Why Do Humpback Whales Periodically Change Their Tune?

Humpback whales make some incredible vocalizations, which are often referred to as songs. These songs, which include a variety of sounds ranging from moans to squeaks, can last for hours, and are transmitted between individual whales, so that eventually all of the whales in a pod or in a particular region are singing the same tune. However, each whale adds his own variations, so the tune becomes increasingly complex over time. Now, a team of marine biologists has closely examined how these songs evolve, noting that every few years, the songs seem to become so complex that they are ultimately dropped in favor of something simpler.

An evolving song of the sea:

• The researchers, led by University of Queensland marine biologist Jenny Allen, analyzed 13 years' worth of recordings of 95 humpback whales from eastern Australia. They listened to a total of 412 song cycles and ranked their complexity.
• The songs often travel great distances, as they are passed between various humpback whale populations, from the Indian Ocean to the South Pacific, for example.
• Only male humpback whales sing; researchers don't know exactly why they do this, although most theorize that it has to do with attracting females or impressing other males.