Whales, marine mammals found in every ocean, play diverse roles in marine food webs. Understanding their diets reveals unique adaptations and ecological significance. This article explores their specialized feeding strategies.
All Whales Consume Animal Matter
All whales are carnivores, meaning their diet consists entirely of other animals. The specific types of prey vary widely among species. Whales are categorized into two suborders: baleen whales (Mysticeti) and toothed whales (Odontoceti). Each has developed distinct feeding mechanisms and dietary preferences to thrive in marine environments.
Baleen Whales: Filter Feeders
Baleen whales, including some of the largest animals on Earth, employ a unique filter-feeding system. Instead of teeth, they possess baleen plates, comb-like keratin structures, that hang from their upper jaws, forming a sieve. To feed, they take in vast quantities of water and prey, then use their tongue to push water out through the baleen, trapping food.
Their primary food sources are small organisms that congregate in large numbers, such as krill, copepods, and small schooling fish. Blue whales, for instance, consume up to 4 tons of krill daily to sustain their enormous size. Humpback whales use bubble-net feeding, releasing bubbles to corral prey before engulfing them. Other baleen whales, like right and sei whales, are “skim feeders,” swimming slowly with mouths open to filter plankton. Gray whales are bottom feeders, stirring sediment to filter invertebrates.
Toothed Whales: Active Hunters
Toothed whales, encompassing species like orcas, sperm whales, dolphins, and porpoises, are active predators with teeth for grasping prey. Their diets are diverse, ranging from fish and squid to larger marine mammals such as seals, sea lions, and even other whales. Sperm whales, for example, dive to extreme depths to hunt giant squid.
These whales employ sophisticated hunting techniques, with echolocation being a prominent strategy for locating prey in dark or murky waters. They emit high-frequency sound pulses and interpret the echoes to create a detailed map of their surroundings. Many toothed whale species, especially orcas, exhibit cooperative hunting behaviors. They work together to herd schools of fish into “bait balls” or to disorient larger prey. Some species use jaw movements or tail strikes to stun their prey before consumption.