The black leaf monkey is a typical tree-dwelling leaf monkey in tropical Southeast Asia and South Asian tropical areas. It mainly lives in tropical rainforests, monsoon forests and South Asian tropical monsoon evergreen broad-leaved forests on both sides of rivers and low mountain valleys. The altitude of its habitat is between 600-1200 meters. They live in tropical and subtropical areas with lush forests, thick bushes, steep mountains and many caves. The black leaf monkey is good at climbing and jumping. Cliffs with sparse trees and few people and animals are their main places for activities and foraging. At night, they live in natural caves between cliffs. The black leaf monkeys living in the northern part of the distribution area have long and dense hair, and in winter, they accumulate thick fat under the skin, so they have strong cold resistance.

The estrus period of black leaf monkeys is mostly in autumn and winter, and the reproductive period of females is mostly in winter and spring from December to March of the following year. They are sexually mature at 4-5 years old. Adult individuals have mating behavior all year round. The conception rate is higher in summer and autumn. The gestation period is about 180 days. They give birth mostly in spring, and cubs can also be seen in other seasons. The lactation period is about 6 months. Generally, one cub is born per litter, and occasionally two cubs. The life span of black leaf monkeys is 1-12 years.

Poaching is considered the main reason for the rapid decline of the wild population of black leaf monkeys. At the same time, they are also facing various forms of habitat degradation, such as expansion of cultivated land, cutting of firewood, grazing of livestock, self-shrub and hydropower construction and tourism development.

There are more than 10 nature reserves in Yunnan (Xishuangban Nature Reserve, Luchun Huanglianshan Nature Reserve, Pingbian Daweishan Nature Reserve, Jinping Watershed Nature Reserve, Malipo Laojunshan Nature Reserve, Jingdong Wuliangshan Nature Reserve, Xinping Ailaoshan Nature Reserve, Lincang Daxueshan Nature Reserve, Cangyuan Nangunhe Nature Reserve, Yingjiang Tongbiguan Nature Reserve and Gaoligongshan Nature Reserve) to protect gray leaf monkeys. Most of these reserves were established between 1980 and 1986. They are all national and provincial nature reserves with a total area of about 536,000 hectares. Since the establishment of the reserve, the habitat of the gray leaf monkey has been protected; in addition, due to publicity and strict law enforcement, the public's awareness of protection has been improved, and poaching of gray leaf monkeys inside and outside the reserve has been basically stopped.

The black leaf monkey is mainly distributed in southeast Asia, in the hills of tropical and subtropical areas along the coast and inland edges, and in the mountains on both sides of the river valley. Its distribution roughly coincides with the distribution of limestone. It is found in China and Vietnam. In China, it is distributed in the areas west of Zuojiang River in Guangxi Autonomous Region, Guizhou Province, and nature reserves in Yunnan. In Guizhou Province, it is distributed in Suiyang, Zheng'an, Daozhen, Wuchuan, Tongzi, Yanhe, Xingyi, Anlong, Ceheng, Zhenfeng, Liupanshui and other counties (cities).

The daily activity rhythm of the black leaf monkey is characterized by a foraging peak in the morning and afternoon, and a long rest period at noon. The activity rhythm has obvious seasonal changes, mainly manifested in that the foraging peak in the rainy season is delayed by 1 hour compared with the dry season; the time spent on foraging in the foraging peak in the dry season is significantly increased, and a small foraging peak appears at noon. The activity patterns of the black leaf monkey also change in different seasons. When the temperature is high in summer, the activity around noon is significantly reduced; when the weather is high in autumn, it is its estrus period, so the activity is very frequent; when the weather is cold in winter, it often stays in the cave all day. The black leaf monkey is agile and light, good at climbing and jumping, especially active in the morning and evening, and lives in natural caves between cliffs at night.
They like to live in groups, usually