Five people from He's office, and about 70 people from six protection stations and a panda domestication and reproduction center at the reserve take turns to work in the wild. They often go into the forest in groups of three to five people, and stay for periods between several days to two weeks.

He Liwen and his colleagues have encountered many challenges while out in the wild, either because of the difficult mountain terrain, changeable weather or both. He still remembers once, when engaged in a survey, the group had hiked to an altitude of 3,700 meters with a plan to return the following morning. However, 10 minutes into their descent, they met heavy fog and were forced to wait it out since they could not see where they were going. When the fog lifted and the group were able to resume, it rained heavily. Between 7:30 am and 7 pm, the group descended to a height of 1,800 meters but the rain never stopped.

The group was soaked through, and were quivering with the cold, but they struggled to light a fire because of the persistent downpour. Finally, five of the team held aloft a piece of canvas like a tent to offer some protection from the rain and lit a fire underneath.

"As we had walked, eaten and even slept in the rain, all of us were soaked. The rain didn't stop until 4 am the next day. It was really a tough experience," he said.

Over the years, He has seen the progress in protecting the animals and ecology of the reserve firsthand. "Cameras can capture more images of mother pandas and their babies, and we can see animals more frequently in the wild than before.