The primary objective of this proposal is to clarify the ecology of two species of frugivorous New World monkeys: Pithecia pithecia and Chiropotes satanas. These two species overlap significantly in their distributions and in broad terms utilize similar foods. The pithecines also possess a rather unique anterior dental complex with large canines and general hypertrophy of the anterior dentition. How does this dental structure relate to physical characteristics of their food stuffs? How do the species differ in food choices in their areas of sympatry? This research will test a series of linked hypotheses regarding the choice and processing of foods by the two species. Specifically, the PI will, through both field observation and laboratory analysis (1) test the ability of the dentition of these species to reduce hard dietary items (2) determine the importance of each item to the nutrition of each species (3) study the use of the large anterior teeth (especially the canines) in food processing as well as the grinding role of the molars (4) determine the relative importance of each item to the diet of the two species. Through this analysis the researchers should clarify the relationship of teeth to dietary choices and the role of the later in preventing competition between closely related species.
