Two-thirds of the world's fresh water is found in the river and its 1,000 tributaries. You'll meet up to three-fourths of all known species of plants and animals and thousands of unnamed species as well. Survival here depends on a highly complex system of interdependence and adaptation . In the equatorial ecosystem , birds eat insects and plants. Snakes eat birds and frogs.
Frogs eat insects and each other.
Plants provide homes for insects and animals and depend on those animals to disperse their seeds. Leaf cutter ants provide an excellent example of a symbiotic relationship. Leaf cutters are herbivores that can't digest cellulose . Fecal fluid from worker ants contains amino acids and enzymes that fertilize the fungus and break down the leaf proteins into smaller protein molecules that ants can digest. Adaptation is another key factor in survival.