by The melodious sound of whales singing can be a soothing soundscape that helps people relax or it could create a sense of calm if you were alone on the open ocean at night. When whales sing, we think they are communicating with beautiful, complex songs that travel through the water for miles.
The whale song has fascinated people for decades, but the exact purpose and mechanisms behind it are still shrouded in mystery. Now, advances in underwater acoustic recording technology and whale research are pulling back the curtain on the secret life of singing whales.
Scientists have identified many possible functions of whale singing, including attracting others, navigating, communicating over long distances, and expressing emotions. Male humpback whales are known for their complex song which lasts up to 30 minutes, and is repeated for hours during the mating season. This suggests that whale song plays a central role in courtship.
Meanwhile, there are recognizable patterns in blue whale songs that all whales in a population share across large ocean regions – evidence that songs may function for large-scale communication and cohesion within social groups. Gray whales also seem to dictate migration songs, with specific types of songs sung during different stages of their epic journey down the Pacific coast.
But how exactly do whales create their ethereal bravery? Their anatomy provides some clues. Toothed whales like orcas and sperm whales have a single nasal passage that connects their blowhole to their larynx. They use the larynx to block and seal the airway while underwater, and create sound using a vocal organ in their nasal passage.
Mammals, including humans, have folds of tissue that we call vocal cords. These are found in a specialized region called the larynx.
As air is exhaled from the lungs, pairs of folded tissues of the larynx vibrate and this creates sound. Baleen whales like humpbacks and blue whales have two nasal passages that are thought to be involved in song production.
These passages connect to laryngeal sacs surrounded by muscles that can vibrate to modulate sound. To find out how whales create sound a team of scientists studied the larynxes of three different species of baleen, sei, humpback and minke whales. They then created an air supply that would mimic the lungs of a whale. As they blew air between the fatty pad and the surface of the vocal fold sound.
Whales have very large brains. Interestingly, the largest whale, the blue whale, does not have the largest brain. Although a blue whale can measure anything up to 90ft in length, their brain weighs around 7kg (15lb). However, the sperm whale weighs about 9kg. For comparison an adult human brain is about 1.4kg and an elephant brain about 5kg.
In the brain of whales there are entire lobes dedicated to auditory processing – perfect for making and analyzing the nuances of complex whale songs. Their ears are the only mammalian ears adapted to work underwater. They also operate at low frequencies, which are suitable for long-range communications. The ears also “swim” inside their head so they can see which direction the sound is coming from.
Advanced technologies are enabling new insights into the acoustic qualities of whale song. Guided hydrophones can trace songs back to individuals, and acoustic tags attached to whales record data on song use and production.
Command software can then visualize whale song to provide subtle indications that whales combine such song elements into hierarchical sequences similar to the structures we see in human language. This raises profound questions about the language abilities of whales.
We know that whales can hunt in packs, and this requires a level of communication to organize themselves so that all the prey does not get lost. They can chase their prey, isolate them and finally capture them. Whale song, we believe, allows the whales to communicate and coordinate their hunt.
Whale song represents a complex form of culture and communication that we are only beginning to understand. Each population has a distinct musical dialect that is transmitted between generations for reasons that are still largely a mystery to us.
Unlocking the secrets of whale songs could reveal their behaviour, social structures and intelligence.
But perhaps there is not much time to appreciate these wonderful Celtic ballads. Noise pollution, climate change, hunting, and ship collisions are threatening singing whales. Whale song recordings take on a new urgency as fragile acoustic environments and whale populations change rapidly.
If we listen closely, whale songs may reveal wonders about our world and the lives of whales. But first we must ensure that these stirring melodies continue to permeate the world for generations to come.
Dr James Williams is a senior lecturer in education at the University of Sussex
