Comparing effects of food mechanical properties on oral processing behaviors in two sympatric lemur species

Abstract

AbstractObjectivesThe link between diet and the masticatory apparatus in primates is complex. We investigated how food mechanical properties (FMPs) and food geometry affect feeding behaviors and subsequent jaw loading. We compared oral processing in two sympatric lemur species with distinct diets and mandibular morphologies.Materials and MethodsAll‐day focal follows ofLemur catta(Lc) andPropithecus verreauxi(Pv) were conducted in both the dry and wet seasons at Beza Mahafaly Special Reserve. We collected activity budget data, filmed feeding bouts, and collected food items to measure their mechanical properties with an FLS‐1 portable tester. Feeding videos for the top food items they spent the most time consuming were analyzed frame‐by‐frame to assess bite and chew numbers and rates.ResultsLcbite more and at a slower rate on tougher (maximum) foods, chew more for tougher (average) foods, and chew less for stiffer leaves.Pvinitially increase chew number for tougher (average) foods, but their behavior is less affected as food toughness increases.Pvchew less and more slowly but spend more of the day feeding thanLc. Additionally, they have a tougher (maximum) diet thanLc.DiscussionLcadjust their feeding behaviors depending on the FMPs of their top food items, whilePvfeed more consistently. The more robust masticatory apparatus ofPvmay not require them to adjust their feeding behaviors for more mechanically challenging foods. Furthermore, the two species show distinct differences in chewing. Exploring chewing on a daily scale could aid in understanding its impact on the loading of the masticatory apparatus.