Can Dental Microwear Textures Record Inter-Individual Dietary Variations?

Background Dental microwear analyses are commonly used to deduce the diet of extinct mammals. Conventional methods rely on the user identifying features within a 2D image. However, recent interdisciplinary research has lead to the development of an advanced methodology that is free of observer error, based on the automated quantification of 3D surfaces by combining confocal microscopy with scale-sensitive fractal analysis. This method has already proved to be very efficient in detecting dietary differences between species. Focusing on a finer, intra-specific scale of analysis, the aim of this study is to test this method's ability to track such differences between individuals from a single population. Methodology/Principal Findings For the purposes of this study, the 3D molar microwear of 78 individuals from a well-known population of extant roe deer (Capreolus caprelous) is quantified. Multivariate statistical analyses indicate significant seasonal and sexual differences in individual dental microwear design. These are probably the consequence of seasonal variations in fruit, seed and leaf availability, as well as differences in feeding preference between males and females due to distinct energy requirements during periods of rutting, gestation or giving birth. Nevertheless, further investigations using two-block Partial Least-Squares analysis show no strong relationship between individual stomach contents and microwear texture. This is an expected result, assuming that stomach contents are composed of food items ingested during the last few hours whereas dental microwear texture records the physical properties of items eaten over periods of days or weeks. Conclusions/Significance Microwear 3D scale-sensitive fractal analysis does detect differences in diet ranging from the inter-feeding styles scale to the intra-population between-season and between-sex scales. It is therefore a possible tool, to be used with caution, in the further exploration of the feeding biology and ecology of extinct mammals.

[1]  S. McNaughton,et al.  Silica as a Defense against Herbivory and a Growth Promotor in African Grasses , 1985 .

[2]  A. Walker,et al.  Quantitative differences in dental microwear between primate species with different diets and a comment on the presumed diet of Sivapithecus. , 1984, American journal of physical anthropology.

[3]  N. Dominy,et al.  Mechanical Defences to Herbivory , 2000 .

[4]  F J Rohlf,et al.  Use of two-block partial least-squares to study covariation in shape. , 2000, Systematic biology.

[5]  A. Walker,et al.  Interpreting the diet of extinct ruminants: the case of a non-browsing giraffid , 1988, Paleobiology.

[6]  M. Teaford,et al.  Technique and Application in Dental Anthropology: Dental microwear analysis: historical perspectives and new approaches , 2008 .

[7]  G. Merceron,et al.  Paleoenvironment of Dryopithecus brancoi at Rudabánya, Hungary: evidence from dental meso- and micro-wear analyses of large vegetarian mammals. , 2007, Journal of human evolution.

[8]  Christopher A. Brown,et al.  Dental microwear texture analysis shows within-species diet variability in fossil hominins , 2005, Nature.

[9]  J. Vincent,et al.  Variations saisonaières du régime alimentaire du chevreuil (Capreolus capreolus) selon le sexe en milieu forestier à forte densité (forêt domaniale de Dourdan) , 2001 .

[10]  R. Iman,et al.  Rank Transformations as a Bridge between Parametric and Nonparametric Statistics , 1981 .

[11]  N. Morellet,et al.  Spatial heterogeneity of winter forest resources used by deer , 1999 .

[12]  G. Merceron,et al.  How could sympatric megaherbivores coexist? Example of niche partitioning within a proboscidean community from the Miocene of Europe , 2008, Naturwissenschaften.

[13]  M. Hermy,et al.  Impact of season, habitat and research techniques on diet composition of roe deer (Capreolus capreolus): a review , 1999 .

[14]  M. Teaford,et al.  Seasonal or ecological differences in diet and molar microwear in Cebus nigrivittatus. , 1989, American journal of physical anthropology.

[15]  R. Andersen,et al.  The European roe deer: the biology of success. , 2000 .

[16]  F. James Rohlf,et al.  Biometry: The Principles and Practice of Statistics in Biological Research , 1969 .

[17]  M F Teaford,et al.  Error rates in dental microwear quantification using scanning electron microscopy. , 2006, Scanning.

[18]  John Aitchison,et al.  The Statistical Analysis of Compositional Data , 1986 .

[19]  H. Covert,et al.  Dental microwear and diet: implications for determining the feeding behaviors of extinct primates, with a comment on the dietary pattern of Sivapithecus. , 1981, American journal of physical anthropology.

[20]  R. A. Crovelli,et al.  An objective replacement method for censored geochemical data , 1993 .

[21]  A. Boucot.  Evolutionary Paleobiology of Behavior and Coevolution , 1990 .

[22]  C. Blondel,et al.  Tooth microwear pattern in roe deer (Capreolus capreolus L.) from Chizé (Western France) and relation to food composition , 2004 .

[23]  M. Ozbek,et al.  Morphological evaluation of rat incisor enamel and dentin induced by pregnancy and lactation using a scanning electron microscope. , 2009, The Journal of veterinary medical science.

[24]  P. Duncan,et al.  Food selection by European roe deer (Capreolus capreolus): effects of plant chemistry, and consequences for the nutritional value of their diets , 2009 .

[25]  M. Germonpré,et al.  Predormancy omnivory in European cave bears evidenced by a dental microwear analysis of Ursus spelaeus from Goyet, Belgium , 2009, Proceedings of the National Academy of Sciences.

[26]  A. Walker,et al.  Mecrowear of mammalian teeth as an indicator of diet. , 1978, Science.

[27]  N. Solounias,et al.  Differences in Tooth Microwear of Populations of Caribou (Rangifer tarandus, Ruminantia, Mammalia) and Implications to Ecology, Migration, Glaciations and Dental Evolution , 2007, Journal of Mammalian Evolution.

[28]  N. Solounias,et al.  Advances in the Reconstruction of Ungulate Ecomorphology with Application to Early Fossil Equids , 2002 .

[29]  D. Wilson,et al.  Optimal Foraging, Specialization, and a Solution to Liem's Paradox , 1998, The American Naturalist.

[30]  F. Chayes.  On correlation between variables of constant sum , 1960 .

[31]  Peter S. Ungar,et al.  Dental Microwear Texture Analysis of Varswater Bovids and Early Pliocene Paleoenvironments of Langebaanweg, Western Cape Province, South Africa , 2007, Journal of Mammalian Evolution.

[32]  J. Moradian-Oldak,et al.  The structural biology of the developing dental enamel matrix. , 1999, Journal of structural biology.

[33]  A. Sempéré,et al.  Food availability as a factor in habitat use by roe deer , 1989 .

[34]  P. Ungar,et al.  Microwear evidence for Plio–Pleistocene bovid diets from Makapansgat Limeworks Cave, South Africa , 2006 .

[35]  J. Vincent,et al.  Le problème de la détermination de l’âge : une source d’erreur négligée dans le calcul des tables de vie transversales , 1994 .

[36]  J. Angibault,et al.  The influence of increasing density on body weight, kid production, home range and winter grouping in roe deer (Capreolus capreolus) , 1995 .

[37]  R. Wrangham,et al.  Evolutionary Consequences of Fallback Foods , 2007, International Journal of Primatology.

[38]  P. Duncan,et al.  Are European roe deer browsers ? A review of variations in the composition of their diets , 1996, Revue d'Écologie (La Terre et La Vie).

[39]  Peter S Ungar,et al.  Dental microwear texture analysis: technical considerations. , 2006, Journal of human evolution.

[40]  M. Teaford,et al.  In vivo and in vitro turnover in dental microwear. , 1989, American journal of physical anthropology.

[41]  R. F. Gerlach,et al.  Enamel mineralization in the absence of maturation stage ameloblasts. , 2009, Archives of oral biology.

[42]  A. Walker,et al.  Dental caries in South African rural black women who had large families and long lactations. , 1983, The Journal of tropical medicine and hygiene.

[43]  S. Shen,et al.  The statistical analysis of compositional data , 1983 .