Blue whales execute acrobatic '360-degree rolls' to feed
Blue whales are now the only known rorqual whales that can complete a full circle roll when feeding on krill, a study has revealed.
According to the study, other whales can only go around 90-150 degrees, Discovery News reported.
The Blue whales manage the trick in two steps.
Lead author Jeremy Goldbogen said that the first phase started with a "180 degree roll prior to mouth opening, when the lunge occurs as the whale opens its mouth and engulfs the prey-laden water, which in this case is krill."
For the second phase, there's "a further 180-degree roll in the same direction to complete the 360-degree spin. This maneuver is powered by several powerful fluke strokes and the tilting of the animal's flippers."
Goldbogen, a postdoctoral researcher at Cascadia Research Collective, and his colleagues found the move after they attached suction cup multi-sensor tags to the Blue whales foraging in the waters off of southern California.
The researchers also recorded the full circle when the marine mammals were in a searching mode between lunges.
"We think that this behavior improves the whale's chances of engulfing the most amount of krill possible," Goldbogen said.
He said that because of their enormous size, they can be easily detected by krill, however, If they attacked krill from below they might be able to avoid being seen.
"So essentially, the whales spin over and engulf the krill patch while inverted, from below," he said, adding that it's an "ambush strategy."
The study has been published in Royal Society Biology Letters.