Mute swan cygnets are set to hatch at the North Longhu Wetland Park in Zhengzhou City, central China's Henan Province. Mute swans are less vocal than other swan species, hence the name. The park has become an ideal destination for migratory birds to breed because of an improved environment. Over the past two years, the number of mute swans in the park has reached 33. The third generation of mute swan babies here are expected to be hatched around June 5.