Meeting Abstract
Migration is an integral feature of modern mysticete whale ecology, and the demands of migration may have played a key role in shaping mysticete evolutionary history. Constraining when migration became established and assessing how it has changed through time may yield valuable insight into the evolution of mysticete whales and the oceans in which they lived. However, there are currently few data which directly assess prehistoric mysticete migrations. Here we show that calcite δ18O profiles of modern whale barnacles (coronulids) accurately reflect the known migration routes of their host whales. We then show that δ18O profiles from well-preserved fossil coronulids exhibit trends and ranges similar to those of modern specimens, indicating that multiple Plio-Pleistocene whale populations of both the humpback and gray whale lineage were undertaking migrations of similar extent to those of the present day. We also find that Pleistocene whales congregating on the Pacific coast of Panama included individuals belonging to several different subpopulations, as the recovered δ18O profiles indicate very different migratory paths. Continued work on this project is aimed at integrating fossil coronulid δ18O profiles with paleoceanographic models and emerging proxies that can independently constrain seawater temperature and isotopic composition in order to more tightly constrain the migratory pathways of prehistoric mysticete whales.
