Around 3,100 different species of flora have been recorded across Hong Kong, about 2,100 of which are native to the region. The plant life is typical of a subtropical region, though some species from Southeast Asia can be found right at the northern end of their distribution range. In older parts of the city, banyan trees grow with their roots snaking across the granite walls. In the winter months, bauhinia plants in flower can also be found in Hong Kong’s parks.
Mangroves are habitats of enclosed intertidal mud flats with wave action greatly reduced, located near sources of fresh water. Popular mangrove habitats in Hong Kong are located along Deep Bay, such as Pak Nai and Tsim Bei Tsui, where salinity is very low under the influence of fresh water from the Pearl River, and along some mud flats where salinity is lowered by surrounding streams, such as Three Fathoms Cove and Ting Kok. Trees living in this habitat are called mangrove trees.
The tidal range of Hong Kong is about 2.5 metres and the distribution of species is situated into this area must be tolerant of both conditions that the shores are covered with sea water during high tide and the shores are exposed to the air directly during low tide, for hours or days. Species which have adapted to these different conditions are described as specialised to successfully exploit narrow vertical zones on the rocky shore.
The species inhabiting Hong Kong rocky shores varies in accordance with the exposure to the wave action from the sea. The sessile filter feeding organisms inhabit the wave exposed shores. They are able to attach on the rock surface and remove food particles in the turbulent water while the mobile herbivores and carnivores inhabit in the sheltered shores. The varieties of the organisms also different from seasons, especially in Hong Kong where oceanic currents change with season: very few erect foliose macro-algae are found in summer because they may suffer from the burning heat; a lot of foliose algae are found on the shores in winter.
There are two kinds of freshwater habitats: lentic water, such as lakes, ponds, ditches, and lotic water, such as rivers, streams. Streams are an example of a lotic habitat Hong Kong.
There are three main factors to differentiate the habitats in Hong Kong: variability of current, amount of detritus and variable oxygen content. These factors contribute to make the animals adapted in different ways. They have to attach themselves to the surfaces, become predominantly detritus feeders and have a mechanism for obtaining maximum oxygen supply.
Larger animals resident in the Hong Kong countryside include barking deer, civet cats, squirrels, wild boar, Chinese Porcupines, Chinese Pangolins and Mongooses. Most of these animals are very shy, however, Kadoorie Farm, displays several of Hong Kong’s indigenous species as part of its conservation programme. There are 300 species of butterflies and dragonflies that live locally, and on sunny days it is not uncommon to see snakes.
Large birds of prey circling above Hong Kong’s harbour are Black-Eared Kites, and are also common above Hong Kong Island. Mai Po marshes, an area of wetlands, is an important part of many birds’ migrations from northern China, Mongolia and Siberia. Some species spend the winter in the Mai Po area, while others use it as a feeding and resting area before continuing their journey. The WWF reports that over 340 species of birds have been recorded in these wetlands.
The most eye-catching inhabitant of the local seas is the Chinese pink dolphin. Other surprises are that Hong Kong is also home to almost 1,000 species of fish, more species of coral than the Caribbean, and has a nesting site for Green Turtles on a beach on one of its outlying islands.