Dear MARMAM community,
On behalf of my co-authors, I am pleased to share our recent publication in Frontiers in Marine Science (Section Marine Megafauna):
Tyarks, Saskia Cathrin; Aniceto, Ana Sofia; Ahonen, Heidi; Pedersen, Geir and Lindstrøm, Ulf (2022).
Changes in humpback whale song structure and complexity reveal a rapid
evolution on a feeding ground in Northern Norway.
Front. Mar. Sci. 9:862794. doi:
https://doi.org/10.3389/fmars.2022.862794
Abstract:
Singing behaviour by male humpback whales (Megaptera novaeangliae)
has traditionally been associated with low-latitude breeding grounds.
However, in recent years, this vocal behaviour has been increasingly
reported outside these areas. All singers in a given population sing the
same version of a song and this song is continually evolving over time
with modifications on different levels within the song structure.
Tracing changes in whale song will help to undercover the drivers
underlying this vocal display and contribute to the understanding of
animal culture and its evolution. To determine the progressive changes
in songs found on a subarctic feeding ground and migratory stopover, a
detailed analysis of humpback whale song recordings from Northern Norway
was conducted. Passive acoustic data from the Lofoten-Vesterålen Ocean
Observatory (LoVe), collected using a bottom-moored underwater
hydrophone, were used from January - April 2018 and January 2019. Two
measures of the song structure were examined: (1) sequence similarities
using the Levenshtein distance and (2) song complexity using a principal
component analysis (PCA). In total, 21 distinct themes were identified
which presented highly directional, structural changes over time. Two
themes from 2018 reoccurred in 2019, whereas all other themes in 2019
appeared to be evolved versions of 2018 themes. All songs grouped into
three general clusters, reflecting the rapid evolution over the study
period. With all sampled animals singing the same version of the song,
this might indicate that the singers are either from the same breeding
population or that song learning occurred before the study period. Song
complexity appeared to follow the trend of song progression; songs
became more complex as they evolved over the months in 2018 and
decreased in complexity between the years, returning to a more
simplified song in 2019. The results confirm that humpback whale song
exhibits a rapid progression on a shared subarctic feeding ground, with
strong potential for song exchange and opportunities for cultural
transmission between populations in the North Atlantic.
The article is open access and can be downloaded following the link below:
https://www.frontiersin.org/articles/10.3389/fmars.2022.862794/full
If you have any questions regarding our work please contact this email:
Kind regards,
Saskia Tyarks (formerly Martin)
(she/her)
Department of Biology, Lund University, Sweden
Department of Arctic and Marine Biology, Arctic University of Norway (UiT), Tromsø, Norway