A staff member feeds Asian elephants during a public awareness activity on the occasion of World Elephant Day in a tourism area in the Dai Autonomous Prefecture of Xishuangbanna, southwest China's Yunnan Province, Aug. 12, 2019. (Xinhua/Yang Zongyou)

Tourists watch an Asian elephant parade during a public awareness activity on the occasion of World Elephant Day in a tourism area in the Dai Autonomous Prefecture of Xishuangbanna, southwest China's Yunnan Province, Aug. 12, 2019. (Xinhua/Yang Zongyou)

Tourists feed Asian elephants during a public awareness activity on the occasion of World Elephant Day in a tourism area in the Dai Autonomous Prefecture of Xishuangbanna, southwest China's Yunnan Province, Aug. 12, 2019. (Xinhua/Yang Zongyou)

Volunteers feed Asian elephants during a public awareness activity on the occasion of World Elephant Day in a tourism area in the Dai Autonomous Prefecture of Xishuangbanna, southwest China's Yunnan Province, Aug. 12, 2019. (Xinhua/Yang Zongyou)

Staff members feed Asian elephants during a public awareness activity on the occasion of World Elephant Day in a tourism area in the Dai Autonomous Prefecture of Xishuangbanna, southwest China's Yunnan Province, Aug. 12, 2019. (Xinhua/Yang Zongyou)

Volunteers feed Asian elephants during a public awareness activity on the occasion of World Elephant Day in a tourism area in the Dai Autonomous Prefecture of Xishuangbanna, southwest China's Yunnan Province, Aug. 12, 2019. (Xinhua/Yang Zongyou)

Staff members celebrate the birthday of Yang Niu, a four-year-old Asian elephant, during a public awareness activity on the occasion of World Elephant Day in a tourism area in the Dai Autonomous Prefecture of Xishuangbanna, southwest China's Yunnan Province, Aug. 12, 2019. (Xinhua/Yang Zongyou)