It has long been believed that gibbons were monogamous, but more recent research shows that this is not quite true – extrapair copulations, partner changes and polyandrous groupings are also possible. There is no set breeding season for gibbons. The gestation period is about 7 months, usually resulting in the birth of a single baby with birth weight of about 308g. It then takes about 2 years for the baby to be weaned and about 8 years before the offspring are ready to breed themselves. Once the offspring are capable of looking after themselves, they are chased away by their parents.