Humpback whales dives deep into the ocean to perform a series of rapid accelerations with mouth agape into a dense prey patch. On each of these bouts, or lunges, the whale engulfs about 10 kilograms of Herring contained within some 70,000 liters of water,a volume heavier than its own weight—in a few seconds. During a lunge, the whale oscillates its tail and fluke to accelerate the body to high speed and opens its mouth to about 90 degrees. The drag that is generated forces the water into its oral cavity, which has pleats that expand up to 4 times their resting size. After the whale’s jaws close, the sheer size of the engulfed water mass is evident as the body takes on a “bloated tadpole” shape. In less than a minute,all of the engulfed water is filtered out of the distended throat pouch as it slowly deflates, leaving the prey inside the mouth. Over several hours of continuous foraging, a whale can ingest more than a ton of Herring, enough to give it sufficient energy for an entire day.
© Ramdas Iyer Photography