These include severely cold weather and snow-blanketed roads in winter and mosquitoes and snakes in summer. In summer, the researchers often wake up at 4 am to track monkeys in the wild and do not return to their base until 8 pm.
In the early years, before the advent of electronic tagging, they would pack camping equipment and food, and sometimes remain in the wild for weeks on end doing tracking work.
"Often as the monkeys were jumping from tree branch to tree branch we would be scrambling along on the ground trying to keep up," Huang says. "No matter what the weather was we would be out there looking for them, and the monkeys have scratched almost all of us at some time or other."
One of the greatest challenges for the monkeys is the harsh climate, winter lasting as long as six months and temperatures dropping to -20 C. Some young, weak individuals have died of starvation and the cold.
In 2005, researchers began to provide food to the monkeys, starting with usnea, a kind of parasitic plant growing on pine trees. However, it was too difficult to collect enough of this in winter, and so they started to feed the monkeys apples wrapped in usnea instead.
The monkeys were very cautious at first and they took three months to try the apples and adapt to the new diet, Huang says.
"It was a breakthrough. It allowed us to closely observe the monkeys and laid the foundation for further research on them."
Nowadays, the researchers get up at daybreak to track the monkeys, and feed them three or four meals a day, with usnea, apples, pine cones and other foods.
Over the years, the number of the snub-nosed monkey population in the reserve has risen from about 500 in the mid-80s to more than 1,300 now.
Yang Jingyuan, head of the reserve's scientific research institute, says the achievement is the result of several major national campaigns such as the country's natural forest protection project started at the beginning of the century.
"These projects have reduced human activity and damage to their habitats, and gradually increased their range of activity. The maturing protection network and supply of food in winter has also played a crucial role."
In 2011, the State Forestry Administration of China turned the Dalongtan base into a national research center for golden snub-nosed monkeys. Its activities include artificial breeding, disease research, habitat protection and supplying food in winter.
It collaborates in research with many universities and often receives international scientific research groups.
With greater support from the national government in recent years, the center has carried out more key protection projects related to the species, such as restoring fragmented or degraded habitats and finding potential new habitats in the region.
At its Dalongtan base, the center has set up a 4G monitoring platform that includes technologies such as wireless sensoring, satellite navigation and positioning and cloud services.
"The projects not only benefit the habitat protection and management of the snub-nosed monkeys but may provide an example for protecting other endangered animals," Yang says.
