Why humpback whales learn songs: Courting or ranging?

Abstract

Singing humpback whales within a population appear to continuously modify the content of their songs such that at any given time, most whales in a particular region are singing stereotypically‐structured songs. This phenomenon is widely regarded as evidence that humpback whales learn songs from conspecifics, and is often cited as evidence that humpback whale songs are a reproductive acoustic display comparable to the songs of songbirds. An alternative possibility, however, is that humpback whales copy the songs of their neighbors because this maximizes their ability to passively or actively track the positions of other whales. In particular, comparing incoming sounds to memories of self‐produced sounds may enhance a whale’s capacity to judge the distance that the sound has traveled by increasing the whale’s ability to identify degradation cues that vary systematically as a function of propagation distance. An increased capacity to accurately estimate the position of sound sources might in turn improve a whale’s ability to segregate songs when multiple singers are audible. This alternative perspective suggests that song learning by humpback whales is an adaptation for auditory spatial perception, rather than the result of sexual selection for a communal vocal display that increases the responsiveness of females.