Evaluating the fidelity of enamel isotopic data and environmental variation in paleoecological studies: A case study in wild, known-aged, modern white-tailed deer (Odocoileus virginianus)
Document Type
Article
Publication Date
7-15-2023
Publication Title
Palaeogeography, Palaeoclimatology, Palaeoecology
Abstract
Stable carbon and oxygen isotope variability in herbivore enamel is frequently used to evaluate seasonal changes in the diets of fossil taxa as well as their broader ecosystems. Unfortunately, these reconstructions are often based on small samples (i.e., < 5 individuals) and the impacts of inter- and intraindividual variation on these data are largely unknown due to the lack of a modern comparative framework from wild herbivore populations. In this study, we used serially-sampled isotope values from the mandibular dentition (M1, M2, M3) of five wild, male white-tailed deer (Odocoileus virginianus) with known life histories from the Piedmont National Wildlife Refuge (PNWR; central Georgia, USA), to test the fidelity to which seasonal ecosystem-level variability is reflected in enamel carbon and oxygen isotope values. δ13C values across all individuals and sampled teeth fell within −21‰ and − 15.8‰, thereby indicating a diet dominated by C3 vegetation throughout the spring, summer, fall and winter months. We find significant (p < 0.05) inter-individual differences in the means of M1, M2 and M3 δ13C and δ18O values, with the exception of M2 δ18O values. M1 δ13C values were consistently depleted, while δ18O values were consistently enriched (relative to M2 and M3) across all individuals sampled, likely indicative of pre-weaning, milk-dominated diet. Finally, there was little change in δ18O values across the M1, M2 and M3 despite dramatic fluctuations in temperature at the PNWR. We hypothesize that the primary driver of this pattern is the depletion of M2 δ18O values due to the amount effect. These data support a complex relationship between enamel isotopic variation and the fluctuation of abiotic and biotic ecosystem variables that should be more fully considered in paleoecological analyses.
Department
Biological and Environmental Sciences
Volume Number
622
DOI
10.1016/j.palaeo.2023.111587
Recommended Citation
Malasek, Taylor; Barding, Erin; Bender, Michael J.; Bonham, Alexandra; Mead, Alfred J.; Pilgrim, Zachary; Powers, Patrick; Patterson, Jessica R.; and Patterson, David B., "Evaluating the fidelity of enamel isotopic data and environmental variation in paleoecological studies: A case study in wild, known-aged, modern white-tailed deer (Odocoileus virginianus)" (2023). Faculty and Staff Works. 409.
https://kb.gcsu.edu/fac-staff/409