Amateur groups spearhead efforts to prevent illegal activities.

For much of the past year, Liu Yidan has patrolled the back roads of China in a black jeep, hunting for bird poachers.

The former restaurateur is part of a growing and increasingly proactive network of vigilantes in China who monitor the countryside and animal markets to combat wildlife poaching, a practice that is endangering the existence of some species.

They hack down nets, track poachers with drone-mounted cameras and chase traffickers.

Their efforts peak in spring and autumn, when poachers are out in force as more than 50 million migratory birds fly through China.

"It's impossible to cut them (the nets) all down," Liu said. "While birds can fly around the world, when they come to China they often reach their end," the 52-year-old said, speaking on the shores of Poyang Lake in Jiangxi province.

Poyang, China's largest freshwater lake, is located in the east of the country and attracts hundreds of thousands of migratory birds, including swans, geese and rare cranes.

Mist nets and packets of Carbofuran, a pesticide used to drug birds, were found by correspondents in a protected nature reserve.

The informal network attracts thousands of volunteers, reflecting growing public concern over environmental degradation and frustration at what they see as lax enforcement of environment laws - although the State Forestry Administration, which oversees nature conservation, says it operates a zero-tolerance policy.

Unlike many environmental NGOs in China that have tended to focus on local issues, Liu's team is part of a coalition of about 40 groups around the country aiming to protect birds and wildlife, especially from poachers.