Researchers are speculating why blue whales across the globe have been "shifting the pitch" of their songs.© myanimalblog.files.wordpress.com
An article in Endangered Species Research reports that male blue whales have begun changing their tunes—literally. In the article, Professor John Hildebrand of the Scripps Institution of Oceanography describes how whales across the globe have been “shifting the pitch” of their songs, resulting in a “song that is now about 30 percent lower than it was in the 1960s.” While the drop in pitch is thus far undisputed, the reason behind the change is up for debate.
Hildebrand has a curious theory. He believes that the recent change in song may be a result of the rising number of whales swimming through our planet’s oceans. Before whale hunting was banned in 1966, blue whale populations were exceptionally low, which meant that males had to work harder to find and attract female partners. For that reason, Hildebrand believes, many males pushed their songs to a higher frequency “so that more of the girls [could] hear it.” But now that whale populations are steadily growing, males no longer need to shout across the seas in order to be heard. Thus, their songs have returned to a lower, less desperate, tune.
Hildebrand further theorizes that the males have lowered their tunes in order to sound more appealing to mates; many male species use lower tones in order to attract a female mate—including humans.
“If you put some headphones on and play a bunch of male voices and you tell them [human females] to pick out the sexy voice, do they pick the weak little voice or do they pick the big booming voice?” Hildebrand asks. "You know the answer.”