Reptiles are the first group of vertebrates that became truly capable of living on land. They possess dry, keratin scales for protecting their body from water loss and have developed advanced respiratory and blood circulation systems, the ability to undertake internal fertilization and leathery shells for protecting eggs as part of their adaptations to reduce dependence on water.
Reptiles comprise members of distinctive morphology and life habits. In Hong Kong, they belong to either Testudines (Turtles and Tortoises) or Squamata (Lizards and Snakes). Turtles are characterised by their outer hard, keratin shell that effectively protects the body against predators (except for soft-shelled turtles which have a soft shell adapted for life in water). Apart from sea turtles, all other native turtles that occur in Hong Kong are semi-aquatic or aquatic species inhabiting freshwater streams and ponds. Lizards are represented by members of six major families in Hong Kong: geckoes (Gekkonidae), skinks (Scincidae), agamids (Agamidae), lacertids (Lacertidae), dibamids (Dibamidae) and monitor lizards (Varanidae). Different families represent members of different appearance and size, as well as in behaviour and habits. Snakes constitute the largest group of reptiles in Hong Kong. They are characterised by an elongated, limbless body covered with overlapping scales. They have remarkably distensible jaws, which allow them to swallow prey of much larger size than their normal mouth size. While there are 14 venomous land snake species, including the well-known Bamboo Snake (Trimeresurus albolabris), most of them are harmless and some do not even bite.
Hong Kong has a high diversity of reptiles, constituting 20% of the species native to China. Our reptiles comprise 12 species of turtles (including five species of sea turtles), 25 species of lizards and 53 species of snakes (including six species of sea snakes). Among these, only Bogadek's Burrowing Lizard (Dibamus bogadeki), Hong Kong Tree Gecko (Hemiphyllodactylus hongkongensis) and Hong Kong Blind Snake (Indotyphlops lazelli) are considered endemic to Hong Kong.
Compared with amphibians, the habitats of reptiles are more diverse as they have a much higher tolerance to desiccation. Although many other species inhabit forests, streams and marshes, open shrublands, grasslands and even mangroves offer suitable habitats for some species. For instance, Chinese Gecko (Gekko chinensis) is widely distributed and abundant throughout the territory from natural hillsides to village settlements, and Mangrove Water Snake (Enhydris bennettii) is associated with mangroves and mudflats.
