Lunge Feeding: How do blue whales eat?

My name is Monica and I'm a science educator. Join me as we take a close look at research expeditions to track blue whales and better understand this incredible ocean species. Have you ever gone a while without eating? You start to feel hungry and tired, maybe even cranky. Our food gives us fuel to move around, to communicate, and to stay healthy and fit. That's the case for all the animals on the planet. Now, I'm sure you can guess that the biggest animal on Earth needs a lot of food. In a single day, a blue whale can eat up to 16 tons of food. That's more than enough to fill a dump truck. But what kind of food do you think they eat? What if I told you that blue whales eat these? They're krill, small shrimp-like creatures that live in the open ocean, and they're about the size of a paper clip. But when you group them together, they form huge red clouds in the water. They're usually down deep, but once in a while, they come right up to the surface. Krill are the blue whale's favorite food, even though they're so tiny. That would be like you or me eating crumbs. How on Earth can a whale ever fill up by only eating itty-bitty pieces of food? Marine biologist Dr. Jeremy Kizka is trying to figure that out. What I love the most about being out in the ocean is that I can try to answer the questions I'm interested in, where these whales are going, what they're eating. I wonder how challenging it is for them to find enough food. For a blue whale, it's not as simple as heading to the kitchen to make a peanut butter and jelly sandwich. They need to travel the world's oceans looking for their meals. Krill is not distributed everywhere in the ocean, so blue whales need to find them, and they need to find these dense aggregations of krill. And if they don't find them, well, they're going to move and try to find other areas, which is very costly in terms of energy that they spend. Because of all the energy they use trying to find the krill, they need as much as possible when they do. Gotta fill their bellies! They do that with one of the most amazing feeding strategies in the world. It's called lunch feeding. Blue whales have the biggest jaws in the animal kingdom, and they can open them wide. Try it! Open your mouth as wide as you possibly can! The whale accelerates towards the krill and takes one enormous mouthful. A stretchy layer of fat and muscle in its throat expands like a giant accordion. But the whale doesn't swallow all that water. It squeezes it back out. The krill gets trapped behind bristly plates called baleen, which act like a filter. The baleen is made out of keratin, just like our fingernails. When the water is gone, the whale swallows all the krill left in its mouth. To maximize the energy intake, what they need to do is to find the densest patches of krill. Eating a million krill at once uses a lot less energy than trying to catch them one by one, that's for sure. Whales aren't the only animal that have a special way of eating. Just look around you. Can you think of other cool ways that animals eat? Some drink nectar by visiting flower after flower with a long tongue. Some pluck fruit right off of trees. And others wait for the food to come to them. Each one is trying to get the energy it needs without using up too much energy to get it. But there's another thing all animals have in common, and it comes after they eat. Blue whales poop a lot. And whenever they do so, they actually fertilize the ocean. Their poop is rich in nutrients that are vital for the basis of the food chain. So blue whales are these gardeners of the ocean. Gardeners of the ocean? I like that. Whales get energy and nutrients from the krill they eat, and then they give some of those nutrients back to the ocean when they poop. Hey, it's natural. That cycle of energy and nutrients, eating and pooping, happens in all types of ecosystems, connecting all sorts of animals and plants. Near you, you might see animals like rabbits, squirrels, or even worms. These are all amazing foragers and fantastic nutrient recyclers. So next time you go outside, take a close look at how animals are finding, eating, and recycling their food. And record what you see, just like the marine biologists do when they study blue whales. Just remember to bring your favorite snack. All that research will definitely make you hungry. My favorite meal at sea? I think it's pasta with tons of cheese. Pasta with cheese. Sounds a lot better than krill to me.