This aerial photo taken on Dec. 16, 2022, shows a group of grey cranes resting on the frozen surface of Hengshui Lake in Hengshui, north China's Hebei Province. (Photo by Li Ming/Xinhua)
SHIJIAZHUANG, Feb. 22 (Xinhua) -- Fifty tundra swans were spotted at a nature reserve in north China's Hebei Province on Tuesday, marking the start of the spring bird migration season at the reserve.
The 50 birds, under second-class national protection, are the first batch of migratory birds to arrive at the Hengshui Lake national nature reserve this spring, said Zhang Yuguang with the reserve.
The annual bird migration season at the reserve usually lasts from mid-February to mid-to-late April, peaking in March, said Zhang, adding that more species are expected to stop over, including Baer's pochard, white spoonbill, whooper swan, egret, and night heron.
Located in Hengshui City, Hengshui Lake is the only national reserve on the North China Plain that maintains a complete wetland ecosystem of swamps, water, mud flats, meadows, and woodlands.
The number of bird species at the lake has now reached 333, and its wetlands have become an important stopover for birds on their southbound trips. ■