A female orangutan reaches her sexual maturity when she is 12-13 years old. Orangutans have one of the slowest reproduction cycles among all mammalians. Usually in the age of 15 she delivers her first young that rears and educates for 15 years. After 8 years from her confinement, she is able to become pregnant again giving birth to one young. If it happens she delivers twins, one of them is condemn to death. In general, one female can deliver 2-3 offspring during her entire lifetime.