L’écologie de la Mone de Lowe (Cercopithecus campbelli lowei) en Côte d’Ivoire

Lowe’s guenon ( Cercopithecus campbelli lowei) is still one of the commonest monkeys of the Ivory Coast. It is found in all forest types, from old mature rain forest to secondary growth. Although these monkeys spend most of their time in the middle and lower layers of the forest, they occasionally visit the canopy or descend to the ground. The various types of locomotion are described and illustrated. Most of the detailed information obtained on the ecology and behaviour of the Lowe’s guenon is based upon observations made from 1967 to 1969 on a wild troop living on the grounds of the Swiss Research Center, at Adiopodoumé. The history of this group has been recorded since 1964. Comparative observations were made on various wild troops in western Ivory Coast, and on 2 free ranging pets at the Lamto field station in 1967. The home range of the Adiopodoumé troop is small, covering about 3 hectares. The monkeys use the same sleeping trees for long periods of time and regularly visit fruit trees and places where they are given bananas. There is no rigid daily time schedule, and most of the home range is visited every day. The wild troop does not allow adult foreign conspecifics to settle on its territory, but a one year old male infant was accepted in February 1969. The staple food of the Lowe’s guenon consists of fruits, tlowers and leaves. Thirty two species of food plants are recorded. The monkeys are also very fond of insects, which they actively hunt both in trees and on the ground. Insect hunting is selective, some unpalatable species being deliberately rejected. Water is licked from leaves and branches, or scooped out of tree holes. Breeding is seasonal, all infants being born between mid- November and mid-January, at the verv end of the long rains and the beginning of the dry season. Thus the females appear to conceive during the annual peak in rainfall and during the annual decline in temperature. The social structure of the troop is described. Although it includes more males than females, the Adiopodoumé troop is a « one male group », centered around the adult male. He acts as a leader and spends a great deal of time watching. The « war ning bark » is his prerogative. Unlike mature females who readily act as « aunts », the adult male does not show interest in infants, even newborn ones, and juveniles. However he allows them to play close to him. Subadult males are bolder and more inquisi tive than any other troop member. Juveniles and infants are very active players. No overt and rigid social hierarchy exists within the troop, although in certain circumstances younger individuals give way to older ones. Early in 1969 a splitting of the group was observed. It took place progressively and quietly. In February, two males, 4 and 3 years old, and one 4 year old female, began to separate from the rest of the troop during the day, returning to the traditional sleeping trees at night. They left the troop’s home-range for good around the 1st of March. Lowe’s guenon often associates with other species of Cerco- pithecus (C. petaurista mainly) and Colobines ( Colobus pohjkomos and C. badins). These mixed troops are more than chance aggre gations of different species on the same food trees. In Lamto, the two free ranging male Cercopithecus campbelli lowei reacted immediately to the distress calls of a young female C. petaurista living with them, and would come to her rescue if she was in danger. Interactions with other Vertebrates are described. Reactions to soaring birds of prey are not stereotyped : in Adiopodoumé, the monkeys were not afraid of the common black kites, whereas an approaching buzzard sent them « diving » into thick foliage. Play interactions were observed with roosting hornbills, and even a pet mongoose. Breeding periodicity, which permits an eventual use of sea sonal food surpluses, and the ability to descend to the ground and cross open spaces, might « pre-adapt » this forest monkey to life in wooded savannas. These two characteristics certainly help one to understand the wide range of Lowe’s guenon and its ability to live in the forest-savanna boundary