Ecuador has 1,600 bird species (15% of the world's known bird species) in the continental area and 38 more endemic in the Galápagos. In addition to more than 16,000 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, as the famous place of birth to Darwin's Theory of Evolution, and as a UNESCO World Heritage Site.