1Anthropology, University of Florida, 2Anthropology, The Ohio State University, 3Tai Monkey Project, Cote d'Ivoire
Saturday All day, Park Concourse
Colobus polykomos and Procolobus badius from Taï Forest, Cȏte d’Ivoire are known to differ in diet, mandibular morphology, and patterns of dental wear; however, little is known about species-specific differences in ingestive behavior that may be correlated with these variables. From July 2010 through March 2011, we used focal animal sampling to record the ingestive behaviors associated with all foods consumed by both taxa. During five-minute scans the number of ingestive actions was recorded to include food species, food part, incisal bites, canine punctures/scrapes, and masticatory cycles. Data from 270 scans of Procolobus and 387 scans of Colobus were analyzed. We operated under the null hypothesis that once food species and part (young leaves, mature leaves, ripe fruit, unripe fruit) are accounted for, incisor use and masticatory work (cycles per ingestive event) will be similar in the two taxa.
Colobus uses its incisors more often per action than Procolobus, and this is largely attributable to incisal work performed by the former on two foods (Bussea occidentalis fruit and Pentaclethera macrophylla seed pods) in which the average incisal bites per action is >20. Overall, masticatory work is greater in Colobus, averaging 18 chewing cycles per action compared to 15 in Procolobus. This is attributable to the greater reliance on young leaves by Procolobus. Another factor is the intensive chewing of Pentaclethera by Colobus. Few foods account for a majority of ingestive effort in Colobus, whereas in Procolobus this effort is more evenly distributed among food species and plant parts.
Supported by NSF BCS-0922429 and 0921770