Barbary apes are threatened with extinction in their native habitat in north Africa, scientists say, but the species is doing well in Europe, and some have even been repatriated.
The challenge now, says Ellen Merz, a Swiss ethnologist who has been studying them since 1972, "is to protect them in their native countries and save the forests where they live there from felling and over-grazing".
"I hope we'll be able to save them," she said, "but it's not guaranteed."
Barbary apes, which in fact are monkeys, also roam Gibraltar, the British island off Spain.
In France, they have been living for 36 years at the Kintzheim reserve deep in the forest on the northeast border with Germany.
There are now 298 of them in the park, known as "Monkey Mountain," which covers 24 hectares (60 acres) of pines, firs, and oak and beech trees, and overlooks the half-timbered houses of the village of Kintzheim.