Published: 10.06.2021 Updated: 15.06.2021
"It has long been an established truth that humpback whales only sing while they are on southern latitude breeding grounds, but it is increasingly discovered that they also sing outside the breeding season and in other areas and time of year. Here we also document this along the Norwegian coast," says Saskia Martin.
Saskia, a master's student at the UiT - the Arctic University of Norway, has recently published the study reporting the unique recordings in the journal Frontiers in Marine Science.
According to IMR researchers Ulf Lindstrøm and Geir Pedersen, who have both contributed to the study, these are the first scientifically published observations of humpback whale singing along the coast of Norway.
"The song probably contributes to cultural exchange between populations of humpback whales in the North Atlantic," the researchers say.
Cultural exchange means that the whales learn songs from each other. The song of the male humpbacks change over time and is built up by basic elements (units) which combines into phrases and themes. Multiple themes combine into a song which is repeated multiple times in a song session. The changes appear to be coordinated within the same population.
The song has been interpreted as a way to attract females, but recent studies suggest that it primarily has the function of communication between the males, perhaps as a mean to structure their social hierarchy.
The recordings were made with an underwater microphone (hydrophone) at a depth of 250 meters, northwest of Vesterålen in January–June 2018 and December 2018–January 2019.
The hydrophone is connected to the Lofoten–Vesterålen Ocean Observatory (LoVeOcean), a national infrastructure for research which hosts a wide range of sensors for near real-time ocean monitoring and science.
Saskia Martin's master's project is a collaboration between the Institute of Marine Research, UiT, the Norwegian Polar Institute, and Lund University in Sweden.