Fragile Forest is an outdoor summer habitat for orangutans, chimpanzees and gorillas. During the fall and winter, the great apes may be seen in their winter homes at Jungle of the Apes.

Fragile Forest, with its lushly landscaped habitats, flowing streams, huge deadfall trees and vines, is designed for connection. It helps visitors understand how much these creatures are like us by giving an insight into each individual's personality and into his or her relationship to others in the group. Just like our social life, their relationships change over time as coalitions are forged and power plays take place.

Lichtenstein Chimpanzee Refuge

At Chimpanzee Refuge, you'll observe the fascinating behavior of chimpanzees. Our chimpanzee family lives in a space surrounded by rocky cliffs. Imbedded within the craggy walls of their habitat are 30 feeding tubes, designed to make life interesting. To vary the chimpanzees' daily diet, the keepers drop some of their food items into the food chutes, but not every tube is used every day, and times of the day vary. The chimpanzees need to figure this out. Some of the openings at the bottom of the chutes are varied from day to day as well - some wide enough for a hairy finger (none are hand size) and some so narrow that the chimpanzees will need "tools" to fish out their favorite foods.

The exhibit reproduces their native habitat that includes humid forest, deciduous woodland and mixed savanna. We hope that in these naturalistic surroundings, you'll see the similarities between chimpanzee behavior and that of humans, such as tool-making activities. Chimpanzees are endangered in their wild habitat.

Dana Brown Orangutan Refuge

Dana Brown Orangutan Refuge features orangutans, the mysterious great ape from the remote jungles of Borneo and Sumatra, in a naturalistic habitat. It also helps educate visitors about the Sumatran orangutan as a critically endangered species and the importance of conservation. These animals are active in the daytime.

The 7,000 square foot space is more vertical than the chimpanzee habitat, to accommodate the orangutan family of three that likes life in the trees. They spend most of their time in the trees, only occasionally descending from the branches to travel on the forest floor. The orangutan exhibit is covered by custom-made steel mesh, hand-woven so that it cannot be undone by busy hands.

Here the challenge is to encourage arboreal behaviors, such as those used by orangutans when foraging for food in the rainforest canopy. Food items are lifted into the treetops by means of a unique pulley system. Again, variability of delivery is key to keeping the orangutans' interest. Keepers can activate the feeding devices by means of a remote button, at varied times of day in a random pattern.

Ann & Paul Lux Family Gorilla Habitat

The Zoo's western lowland gorillas have had an outdoor yard since Jungle of the Apes was built in 1987. St. Louis was the first zoo to form a gorilla bachelor group, and currently has a group of bachelor gorillas. Wild gorilla males may choose to live in an all-male group if too young or unable to assume leadership of a family group. In 1998 the American Zoo and Aquarium Association gave the Saint Louis Zoo a Significant Achievement Award for its long-term success in forming an all-male group of gorillas.