Blue whales, the largest creatures ever to have inhabited the planet, are also remarkable acrobats during feeding time.
Scientists recently learned that these gargantuan cetaceans, which can measure to about 100 feet and weigh 150 tons, will often roll 360 degrees before launching surprise lunge-feeding attacks on swarms of tiny shrimp-like krill. (See video posted below; image shows a blue whale feeding on krill but the mammal was not part of the study.)
The whales are capable of gulping 100 tons of krill-laden water in 10 seconds, and the filter-feeders can consume up to four tons of krill per day.
Findings of the study, which utilized suction-cup tracking tags, were published in the journal Biology Letters and described by lead author Dr. Jeremy Goldbogen as “extraordinary.”
Goldbogen, of the Cascadia Research Collective in Washington state, told BBC Nature: “Despite being the largest animals to have ever lived, blue whales still show impressive capacity to perform complex maneuvers that are required to efficiently exploit patches of krill.”
The researcher explained that blue whales perform these spins to orient themselves before lunge-feeding, and that the rolls probably allow the whales to obtain a more panoramic view and more adeptly assault krill patches from below, before the whales are detected and the krill disperses.
“As the blue whale approaches the krill patch, the whale uses its flippers and flukes to spin 180 degrees so that the body and jaws are just beneath the krill patch,” Goldbogen said.
“At about 180 degrees, the mouth just begins to open so that the blue whale can engulf the krill patch from below. As the blue whale engulfs the prey-laden water, it continues to roll in the same direction and completes a full 360 roll and becomes horizontal again, ready to target and attack the next krill patch.”
Smaller rorqual whales, such as humpbacks, have been found to turn their bodies before lunging into prey, but these turns rarely exceed 150 degrees.
The discovery of enormous blue whales performing complete rolls was a surprise for the Cascadia team. “We did not expect to see these types of maneuvers in blue whales and it was truly extraordinary to discover,” Goldbogen said.
The video footage was obtained via a camera attached to one of the whales involved in the study. The accompanying image shows a blue whale during a feeding event witnessed by this reporter during a voyage off Santa Barbara. Note the krill spilling from the whale’s mouth.