Blue whales (Balaenoptera musculus) reveal their agile side thanks to video cameras and motion sensors strapped to their bodies. The scientists equipped 22 B. musculus to capture the whales doing underwater pirouettes as they lunge at patches of krill.
The scientists published their findings in the journal Biology Letters. The maneuvers, including the pirouette, enables the whales to position their jaws underneath their pray and take the biggest possible mouthful before the krill scatter, states Jeremy Goldbogen, a zoologist at the Cascadia Research Collective in Washington.
The 360º strategy has been previously observed in other animals. Spinner dolphins revolve through the air and are thought to be shaking off suckerfish pests that hang on their bodies and alligators engage in death rolls, clasping their jaws around their victims while rolling rapidly to subdue and dismember them. But this phenomenon has never been seen in such a large animal, which comes as a surprise since the blue whale has relatively small flippers and tail fins. Humpbacks are known to roll but only for 90º.
The flipper movement in the video helps explain how the whales create the spin. This is possible with their smaller flippers because more of a blue whale’s body mass is distributed “around its longitudinal axis”, states Goldbogen.
Only 10% of all lunges involve a full roll, which indicates that the tactic might be limited to when krill are in small, dense patches, Goldbogen continues.
Reference: “Underwater acrobatics by the world’s largest predator: 360° rolling manoeuvres by lunge-feeding blue whales” by Jeremy A. Goldbogen, John Calambokidis, Ari S. Friedlaender, John Francis, Stacy L. DeRuiter, Alison K. Stimpert, Erin Falcone and Brandon L. Southall,23 February 2013, Biology Letters.