Photo taken on Dec. 15, 2020 shows maple leaves at a park in Minhang District, east China's Shanghai. (Xinhua/Zhang Jiansong)

Photo taken on Dec. 15, 2020 shows maple leaves at a park in Minhang District, east China's Shanghai. (Xinhua/Zhang Jiansong)

Photo taken on Dec. 15, 2020 shows maple leaves at a park in Minhang District, east China's Shanghai. (Xinhua/Zhang Jiansong)

Photo taken on Dec. 15, 2020 shows maple leaves at a park in Minhang District, east China's Shanghai. (Xinhua/Zhang Jiansong)

Photo taken on Dec. 15, 2020 shows maple leaves at a park in Minhang District, east China's Shanghai. (Xinhua/Zhang Jiansong)

A light-vented bulbul is seen among maple leaves at a park in Minhang District, east China's Shanghai, Dec. 15, 2020. (Xinhua/Zhang Jiansong)