Orangutans are sexually dimorphic (with two distinct gender forms): males are significantly taller than females are and weigh more than twice as much as females do. Both male and female orangutans range in color from bright orange to maroon or dark chocolate. The form of orangutans is well-adapted to an arboreal life-style. Their arms are very long and reach to their ankles when they stand upright. They have very long fingers and dexterous hands. Their feet are broad and look very similar to their hands, with long, grasping toes for climbing. They are the only primate with two distinct forms of mature males. Flanged males, with cheek pads, long hair, a large throat sac, and long calls, are intolerant of other mature males. Nonflanged males do not develop the secondary sex characteristics of flanged males: cheek pads, long hair, long calls, large size, and defense of territory. The nonflanged males are closer to females in body size. Both forms can impregnate females and contribute to the population's reproduction. The transition from unflanged to flanged is dependent upon complex social cues not yet fully understood. Like other great apes, orangutans have no tail, are large-brained, and are sapient (aware of themselves as individuals)

 

Association of Zoos & Aquariums (AZA) SAFE Orangutan Program 

As orangutans are highly dependent upon arboreal lifestyle, they are very susceptible to habitat disruption. Palm oil plantations have destroyed much of their native habitat; among this and other threats, it is estimated that orangutans have lost over 80% of their habitat in the last two decades. It is estimated that there are less than 100,000 orangutans left globally according to the IUCN Red List. 

Brookfield Zoo Chicago participates in the AZA SAFE Orangutan Program to help identify survival threats, support recovery, and offer you opportunities to learn more about at-risk species. 
 

Threats 

• • Deforestation and habitat loss and fragmentation 

• • Illegal hunting / trafficking and pet trade 

How We Care 

• • Brookfield Zoo Chicago cares for five orangutans (two male, three female). 

• • As you visit Tropic World and soon Bramsen Tropical Forests, the Zoo aims to connect you to the great conservation work being achieved through the Orangutan SAFE conservation objective of protecting, connecting, and restoring orangutan habitat.