Orangutans (Pongo spp.) Fact Sheet: Physical Characteristics

• Skin dark gray
• Arms about twice as long as trunk
• Legs are short, a little more than half the length of the arms
• Cheek teeth bunodont (low, rounded)
• Pelage
• Long, flowing, reddish pelage
• Face of males and females sparsely covered, but may have beard and moustache.

• Highly dimorphic; large males may have a body mass more than twice that of females (Delgado & Schaik 2000)
• Males that are sexually mature have two distinct body types: one larger and dominant, one smaller but still breeds (Utami et al. 2002)
• Hanging throat sac present in both sexes, but much larger in males
• Very large cheek pads in males
• Males are larger and heavier than females
• Males have larger canines and first lower premolars
• Males have more pronounced beard and moustache
• Little dimorphism is displayed at birth, making sex identification difficult

Sub-specific Differences: May be due to individual rather than sub specific differences

• Bornean orangutans (P. p. pygmaeus)
  • male facial flanges curved forward
  • male gular (throat) sacs larger and pendulous
  • darker color of hair and face
  • hair shorter and less dense
• Sumatran orangutans (P.p. abelii)
• male facial flanges lie flat
• male gular (throat) sac smaller
• lighter color of hair and face
• hair longer, thicker, more wooly

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Delgado and van Shaik, (2000)
Groves, (1971)
Utami et al. (2002)