Bubble net feeding is a unique and specialized feeding strategy used by humpback whales only in specific parts of the world, and only by certain individuals within those populations. What is of great interest is this feeding technique is a learned behavior that is socially passed on to other individuals within a population. This includes a unique feeding call only used with this feeding strategy. During these bubble net feeding events, humpback whales trap schools of fish (herring in the Northeast Pacific) through a combination of bubble blowing and specialized vocalizations.

In a typical bubble net feeding scenario, groups of 2 to 15 whales will descend together to a depth of approximately 20 – 60 metres and organize themselves into two known roles: callers and bubble blowers. It is currently believed that the callers will remain below a school of fish to vocalize a “bubble net feeding call” while the remaining members of the feeding group will swim upwards in a tightening spiral while blowing bubbles out of their blowholes to create the bubble net.

Experimental studies investigating how herring respond to being enclosed by a bubble net revealed that they are extremely unlikely to attempt to swim through the curtains of bubbles that surround them, even in the presence of a simulated predator. Other studies exploring the differences in the acoustic propagation of bubble net feeding calls found that the calls become the loudest within the physical bubble net spiral. This essentially creates a “wall of sound” and is believed to promote schooling behaviour and further prevent prey from escaping the quieter waters within the center of the bubble net. As the bubble net rises and begins to reach the surface with the fish enclosed within the center, every whale in the feeding group will lunge through the net with their mouths agape to eat the trapped fish.”