SHIJIAZHUANG -- White cranes were spotted at a national nature reserve in North China's Hebei province, according to the local resource protection bureau Tuesday.

Two white cranes, a species under first-class state protection in China, were seen flying over the Hengshui Lake national nature reserve. One of the birds landed on the water, while the other flew away without stopping, according to Huo Hengmao, a photographer who snapped pictures of the rare birds at the reserve.

Attracted by a good ecological environment and abundant food, white cranes, as migratory birds, stop over at the reserve en route to the north, said Zhang Yuguang with the reserve's resource protection bureau.

There are only around 5,000 white cranes in China, Zhang added.

Since the spring migration season began, other endangered bird species including Baer's pochard, oriental white stork, whooper swan, and white spoonbill have also been spotted at the reserve.

Located in Hengshui City, Hengshui Lake is the only national reserve on the North China Plain that maintains a complete wetland ecosystem consisting of swamps, water, mud flats, meadows, and woodlands.