This is the orange-bellied leafbird (Chloropsis hardwickii) - a resident of Hong Kong, and photographed in Sai Kung. The scientific name commemorates the English naturalist Thomas Hardwicke (not to be confused with Witwicky, a surname frequently used for humans in the Transformers brand).
There is some debate as to the extent to which the leafbirds consume nectar, but you can clearly see the pollen on this feathers near the beak, and so he is also acting as a pollinator.
The male is resplendent, as these photos show, whereas the female is mainly green all over. They are sexually dimorphic in their plumage, which means that the male and female exhibit different characteristics beyond the differences in their sexual organs. They have forked, brush-tipped tongues and fairly hefty, long, down-curved bills with stiff, hair-like feathers at the base that protect their eyes from the legs and wings of their insect prey.
This was shot earlier in the year, on another of its favourite trees.
This lovely bird feeds on insects, spiders and nectar. The best way to see them is to find their favourite trees, and as they are creatures of habit, your patience will be rewarded, as they will return (eventually, later rather than sooner in my experience) to the same trees to feed. The smaller white flowering trees in Lions Park is a great place to start (or just follow the other photographers). This is where I captured these images of this bird, which is often too high up in the canopy looking for insects, to be easily shot.
Orange-bellied leafbirds make their nests from roots and fibers which are suspended from the edges of twigs at the end of a tree branch. They do not migrate, staying with us all year round, which increases your chances of spotting one.
Click the images below to see them larger.
With their beautiful plumage, and their melodious songs, as well as their capacity to mimic sounds, they have become very popular cagebirds, and are hunted for this purpose. Some populations of leafbirds in Asia have been locally depleted by the numbers captured for the trade, and of course the amount of suitable habitat has declined with deforestation.