Lanzhou, 9 Feb (Xinhua) -- During the Chinese New Year, watching wintering giant swans in the Hekou area of the Lanzhou section of the Yellow River has become a new hobby for many Lanzhou citizens. It has been found that the number of giant swans that have come here to overwinter in the past two years has been increasing. In winter, the Yellow River flows slowly, and the giant swans dance on the water, playing and playing, which adds a lot of fun to people.
This is the wintering giant swan photographed by the monitoring team in Gansu. (Courtesy of the interviewee)
While watching the giant swans, people can't help but wonder: Why do the giant swans meet in the Lanzhou section of the Yellow River for wintering? What is their migration pattern? Zhang Lixun, a professor at the School of Ecology of Lanzhou University, led a team of wildlife diversity monitoring and conservation to carry out monitoring and research on the habitat of wintering giant swans in Gansu for four consecutive years since 2019, and formed preliminary conclusions on the number, habitat distribution range and formation causes of wintering giant swans.
Zhang Lixun introduced that the wintering giant swans in Gansu are mainly distributed in the three inland river basins of the Shiyang River, Heihe River and Shule River in Hexi Region, as well as the five major habitats of Gahai Lake in Gannan Prefecture and Sanjiangkou in the Lanzhou section of the Yellow River in the Yellow River Basin.
Monitoring shows that since 2019, the number of giant swans wintering in Gansu from October to March of the following year has remained above 800, and the number of wintering giant swan larvae in 2022 is 157, the highest proportion in the calendar year, accounting for 18% of the total. Among the above five habitat distribution ranges, the number of giant swans in the Heihe River Basin is the largest, accounting for more than 50% of the number of wintering giant swans in Gansu Province.
Zhang Lixun said that the wintering giant swans mainly come from Places such as Russia and Mongolia, and Gansu is one of the main habitats of the wintering giant swans. They begin to move southward to China in October of each year, stabilize in numbers in January of the following year, and then leave China in March and gradually move back to their original locations. They are mainly distributed in Xinjiang, Gansu, Sichuan, Ningxia, Shaanxi, Henan, Shandong and other places in China, forming a "fan" shape in the vast area north of the Yangtze River. "The number of wintering giant swans is directly related to the size of the water area of the regional wetland and the number of edible grass species in the water."
In the next step, the monitoring team will also conduct in-depth research based on relevant data such as climate change and ecological environment changes, and further reveal the intrinsic relationship between the number and habitat distribution range of wintering giant swans and local ecological changes.