Fin whale singalong: evidence of song conformity

Mechanisms driving song learning and conformity are still poorly known yet fundamental to understand the behavioural ecology of animals. Broadening the taxonomic range of these studies and interpreting song variation under the scope of cultural evolution will increase our knowledge on vocal learning strategies. Here, we analysed changes in fin whale (Balaenoptera physalus) songs recorded over two decades across the Central and Northeast Atlantic Ocean. We found a rapid (over 4 years) replacement of fin whale song types (different inter-note intervals - INIs) that co-existed with hybrid songs during the transition period and showed a clear geographic pattern. We also revealed gradual changes in INIs and note frequencies over more than a decade with all males adopting both rapid and gradual changes. These results provide evidence of vocal learning of rhythm in fin whale songs and conformity in both song rhythm and note frequencies.