The humpback whales of Alaska have developed an ingenious method of fishing for herring, but it only works if they all co-operate.
The humpback has the most diverse feeding repertoire of all baleen whales. Its most inventive technique is known as bubble net feeding; a group of whales swims in a shrinking circle blowing bubbles below a school of prey.
The shrinking ring of bubbles encircles the school and confines it in an ever-smaller cylinder. This ring can begin at up to 30 metres (98 ft) in diameter and involve the cooperation of a dozen animals.
Using a crittercam attached to a whale’s back, researchers found that some whales blow the bubbles, some dive deeper to drive fish toward the surface, and others herd prey into the net by vocalizing.
The whales then suddenly swim upward through the “net”, mouths agape, swallowing thousands of fish in one gulp. Plated grooves in the whale’s mouth allow the creature to easily drain all the water initially taken in.
A study published in the April 26, 2013 issue of Science documents a new form of bubble-net feeding called lobtail feeding among a population of whales in the Northern Atlantic Ocean. This technique involves the whale slapping the surface of the ocean with his tail between one and four times before creating the bubble net.
Using network-based diffusion analysis, the authors argue that the whales in this group learned the behavior socially from other whales in the group over a period of 27 years in response to a change in the primary form of prey.
This video was first published by BBC Earth on 02 Jan 2015.