Data from: Extreme diversity in the songs of Spitsbergen’s bowhead whales

Almost all mammals communicate using sound, but few species produce
complex songs. Two baleen whales sing complex songs that change annually,
though only the humpback whale (Megaptera novaeangliae) has received much
research attention. This study focuses on the other baleen whale singer,
the bowhead whale (Balaena mysticetus). Members of the Spitsbergen bowhead
whale population produced 184 different song types over a 3-year period,
based on duty-cycled recordings from a site in Fram Strait in the NE
Atlantic. Distinct song types were recorded over short periods, lasting at
most some months. This song diversity could be the result of a possibly
increasing population, or immigration of animals from other populations
that are no longer isolated from each other by heavy sea ice. However,
this explanation does not account for the within season and annual
shifting of song types. Other possible explanations, is that the
extraordinary diversity in songs is the result of weak selection pressure
for interspecific identification or for maintain song characteristics or,
alternatively, strong pressure for novelty in a small population.