Like dancers on stage, the humpbacks move in synchronization. The lead whale expertly executes a looping series of turns toward the water's surface—a spiral of bubbles trailing behind. Then, suddenly, the pod surges. The whales burst through the ring of bubbles, mouths agape.
These aren't trained humpbacks, pirouetting for the pleasure of onlookers. Instead, these massive beasts are hunting using an ingenious method known as bubble-net feeding. A new video that surfaced on GoPro's blog shows its Karma drone capturing the whales in action just west of the Maskelyne Island in British Columbia, Canada.
In the recording, the fish can be seen jumping out from the water within the bubble loop. Just seconds later, the whales appear to gulp down their prey. But a lot more is happening than initially meets the eye.
As David Attenborough explains in a 2015 BBC Earth video about humpbacks, the lead whale of the group is responsible for locating the prey as well as creating the bubble curtain. As the leader spirals to the surface, it expels air from its blowhole, creating a cylindrical wall of bubbles to contain its food of choice, which includes a range of seafood krill, herring, mackerel and more.
A second creature loudly vocalizes under the surface in what is known as a "trumpeting feeding call." Researchers believe that this noise propagates through the bubbles, creating an ingenious net of noise and air. Meanwhile, the remainder of the pod herds the prey upwards, where they remain trapped within the bubble curtain.
The final scene in this dramatic play is the joint plunge to the surface to capture the hapless fish. As can be seen in the latest video, the whole dance happens in mere moments.
To actually eat the prey, however, requires an extra step. Humpbacks have a row of hundreds of so-called baleen plates that protrude in a line from the upper jaw. Each is composed of keratin—the same material that makes up your fingernails—and is covered in bristles. But these plates aren't for chewing, they allow the whale to filter out their delicious prey from the gallons of water they gulped, without letting the meal escape.
Bubble feeding has been known for decades, and is thought to be unique to humpbacks. But only recently have researchers started to pin down the complicated choreography behind the dance. In 2004 and 2005, a team from New Hampshire University attached digital recording acoustic tags to humpback whales to precisely track their movements through the water and create the first first visualization of their underwater movements.
Other scientists have since refined these models, suggesting in a 2011 study that there are actually several distinct patterns to these complicated loops. The variation in hunting styles may come from the fact that whales aren't born with the know-how of bubble feeding, Jane J. Lee wrote for National Geographic in 2013. Rather, the dance is learned through social interactions. And in regions where the whales' prey has changed, so has the style of hunting. This ensures the dance is still effective for corralling fish or crustaceans.
Though studying these pretty dances may seem to be more folly than function, the research has proven critical for the conservation of the species. Increasing shipping traffic and fishing causes more and more underwater noise and deadly entanglements. But by better understanding their complex feeding behaviors, scientists can more easily protect these aquatic giants.