A flock of wild birds was seen flying to the Zaohe River to roost for winter in Xi'an City in northwest China's Shaanxi Province on February 3.

The Zaohe River used to be a foul-smelling polluted river that had long harmed the water quality of the Weihe River (the largest tributary of the Yellow River). After years of continuous management and restoration, the Zaohe River has improved its ecology and since 2018 has attracted many wild animals, according to the Ministry of Ecology and Environment.

(All images via VCG)

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