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Blue whales are capable of swallowing an incredible half a million calories in a single mouthful.

Now, new research has shed light on exactly how they do this – and it appears that being ambidextrous is key.  

Like many other animals, ranging from primates to insects, blue whales display laterality, or ‘handedness’ – generally a bias towards the right.

But a unique study using video cameras attached to the backs of the mighty cetaceans has shown how the whales switch laterality when feeding.

This allows them to do 360 barrel rolls to the left, while keeping their right-eye on their prey.  

Blue whales are capable of swallowing an incredible half a million calories in a single mouthful. Now, new research has shed light on exactly how they do this - and it appears that being ambidextrous is key. A blue whale dives into the water off the California coast

Blue whales are capable of swallowing an incredible half a million calories in a single mouthful. Now, new research has shed light on exactly how they do this – and it appears that being ambidextrous is key. A blue whale dives into the water off the California coast

WHY WHALES ROLL TO THE LEFT

Handedness is thought to result from the way different sides of the brain dominate. 

In humans, more than 90 per cent of the population are right-handed because they have a dominant left hemisphere. 

Due to crossed wiring, the left half of the brain generally controls the right side of the body.

Rolling to the left while lunge feeding allows the blue whale’s dominant right eye to target the krill more effectively, the scientists believe.

Blue whales, which weigh as much as 25 elephants and are the largest animals ever to have lived on Earth, are famous for their dramatic ‘lunge feeding’ acrobatics close to the ocean surface.

As they launch themselves upwards into swarms of the tiny crustaceans, called krill, on which they feed, the whales execute 360 degree barrel rolls. 

And according to the video evidence, they almost always roll to the left.

This is in marked contrast to the way they normally feed at greater depths, when they execute 90-degree right-handed side rolls.

Lead researcher Dr Ari Friedlaender, a cetacean expert at Oregon State University’s Marine Mammal Institute, said: ‘The patches of prey near the surface, between 10 and 100 feet deep, are usually smaller and less dense than prey patches found deeper and the blue whales showed a bias toward rolling left – presumably so they can keep their right eye on the prey patch and maximise their effort.

‘We were completely surprised by these findings, but when considering the means by which the whales attack smaller prey patches, the behaviour really seems to be effective, efficient, and in line with the mechanisms that drive their routine foraging behaviours.’

It was the first known example of an animal altering handedness to adjust to the context of a performed task, said the scientists writing in the journal Current Biology.

Over a period of six years, the team attached suction ‘tags’ fitted with video cameras, hydrophones and motion sensors to the backs of 63 blue whales off the coast of southern California.

The tags were designed to detach after several hours and float to the surface, so they could be recovered and their data downloaded.

A unique study using video cameras attached to the backs of the mighty cetaceans has shown how the whales switch laterality when feeding. This allows them to do 360 barrel rolls to the left, while keeping their right-eye on their prey (pictured)

A unique study using video cameras attached to the backs of the mighty cetaceans has shown how the whales switch laterality when feeding. This allows them to do 360 barrel rolls to the left, while keeping their right-eye on their prey (pictured)

A unique study using video cameras attached to the backs of the mighty cetaceans has shown how the whales switch laterality when feeding. This allows them to do 360 barrel rolls to the left, while keeping their right-eye on their prey (pictured)

Handedness is thought to result from the way different sides of the brain dominate. 

In humans, more than 90 per cent of the population are right-handed because they have a dominant left hemisphere. 

Due to crossed wiring, the left half of the brain generally controls the right side of the body.

Rolling to the left while lunge feeding allows the blue whale’s dominant right eye to target the krill more effectively, the scientists believe.

At greater depths where there is little light and the krill swarms are denser, vision is less important.

Dr Friedlaender added: ‘The brain/eye phenomenon is what leads to handedness in humans and tool-use among apes. The most curious aspect was how so many of the whales exhibited lateralisation to the left when swimming upwards at a steep angle to get prey.

‘Not only is this the first report of handedness in blue whales, showing a preference for the right side as most mammals do, but we show that their side preference can change based on what the whales are doing.’



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