My, what big incisors you have! All the better to eat tough-skinned fruit.

The Tana River mangabey is a member of the Cercocebus genus of monkeys. It is endemic to Kenya. Cercocebus mangabeys have large incisors, enlarged premolars, and thick molar enamel. These dental adaptations are hypothesized for feeding on tough-skinned fruit, hard nuts, and seeds. However, there is not much data on how mangabeys dentally process their food items. During the summer of 2009, I took videos of Tana River mangabeys (C. galeritus) eating doum palm fruits (Hyphaene compressa). The doum palm fruit is one of their top diet items and one of the most puncture resistant fruits in their diet. I analyzed 20 videos. I identified six dental processing activities: incisal bites, incisal picks, incisal scrapes, canine punctures, postcanine scrapes, and postcanine crushes. I recorded 1629 processing activities. The mangabeys predominantly used their incisors (339 bites, 98 picks, and 933 incisal scrapes). The mangabeys also used their postcanine dentition (217 crushes, and 41 postcanine scrapes). All postcanine crushes involved a small piece that the mangabey had bitten off the fruit with its incisors. One of the mangabey’s most puncture resistance foods requires the use of their large incisors and their thickly enameled postcanines.