The monkey's most striking feature is a white nose spot which stands out against the dark face. The putty-nosed guenon is found on Bioko Island and on the mainland from north of the Zaire and Itimbiri rivers west to Nigeria and, in patches, on to Liberia. The monkey is found in all evergreen forests, from lowland to montane, primary, secondary, and narrow galleries and patches. It is uncommon in swamp or mangrove forests. Competing primates usually limit the putty-nosed's range rather than plant content.
Females give booming rallying calls, very loud 'pyows' and alarm hacks.
They eat fruits, seeds, flowers, foliage and invertebrates. Both sexes eat a similar proportion of insects, primarily caterpillars, ants and spiders. No recent births have been reported.