A rare gray-feathered egret on Xiaogan Island in Zhoushan, Zhejiang province. [Photo/Tide News]

A bird monitoring team from Zhoushan's forestry department has observed two rare gray-feathered egrets on Xiaogan Island in Zhoushan, Zhejiang province.

These egrets, distinguished by their gray feathers, were seen resting among other egrets on the tidal flats. Apart from their unique plumage, they share all other characteristics with typical white egrets.

Research from Xiamen University's animal laboratory in 2003 revealed that egrets carry a recessive gene for black feathers. For this gene to manifest, both parents must contribute the recessive gene, making the occurrence of gray feathers extremely rare.

According to the monitoring team, the gray-feathered egrets exhibit no significant differences in lifestyle or breeding behavior compared to their white-feathered counterparts.

China has few records of dark-feathered egrets, with the earliest sightings dating back to the 1990s in Hong Kong. Subsequent observations have been made in Fujian's Xiamen, Jiangxi's Shangrao, Zhejiang's Ningbo, Liaoning's Dalian, Guangdong's Zhaoqing, and Anhui's Ma'anshan.

This recent sighting in Zhoushan marks the second recorded instance in the area after the one in 2023.