Taiwan's terrestrial fauna is particularly abundant, including some 84 species of mammals, 500 species of birds, 91 species of reptiles, 37 species of amphibians, 400 species of butterflies, and over 19,000 species of insects. In addition, many invertebrates have yet to be investigated and identified. Over the past decade and more, ESRI has conducted a systematic inventory of Taiwan's wildlife of each county and metropolitan area and has worked on biological, ecological and genetic studies of rare, endemic and exotic species, as well as related research on ecological engineering.
