By studying the feeding patterns of blue whales, scientists have discovered that the world’s largest animal is, in fact, ‘right-handed’. They have also noticed that, on several occasions, the mammals would use their left side when scouting for their favorite prey, crustaceans known as krill.
Blue whales (Balaenoptera musculus) feed by opening their mouths and dashing into swarms of krill. They then eliminate the excess water through their baleen plates in their mouths, leaving the krill inside to be swallowed.
Published in the journal Current Biology, the paper states that blue whales opt to use their left side when catching prey in order to maximise their chances of getting as much food as possible.
“To the best of our knowledge, this is the first example where animals show different lateralized behaviors depending on the context of the task that is being performed,” states co-author of the study and Stockholm University professor, James Herbert.
The study tracked 63 whales off the coast of California, over the course of six years. Researchers used front- and rear- facing cameras that contained sensors for measuring depth and movements in all directions.
By analyzing the footage, it was revealed that blue whales would roll about ninety degrees to the right as they prepare to lunge towards the prey. However, when they’re approaching the surface where krill reside, the blue whales do full 360-degree rolls to the left.
According to the study, this allows the blue whale to keep their right eye facing toward the surface, where it can keep its sights on the prey. Blue whales generally steer towards the right side when in deep water and don’t rely that much on sight due to low visibility and higher amounts of krill.
When the water is between ten and one hundred feet, most blue whales choose to roll left. “Lefty” animals are considered to be rare in the animal kingdom, even unusual according to researchers.
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