The Little Egret is a common waterbird in Hong Kong.
Since most Little Egrets are residents in Hong Kong, they occur throughout the year in various types of wetlands including freshwater marshes and intertidal mudflat. You may find Little Egrets preying or resting at the shallow waters in many coastal areas..
There is a very comprehensive description of the Little Egrets in Wikipedia:
https://en.wikipedia.org/wiki/Little_egret
For sharing, here are some pictures taken near the place I am based.