In a protected forest on the southern edge of Brazil's Amazon Rainforest, lives one of the most intelligent and agile monkeys of the New World, the white-whiskered spider monkey. Their long tails are like a 5th limb and they rarely leave the treetops for the forest floor. These agile acrobats are the "ambassadors" of the oldest tropical forest on earth in one of the most biodiverse countries of the world. Habitat loss has endangered these monkeys, but the private Christalino Reserve and ecolodge is a refuge for them. These social animals live in a troop, eating mostly fruit and green leaves. Saki monkeys co-exist, making long junmps between trees, and howler monkeys noisily announce their territory. Leafcutter ants harvest leaves to fertilize their crop of fungus, organized in a complex social system, and other ant species each have a special function. The white-lipped pecarry has a distnctive pungent smell, and are always on the alert for predators. River otters feast on fish, as the wet season approaches.