Ever wondered where the raucous, squawking cockatoos that circle Central's towering buildings originally came from? For starters, Hong Kong's wild cockatoo populations are not Australian; the prevalent species found here is the lesser sulphur-crested cockatoo, which is native to the Indonesian islands east of the Wallace Line. Sizeable cockatoo colonies exist in and around Hong Kong Park, the Zoological and Botanical Gardens, Government House, Queen Mary Hospital, the University of Hong Kong and the Happy Valley cemeteries. Various species of trees commonly planted in Hong Kong have aided the species' naturalisation. In particular, camphor laurel trees, mature banyans and other types of ficus provide knotty crevasses suitable for nesting, and leaves from other common species, such as the Chinese fan palm, can be used to make nests. One of Hong Kong's more pervasive urban myths maintains that the ancestors of today's flocks - and possibly even a few of the originals, given the species' longevity - were cage pets and aviary specimens released during the Japanese invasion in 1941, or the years of occupation, which subsequently naturalised. While this is as good an explanation as any - and some bird owners probably did release them into the wild (I would rather free mine than have them starve to death in an untended cage) - there is no conclusive proof one way or another. As is so often the case with historical legend in Hong Kong - especially anything to do with the war years - boring old details, such as objectively provable facts, need never get in the way of a good story. Endless repetition down the years eventually accords whatever the tale might be - whether it is truth, fiction or some-where in between - the time-hallowed ring of authority. Extensive trapping for the bird trade in recent decades in Sumba, Sumbawa, Timor and smaller islands in their native Indonesia have decimated population numbers. Combined with massive habitat loss through deforestation, the bird trade has ensured that where native populations still survive, movement corridors between habitats cannot adequately ensure genetic diversity. Remnant indigenous populations are becoming significantly inbred and Hong Kong's cockatoo populations now have a more diverse gene pool than those in their native Indonesia. Lesser sulphur-crested cockatoos are now listed on the Convention on the International Trade in Endangered Species as critically endangered, yet every so often these friendly, inquisitive little birds are still available for sale in local bird shops, which sadly demonstrates, if any further proof were needed, the yawning gap between legislation and enforcement that exists in 'Asia's World City'.