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SPEAKING WHALE
Studies over the last 40 years have shown that blue whales have evolved sophisticated modes of communication that allow them to speak to one another across immense oceans.
During the darkest days of the Cold War, U.S. Navy officials listened out for Soviet submarine activity in the northern Pacific Ocean with the latest hydrophone system. They noted that one of the main sounds they continually heard were those of whales, often many miles away, communicating to one another across the sea.
Since scientists have gained access to that network of undersea listening outposts, they have worked to find out how and why whales communicate to one another across the oceans.
BLUE WHALE SOUNDS
Sound is the most effective way to communicate across a vast expanse of ocean—traveling at a speed five times greater under water than in the air—so it’s not surprising to discover that blue whales have evolved the ability to communicate with sound across the water.
Tests and studies have shown that all whale species use sound for a number of different purposes: to navigate, to detect food, and to communicate with one another over long distances. Despite breakthroughs in determining the role of sound in whale activities, much about blue whale sounds remains something of a biological mystery.
As you would expect from the largest animal on the planet, blue whales have exceptionally deep voices and are able to be vocal at frequencies as low as 14 Hz—well below the ability of human hearing—with a volume greater than 180 decibels, which makes the blue whale the loudest animal on the planet.
The sounds they make that humans can hear are characterized by low grunts, humming, moans, and clicks. The deep vibrations and sounds created by a blue whale can travel thousands of miles across the sea and may have evolved to take advantage of the ocean's sound channel.
DO BLUE WHALES HAVE DIALECTS?
Although there is no way to know if blue whales have accents, research into the calls and sounds of blue whales suggests that they may have different dialects, depending on where in the ocean they are found.
In 2007, researchers from the Scripps Institution of Oceanography at the University of California found that blue whales in different parts of the sea actually make different sounds.
The Scripps team was able to create a map categorizing blue whale species types into nine geographical regions around the world based on their song ‘dialects.’
The study found that while some dialects are relatively confined to coastal areas, others are spread over broad geographic areas, such as the entire North Pacific Ocean. By listening to the animals, researchers can tell something about the regions in which the blue whales are interacting and breeding, which is important for managing and conserving whale populations.
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