Rare footage of a blue whale hoovering up a ball of krill has been taken in the Southern Ocean off the coast of New Zealand. Researchers from the Hatfield Marine Science Center at Oregon State University recorded the whale twisting its body to lunge feed on the tiny prey.
On another occasion a whale passed through a mass of krill without feeding. The researchers believe the blue whale uses a lot of energy in slowing down to feed (from around 6 mph to 1 mph) and then getting going again, so unless the krill group is large enough to replace the lost energy, it’s not worth eating.
Blue whales in the waters around Antarctica was once thought to number around 200,000 but decades of whaling reduced them to a fraction of this figure. Today, around 2,000 are thought to survive.
The footage here was taken by trained drone operators to carefully avoid disturbing the whales. Drones should always be used responsibly and where appropriate under permit, with minimal disturbance to the wildlife (or people!).