CHANGSHA, Jan. 20 (Xinhua) -- Every winter, Cao Jianjun waits for his "friends" at a national wetland park in central China's Hunan Province.
In 2013, Cao caught the Chinese merganser, an endangered bird species under class-one state protection for the first time in the province's Shuangpai County. Since then, his camera lens has captured more and more of the beautiful birds.
"I did not know the birds when I first caught them, but I realized they were different from other birds that I usually saw," said the 61-year-old photographer. "So I was quite excited when experts told me they were one of the oldest species in the world."
The Chinese merganser, dubbed "the giant panda in bird species" or "ecological test paper" of water environment, has high requirements for its habitat and water environment.
Over the past eight years, Cao has taken more than 60,000 pictures of the birds in the county, which has become a major habitat for the merganser and other migratory birds.
"Cao often squats alone on the bank of the river for a whole day with food and a tent in order to take perfect pictures," said Jiang Yanbin, a staff member of the wetland park.
The county has made a lot of efforts to address the ecological problems in recent years. With the improving environment, the county is not only a habitat for migratory birds but a hot tourist destination featuring bird watching and leisure activities.
China is creating a better environment for migratory birds. Nets and other fishing gear were a huge threat to the birds along the Yangtze River, but the threat is vanishing as the country has launched a complete 10-year fishing ban in the key waters of the Yangtze since the beginning of 2021.
Besides photography, Cao also volunteers to patrol the habitat for the purpose of protecting the birds.
"More volunteers, including villagers and retired teachers, join us to guard them," said Cao. "Protecting their habitat is also to protect our home."