Viewing the lives of whales through a molecular lens

Genetics and genomics tools are providing unprecedented insights into the hidden social lives of baleen whales, from parentage to diet to defining population segments. Genetic information reveals simple yet critical information about individual whales, from their sex to their age to their kin. Integrating genetic and genomic information with other data such as photo-identification records, stable isotope data on foraging ecology, and hormone studies on reproductive status can provide detailed pictures of individuals and populations. Here we show through published examples how such datasets can be used to provide information on mating systems and assess population recovery. Genetic tools such as DNA diet studies have been instrumental at uncovering new aspects of whale ecology, such as identifying previously unknown prey that are key to the persistence of non-migratory baleen whale populations. Finally, we discuss how genetics, acoustics, and culture interact in whale populations, and how these data are being used in complementary ways to identify units to conserve.