Orangutans have evolved in a vertically-oriented, highly complex environment for millions of years and have lived in managed, horizontally-oriented animal care facilities for only a few score years. We often tend to build new exhibits by first looking to existing exhibits at other zoos, but we should begin by considering the orangutans’ tropical rainforest home, orangutan physical and psychological needs, orangutan health, human safety and ease of use in conjunction with previous exhibit models before undertaking new construction.
In the wild, orangutans primarily move through the canopy using both their arms and legs. One of the most important aspects of the managed physical environment is the amount of arboreal space available for both rest and locomotion (Maple, 1979; Maple & Stine, 1982; Jones, 1982). Horizontal arboreal pathways and nesting/resting platforms are the main elements of the natural physical environment for orangutans (Jones, 1982). The lack of opportunity for arboreal locomotion promotes lethargy and contributes to obesity (Maple, 1980). The combination of lethargy and living on the ground causes health hazards. Coprophagy or playing with feces often becomes more common, especially if there are no other stimulating objects in the enclosure (Hill, 1966; Maple, 1980).
Resting platforms are necessary for orangutans to fully utilize climbing structures. There should be a sufficient number of platforms so that dominant animals don’t exclude subordinates in the group. The climbing structures also need to be designed to prevent subordinate animals from being trapped at a dead-end. Platforms should be large enough for the orangutans to build nests for resting. The appropriate size will vary with the size of the individual orangutans; critically, platforms must be sturdy enough to support the weight of the orangutans as well as their nesting materials, which can at times be substantia
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