The largest of the Earth's tropical rainforests, the Amazon may be home to as many as half of the Earth's species, millions of them yet undiscovered. Most of the Amazon rainforest's inhabitants are insects, but more than 500 mammal, 175 lizard and 300 additional reptile species are known to live here, along with more than 33 per cent of the world's bird species. Both the plants and animals of the Amazon rainforest are perfectly adapted to their environment.
The canopy's characteristics
One of the world's most complex ecosystems, the Amazon rainforest canopy is a miracle of adaptation. The rainforest canopy's leaves are so dense that they keep 80 per cent of the available sunlight from reaching the forest's lower regions. This gives the canopy's trees plenty of sunlight to sustain their growth. The canopy's trees have also developed a sophisticated drainage system with very smooth oval-shaped, pointed leaves. The slick surface and shape of these leaves means that water won't collect on them. In an environment where the average humidity is between 77 and 88 per cent, and rainfall runs up to 600 cm a year, anything the trees can do to remain dry protects them from attacks by mould and fungi.
Although aerial views of the canopy make it look like an unbroken sea of green, the canopy's trees don't actually touch. Their separation may be an adaptation to prevent disease from spreading among them, but it also means that tree-dwelling creatures have to fly, leap or swing their way across the canopy.
The canopy as a food source
The massive amounts of sunlight reaching the canopy mean massive amounts of photosynthesis are occurring, and the canopy trees are some of the best nourished on Earth. They yield enormous quantities of flowers, fruits and seeds in addition to their leaves, making them prime habitat for animals and birds. The canopy also protects the plants on the forest floor from harsh sunlight and strong wind.
The rainforest floor
In the dim conditions on the rainforest floor live thousands of plant and animal species. It's here that most decomposition of the rainforest's dead material occurs, providing sustenance for new growth. Vines, seedlings and some occasional ground-cover plants grow in the spaces between the mature trees. Many of the Amazon rainforest plants are prized for their medicinal value. The roots of the rainforest floor's Suma vine, for example, have a saponin content approaching 11 per cent. Saponins are being studied for their cholesterol-lowering properties.
Animals of the rainforest
Just as its canopy-dwelling golden lion tamarin monkeys have been hunted to the brink of extinction, a newly discovered species, the Mura's saddleback tamarin, has emerged. The black market price for the spectacular reddish-gold pelts of the golden lion tamarin can reach as high as £13,000. The tiny Mura's saddleback weighs only 255 g, but the rainforest also shelters the world's largest rodent, the capybara, which can reach 90.7 kg. Anteaters, armadillos and sloths are here, as are jaguars and ocelots, spectacled bears, speckled deer, tapirs, peccaries and dozens of bat species. They join roughly 1,500 bird species, reptiles, lizards, tortoises, frogs and enough ants to constitute 30 per cent of the weight of all the animals in the Amazon Basin.
Interdependency is the key to survival for the Amazon rainforest's plants and animals. A perfect example of this is the relationship between the strong-jawed agouti, a rodent living on the rainforest floor, and the Brazilian nut tree, which produces nuts only the agouti's jaws can crack. The agouti buries the cracked nuts it hasn't eaten, acting as a rodent Johnny Nutseed by planting the next generation of trees to feed its own descendants. Relationships like these are common among animal species as well.