Amazon rainforest This constitutes the largest collection of living plants and animal species in the world. The region is home to about 2.5 million insect species, tens of thousands of plants, and some 2,000 birds and mammals. To date, at least 40,000 plant species, 2,200 fishes, 1,294 birds, 427 mammals, 428 amphibians, and 378 reptiles have been scientifically classified in the region. One in five of all bird species are found in the Amazon rainforest, and one in five of the fish species live in Amazonian rivers and streams. Scientists have described between 96,660 and 128,843 invertebrate species in Brazil alone. The
Amazon biome form barriers to the geodispersal of plants, animals and even insects. Thus the white-fronted capuchin ("Cebus albifrons") and hairy saki ("Pithecia hirsuta") are found west of the Tapajós, while the white-nosed saki ("Chiropotes albinasus") is only found east of the river. The World Wildlife Fund divides the biome into ecoregions, often defined as the regions lying between major tributaries of the Amazon. Most of the interior of the Amazon basin is covered by rainforest. The dense tropical Amazon rainforest is the largest tropical rainforest in the world. It covers between of the Amazon biome. The somewhat vague numbers are because