Four baby swans and their black swan parents paddle on a pond at the Old Summer Palace in Beijing on Jan 12, attracting the attention of many tourists.[Photo by Chen Jiannan/ For China Daily]

Four baby swans and their black swan parents paddle on a pond at the Old Summer Palace in Beijing on Jan 12, attracting the attention of many tourists.[Photo by Chen Jiannan/ For China Daily]

Four baby swans and their black swan parent paddle on a pond at the Old Summer Palace in Beijing on Jan 12, attracting the attention of many tourists.[Photo by Chen Jiannan/ For China Daily]

Tourists flock to see swans at the Old Summer Palace in Beijing on Jan 12.[Photo by Chen Jiannan/ For China Daily]