title: Primate dietary ecology in the context of food mechanical properties.
abstract: Substantial variation exists in the mechanical properties of foods consumed by primate species. This variation is known to influence food selection and ingestion among non-human primates, yet no large-scale comparative study has examined the relationships between food mechanical properties and feeding strategies. Here, we present comparative data on the Young's modulus and fracture toughness of natural foods in the diets of 31 primate species. We use these data to examine the relationships between food mechanical properties and dietary quality, body mass, and feeding time. We also examine the relationship between food mechanical properties and categorical concepts of diet that are often used to infer food mechanical properties. We found that traditional dietary categories, such as folivory and frugivory, did not faithfully track food mechanical properties. Additionally, our estimate of dietary quality was not significantly correlated with either toughness or Young's modulus. We found a complex relationship among food mechanical properties, body mass, and feeding time, with a potential interaction between median toughness and body mass. The relationship between mean toughness and feeding time is straightforward: feeding time increases as toughness increases. However, when considering median toughness, the relationship with feeding time may depend upon body mass, such that smaller primates increase their feeding time in response to an increase in median dietary toughness, whereas larger primates may feed for shorter periods of time as toughness increases. Our results emphasize the need for additional studies quantifying the mechanical and chemical properties of primate diets so that they may be meaningfully compared to research on feeding behavior and jaw morphology.
authors.affiliation: Department of Anthropology, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States; Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States. Electronic address: scoinerc@nd.edu.
authors.forename: Susan
authors.initials: S
authors.lastname: Coiner-Collier
authors.affiliation: Department of Anthropology, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States.
authors.forename: Robert S
authors.initials: RS
authors.lastname: Scott
authors.affiliation: Department of Basic Medical Sciences, Mercer University School of Medicine, Macon, GA, United States.
authors.forename: Janine
authors.initials: J
authors.lastname: Chalk-Wilayto
authors.affiliation: Wildlife Conservation Research Unit (WildCRU), Department of Zoology, University of Oxford, Oxford, UK; Orang-utan Tropical Peatland Project (OuTrop), Palangka Raya, Indonesia.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Cheyne
authors.affiliation: Department of Biology, Marshall University, Huntington, WV, United States.
authors.forename: Paul
authors.initials: P
authors.lastname: Constantino
authors.affiliation: Department of Anthropology, Dartmouth College, Hanover, NH, United States.
authors.forename: Nathaniel J
authors.initials: NJ
authors.lastname: Dominy
authors.affiliation: Department of Social Sciences, Florida Gulf Coast University, Fort Myers, FL, United States.
authors.forename: Alison A
authors.initials: AA
authors.lastname: Elgart
authors.affiliation: School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, United States.
authors.forename: Halszka
authors.initials: H
authors.lastname: Glowacka
authors.affiliation: Department of Biological Sciences, University of Southern California, Los Angeles, CA, United States.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Loyola
authors.affiliation: Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University, Stony Brook, NY, United States.
authors.forename: Kerry
authors.initials: K
authors.lastname: Ossi-Lupo
authors.affiliation: Department of Anthropology, University of Illinois, Urbana-Champaign, Urbana, IL, United States.
authors.forename: Melissa
authors.initials: M
authors.lastname: Raguet-Schofield
authors.affiliation: Department of Environmental Sciences, Universidade Federal de Sao Paulo, Campus Didema, Sao Paulo, Brazil; Southern Muriqui Conservation & Research of Southern Brazilian Atlantic Forest, Pró-Muriqui Association, Sao Miguel Arcanjo, SP, Brazil.
authors.forename: Mauricio G
authors.initials: MG
authors.lastname: Talebi
authors.affiliation: Southern Muriqui Conservation & Research of Southern Brazilian Atlantic Forest, Pró-Muriqui Association, Sao Miguel Arcanjo, SP, Brazil; Ciencias Biologicas, Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Enrico A
authors.initials: EA
authors.lastname: Sala
authors.affiliation: Department of Anthropology, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States.
authors.forename: Pawel
authors.initials: P
authors.lastname: Sieradzy
authors.affiliation: Department of Orthopaedic Surgery, Duke University School of Medicine, Durham, NC, United States; Department of Evolutionary Anthropology, Duke University, Durham, NC, United States.
authors.forename: Andrea B
authors.initials: AB
authors.lastname: Taylor
authors.affiliation: Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, OH, United States.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Vinyard
authors.affiliation: Department of Anatomy, Kansas City University of Medicine and Biosciences, Kansas City, MO, United States.
authors.forename: Barth W
authors.initials: BW
authors.lastname: Wright
authors.affiliation: Institute for Population Genetics, University of Veterinary Medicine, Vienna, Austria; Austrian Academy of Sciences, Austria.
authors.forename: Nayuta
authors.initials: N
authors.lastname: Yamashita
authors.affiliation: Smithsonian Tropical Research Institute, Balboa, Panama.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Lucas
authors.affiliation: Department of Anthropology, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States.
authors.forename: Erin R
authors.initials: ER
authors.lastname: Vogel
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004032:Diet; D055119:Elastic Modulus; D005247:Feeding Behavior; D005260:Female; D005504:Food Analysis; D008297:Male; D008409:Mastication; D011323:Primates / Q000502:physiology*
keywords: Feeding behavior; Food mechanical properties; Primate diet; Toughness; Young's modulus