Scientists have finally found how blue whale manage to remain so big. A new study published recently in the journal Science Advances has revealed eating tactics of these gentle giants.
In spite of being the biggest recorded animal ever to inhabit our planet (even bigger than the largest dinosaur species Argentinosaurus, which weighed around 100 tons and was 130 ft tall), blue whales eat something as tiny as krill. According to experts, these gigantic mammals are capable of eating as much as 4 tons of krill every day.
Previously it was known that blue whales consume krill along with a mouthful of seawater and then release the water by means of their filtering baleen using their tongues (just the tongue of the creature can be as heavy as an elephant).
The new study, however, is suggesting that things might not be that simple. NOAA ecologist Elliot Hazen said that scientists have always wondered how blue whales manage to eat efficiently for supporting their gigantic body. According to him, this new study helped scientists to know that optimizing the feeding behavior of the blue whales is a completely separate specialization, which allows them to make the most of the food they manage to gather.
Studies conducted previously suggested that when hungry these massive mammals just open their mouths and pull in as much krill as possible. However, the new study is suggesting that the feeding behavior of these marine creatures is much more nuanced.
The study allowed the team under Dr. Hazen to hypothesize that the baleen whales, like most other terrestrial malls, should be competent bulk foragers. Both blue whales and the baleen whales are known for using a technique called bubble netting. For those who don’t know: the technique requires whales to swim in teams and dive blow krill swarms sending up a huge fountain of bubbles for alarming and displacing the group. This makes it much easier for the whales to catch the unsettled krill.
During this new study, the researchers succeeded in discovering another effective tool that blue whales use frequently for hunting. They found that although around 2 million krill can travel as a group, all krill patches are not equally dense. The whales are aware of this and thus when they feed on low-density krill patches, they save oxygen by lunging much fewer times per dive.
The researchers examined both krill density in each area and the maximum lunges taken by the blue whales per dive and calculated that these creatures are capable of optimizing both oxygen and energy for yielding the best possible results.