JINAN, Jan. 21 (Xinhua) -- In the Yellow River Delta of eastern China, flocks of oriental white storks glide gracefully overhead or forage across the vast wetlands. For Zhu Shuyu, this familiar scene today stands in sharp contrast to his unexpected first encounter with the endangered species 29 years ago.

"Back then, a flock of 19 large white birds was spotted foraging along the shoreline," recalled Zhu, now a senior engineer with the management committee of the Yellow River Delta National Nature Reserve in the city of Dongying, Shandong Province.

The sighting during a bird survey at a local reservoir marked the first confirmed record of the species in the wild within the Yellow River Delta.

The oriental white stork, a top-level protected species in China, is listed as endangered by the International Union for Conservation of Nature.

The Yellow River Delta, where the Yellow River empties into the Bohai Sea, covers about 153,000 hectares, over 70 percent of which is wetland.

It serves as a vital wintering and stopover site for migratory birds around the world. Two of the globe's nine major flyways -- the East Asian-Australasian flyway and the West Pacific flyway -- pass through the reserve, drawing millions of birds to rest here each year.

"The wetland ecosystem has improved significantly. More birds are arriving and new species are being recorded almost every year," Zhu said. The city even hosts annual birdwatching events that attract enthusiasts from overseas, he added.

After the rare oriental white storks were first seen in 1997, China launched a series of wetland restoration and habitat protection projects in the delta. These measures have helped the stork breed more than 4,200 offspring in the delta by 2025.

Over the past three years, the reserve authorities have replenished more than 520 million cubic meters of water, restored 3,467 hectares of native vegetation and created an additional 4,933 hectares of freshwater wetland.

"The Yellow River Delta is globally recognized as a key site for bird conservation, supporting both breeding populations and birds migrating along the East Asian-Australasian Flyway," said James Fitzsimons, senior advisor of Global Protection Strategies of the Nature Conservancy.

Fitzsimons stressed that China's coastal wetland protection efforts carry major global significance.

China has set up over 2,200 wetland protection areas, including 82 Wetlands of International Importance, 80 nationally important wetlands, and 22 international wetland cities. With over 53.33 million hectares of wetland areas under protection, China has built the largest wetland conservation system in Asia.

As bird populations grow, monitoring efforts have been stepped up. Multiple teams conduct monthly surveys in the delta nature reserve using satellite tracking and AI-powered, around-the-clock surveillance systems that can automatically identify and count birds.

Dongying, a petrochemical hub where the secondary industry contributes about 60 percent of total economic output, aims to strike a balance between bird conservation and economic development.

Oriental white storks usually nest in tall trees, but such trees are scarce in the city due to high soil salinity. As a result, many storks have built nests on power transmission towers instead. Their acidic droppings are conductive, posing risks to grid safety.

Early attempts to deter the birds with special windmills, acoustic devices and spikes proved ineffective. Later, power grid authorities developed insulators that effectively prevent damage from bird droppings.

Local authorities have also scaled up renewable energy development to drive greener growth. In October 2025, a 26-megawatt offshore wind turbine, which set world records for single-unit capacity and rotor diameter, was connected to the grid in Dongying. A single turbine can generate 100 million kilowatt-hours of electricity annually.

Experts dismissed claims that building such wind turbines could threaten migratory birds.

"During regular patrols, we have never seen birds collide with the turbines," Zhu said. He added that birds migrate along wide corridors and can adjust their flight paths, so turbines installed in open coastal areas generally do not disrupt their migration.

Zhu added that wind farms have been avoided in some valleys in north China's Hebei Province, which serve as critical migratory corridors.

The Yellow River delta reserve is home to 1,635 species of wild animals, including 376 bird species. Each migration season, millions of birds gather in the wetlands, attracting birdwatchers from home and abroad and boosting local tourism.

"We never thought these birds would bring even more tourists in the winter," said Wang Yan, deputy manager of a homestay near the Yellow River estuary. "Thanks to bird-watching activities, we have had an average of over 30 bookings per day since November, even higher than during the peak tourist season." ■