Song Morphing by Humpback Whales: Cultural or Epiphenomenal?
by Eduardo Mercado III
Published online 15 January 2021
Frontiers in Psychology 11:574403 (2021);
https://www.frontiersin.org/articles/10.3389/fpsyg.2020.574403/full
Abstract: Singing humpback whales (Megaptera noavaengliae) collectively and
progressively change the sounds and patterns they produce within their songs
throughout their lives. The dynamic modifications that humpback whales make to
their songs are often cited as an impressive example of cultural transmission
through vocal learning in a non-human. Some elements of song change challenge
this interpretation, however, including: (1) singers often incrementally and
progressively morph phrases within and across songs as time passes, with
trajectories of change being comparable across multiple time scales; (2)
acoustically isolated subpopulations singing similar songs morph the acoustic
properties of songs in similar ways; and (3) complex sound patterns, including
phrases, themes, and whole songs, recur across years and populations. These
properties of song dynamics suggest that singing humpback whales may be
modulating song features in response to local conditions and genetic
predispositions rather than socially learning novel sound patterns by copying
other singers. Experimental and observational tests of key predictions of these
alternative hypotheses are critical to identifying how and why singing humpback
whales constantly change their songs.
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