Meeting Abstract
Migration is a defining feature of modern mysticete whale ecology, but the prehistoric history of this behavior remains largely unknown. Understanding when migration became established and whether migration paths have been stable through time could yield valuable insights into mysticete evolutionary history, and may also have implications for crafting conservation strategies. The fossil record of coronulids – the epizoic barnacles that live attached to the skin of some mysticetes – offers a potential proxy for reconstructing prehistoric migration routes. Killingley (1980) demonstrated that the oxygen isotope profiles of modern-day gray whale barnacles (Cryptolepas rhachianecti) preserve a high-resolution geochemical record of a whale’s annual migration path, and we have demonstrated that isotopic analysis of modern-day humpback whale barnacles (Coronula diadema) can also be used to reliably reconstruct whale migration paths. Here we present initial results from ongoing analyses of Plio-Pleistocene specimens of both Coronula diadema and Cryptolepas rhachianecti. Calcite preservation is in most cases excellent, and diagenetic alteration can be diagnosed by textural and trace metal analysis. Oxygen isotope profiles recovered from well-preserved specimens reveal patterns suggesting that Plio-Pleistocene whales were undertaking migrations similar to those of today. Combining barnacle isotope profiles with local proxies and oceanographic models may ultimately enable the reconstruction of prehistoric whale migration pathways, allowing us to better understand the role of migration in mysticete evolutionary history and the behavioral stability of migration across varying climate states.
