Range sizes and shifts of North American Pleistocene mammals are not consistent with a climatic explanation for extinction

Abstract

The cause of the terminal Pleistocene extinctions in North America is debated but is most commonly ascribed to climate change or anthropogenic overkill. Based on contemporary extinction theory from conservation biology, we predict that in a climatically induced extinction event, species with small geographic ranges are most likely to suffer extinction. We use two methods to reconstruct Pleistocene range sizes for 194 taxa using data from the FAUNMAP database to conduct analyses in ArcGIS. Furthermore, because this extinction event was size selective, we reconstruct range shifts between the Pleistocene and Holocene for 157 species to assess whether climate change preferentially impacted extant large-bodied species. We find that the extinction event did not preferentially impact taxa with small geographic ranges, and that displacement distances were no different for large- and small-bodied species. These results are not consistent with an extinction induced by climate change but may be concordant with anthropogenic causes.