The baby was born at Mulhouse Zoo, which is coordinating the European Endangered Species Programme to save the Roloway monkeys, native to a small
area of eastern Ivory Coast and the forests of Ghana.
The two-week-old baby has been named Owabi after a wildlife sanctuary in western Ghana.
There are fewer than 200 Roloway monkeys remaining in the wild and only 27 in captivity, Mulhouse Zoo veterinarian Benoit Quintard said.
"The Cercopithecus Roloway is a very endangered species," he said. "Births of this species are very rare in zoos." Roloway monkeys are between 44 and 57 centimetres (17 and 22 inches) long, with tails that can reach lengths of 86 centimetres (34 inches), and on average weigh about five kilogrammes (11 pounds).
Predominantly black, with white areas at the throat and the interior side of the arms, Roloway monkeys are distinguished by their pointed white beards.