Western lowland gorilla Momoko gave birth Wednesday at Tokyo's Ueno Zoo, officials at the facility said Thursday.
The 29-year-old mother and the baby, whose sex is not yet known, are both in stable condition, the officials said.
It is Momoko's third baby, but the first time she has given birth amongst other gorillas rather than on her own. Soon after giving birth at just past 6 p.m. Wednesday, Momoko began holding the baby and looking after it, they said.
The western lowland gorilla inhabits western Africa and is threatened with extinction.
Momoko was transferred to Ueno Zoo in 1999 from Chiba Zoological Park in the city of Chiba for breeding.