How Developed Is a Newborn Gorilla?

After a pregnancy that lasts on average 257 days (humans: 265 days), gorillas usually give birth in less than half an hour and the mother doesn't seem to feel any great pain. However, difficult births do occur and can take up to three days. Twin births occur approximately as often as in humans, but free-ranging mothers usually do not raise both twins. Newborn western gorillas weigh between 1,396 and 3,058 g (2,200 g on average), compared to 3,300 g in humans. This means that while adult females and males weigh approximately twice and three times as much as average humans, their newborn babies are only two thirds the weight of newborn humans.   >