HAIKOU－After driving nearly 800 kilometers over three days, 35-year-old Cheng Cheng, who had tirelessly slogged through the swamp for hours, finally found a perfect spot to observe an endangered waterbird.

Cheng, a lover of nature and an expert on wetlands and waterbirds, is the founder of the Hainan Bird-Watching Society, a nonprofit organization in Hainan province established in 2015.

In just two hours, Cheng's team spotted and recorded over 1,800 birds of various species during this year's annual bird-watching survey from Jan 15 to 17 across the island province, which is rich in aquatic habitats.

Hundreds of thousands of migratory birds winter in Hainan every year as it is located along their migration route from East Asia to South and South East Asia.

The team, consisting of over 50 experts, enthusiasts and volunteers, had to stand barefoot in the swamp under the scorching sun for hours at a time to collect as much information as possible on the different species of migratory birds, Cheng said.

"However, it is worthwhile doing whatever we can to protect the birds during their long and risky migration," she added.

The most rewarding experience of the trip was spotting seven black-faced spoonbills in Ledong Li autonomous county, said Li Fei, an expert on the team who observed the endangered species through his monocular telescope that can magnify images up to 30 times.