Abstract

ABSTRACT

Late Pleistocene Fossils Recontextualize the Ecology of Introduced Turkeys in California

Managing invasive species is a central challenge in conservation biology given funding constraints and the potential for unanticipated ecological consequences. New techniques that bring Quaternary fossil records and zooarchaeological assemblages into such discussions reveal that many introduced species have unexpected histories and may represent ecological or taxonomic substitutes for extirpated or extinct species. Wild turkeys (Meleagris gallopavo) are a non-native, potentially invasive species in California introduced in the 1900s as a game animal. However, they are congeneric with the California turkey (Meleagris californica), an endemic species that went extinct at the end of the Pleistocene. To assess these two closely related species' potential ecological overlap and thus provide a currently unaccounted for baseline of turkey ecology in California, a species distribution model (SDM) for Meleagris californica was developed based on bioclimatic data and fossil localities from the Last Glacial Maximum. This model was then projected into current landscapes using present-day climatic data as a counterfactual of this extinct species distribution as if it never went extinct. This projection was then compared to an SDM for extant Meleagris gallopavo generated using present-day observations. Model overlap and variable importance indices strongly suggest that Meleagris gallopavo in California today largely occupies geographic and environmental spaces similar to those used by Meleagris californica. Cross-validation using other techniques may be needed to confirm the species' role as an ecological substitute.