Zhang Hemin puts a panda cub into an incubator at Wolong reserve's breeding center in Sichuan Province.  [China Daily]

In 1983, the 22-year-old biology student from Sichuan University joined Wolong Nature Reserve. He was sent to study wildlife management at Ohio University in the United States in 1987.

Throughout the 1980s, just one panda cub was born in captivity at the reserve's breeding center, but it failed to make it beyond the first two years of its life.

News from other parts of the world was equally depressing. Ever since the United States received its first pair of pandas, following former president Richard Nixon's visit to China in 1972, the country's scientists had been bent on giving the "couple", and themselves, a baby. Between 1983 and 2000, five panda cubs were born in the United States, none of whom lived for longer than 10 days.

By the time Zhang returned to Wolong, the foreign experts who had previously led research efforts left and the continued existence of the breeding center was in serious question.

"People were disheartened by the lack of progress on the panda reproduction front," Zhang says. "But I decided to give it one last shot - to do it my way."

In retrospect, the answer to all the questions that had been plaguing panda researchers for years was beguilingly simple. "It's about love," Zhang says. "We loved them the way they wanted and it paid off."

Spending no less than 14 hours a day with his pandas, Zhang would occasionally lie down on the ground and murmur into their furry ears. "I wanted to be accepted by them," he says.

He was bitten once, by a 2-year-old female who later becomes a mother of 15 - an incident that left him recovering in bed for two months. But there were no hard feelings.

"A panda's teeth can easily cut through bamboo, let alone human bones," Zhang says. "But she spared me."

According to the director, the fact that pandas were often spotted in the wild alone led scientists to believe that these were solitary animals.

"It's true that pandas are territorial animals but they are also social animals," he says. "There must be something going on between them that we have no way of knowing."

The director arranged for all the pandas in the breeding center to see and play with one another for a few hours each day, a measure that was met with initial opposition from the caretakers.

"It's not uncommon for fighting to erupt when two pandas meet for the first time, and one of them may get hurt. But given enough time, they'll stop being bellicose and really start getting to know each other," Zhang says. "What do we say? Friendship grows from an exchange of blows."

In some cases, hostility between the opposite sexes was replaced by flirtation. And the black-eyed animals, despite their reputed shyness, turned out to be no shrinking violets.

Meanwhile, new fixtures - trees, rocks and even swings - were also added to create what Zhang calls a "varied environment".

"Watching them pacing up and down impatiently in their shoebox-size enclosures made me wonder whether it was a panda house or a mental asylum," he says, referring to the situation before the changes. "Pandas got depressed before they got ill."

With open space to have fun and to nurture love, female pandas in the breeding center started to give birth, sometimes to twins.