HKBWS Vicky

Category A-D are residents species, winter visitors, summer visitors, migrants and introduced species that population has been well established in the wild (歸化/野化種)
Category E and F are birds that are released/escape from captivity and regarded asboubtful because of the possibility of mistaken identification.

Please correct me if for any mistakes.

You can also refer to "Avifauna of Hong Kong" for more detailed definitions.