Hong Kong's climate and physical environment provides a wide range of habitats and supports a rich and varied fauna. These include about 450 species of birds, 50 species of mammals, 80 species of reptiles, 23 species of amphibians, 230 species of butterflies and 100 species of dragonflies.

    The Mai Po Marshes form one of the most important wildlife conservation sites in Hong Kong. Together with the Inner Deep Bay area, the Mai Po Marshes area was listed as a 'Wetland of International Importance' under the Ramsar Convention in September 1995. About 1 500 hectares of mudflats, fish ponds, marshes, reedbeds and dwarf mangroves provide a rich habitat for migratory and resident birds, particularly ducks and waders. Some 300 species of birds have been observed in this area, many of which are considered globally threatened and endangered, such as the black-faced spoonbill, Oriental stork, Nordmann's greenshank and Saunders' gull. To conserve the ecological value of the area, the Agriculture, Fisheries and Conversation Department (AFCD) implements a wetland conservation and management plan there.

    The traditional fung shui woods near old villages and temples and the secondary forests provide important habitats for many woodland birds. Sightings in wooded areas include warblers, flycatchers, robins, bulbuls and tits.

    Areas around the Kowloon reservoirs are inhabited by monkeys descended from animals that had been released or had escaped from captivity. There are breeding groups of long-tailed macaques and rhesus macaques, and their hybrids. Feeding of monkeys has been prohibited since July 1999 to prevent unnatural growth of the monkey population. Other mammals like barking deer, leopard cats, Chinese porcupines, small Indian civets, wild boar and bats are quite common in the countryside. Sightings of less common species such as Eurasian otters and Chinese pangolins are occasionally reported.

    Hong Kong has over 100 species of amphibians and reptiles, and about 50 of these are snakes. Most snakes in Hong Kong are harmless and there have been few cases of people being bitten by highly venomous snakes. Among the nine native species of chelonians in Hong Kong, the green turtle is of particular interest as it is the only known species of sea turtle breeding locally. In August, a green turtle nesting in Hong Kong was fitted with a satellite transmitter and tracked by the AFCD as part of its plans for the long-term conservation of this highly endangered species. The turtle was found to migrate along the South China coastline to the shallow coastal waters off the eastern part of Hainan Island. It is expected to stay in the shallow water feeding ground and return to nest at Sham Wan, Lamma Island, three to five years later. This first use of a satellite to track Hong Kong's sea turtles will enhance understanding of them and benefit conservation work. There are 23 species of amphibians found in Hong Kong and three of them — Hong Kong cascade frog, Hong Kong newt and the endemic Romer's tree frog — have been listed under the Wild Animals Protection Ordinance due to their rarity locally.