Carbon and oxygen isotopes ratios from herbivore teeth have previously been used as paleo-environmental proxies in temperate zones. However, their utility in tropical zones remains uncertain. In this study, sequential sub-samples from white-tailed deer (Odocoileus virginianus) teeth (second and third molars) from the Maya archaeological site of La Joyanca, located in northwestern Petén, Guatemala, show that δ18O of enamel carbonate corresponds broadly to modern observed precipitation δ18O over the 10-month period of tooth formation, capturing rainfall seasonality. The analyses also detect significant diachronic differences in the δ18O between the periods 1100-1000 BP (850-950 A.D.) and 1000-900 BP (950-1050 A.D.) at La Joyanca. The δ13C in both periods are indicative of a C3-plant based diet, which suggests cultivation of maize did not differentially affect deer diet during this period.
Keywords: Carbon-13; Maya; Yucatán; enamel; isotope ecology; oxygen-18; paleoclimate; paleoecology; teeth.