Studies of minke whales in Antarctica have revealed some more secrets about how these amazing creatures feed.
Data taken over several weeks showed the minke’s feeding in a way unique to other whales; spending most of their feeding time under the sea ice and skimming just below the frozen water, scooping up large volumes of krill.
Minke whales use baleen plates to feed – comb-like bristles that hang from the upper jaw allowing them to filter-feed. Unlike toothed whales, when minkes open their mouths water and prey, such as krill or small fish, pour in. The water floods back out but the baleen filters out the prey for the whale to then swallow. Other baleen whales that feed in icy waters tend to stick to feeding in the open water and the edges of the sea ice.
These studies also revealed that the minkes were gulping a huge number of mouthfuls of krill per dive compared with other baleen whales. This practice is known as lunge feeding, and the minkes lunged up to 24 times during a single dive, nearly once every 30 seconds. By contrast, blue whales, the largest baleen whales, can lunge only a few times during a dive because they gulp down much larger mouthfuls relative to their body size, resulting in immense drag.
Ari Friedlaender, a marine mammal ecologist at Oregon State University’s Marine Mammal Institute in Newport, who led the team, said that the information they gathered in just a short space of time also casts more doubt over the controversial ‘research’ hunting of minke whales by the Japanese. “We learned more in 2 weeks of studying these creatures in the Antarctic than the Japanese have ever produced,” Friedlander says.