The common green magpie (Cissa chinensis) is a type of magpie bird belonging to the genus Corvidae. I found this bird calling as I walked in Luk Keng. This is an "introduced" species, as it would not normally be found in Hong Kong.
It is normally found in evergreen forests across southeast Asia, mainly in northeast India, central Thailand, and Malaysia. They do not migrate.
They typically form mated pairs for life and have been known to live for 10-15 years.
If born and brought up in captivity, this bird species have been known to be traded as pets...which is where some of these released individuals probably came from. However, a highly social and intelligent bird perhaps should not be kept in a cage...eh? What do you think?
These birds are strictly carnivorous in nature, and will mostly kill and eat small invertebrates, reptiles, mammals, and often other young birds, for example in nests, or eating the eggs.
Side note:
All pets should only be bought from a reputable source. It is recommended that as a potential pet owner you carry out your own research prior to deciding on your pet of choice. Being a pet owner is very rewarding but it also involves commitment, time and money. Ensure that your pet choice complies with the legislation in your state and/or country. You must never take animals from the wild or disturb their habitat. Please check that the pet you are considering buying is not an endangered species, or listed on the CITES list, and has not been taken from the wild for the pet trade.