Kadoorie Farm and Botanical Gardens do a lot of work for animal rescue in Hong Kong. This is a crested serpent eagle (Spilornis cheela), a medium-sized bird of prey, that has been at the farm for some time.
These lovely birds have a large looking head with long feathers on the back of the head giving them a maned and crested appearance. The face is bare and yellow joining up with the - word for today: ceres (This is a waxy structure called a cere -from the Latin cera, which means "wax"- which covers the base of their bill. The cere is typically bare and often brightly colored).
Here is a juvenile...
You can also see the powerful feet are unfeathered and heavily scaled. They fly over the forest canopy on broad wings and can often heard calling with a loud, piercing and familiar three or two-note call.