ECOLOGICAL CORRELATES OF RANGE SHIFTS OF LATE PLEISTOCENE MAMMALS

Understanding and predicting how species’ distributions will shift as climate changes are central questions in ecology today. The late Quaternary of North America represents a natural experiment in which we can evaluate how species responded during the expansion and contraction of the glaciers. Here, we ask whether species’ range shifts differ because of taxonomic affinity, life history traits, body size, topographic heterogeneity, and whether the species survived the megafaunal extinction. There was no difference in range shifts between victims and survivors of the megafaunal extinction. In general, the change in the size of a species’ range is not well correlated with any of the ecological or life history traits evaluated. However, there are significant relationships between some variables and the movements of the centroids of ranges. Differences in the distances shifted exist among orders, although this is likely a result of body size differences as larger-bodied species show larger shifts. Although there are a few exceptions, the distance that species shifted their range was weakly correlated with life history traits. Finally, species in more topographically heterogeneous areas show smaller shifts than species in less diverse areas. Overall, these results indicate that when trying to predict species range shifts in the future, body size, life span, and the topographic relief of the landscape should be taken into account.