How do bowhead whales in the unbroken darkness of the Arctic's polar winter keep busy during breeding season? Why, they sing, of course.
From late fall to early spring, off the east coast of Greenland, some 200 bowheads hunted to the edge of extinction serenade each other with compositions from a vast repertoire of song, according to a study published on Wednesday.
"It was astonishing," said lead author Kate Stafford, an oceanographer at the University of Washington's Applied Physics Laboratory in Seattle who eavesdropped on these subaquatic concerts.
"Bowhead whales were singing loudly, from November until April" – non-stop, 24/7 – "and they were singing many, many different songs." Stafford and three colleagues counted 184 distinct melodies over a three-year period, which may make bowheads one of the most prolific composers in the animal kingdom.
"The diversity and interannual variability in songs of bowhead whales in this study are rivalled only by a few species of songbirds," the study found. Unlike mating calls, songs are complex musical phrases that are not genetically hard-wired but must be learned.
Only a handful of mammals—some bats and a family of apes called gibbons, for example—vocalize in ways akin to bird song, and when they do it is quite repetitive.