I have a feeling that the blurb on the CNNGO website somewhat misrepresents what the HKBWS members do in the park:
"This leafy green lung in the heart of Hong Kong is an exotic bird-watcher's paradise. Turn up at 8 a.m. on Wednesdays at the park's artificial lake for a free two-hour bird-watching meeting in the massive walk-through aviary."
David