In Malay orang means “person” and utan is derived from hutan, which means “forest.” Thus, orangutan literally means “person of the forest.”
Orangutans’ arms stretch out longer than their bodies – up to 8 ft. from fingertip to fingertip in the case of very large males.
When on the ground, orangutans walk on all fours, using their palms or fists. Unlike the African apes, orangutans are not morphologically built to be knuckle-walkers.
From the age of thirteen years (usually in captivity) past the age of thirty, males may develop flanges and large size.
When males are fighting, they charge each other, grapple, and bite each other’s heads and cheekpads. They sometimes look like Sumo wrestlers.
For the first few years of his/her life, a young orangutan holds tight to his/her mother’s body as she moves through the forest canopy.
Like humans, orangutans have opposible thumbs. Their big toes are also opposible. Unlike humans, approximately one third of all orangutans do not have nails on their big toes.
Orangutans have tremendous strength, which enables them to brachiate and hang upside-down from branches for long periods of time to retrieve fruit and eat young leaves.
Although in the wild, females usually give birth to their first offspring when they are 15-16 years of age, in captivity females as young as eight years old have given birth. Likewise male orangutans in captivity as young as eight years old have fathered offspring.
Bornean and Sumatran orangutans can breed together in captivity, producing viable offspring. So many Bornean/Sumatran crosses were once present in American zoos (before such breeding was banned) that there were more crosses in captivity than “pure” Bornean orangutans.