The Intricate Social and Feeding Behaviors of Humpbacks

Beyond their impressive size and migrations, humpback whales exhibit some of the most fascinating behaviors in the marine world. From ingenious, cooperative hunting strategies to breathtaking aerial displays, their actions provide a window into a complex social life. Studying these behaviors helps researchers in marine biology understand not just humpbacks, but the health of the entire ocean ecosystem they inhabit.

Bubble-Net Feeding: A Masterclass in Teamwork

One of the most remarkable humpback behaviors is bubble-net feeding. This is a complex, coordinated hunting technique that is a stunning example of animal cooperation. It is most commonly observed in the feeding grounds of the North Pacific, such as the waters off Alaska and Canada.

The process is incredible to witness. A group of whales will locate a school of small fish or krill. One whale, often the leader, will dive down and begin to release a steady stream of bubbles from its blowhole while swimming in an upward spiral. Other members of the group may also join in, creating a “net” or curtain of bubbles that encircles the prey. The fish are frightened by the bubbles and will not swim through the wall, so they become tightly packed into a bait ball near the surface. On a coordinated signal, all the whales in the group surge upward through the center of the net, mouths wide open, engulfing thousands of prey in a single gulp. This is a learned behavior, passed down through generations, and not all humpback populations practice it.

The Acrobatics of the Ocean

Humpback whales are famous for their surface activity, which makes them a delight for observers. These behaviors are not just for show; they are forms of communication, maintenance, or social display.

Breaching is the most iconic of these behaviors. The whale propels itself out of the water, sometimes clearing the surface entirely, before crashing back down with an enormous splash. The sound of a 40-ton body hitting the water can be heard from miles away. Scientists believe breaching may serve several purposes: to dislodge parasites like barnacles and whale lice, to communicate with other whales over long distances, as a sign of agitation, or perhaps simply for play.

Pectoral Slapping, or a “pec slap,” is when a whale lies on its side and repeatedly slaps one of its long flippers against the water’s surface. This also creates a loud sound and is thought to be another form of communication.

Lobtailing, or tail slapping, involves the whale lifting its powerful fluke out of the water and bringing it down forcefully, creating a thunderous boom. This is often seen as a sign of aggression or a warning to other whales or nearby boats.

4. They Don’t Have Teeth

Despite their massive size and ability to swallow tons of food, humpback whales have no teeth. They belong to a group of whales known as baleen whales, or *Mysticeti*. Instead of teeth, they have a series of baleen plates hanging from their upper jaw. These plates are made of keratin, the same protein found in human hair and fingernails. Each plate is fringed with bristles, forming a dense mat that acts as a giant filter.

To feed, a humpback opens its mouth and takes in an enormous volume of water filled with prey. Its lower jaw has pleats that can expand like an accordion, allowing it to hold a volume of water larger than the whale’s own body. It then uses its massive tongue to force the water out through the gaps in the baleen plates. The water is expelled, but the krill, plankton, and small fish are trapped by the bristles, ready to be swallowed.

Takeaway: The largest animals in the ocean feed on some of the smallest. This efficient filter-feeding system allows them to consume up to 3,000 pounds (1,360 kg) of food per day during the feeding season.

5. Their Flippers are Uniquely Engineered for Agility

We’ve already mentioned that the humpback’s long pectoral fins are a key identification feature, but their design is a marvel of marine biology and fluid dynamics. The leading edge of the flipper is not smooth; it is lined with the same large bumps, or tubercles, found on their head. For a long time, scientists were unsure of their purpose.

Research has revealed that these tubercles are a brilliant hydrodynamic adaptation. They function to channel the flow of water over the flipper, which helps to maintain lift and prevent stalling at sharp angles of attack. In simpler terms, they allow the whale to make incredibly tight turns and maneuvers for its size. This agility is crucial for rounding up agile prey during feeding and for navigating complex social interactions on the breeding grounds. This principle is a form of biomimicry; engineers have studied the design of humpback flippers to create more efficient and stable wind turbine blades, fans, and airplane wings.

Takeaway: The bumps on a humpback’s flippers are not just a curiosity; they are a high-tech solution to the challenges of moving a massive body through water with grace and precision.

6. A Humpback Calf Drinks a Bathtub’s Worth of Milk a Day

The life of a newborn humpback whale is a race against time. After a gestation period of about 11 months, a calf is born in the warm, protected waters of the breeding grounds. It is already immense at birth, measuring around 15 feet (4.5 meters) long and weighing up to two tons. The calf has very little blubber and would not survive the cold of the polar feeding grounds.

To prepare it for the long migration ahead, the mother provides it with incredibly rich milk. Humpback milk can be 40% to 60% fat, with the consistency of cottage cheese. The calf drinks astonishing quantities, consuming up to 130 gallons (nearly 500 liters) every single day. On this diet, a calf can gain over 100 pounds (45 kg) daily. This rapid weight gain is essential for building the thick layer of blubber needed for insulation and energy storage before it makes its first journey to the cold feeding waters with its mother.

Takeaway: The calm tropical waters where humpbacks are born are not a vacation spot; they are a critical nursery where calves must quickly gain the strength and insulation needed to survive their first year of life.