The Tai Po Kau (大埔滘) Nature Reserve is a splendid example of reforestation.
tai po kau
Tai Po Kau Forest Reserve
Info from Hong Kong's Great Outdoors
Excellent trail system, through regenerating sub-tropical forest. The blue and red trails are shorter, initially running close to a stream; the yellow and brown trails climb higher. One of Hong Kong’s best birding sites.
From Shatin, take bus 72 from Shatin New Town Plaza (near KCR station), or taxi from KCR East Rail Tai Po Market Station.
Tai Po Kau article on this site
Tai Po Kau Forest Nature Reserve gives an overview, info on colonisation by birds, and briefly outlines trails.
Tai Po Kau Forest Reserve is part of a longer article on HK forests.
Though there are places where wildlife is on the rebound, none is any more than a shadow of Hong Kong's forests past.
There are many good birdwatching locations throughout Hong Kong.