Humpback whales, majestic marine mammals recognized for their acrobatic displays and complex vocalizations, are among the largest creatures in the ocean. Their immense size, often reaching up to 60 feet in length and weighing between 50,000 to 80,000 pounds, necessitates a substantial and consistent food intake. The ability to sustain such a large body mass and fuel their extensive migrations across vast ocean stretches is directly tied to their specialized diet and highly efficient feeding behaviors. Understanding what and how these whales eat provides insight into their survival in diverse marine environments.
Their Primary Diet
Humpback whales are baleen whales, meaning they possess baleen plates in their mouths instead of teeth. These plates, made of keratin, hang from their upper jaw and function as a filter, allowing them to strain small prey from large volumes of water.
Their diet primarily consists of krill, small shrimp-like crustaceans. Beyond krill, humpback whales also consume various species of small schooling fish. Common examples include herring, mackerel, capelin, sand lance, salmon, pollock, and haddock. They may also opportunistically feed on plankton and squid.
Unique Feeding Strategies
Humpback whales employ several distinct strategies to capture their small prey, showcasing remarkable adaptability and, at times, cooperation. One of their most recognized methods is “bubble-net feeding,” a highly coordinated group effort.
In this technique, a group of whales, ranging from two to over a dozen, works together to corral their prey. They dive below a school of fish or krill and then release streams of bubbles from their blowholes while swimming in a circular or spiral pattern. The rising curtain of bubbles acts as a physical and visual barrier, concentrating the prey into a dense “bait ball” near the surface. Once the prey is tightly packed, the whales simultaneously lunge upwards through the center of the bubble net with their mouths wide open, engulfing large quantities of food and water.
Another common feeding method is “lunge feeding,” which can be performed by individual whales or small groups. During lunge feeding, the whale accelerates rapidly through a school of prey with its mouth agape, engulfing a significant volume of water and food. Their expandable throat grooves, which can number from 14 to 35, stretch considerably to accommodate this massive intake. After capturing the water and prey, the whale expels the water through its baleen plates, trapping the food, which it then swallows.
Seasonal Eating and Dietary Importance
Humpback whales exhibit a distinct seasonal feeding pattern tied to their extensive annual migrations. They feed intensely during the summer months in cold, nutrient-rich polar waters. This period is important for them to consume vast quantities of food, building up significant fat reserves, or blubber, to sustain them throughout the year. An adult humpback whale can consume approximately 1 to 2.5 tons (around 900 to 2,200 kilograms) of food daily during these active feeding periods.
As winter approaches and food availability in polar regions diminishes, humpback whales migrate thousands of miles to warmer, tropical waters for breeding and calving. During this migration and while in their breeding grounds, they typically fast or eat very little, relying almost entirely on the fat reserves accumulated during their summer feeding. This fasting period can last for several months, emphasizing the importance of their intense summer feeding for survival and reproduction.