Arbors and cuttings: New trials for Green Corridor Project at Bossou-Nimba
Gaku Ohashi, Ryo Hasegawa, Kourouma Makan, Tetsuro Matsuzawa
Since 1976, wild chimpanzees have been studied at Bossou, Guinea, in West Africa. The Bossou group itself is extremely endangered. Since the beginning of our study more than 30 years ago, no female chimpanzee immigration has been recorded, whereas all of the female chimpanzees born at Bossou disappeared around sexual maturation.
As a result, the percentage of aged individuals is increasing in the group. To make matters worse, the number of Bossou chimpanzees suddenly decreased to 12 in 2003, due to an epidemic of respiratory disease. For the group’s survival, individual immigration from the nearest groups is essential.
About 10 km away from Bossou, at least one chimpanzee group lives in the Nimba Mountains. In order to promote individual interchange between the Bossou and Nimba groups, we started in 1997 the “Green Corridor Project”, which has involved planting trees along a 4 km long expanse of savanna area separating Bossou from Nimba. Owing to this effort, we can see today small forest patches growing in this area .