World’s gibbon population faces threat of extinction
The world’s gibbon population is facing the threat of extinction. Chen Liang finds out what is being done to preserve what’s left of the population in China.
Western black-crested gibbon is more endangered than the giant panda, even though it is the country’s most populous gibbon. With a global population of 1,100-1,400, it was listed as critically endangered on the International Union for Conservation’s Red List. The gibbon, Nomascus concolor, has a discontinuous distribution across southwestern China, northwestern Laos and northern Vietnam. Yunnan province has the biggest population, with nearly 80 percent of the primate species living in moist evergreen broadleaf forests on the Ailao Mountains and Wuliang Mountains.
Fortunately, their habitats on the mountain ranges are by and large unspoiled.
“Placing 1,000-1,300 western black-crested gibbons and their habitats under protection has become the country’s biggest hope to keep gibbons singing in the wild,” says Long Yongcheng, the chief scientist with The Nature Conservancy’s China Office. He was speaking at the launch ceremony for a trekking event on the Ailao Mountains, held recently in Kunming.
Gibbons’ singing was often described in ancient Chinese poems, the biologist said, as they could be found as far north as today’s Gansu and Shanxi provinces. “But now, few people know the existence of gibbons in the country,” he says. “Fewer have the luck to listen to their duets in the wild.”
That is because the country’s six gibbon species can only be found in Yunnan and Hainan provinces, and the Guangxi Zhuang autonomous region. The total population stands at about 1,500.
Of them, a small area between northern Vietnam and Guangxi is the only habitat in the world where the eastern black-crested gibbon is found. With 18 families of about 100 animals, they have been “wandering around the borders”, according to Fan Pengfei, one of the country’s leading gibbon researchers.
The Hainan gibbon, found only in the island province, is also one of the world’s most endangered primate species. The newest figure is two families of 23 mammals, Long says, all residing in Bawangling National Nature Reserve. In 2003, there were only two groups of 13 gibbons.
Northern white-cheeked gibbon, with a population of more than 2,000 in southern Yunnan in the 1960s and a population of about seven groups of 40 animals in 1989, has not been sighted for many years. “It might be extinct already in the country,” Long says.
Hoolock gibbon is distributed in the country mainly in Yingjiang, Tengchong and Baoshan of western Yunnan, with a population of 150 in 40 families.
The white-handed gibbon that lives in the southernmost part of Yunnan had three families of about 10 mammals in 1992, and hasn’t been spotted for several years. “The status of the western black-crested gibbon is the only one that is not so gloomy,” Long says.
About 150 groups of 700-800 western black-crested gibbons are living on the Ailao Mountains, of which an estimated 500 gibbons in 124 groups were recorded in the Ailao Mountains nature reserves within Xinping county, in a survey done in 2009 and 2010.
“Thus, Xinping has the world’s largest population of western black-crested gibbon with the highest density,” says Yang Xianming, director of the Ailao Mountains National Nature Reserve’s Xinping Bureau.
While the other gibbons living in the country face serious threats of habitat loss and poaching, Yang says, the western black-crested gibbons still dominate the country’s largest primitive middle-mountain moist broadleaf forests on the Ailao Mountains. In Xinping, moist broadleaf forests cover more than 30,000 hectares, Yang says.
The forests, often distributed 1,800 meters above sea level, are much higher than human settlements in the area, Yang says. On the lower slopes, the residents have enough collective forests for firewood and construction-material wood. People of the Dai ethnic group living in the area have no deeprooted tradition of hunting.
“We don’t have too much pressure from hunting and logging,” Yang says. “Since a massive mudslide killed more than 40 people in 2002, our (county) government has paid special attention to environmental protection.”
In the past decade, more than 40 villages near the reserve were relocated to lower areas. Besides 14,000 hectares of the forests within the jurisdiction of the national reserve, the local government allocated an area of 10,000 hectares as countylevel nature reserve and a 4,000-hectare State-owned forest to the reserve’s management.
“That means 28,000 hectares of intact forests without any village,” Yang says. “It has truly simplified our management work.”
Now, Yang is most concerned about forest fires and a shortage of manpower.
“The dry season between November and May is the busiest season,” he says. “The mountains are so vast and precipitous that if there is fire, it will be disastrous for the forest and gibbons.”
Only 14 formal employees and 50 temporary patrolmen are managing the reserve, Yang says, doing everything from fireproofing to animal monitoring.
“For our 500 gibbons, we have only five patrolmen exclusively responsible to monitor them in the forests,” he says.
“It’s far from sufficient. But we have the confidence that these forest spirits will be able to swing freely through our forest canopies.”
A female western black-crested gibbon feeds in the canopy of a moist evergreen broadleaf forest in Yunnan province.
The Ailao Mountains in Yunnan is home to the country’s best preserved moist broadleaf forests.
A male western black-crested gibbon feeds on tender leaves.