title: Tooth wear and feeding ecology in mountain gorillas from Volcanoes National Park, Rwanda.
abstract: OBJECTIVE
  Ecological factors have a dramatic effect on tooth wear in primates, although it remains unclear how individual age contributes to functional crown morphology. The aim of this study is to determine how age and individual diet are related to tooth wear in wild mountain gorillas (Gorilla beringei beringei) from Volcanoes National Park, Rwanda.
  
  
  METHODS
  We calculated the percent of dentine exposure (PDE) for all permanent molars (M1-M3) of known-age mountain gorillas (N = 23), to test whether PDE varied with age using regression analysis. For each molar position, we also performed stepwise multiple linear regression to test the effects of age and percentage of time spent feeding on different food categories on PDE, for individuals subject to long-term observational studies by the Dian Fossey Gorilla Fund International's Karisoke Research Center.
  
  
  RESULTS
  PDE increased significantly with age for both sexes in all molars. Moreover, a significant effect of gritty plant root consumption on PDE was found among individuals. Our results support prior reports indicating reduced tooth wear in mountain gorillas compared to western gorillas, and compared to other known-aged samples of primate taxa from forest and savanna habitats.
  
  
  CONCLUSIONS
  Our findings corroborate that mountain gorillas present very low molar wear, and support the hypothesis that age and the consumption of particular food types, namely roots, are significant determinants of tooth wear variation in mountain gorillas. Future research should characterize the mineral composition of the soil in the Virunga habitat, to test the hypothesis that the physical and abrasive properties of gritty foods such as roots influence intra- and interspecific patterns of tooth wear.
authors.affiliation: Center for the Advanced Study of Human Paleobiology, Department of Anthropology, The George Washington University, DC.
authors.forename: Jordi
authors.initials: J
authors.lastname: Galbany
authors.affiliation: Dian Fossey Gorilla Fund International, Atlanta, GA.
authors.forename: Olive
authors.initials: O
authors.lastname: Imanizabayo
authors.affiliation: Departamento de Biotecnología, Universidad de Alicante, Alicante, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Romero
authors.affiliation: Dian Fossey Gorilla Fund International, Atlanta, GA.
authors.forename: Veronica
authors.initials: V
authors.lastname: Vecellio
authors.affiliation: Institute of Human Origins, Arizona State University, Tempe, AZ.
authors.forename: Halszka
authors.initials: H
authors.lastname: Glowacka
authors.affiliation: Mountain Gorilla Veterinary Project, University of California at Davis, CA.
authors.forename: Michael R
authors.initials: MR
authors.lastname: Cranfield
authors.affiliation: Hard Tissue Research Unit, New York University College of Dentistry, NY.
authors.forename: Timothy G
authors.initials: TG
authors.lastname: Bromage
authors.affiliation: Rwanda Development Board, Department of Tourism and Conservation, Kigali, Rwanda.
authors.forename: Antoine
authors.initials: A
authors.lastname: Mudakikwa
authors.affiliation: Dian Fossey Gorilla Fund International, Atlanta, GA.
authors.forename: Tara S
authors.initials: TS
authors.lastname: Stoinski
authors.affiliation: Center for the Advanced Study of Human Paleobiology, Department of Anthropology, The George Washington University, DC.|Division of Mammals, National Museum of Natural History, Smithsonian Institution, DC.
authors.forename: Shannon C
authors.initials: SC
authors.lastname: McFarlin
mesh_terms: D000818:Animals; D000885:Anthropology, Physical; D004463:Ecology; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D006071:Gorilla gorilla / Q000502:physiology*; D008297:Male; D012432:Rwanda; D057085:Tooth Wear / Q000503:physiopathology*
keywords: Gorilla beringei beringei; aging; dentine exposure; diet