Ramble across the Rainforest in the Company of a Group of Monkeys

Copyright by David Rouge
Copyright by David Rouge
Copyright by David Rouge

 

In 2004, the PHP diversified its activities and began habituating a large group of agile mangabeys (Cercocebus agilis) which have since been followed daily. Agile managbeys are medium sized monkeys (males 7-12kg, females 5-7kg) which very much live up to their generic name by their vibrant nature. They are mostly ground-dwelling, and feed on a diverse array of fruits, seeds, stems, mushrooms, eggs, insects, crustaceans, and even certain mammals. The group can be observed at leisure at distances of under 10m whilst their active hands rummage through leaf litter in search of insects, investigating and extracting all that is possibly edible from holes in trees, digging up mushrooms, storing seeds in their cheek pouches, and grooming their companions.

Agile mangabeys also have a vast vocal repertoire, with the males possessing a vocal sac to amplify their distinctive ‘whoops’ across the forest - allowing them to communicate to the rest of their group and other groups.

The group followed at Bai Hokou is of an exceptional size, numbering more than 200 individuals, ranging in an area covering many km2, and focused around the bai system. The habituation process allows this otherwise secretive and relatively unknown species to be easily observed in the dense vegetation. From the first months, the PHP were able to make exceptional observations such as opportunistic hunting of young antilopes (duikers) by the males, and a mid-year birthing season. However, with the potential to form such large groups, the social organisation of agile mangabeys is evidently complex, and much is still to be learnt.

The starting point for this activity is at Bai Hokou (35 km from Bayanga), which takes about 1 hour by car.