Bornean Orangutan

• Range: Found only on the island of Borneo in Southeast Asia.
  
• Habitat: All levels of lowland primary rain forest. Almost totally arboreal. Rivers and streams make natural boundaries.
  
• Description: Coloration of the orangutan varies from orange to brown or maroon. From the top of the head a fringe of fur lies toward the forehead. On the arms the hair runs in both directions toward the elbow to help shed rainwater. The orangutan has long arms and short legs. Legs may go at right angles to the body for better maneuverability in the trees. Hands are long, slender and prehensile with curved phalanges. The thumb is short and set close to the wrist. Feet are hook-like with a reduced big toe similar to hands. Fingers and toes show strongly curved nails. Lifespan is 30 years in the wild, 50 years in captivity.
  
• Diet: Primarily herbivorous; predominantly fruits, leaves, and bark; some bird eggs.
  
• Behavior: Travel in trees involves the use of all limbs, with the feet as effective as hands. Movement is cautious in adults with no leaping or jumping. On the ground orangutans walk on all fours with feet clenched and “knuckle-walking.” Bipedalism is only seen in captivity, walking with arms held upright for balance. Groups consist of an adult female with one or two young. Males are generally solitary, avoiding other males of their species by bellowing, shaking or throwing branches. Males sometimes become nomadic and leave their native territory.
  
• Breeding: The female orangutan menstrual cycle runs 30 to 35 days. Mating is done in a hanging position. Gestation lasts about 244 days. One baby is born, rarely two, any time of the year. Birth weight is about 1,800 grams. Babies are born approximately every four years.