Ecuador is one of 17 megadiverse countries in the world according to Conservation International. With 1600 bird species (15 percent of the world's known bird species) in the continental area, and 38 more endemic in the Galápagos. In addition to 25,000 species of plants, the country has 106 endemic reptiles, 138 endemic amphibians, and 6,000 species of butterfly. The Galápagos Islands are well known as a region of distinct fauna, famous as the place of birth of Darwin's Theory of Evolution, and a UNESCO World Heritage Site. Despite being on the UNESCO list, the Galapagos islands are endangered by a range of negative environmental effects, threatening the existence of this exotic ecosystem.