The event is to be streamed live on the internet – at www.chimpeden.com – by the Mpumalanga-based institute.
According to Timeslive, A night-vision camera will capture the action if Nina goes into labour when it is dark.
The sanctuary’s executive director, David Devo Oosthuizen, said that thought Nina’s pregnancy was an “accident” – after the failure of a contraceptive implant – the institute decided to share it with its thousands of social media followers around the world.
“We want to tell a story”, he said.
The centre’s vets thought Nina had a massive tumour before realising that she was pregnant.
The sanctuary does not breed chimpanzees because it needs all the space it has for rescued chimpanzees.
Nina is from South Sudan, where she was rescued from poachers who had captured her for the wild bush-meat trade.
She was kept in a zoo in Sudan before the institute removed her along with other chimpanzees, including Thomas, thought to be the baby’s father.
Oostuizen said Nina had been “literally plucked from her mom” by hunters. This might lead to complications because Nina was “deprived of a normal chimpanzee childhood”.
Another factor is that she has not seen how chimpanzee mothers care for their babies because the sanctuary does not breed chimpanzees.
“We are hoping instinct kicks in and she doesn’t reject the baby,” said Oosthuizen.
A first-time chimpanzee mother is usually 15 years old, meaning Nina, at nine, is a gymslip mother.
Despite concerns, the sanctuary is excited about a chimpanzee birth because there are only about 200000 chimps left in the wild.
In 10 years there might be no free-living chimpanzees because of poaching and deforestation, Oosthuizen said.
“Everybody focuses on rhino poaching and, though that is important, chimps are also endangered, if not more so.”