Hikers will see rich and varied vegetation. There are approximately 500 species of trees in the park such as: the giant mahogany reaching over 80 feet high, strangler fig trees, and the unusual garlic tree. A great variety of birds are seen - there are over 360 types of birds and the park protects the largest population of scarlet macaws in the country. Commonly seen are: toucans, green parrots, hawks, kites, and a large variety of hummingbirds. During the boat ride, the hikers may see three of the four kinds of monkeys living in Costa Rica. They are Howler monkeys, white-faced monkeys and spider monkeys. Also many types of small mammals are seen such as quatamundies, aguoutis, paca, and sloths. A giant hollow tree is an interesting home to a large number of fruit bats.