South America's Amazon rainforest, the largest in the world, encompasses 2,722,000 square miles. According to the Shedd Aquarium in Chicago, the Amazon is home to one-third of all known plants and animals. Several Amazonian animals are listed as endangered on the International Union for Conservation of Nature's Red List of Threatened Species. Additional species are considered endangered by the U.S. Fish and Wildlife Service under the Endangered Species Act.
Poison Dart Frogs
The Amazon is home to poison dart frogs, some of which are endangered. Though they range in size from 1 to 2 1/2 inches, poison frogs secrete a venom capable of killing several humans at once. Among the most imperilled is Peru's Oxapampa poison frog, classified as critically endangered by the IUCN. The golden poison frog, the most toxic, is endangered throughout its range along Colombia's Pacific coast.
Among the endangered birds of the Amazon is the hyacinth macaw, the world's largest parrot, and the Lear's macaw. The blue-throated macaw, endemic to Bolivia, is critically endangered according to the IUCN. Though the IUCN classifies the harpy eagle as near threatened, the U.S. Fish and Wildlife Service considers it endangered throughout its range, which encompasses parts of the Amazon.
The IUCN downgraded the Amazon's black caiman from an endangered species in 1996 to one of least concern in 2000, but the U.S. Fish and Wildlife Service still deems it endangered. The black caiman is the world's largest caiman species.
Likewise, the South American river turtle, the continent's largest river turtle, went from endangered in 1994 to a species of least concern in 1996, according to the IUCN. The U.S. Fish and Wildlife Service nonetheless considers it endangered.
Due to severe habitat loss, the brown spider monkey -- one of the largest primates in the Amazon --is also one of the 25 most endangered in the world. Listed as critically endangered by the IUCN, the brown spider monkey is found mainly in Colombia and Ecuador. Also critically endangered are the Maranhao red-handed howler monkey, the blonde capuchin, buff-headed capuchin and the Ka'apor capuchin, all of which are endemic to Brazil. The Brazilian barefaced tamarin and the robust tufted capuchin are categorised as endangered.
The IUCN lists the Amazonian manatee as vulnerable, while the U.S. Fish and Wildlife Service classifies it as endangered. According to the World Wildlife Fund, the Amazonian manatee is believed to be declining, though its population size is unknown. Also endangered is the Amazon's giant otter. Fast and able swimmers, giant otters -- the largest in the world -- can be up to 6 feet long.
Among the endangered mammals of the Amazon is the maned three-toed sloth, the largest sloth species, found only along Brazil's Atlantic coast. Habitat destruction is the biggest threat to the slow-moving herbivore, which descends from tree tops only to urinate and defecate. Another mammal, the South American tapir, is vulnerable, according to the IUCN, and endangered, according to the U.S. Fish and Wildlife Service.