Population Status of Black-crowned Gibbon in Hainan

Hainan black-crowned gibbon is the most endangered primate:

In p>1995, the second China Primates Conference listed Hainan black-crowned gibbon as a highly endangered protected animal.

The p>1998 edition of China Red Book on Endangered Animals points out that the Hainan subspecies of black gibbon is the most endangered species among all primates in China.

In p>1999, the China Primate Expert Group drafted the China Primate Protection Action Plan, which listed Hainan Black-crowned Gibbon as the most endangered primate in China.

In p>21, Time magazine of the United States published a list of 25 most endangered primates in the world, among which Hainan black-crowned gibbon ranked sixth according to the materials of WWF, IUCN and IPS. Among these 25 primates, Hainan black-crowned gibbon is estimated to be less than 5, making it the only primate with less than 1.

In early August p>22, the 19th International Primate Congress was held in Beijing. At the conference, 25 species of primates that are extremely endangered in the world were identified, and Hainan black-crowned gibbon was ranked fifth. When determining the level of primate protection in China, Hainan black-crowned gibbon was ranked as the first.

According to records, at the beginning of the 2th century, the forest coverage rate in Hainan reached 9%, and gibbons were distributed in all counties of the island. In the 195s, the forest area reached 86, hectares, and Hainan black-crowned gibbons were distributed in 12 counties south of Chengmai and Tunchang in Hainan Island, with more than 2, individuals. In the mid-196s, it became extinct in six counties. In 1983, only about 3 species were found on both sides of the main peak of Ying Ge Mountain and the south slope of the main peak of Limuling Mountain, and most of them were isolated into islands.

In 198, the forestry department designated the Futouling forest in Hainan as a protected area, and carried out a series of conservation research work, which enabled Hainan black-crowned gibbon to recuperate in this last small piece of home. By the early 199s, although Hainan Province had completely stopped cutting down natural forests, there were less than seven Hainan black-crowned gibbons in Bawangling Nature Reserve, and Hainan black-crowned gibbons in other areas gradually disappeared due to lack of effective protection and small population. In the following years, the staff of the nature reserve observed several times that the female ape was pregnant and the female ape was holding the newborn ape cub, which accumulated to 4 groups of 24 by February 23. In 2, there were 7 B-group * * * monkeys living under the Axe Ridge, including two adult female apes, one husband ape, two black male apes (one of which may be a minor female ape) and two young apes. By 21, there were only four left in this group, two females, one male and one cub. The reason for the decrease may be clustering; It may also be a natural death, or it may be shot by a hunter.

after more than 2 years of hard protection, Hainan black-crowned gibbon showed a recovery and growth trend. By 28, Hainan black-crowned gibbon only existed in the tropical mountain rain forest "isolated island" with an area of only 2, hectares in Bawangling Nature Reserve, Hainan Province, with 18 monkeys in four groups, including 6 females and 12 males and juveniles. In 1998, under the guidance of Professor Jiang Haisheng of South China Institute of Endangered Animals, a comprehensive and meticulous survey was conducted on Hainan black-crowned gibbons in Bawangling Nature Reserve. The survey results showed that the number of Hainan black-crowned gibbons in Bawangling was 19 in 4 groups. In the spring of the same year, Hainan Diaoluoshan Nature Reserve got a report from local farmers that there were traces of Hainan black-crowned gibbon in Diaoluoshan. Hainan Lusheng Wildlife Investigation Team was stationed in Diaoluoshan in late April. With the help of more than a dozen local farmers, more than 3 investigators (including university teachers, experienced reserve staff and journalists) camped and had a picnic in the rainforest of Diaoluoshan for 8 days and 7 nights, but they still didn't see or hear the trail and chirping of Hainan black-crowned gibbon.

in March, 23, more than 3 experts from Beijing, Guangzhou, Hong Kong and Hainan made an investigation on the biodiversity of a newly discovered tropical rain forest. This rainforest is located at the junction of Baisha, Wuzhishan, Ledong and Changjiang in Hainan, and belongs to the southwest section of Ying Ge Mountain Range, with an area of 8 square kilometers (there are more than 1 square kilometers that have not been investigated). Many typical animals and plants in tropical rainforests have been found, but the chirping of Hainan black-crowned gibbon has not been heard. In October of the same year, experts from Hainan, Guangdong, Shanghai, Beijing, Switzerland, France and other regions and countries, international environmental protection organizations such as Wildlife Conservation International (FFI) and kadoorie farm and botanic garden (KFBG), together with researchers from Hainan Forestry Bureau, conducted a 16-day large-scale investigation on the living environment of Hainan black-crowned gibbon in Bawangling. This is also the first international survey of Hainan black-crowned gibbon.

this survey adopts the triangulation method. During the fixed-point investigation, the investigator stood still at a fixed place and recorded what he saw or heard about Hainan black-crowned gibbon. The fixed location referred to here, also known as the monitoring point, is set in a favorable position where the chirping of Hainan black-crowned gibbon can be clearly monitored, such as high places far away from streams, so as to avoid missing any chirping as far as possible. At that time, experts and team members set up 16 monitoring points at the same time, and the spacing of each monitoring point was 1 km, evenly distributed. In order to seize every opportunity to listen to the chirping of Hainan black-crowned gibbon, the investigators arrived at the monitoring point before the gibbon started chirping, that is, before the first ray of sunlight entered the forest every morning. Monitor the chirping and activities of Hainan black-crowned gibbon all morning.

after the end of the p>11-day monitoring period, the investigators compared their collected singing time, the position and distance from the listener, the singing type, and the number of individuals, coat color, size grade, behavior and activity time of Hainan black-crowned gibbon. The investigation team also spent five days, divided into 13 teams, searching for the sight of Hainan black-crowned gibbon in two wooded areas in the expansion of Bawangling Nature Reserve.

finally, the investigation team got the reliable minimum population number of Hainan black-crowned gibbon in Bawangling Nature Reserve: 13 individuals, including 6 individuals in group A, 5 individuals in group B (including 1 juvenile ape) and 2 males alone. The reason why Hainan Black-crested Gibbon is on the verge of extinction:

Hainan Black-crested Gibbon has a strong dependence on the living environment, and it can only survive in the original monsoon forest, but it can't survive in a single plantation or a cut-down secondary forest.

Hainan black-crowned gibbon is used to moving in trees with a height of more than 15m and a DBH of more than 2cm. Their favorite primitive tropical rain forest has five or six floors, which is rich in food sources. In the selectively cut forest, gibbons are faced with food shortage. Hainan black-crowned gibbon mainly eats the fruits of plants, including Syzygium persicum, Actinidia chinensis or the leaves of Podophyllum japonicum and Ilex hainanensis. If enough food is provided, they may survive in the secondary forest, but it is impossible in the artificial forest.

The strong dependence on the living environment and the continuous destruction of the virgin forests on which they live are the important reasons for the continuous decline of Hainan black-crowned gibbon. With the massive deforestation and reclamation of natural forests, the tropical rain forest on the island has been lost in a large area, most of the tropical rain forest at low altitude has been destroyed, and the remaining rain forest has also become a green "island", which has destroyed and gradually deteriorated the habitat of Hainan black-crowned gibbon. By 28, the habitat of Hainan black-crowned gibbon had lost 75%. Due to the sudden increase of population and poor natural protection, the phenomenon of indiscriminate cultivation, deforestation, indiscriminate hunting and indiscriminate mining is very serious in Hainan Island. The forest area has dropped from more than 8, hectares to less than 2, hectares, including a large area of artificial rubber forest.

the scarcity of numbers naturally leads to inbreeding, which leads to the population getting worse from generation to generation. Many diseases are incurable, which is also a factor that Hainan black-crowned gibbon is on the verge of extinction. For example, postpartum wind, the average life expectancy of Hainan black-crowned gibbon in natural environment is only about 2 years old.

At the same time, the island distribution of the rain forest also caused the population of Hainan black-crowned gibbon to be too small, the population distribution was discontinuous and the reproduction rate was low, and the generation cycle of Hainan black-crowned gibbon was long (7-8 years), which accelerated the extinction of Hainan black-crowned gibbon.

But the biggest harm to the survival of Hainan black-crowned gibbon is human hunting. Hainan black-crowned gibbon is also called black ape, and its skeleton is the medicinal material "black ape bone". Traditional Chinese medicine theory holds that it has the effects of nourishing and beautifying, expelling wind and strengthening bones, relaxing tendons and promoting blood circulation. Hainan black-crowned gibbon moves as a family unit. When one of them is beaten, the whole family can't escape, and the situation is very tragic. In the East, people hundreds of kilometers away, such as Tongshi, enter the nature reserve for poaching, which is a great threat to protected animals such as Hainan black-crowned gibbon, and the number of Hainan black-crowned gibbon has decreased sharply. Many scientists and animal photographers have found in their observation and shooting for several years that it is the black male apes that often disappear among a group of gibbons, and these male apes are probably killed by hunters.