One day in 1995, when investigating what he believes to be yeren feces, he walked into a cave when a bear scratched his face. He turned and ran, eventually escaping the bear.
However, the most difficult thing for him to escape is loneliness."You can't imagine what it's like to have no one talking to you for three months. The loneliness bites my heart like a worm. I've even thought of banging my head into a tree," he was quoted as saying by the Guangzhou Daily.
He has become interested in reading books about plants and wildlife. So far, he said he has written 3 million words of field notes and 80 analysis reports, and collected more than 3,000 specimens.
But Zhang's family members see his obsession with yeren as a waste of time.
He has been married twice since coming to Shennongjia, with each marriage lasting no more than three years. Both women were said to be fans of his who gave up their affluent lifestyles to support him.
"It's tough to be married to someone like me who lives in mountains throughout the year, like a yeren," he said.
Pan married Zhang in 2007 and left him in 2010. "We married hastily. But I back what he is doing. It's unfair to smear him. He persists in Shennongjia out of his passion and love for nature, not stubbornness or profits," Pan told the Global Times on Tuesday.
Commercial stunt?
Zhang says he spends 10 months a year in the mountains. The locals say this was true in the first decade, but after 2004, he was busy participating in various activities and scarcely went into the mountains.
The prices for the items for sale in his museum are clearly marked: a book he wrote costs 23 yuan ($3.4), plus an extra five yuan for his signature, and five yuan more to take a photo with him. The package price for all three is 30 yuan.
To encourage his exploration, the Shennongjia Forestry District gives him 20,000 yuan each year as a living allowance. But that is far from enough. Zhang said he needs to spend about 100,000 yuan each year.
The government launched high-profile scientific investigations into the yeren in the late 1970s, but the expeditions ceased several years later due to poor results.
Now, the local government's attitude toward the yeren issue is "Don't promote, report or support," Wang Zhixian, director of the reserve's administration bureau, told the Global Times.
But the legend of the yeren has become a major attraction for Shennongjia, where tourism is an important source of income.
Throughout Shennongjia, it's common to find yeren used in the names of local restaurants, hotels and snack stands. Some locals even wear yeren costumes and charge tourists to pose for photos with them.
Zhang has promised to one day make public all the evidence he has collated, but is reluctant to do so now. "Once I make it known, will the yeren still live freely and peacefully?"
