Diet of the Roloway Monkey, Cercopithecus diana roloway, in Bia National Park, Ghana

Summary

The roloway monkey, Cercopithecus diana roloway, occupies a peripheral position among African guenons regarding dental and cranial anatomy, and exhibits primitive features in its chromosomes and details of the vocalization system. I studied feeding and ranging behavior of roloway monkeys at Bia National Park in western Ghana in 1976–1977 with the aim of better understanding the dietary strategy of this species relative to other guenons. At that time, Bia included over 300 km² of mostly undisturbed moist evergreen and moist semideciduous tropical forest. I mapped, measured, and identified 1250 feeding trees and recorded >3000 feeding visits to these trees. I studied feeding behavior using two methods, food item visits (FIV) and scans. The roloway monkey diet was found to be highly diverse, including plant parts from > 130 species of trees, climbers, and epiphytes. Major components of the diet were mature fruit pulp, arthropods, oil-rich seeds, and young leaves. Most food items for this monkey were located among twigs and small supports in the terminal branches of emergent trees and within large woody climbers. Among other forest guenons, the roloway monkey’s dietary strategy may be most similar to that of Cercopithecus nictitans, which also consumes a high proportion of seeds, and the two species may competitively exclude each other.