Patterns of frugivory in three West African colobine monkeys

We studied the comparative feeding ecology of three species of colobus (Pro colobus badius, Procolobus verus, and Colobus polykomos) on Tiwai Island, S ierra Leone. We collected dietary data on each species by scan-sampling hab ituated groups. Because these groups were observed in the same study area d uring overlapping time periods, the confounding effects of temporal and spa tial variability in food availability were reduced. Our results show that t he annual diets of the two larger species (Procolobus badius and Colobus po lykomos) include roughly equal proportions of fruits (including seeds), you ng leaf parts, and mature leaf parts, although P. badius had a greater inta ke of floral parts. Procolobus verus consumed almost no mature leaf parts, few fruits and seeds, and many young leaf parts. Colobus polykomos commonly fed from lianas. Seeds were the dominant fruit item eaten by all three col obus, and the fruits they selected were generally dull and non-fleshy, in c ontrast to the brightly-colored, pulpy fruits eaten by guenons. Leguminous plants contributed substantially to the diets of both the larger species, b ut comparisons with other African forest sites indicate that colobine bioma ss is not closely correlated with the abundance of leguminous trees in the forest.