Singing the Blue Whale Blues

A sonorous mystery deepens

Scientists don't know exactly why whales sing, but they do, and they are pros. Their singing is strikingly similar to human music composition.

One possibility is that male whales sing to attract mates.

Now, a new study published in the most recent Endangered Species Research journal has found that over the past few decades, the pitch of the songs of blue whales -- the largest animal in the world -- has been steadily getting lower.

"The basic style of singing is the same, the tones are there, but the animal is shifting the frequency down over time. The more recent it is, the lower the frequency the animal is singing in, and we have found that in every song we have data for," said John Hildebrand, a professor of oceanography in the Marine Physical Laboratory at the Scripps Institution of Oceanography at the University of California, San Diego, in a press release.

The researchers studied two common culprits for recent marine animal behavioral changes -- climate change or human-caused marine noise like sonars.

But they think the reason for the decline in frequency is due to a rather positive bit of news: increasing blue whale numbers following the 1986 global ban on commercial whaling instituted by the International Whaling Commission.

They believe that the higher-pitched songs were necessary when blue whale populations were much lower, in order to project the sound across farther distances to attract faraway mates.

"It may be that when (blue whale) densities go up, it's not so far to get to the closest female, whereas back when they were depleted it may have been that the closest female was a long way away," said Hildebrand.

Blue whales are not out the woods yet. They are still endangered -- and singing the blues.

GET INVOLVED

• Listen to the songs of humpback whales (The Whalesong Project)
• Sign a Whale & Dolphin Conservation Society petition urging the Australian government to protect marine animals from the dangers of the Timor oil spill
• Support Sea Shepherd's efforts to stop Japanese whaling
  
• Sign a Greenpeace letter to Iceland's prime minister Jóhanna Sigurðardóttir urging her to cancel Iceland's five-year commercial whaling quota
  
• Sign the Whale's Revenge petition urging the International Whaling Commission to close the loophole that allows whaling in the name of so-called "scientific research"

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• The Whale Warrior (July 31, 2009)
• Denmark: Humpback Whales Are Tasty (June 23, 2009)
• Illegal Whale Meat Still on Japanese Menus (April 14, 2009)
• Bloody Waters in the Faroe Islands (February 19 , 2009)
• Gray Whales, Meet Big Oil (November 22, 2008)
• Palin Rebuffed As Unique Alaskan Whales Score Major Victory (October 18, 2008)
• Whales Get New Sanctuary in Chile (September 30, 2008)
• Greenland's Request to Kill Humpback Whales Denied (July 1, 2008)
• Greenpeace Activists Jailed in Tokyo (June 22, 2008)
• The Future of Whaling (June 14, 2008)
• US Condemns Iceland's Whale Hunt (May 26, 2008)

image: blue whale (credit: NOAA)