Unlike all other primates, who are gregarious and live in social groups, orangutans are semi-solitary animals. They are born after a gestation period of 8 months, and spend the first 5-9 years with their mother, the longest period of infant dependence of any land mammal, after which females establish a home range nearby, and males enter a period of wandering. Sexual maturity is reached between 12 and 15 years of age, the age at which females usually give birth to their first infant. Offspring are conceived after a courtship of between 3-10 days, which is usually bought to an end by the female. Males play no part in the raising of the young. Orangutans are unusual among primates in having two different types of sexually mature, fertile males, those that have developed the secondary physical characteristics of sexual maturity and those that haven’t.

 

Orangutans are slow moving animals, and spend up to 60% of their day feeding and foraging, and the other 40% resting or sleeping.