Blue Whales Are Smart And Efficient Foragers, Study Reveals

Have you ever wondered how Blue Whales manage to maintain their gigantic body masses? There is more to it than indiscriminate grazing, a new study reveals.

According to CBC, Blue Whales use energy and oxygen depending on the density of prey, which mainly is krill, a shrimp-like crustacean. When the prey is dense, whales lunge deep, disorienting their prey in a rush of bubbling water. They then take in large quantities of Krill with the ocean water which is then strained through baleen plate filters in their mouths. When the prey is scarce they dive fewer times to conserve energy. This finding has revealed that the feeding behavior is sophisticated.

"For blue whales, one of our main questions has been: How do they eat efficiently to support that massive body size. Now we know that optimizing their feeding behavior is another specialization that makes the most of the food available," said Elliott Hazen, a research ecologist with NOAA Fisheries' Southwest Fisheries Science Center and study's lead author.

To understand Blue Whale feeding behavior, researchers tagged 14 whales and used acoustic surveys to measure density of the prey. When the prey was spread out, whales dived less frequently. However when the density increased, they lunged frequently and maximized consumption during every dive.

"Blue whales don't live in a world of excess and the decisions these animals make are critical to their survival," said Ari Friedlaender, the study's co-author.

"If you stick your hand into a full bag of pretzels, you're likely to grab more than if you put your hand into a bag that only had a few pretzels."