Assessing the use of stable isotope values from deer antlers as proxies for seasonal environmental variation

Abstract

IntroductionWe assess the feasibility of white-tailed deer (Odocoileus virginianus) antlers to serve as archives of information on paleoseasonality by analyzing stable isotope values from four modern white-tailed deer collected in central Iowa, USA. Because antlers develop from early spring to early fall, they may serve as an archive for intra-annual seasonal variations and provide snapshots of past climatic and environmental conditions.MethodsIntra-antler samples were collected from the proximal end to distal end along the main beam of each antler and analyzed for carbon and nitrogen stable isotope values from collagen (δ13Ccol, δ15Ncol) and carbon and oxygen stable isotope values in bioapatite (δ13Capa, δ18Oapa). Stable isotope data were then correlated with local climate data (precipitation and temperature) from the months leading up to the date of death of each deer and with the 50-year averages of the region.ResultsNo consistent seasonal patterning was observed between local climate data and isotopic variables across the antlers. δ13Capa values from each antler, however, do show a trend of being negatively correlated with precipitation variables and mean temperature.DiscussionThe results of this exploratory study suggest that individual deer feeding behaviors, mobility, and habitat preferences make it difficult to infer seasonal environmental conditions from antler stable isotope values. We suggest, however, that intra-antler stable isotope data may be useful for wildlife management and conservation studies.