Humpback whales are large marine mammals known for their acrobatic breaches and complex vocalizations. They navigate vast ocean expanses, undertaking some of the longest migrations in the animal kingdom. Understanding their diet and how they obtain food provides insight into their survival in diverse ocean environments.
Main Diet of Humpback Whales
Humpback whales primarily consume small organisms despite their immense size. Their diet largely consists of krill, tiny, shrimp-like crustaceans up to 6 centimeters long. These crustaceans gather in dense swarms, making them an ideal food source for filter-feeding whales. In fact, the name “krill” originates from a Norwegian word meaning “whale food.”
Beyond krill, humpback whales also feed on various small schooling fish, including herring, mackerel, capelin, sand lance, and anchovies. Their diet can also include squid and other small marine organisms, depending on regional availability and seasonal changes. As baleen whales, they possess baleen plates instead of teeth, which filter food from the water. Their esophagus is relatively small, about the size of a grapefruit, requiring the consumption of these small, abundant prey items.
Unique Feeding Strategies
Humpback whales employ specialized and cooperative methods to capture prey. One technique is bubble-net feeding, often involving multiple whales. A group dives beneath a school of fish or krill swarm, releasing air bubbles while swimming in a circular pattern. This creates a “net” of bubbles that encircles and concentrates prey near the surface, allowing whales to swim upwards and engulf large quantities of food.
Another common method is lunge feeding, where a humpback rapidly swims through a dense school of fish with its mouth wide open. As the whale lunges, its throat grooves expand, taking in vast amounts of water and prey. The baleen plates then filter water out, trapping the fish or krill for consumption. These strategies highlight the whales’ complex behaviors for sustenance.
Dietary Needs and Consumption
Humpback whales require large quantities of food to fuel their bodies, especially during feeding seasons in colder, prey-rich waters. An adult humpback can consume up to one tonne (2,200 pounds) of food, primarily krill, daily. Some sources suggest they can eat up to 3,000 pounds (1,360 kilograms) daily. This substantial intake builds significant blubber reserves.
These fat reserves sustain whales during long migrations to warmer breeding grounds, where food is scarce. During these periods, which can last four to six months, humpbacks may eat very little or fast entirely, relying on stored energy. Abundant prey populations in their feeding grounds are important for their survival and reproductive success.