抄録
The natural vegetation of Hong Kong is tropical evergreen forest, but this was almost entirely cleared by people before the eighteenth century. This clearance must have had a major impact on the bird community and undoubtedly caused the disappearance of all forest-dependant species, but these changes are undocumented. The documented history of Hong Kong’s avifauna begins following British colonization in 1860 and parallels a process of progressive restoration of forests, at least in the uplands. At least nine bird species that were present in Hong Kong in 1860 are dependant upon anthropogenic habitats and are therefore considered to have invaded before colonial times. Subsequently 41 species (30% of the breeding avifauna) have colonized. Of these, 22 species are believed to have spread unaided from southern China, while the remaining 19 species are considered to have been introduced by people from sources both within and beyond the region. Unlike the pattern of documented bird invasions elsewhere in Southeast Asia, most of these recent invaders are forest species, reflecting the recent pattern of habitat change. The possible ecological impacts of these invaders (both natural and human-assisted) are reviewed, but they are largely unknown. Hong Kong may provide a model for the evolution of bird communities elsewhere in the region if current patterns of deforestation are permitted to continue.
