The secret behind blue whales’ enormous appetite

WASHINGTON - Scientists from the University of British Columbia, Canada, have found that blue whales take in 90 times as much energy as they burn during a single dive.

Analysing the behaviour of each whale, Bob Shadwick and Jeremy Goldbogen saw that dives lasted between 3.1 and 15.2 minutes and a whale could lunge as many as 6 times during a single dive.

Goldbogen calculated the blue whales’ speeds as they lunged repeatedly during each dive.

Noticing that the whales’ mouths inflated almost like a parachute as they engulfed the krill, Goldbogen tracked down parachute aerodynamics expert Jean Potvin to help them build a mathematical model to calculate the forces acting on the whales as they lunged.

With Potvin on the team, they were able to calculate that the whales used between 3226 kJ of energy during each lunge. Then he calculated that the whales could consume anything from 34,776kJ up to an unprecedented 1,912,680kJ from a single mouthful of krill, providing as much as 240 times more energy as the animals used in a single lunge.

And when the team calculated the amount of energy that a whale could take on board during a dive, they found that each foraging dive could provide 90 times as much energy as they used.

“The key to this is the size factor because they can engulf such a large volume with so much food in it that it really pays off,” said Shadwick. (ANI)