Birth & Care of Young
- Orangutan gestation (pregnancy) lasts around eight and a half months.
- During pregnancy, females are vulnerable to droughts and other conditions affecting food supplies. If food is not plentiful, pregnant females may become weak.
- Generally, one infant is produced with each birth. Twins are rare.
- Females usually give birth on their nests, which are often more than 30 m (99 ft.) up in the trees. These nests are carefully constructed to accommodate the pregnancy weight gain and to prevent the newborn from slipping through a crack.
- Orangutan mothers are the infants only means of transport, support, food, comfort, safety, and often the exclusive source for information and essential learning experiences.
Mother and infant at Busch Gardens Tampa Bay.
Infants & Young
- Infant orangutans weigh about 1.5 kg (3.3 lb.) at birth (small enough to fit in a human's palm) and are completely dependent on their mother. Infants cannot even raise their heads at birth.
- Once infants are born, mother orangutans clean them and begin nursing.
- The legs and arms of the infants are very thin at birth. Their muscles begin to develop once they start climbing trees.
- Infants have large eyes that are open at birth. They are sparsely covered with hair, have wrinkled faces, and are toothless.
- Orangutans have the longest infant development period of all the great apes. It is commonly divided into three stages.
- With the high maternal investment in raising young, there is usually an eight to ten year time span between births.
- Since females generally have only three to four offspring in their lifetime, males may engage in fierce competition for females.
- As a slow—reproducing animal, orangutans are particularly vulnerable to population losses, as they take decades, even centuries to replace.
- Females remain fertile until about 30 years of age.