Zhang Houyi patrols the lake with his old-fashioned rifle, which he once used for hunting birds.

"The farm director told me that, 'You shoot well and we have plenty of birds here, please hunt as many as you can'," Zhang recalls. Short of hunting tools, the farm made dozens of new rifles for the staff.

Representing his farm, Zhang won first place for two consecutive years in shooting competitions among big farms from all over the country.

Zhang's shooting career reached its peak in December 1979, when he killed about 9,000 birds, weighing 3,000 kilograms, after lurking for two days.

It took three trucks to transport the carcasses, recounts Zhang.

But, instead of feeling proud about his "success", Zhang had an epiphany when he saw the piles of dead birds, all somewhat mutilated and bloody.

"It was a terrible scene. Suddenly I felt sorry for the birds," Zhang continues. "They didn't do anything wrong. They did not eat my crops. Why did I kill so many of them?"

He decided to give up hunting and took a step further - he started persuading others not to shoot birds.

When the East Dongting Lake Natural Reserve was founded in the 1980s, Zhang was invited to be an assistant warden for wild birds and was given the responsibility of preventing wild birds from being poached and trapped.

"I don't want to be paid. I'd worked for my conscience and regard it as paying back my debt to the birds," explains Zhang, who now depends on a monthly retirement allowance of 1,100 yuan.

Zhang is especially busy during migratory seasons of spring and winter. He has to frequently check the lake area to ensure the birds' safety.

"I know where they are likely to show up in large population and will pay more attention to the area," Zhang explains, adding his years of experience as a hunter have helped him know the birds' habits.

Still, guarding against poachers and fowlers is a difficult job, especially when he has to look after such a big area alone.