The study found that, although the whales generally turn right to eat krill in deep water, they generally turn left to eat krill in shallower water. This is the first known study to show that any animal shows different lateralised behaviours in different situations – that they change “handedness” and become more ambidextrous depending on the context.
The researchers speculate that the reason that the whales change behaviour is simply to get as much krill as possible into their mouths. Krill are more plentiful in deeper water and the whales make sharp turns or roll to the right. However, krill are sparser in shallower water and using left-handed rolls allows them to keep their right eyes on the target. When seeing with their dominant eyes becomes more important, changing directions helps them catch more krill.
- On a roll: blue whales switch 'handedness' when rolling to scoop food (The Guardian, London)
- Most blue whales are 'right-handed', Swedish-American study shows (The Local, Stockholm)
- World's largest whales are mostly 'right-handed' (The Straits Times, Singapore)
- Humans May Be Forcing ‘Right-Handed’ Whales to Act Like Lefties (Seeker, San Francisco)
- Ballenas azules son diestras a profundidad y zurdas en la superficie (El Siglo de Durango, Mexico)
