An oriental magpie robin is seen at Wuyuan River Wetland Park in Haikou, capital of south China's Hainan Province, July 14, 2019. (Photo: Xinhua)

Kentish plovers search for food at Wuyuan River Wetland Park in Haikou, capital of south China's Hainan Province, July 14, 2019. (Photo: Xinhua)

An oriental magpie robin is seen at Wuyuan River Wetland Park in Haikou, capital of south China's Hainan Province, July 14, 2019. (Photo: Xinhua)

A white wagtail is seen at Wuyuan River Wetland Park in Haikou, capital of south China's Hainan Province, July 14, 2019. (Photo: Xinhua)

A white wagtail searches for food at Wuyuan River Wetland Park in Haikou, capital of south China's Hainan Province, July 14, 2019. (Photo: Xinhua)

A Kentish plover searches for food at Wuyuan River Wetland Park in Haikou, capital of south China's Hainan Province, July 14, 2019. (Photo: Xinhua)

An oriental magpie robin is seen at Wuyuan River Wetland Park in Haikou, capital of south China's Hainan Province, July 14, 2019. (Photo: Xinhua)

Kentish plovers fly above Wuyuan River Wetland Park in Haikou, capital of south China's Hainan Province, July 14, 2019. (Photo: Xinhua)