They’re the largest animals on Earth. Some of them weigh more than a Boeing 737. But despite their size, many whales spend their lives guzzling the ocean’s equivalent of popcorn: shrimp-like krill, tiny fish, and microscopic plankton.
Which begs the question… how do you stay fat eating soup? Let’s dive into the big mouths (literally) of whales and find out what’s on the menu.
Two Types of Whales & Their Distinct Diets
First, a quick anatomy lesson. Whales are split into two categories: baleen whales (Mysticetes) and toothed whales (Odontocetes). The difference? It’s in the mouth.
- Baleen whales have no teeth; instead, they use a giant curtain of keratin plates (like hairy fingernails) to filter food from the water. Think of them as the vacuum cleaners of the sea.
- Toothed whales, on the other hand, have actual teeth and eat like your average carnivore: by chasing and chomping.
Baleen Whales: Slurping Soup by the Ton
Blue whales, the largest animals to ever live, feed almost exclusively on krill. That’s right. An animal the size of a tennis court eats shrimpy things barely a few centimeters long. But they don’t just nibble. They feast. We’re talking up to 4 tonnes of krill per day, that’s roughly 40 million tiny crustaceans swallowed in one afternoon snack (Carwardine, 2019, p. 91).
How? With lunge feeding. Picture this: the whale dives below a swarm of krill, then bursts upward with its mouth open almost 90 degrees, gulping a whopping 65 tonnes of seawater, then filters out the krill using its baleen. It does this 6–15 times per dive. And yes, it burns more calories than your HIIT class.
Check all our articles exploring the unique wildlife of the Azores: Dolphin Conservation Status | Pink Dolphins | Tuna in the Diet of Dolphins | Dolphin Olfactory Abilities | Whale and Dolphin Reproduction | Are Whales Carnivores? | Does Whale Sperm Make the Ocean Salty? | Communication Among Whales and Dolphins | How Do Whales & Dolphins Sleep? | How Long Do Whales Live?
Toothed Whales: Predators with a Bite
Sperm whales are known to dive deeper than 2,000 meters, all for a chance to catch their favorite snack: giant squid. Some females eat 750 squid a day (that’s about 37 per dive). Males may add sharks, rays, and deep-sea fish to their plate too (Carwardine, 2019, pp. 144–145).
Feeding is mostly suction-based, mighty gulps in the darkness of the deep sea: no harpoons, no spears, just evolution’s version of a vacuum cleaner with sonar.
What’s on the Menu? Whale Diets by Species
Whales might inhabit the same ocean, but not their feeding habits. Blue whales consume nearly purely on krill, and larger numbers of liters of seawater are swallowed and filtered by the baleen. Sei whales feed on copepods, squid, and small schooling fish. Gray whales love a bottom-feed buffet; they suck amphipods and crustaceans off the seafloor. In the meantime, sperm whales plunge to greater depths to hunt squid, even of the giant kind, with beaked whales and others supplementing their feeds with fish and octopuses. Every species has developed a way of feeding that perfectly fits its ecological niche.
Check all our articles exploring the unique wildlife of the Azores: Swimming Speed of Whales | Breath-Holding Capacity of Blue Whales | Dolphin Mating Behavior | Collective Nouns for Dolphins | Top 3 Facts & Curiosities about Dolphins | Dolphin Diet and Feeding Habits | Fin Whale Conservation Status | Sperm Whale Diet | Sperm Whale’s Scars | What Does a Whale’s Penis Look Like? | What Does Whale Milk Taste Like? | Portuguese Man-o’-War Jellyfish | What Do Whales Eat? | Can You Hear Whales Above Water?
Conclusion
Even though they’re some of the biggest animals on Earth, some whales filter vast amounts of water to catch their food, while others dive deep to hunt. Each species eats in its special way, ideally suited to where it lives. Next time you see a whale, remember: it may look calm, but it’s a powerful eater with a big job to do in the ocean.
Would you like to know the best times for whale watching?
Take a look at our whale watching calendar and plan your next adventure! Don’t miss the chance to spot these majestic creatures in Azorean waters. 🐋 🌊
References
- Carwardine, M. (2019). Handbook of Whales, Dolphins and Porpoises. Bloomsbury Wildlife.
- Foote, A. D., Vijay, N., Ávila-Arcos, M. C., Baird, R. W., Durban, J. W., Fumagalli, M., … & Morin, P. A. (2016). Genome-culture coevolution promotes rapid divergence of killer whale ecotypes. Nature Communications, 7, 11693. Retrieved from Research Gate.
