It turns out blue whales are mostly ‘right-handed’, except in one instance

21 Nov 2017

Blue whale off the coast of California. Image: Chase Dekker/Shutterstock

The latest research finds that blue whales, the planet’s biggest living creature, tend to be ‘right-handed’.

It sounds like a strange thing to say about a creature that doesn’t have any opposable digits, but a team of scientists using motion-sensing tags has found that the giant blue whale is typically a ‘right-handed’ creature.

In a paper published to Current Biology, a team from Oregon State University identified the creature as having a lateralisation bias towards the right side because its left hemisphere of the brain deals with coordination and motor control while the right side is linked with vision in its right eye.

What caught the researchers by surprise, however, was the fact that despite this right-sided bias, blue whales would suddenly become ‘left-handed’ when it comes to one specific manoeuvre.

When blue whales rise from the depths to approach a krill patch near the surface, they perform 360-degree barrel rolls at a steep angle and nearly always roll to the left, suggesting a bias to this side, even among right-handed whales.

Similar to humans, a small percentage of blue whales have shown themselves to be naturally left-handed.

Highly unusual

“The patches of prey near the surface, between 10 and 100ft 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,” said Ari Friedlaender, lead author on the study.

“These are the largest animals on the planet, and feeding is an extraordinarily costly behaviour that takes time, so being able to maximise the benefit of each feeding opportunity is critical. And we believe this left-sided rotation is a mechanism to help achieve that.”

The blue whale’s left lateralisation bias makes it highly unusual in the animal kingdom and this could be the first discovery of a creature that changes its behaviour depending on the context of a task about to be performed.

To make this discovery, Friedlaender and his team collected data on more than 2,800 rolling lunges for prey by 63 whales off the coast of California.

Colm Gorey was a senior journalist with Silicon Republic