HAIKOU, July 13 (Xinhua) -- While barn swallows are commonly associated with urban landscapes, few would expect to see them soaring over the turquoise waters of the Xisha Islands in the South China Sea.
"Seeing even barn swallows gliding overhead during our first visit to the Xisha Islands was a thrilling surprise," said Liu Tao, a PhD student in ornithology at Hainan Normal University. He attributed their presence to the nearby reefs, where generations of locals have lived.
In late May, Liu led a team to the remote archipelago for a comprehensive monitoring project on the diversity and breeding ecology of seabirds. To date, the team has recorded 19 bird species across the reefs of Qilianyu Islands in the Xisha.
Among these, a rare sighting of Fregata andrewsi, a national first-class protected species, was a particular highlight for Liu, who had previously only seen the bird in documentaries and books.
For Liu, the most unforgettable moment was discovering a massive group of great crested terns. "It was a breathtaking sight. Hundreds of terns took flight at once, like a dark cloud sweeping across the beach," Liu said, noting that the reef was densely packed with eggs, some separated by merely a dozen centimeters.
The project's ability to showcase the South China Sea's rich biodiversity reflects the strength of collaboration between researchers and local residents, united in a common desire to protect the environment.
Uncovering the full avian landscape of the islands requires not only scientific equipment, but also the expertise of local fishermen. Generations of maritime experience have made local fishermen invaluable guides.
"Fishermen know exactly which waters have the most seabirds and which islands serve as gathering spots. This is knowledge you cannot simply learn from textbooks," Liu said.
Under their guidance, researchers successfully located concealed breeding spots where eggs blend with pebbles, as well as nests hidden deep within bushes.
In return, the fishermen have become eager learners, frequently asking researchers about bird species and migration routes. More importantly, they have taken active steps to protect the birds' habitats. They regularly clean up marine garbage and engage in coastal ecological restoration.
One of the fishermen's most challenging tasks has been greening the reefs. After cultivating native saplings on islands, including Yongxing Island, the fishermen transplant them to other reefs.
"With trees, the birds have shade and sheltered spots to breed," they explained. Their persistent efforts have steadily increased vegetation coverage and improved the microhabitats for seabirds.
Liu emphasized the importance of completing an ecological survey for the Xisha reefs. The archipelago operates as a complete ecological loop: coral reefs and seaweed sustain fish, seabird guano nourishes the vegetation, and the birds rely on these rich marine resources.
To safeguard the environment, Li Yupei, the director of the marine reserve management bureau of Sansha City, said Sansha has enacted regulations and established routine patrol mechanisms for seabirds and sea turtles.
The city has also partnered with universities and research institutes to deploy advanced monitoring equipment, including infrared cameras, to track breeding populations and assess ecological risks.
Conservation efforts in the Xisha Islands are a microcosm of China's broader commitment to safeguarding its avian populations.
According to the National Forestry and Grassland Administration, China lies along four of the world's nine major migratory bird flyways and is home to 1,505 bird species, including more than 800 migratory species.
The country has significantly strengthened its legal and institutional frameworks for bird protection. The administration said that 98.4 percent of China's bird species are now protected by law, with 394 species under national key protection.
"For most seabirds, preserving the ecological integrity of these reefs is the best form of protection," Liu said. ■
