Birds are ubiquitous throughout Hong Kong. In fact, even the urban areas of Hong Kong, in particular Kowloon Park, the Zoological and Botanical Gardens in Mid-Levels, and the Hong Kong Cemetery at Happy Valley, support many of the common avifauna. Many common or even rare bird species can be observed in more rural areas such as forests, shrublands or agricultural lands. The Mai Po and Inner Deep Bay Ramsar Site is arguably the most important site in Hong Kong for wetland birds. The area provides a suitable habitat for large numbers of breeding and migrant birds which would otherwise bypass Hong Kong. In addition, a total of 70 bird species was recorded in the Tai Po Kau Nature Reserve (Kwok 1996) with 35 species regarded as resident species.

Over 400 species of birds have been recorded in an apparently wild state during the past 50 years in Hong Kong and of these, over 100 have been recorded breeding locally. Hong Kong is visited by a large number of Eastern Palearctic waders during their migratory passage, and regularly attracts other Palearctic species that are major rarities in other countries (eg Britain and North America). The diversity of the bird community is attributed both to Hong Kong's geographic position and its wide variety of local habitats (Chalmers 1986; Viney and Phillipps 1989; Diskin and Pearse 1994). In addition, Hong Kong records thirteen species which are listed as threatened, endangered or critical by the International Union for Conservation of Nature (IUCN) (Collar et al 1994).

Long term monitoring of waterfowl is undertaken at the Mai Po and Inner Deep Bay Ramsar Site by the Hong Kong Birdwatching Society (HKBWS) with funding from AFCD. Winter counts() of waterfowl have been undertaken each year since the winter of 1992-93. Figure 4.2b shows the trend in total peak winter counts (December to February) for those years, together with the peak waterbird counts for January, which is the winter month in which the highest number of visiting birds are usually observed (HKBWS 2000). These data show that overall winter counts are currently at around the same levels as when monitoring began in 1992, having declined from a peak of around 80,000 counts during the mid 1990s. Figure 4.2c indicates the trend in wintering bird numbers over this period for the five most commonly observed species in the 1999/2000 census and Figure 4.2d indicates the trend in numbers of five less commonly observed species in the same census. Several of the species in these graphs (including Larus ridibundus (Black-headed gull), Anas acuta (Northern Pintail), Phalacrocorax carbo (Great Cormorant), Anas crecca (Common Teal), Anas clypeata (Northern Shoveler), Tringa nebularia (Common Greenshank), and Pluvialis squatarola (Grey Plover)) are considered to be of conservation significance, either because they are classed as threatened in the world (by Birdlife International) or because they are species which Deep Bay supports, or may support, at least 1% of the regional or flyway population as used for implementing the Ramsar Convention. The figures show that numbers of the Black-headed Gull, Northern Shoveler, Grey Plover (which are considered to be of conservation significance) have all declined over the period 1992/93 to 1999/2000.