Male humpback whales produce complex, structured vocalizations known as “songs.” Although the males in any population generally sing the same song, the pattern paradoxically changes over time, with all the males updating their songs to maintain concurrent song matching. How and why males continuously modify their songs while maintaining conformity is not understood. Here, we propose a mechanism that explains both song “evolutions” and large, abrupt “revolutions.” In this model, song change occurs through males copying the songs of others with preference for novel material. Novelties, however, must occur at a threshold rate in the surrounding population for them to be considered viable alternatives and adopted. This process likely involves various levels of cognition. At its simplest, it may require only an urge to copy songs, a perceptual bias toward novelty, and a basic learning model requiring reinforcement. A similar process likely operates in females who use their own mental song template to assess males. The recognition and adoption of novelty drives song change. As this is likely differentially expressed among males, it creates the possibility that song is a display of cognitive ability available to females who have a previously underappreciated role in shaping this complex display.
Noad et al. (Wed,) studied this question.