In 1819, Singapore was mostly covered in rainforests. During that time, it still contained flora shared with the Malay Peninsula, but even then, the biodiversity of fauna was relatively low. Following the establishment of the British trading post, rapid deforestation began due to crop cultivation, and was largely completed by the 20th century. By some estimates, there has been a loss of 95% of the natural habitats of Singapore over the course of the past 183 years.[2] Due to the deforestation, over 20 species of freshwater fish, 100 species of bird, and a number of mammals became locally extinct.[3] A 2003 estimate put the proportion of extinct species as over 28%.[4]
In modern times, over half of the naturally occurring fauna and flora in Singapore is present only in nature reserves, which comprise only 0.25% of Singapore's land area.[2] Estimates made in 2003 have said that the rapid habitat destruction will culminate in a loss of 13-42% of populations in all of Southeast Asia.[5] To combat these problems, the Singaporean government made the Singapore Green Plan in 1992 and the new Singapore Green Plan in 2012 to continue it. The plan aims to keep tabs on the unstable populations of fauna and flora, to place new nature parks, and to connect existing parks. In addition, there were plans to set up a National Biodiversity Reference Centre (now known as the National Biodiversity Centre).[6] The last goal was reached in 2006 when the centre was founded (it also accomplished the establishment of two new nature reserves in 2002[7]). Since its foundation it has been formulating various specific initiatives including attempts to conserve the hornbill and the rare dragonflyIndothemis limbata.[8]
Singapore has roughly 80 species of mammals (out of 11 different orders) including 45 species of bats and three species of non-human primates.[9] Currently the only introduced non-domestic mammal species in Singapore is the variable squirrel.[10] The abundance of bats however has been decreasing rapidly due to habitat loss of over 95%.[11]
Singapore contains a relatively large number of reptiles, a total of about 110 species (4 of which are introduced).[13] Most of the species, roughly 75 are snakes (mainly Colubrid snakes).[14]
Singapore's land area is dominated by urban development that is interspaced by natural reserves, waterways, parks and a large interlinked network of over 300 km of park connectors (PCN).[17] The indigenous fauna that has adapted to the urban environment includes the following:
Smooth coated otters (Lutrogale perspicllata) have expanded to 17 families "fishing for tilapia in waterways and sleeping under bridges". There were reports of people who had their prized koi collection decimated by hungry otters.[18]
Oriental pied hornbills (Anthracoceros albirostris) are native to Singapore, though the species declined to the point of local extinction during the 19th century.[20] These birds made a comeback, having established a thriving population on Pulau Ubin and on occasion, can be sighted throughout Singapore.[21]
Wild boars (Sus scrofa) are native to Singapore with some weighing up to 100 kg. They have been sighted in urban areas close to forested areas. There are reports of wild boars attacking people who have strayed into their territory.[22]
^ abBrook, Barry W.; Navjot S. Sodhi; Peter K. L. Ng (24 July 2003). "Catastrophic extinctions follow deforestation in Singapore". Nature. 424 (6947): 420–426. doi:10.1038/nature01795. ISSN0028-0836. PMID12879068.
^Corlett, Robert T. (July 1992). "The Ecological Transformation of Singapore, 1819-1990". Journal of Biogeography. 19 (4). Blackwell Publishing: 411–420. doi:10.2307/2845569. JSTOR2845569.