The Insane Biology of the Largest Animal to Ever Exist

When we think of the biggest creatures that have ever lived, our minds might wander to the dinosaurs of yore. Diplodocus with its neck reaching up into the sky. Tyrannosaurus rex, that enormous and terrible lizard king. And the longest of them all, Patagotitan, which was about the size of four school buses parked end to end. But what if I was to tell you that the largest known animal to ever exist lives among us? They are here and now, swimming around the depths of our vast oceans. This is the blue whale. Hi, I'm Danielle Dufault, and you're watching Animalogic. Today, we're talking about the mammal with the most, the blue whale. The blue whale is not just the largest mammal on Earth. It's very likely the largest animal to ever exist, ever. No dinos or sea creatures from the past can compare. At least, not that we know of. And if there were, we probably would have found fossils by now. So how big are these blue cuties? Let's try our best to fully comprehend just how big a blue whale can be. A blue whale is an incredibly long animal. The largest examples of blue whales are over 30 meters long. That's 20 average-sized humans laying end to end. Next time you're at your family reunion, recruit your parents, your grandparents, your weird uncle, your kooky aunt, and your two favorite cousins to lay in a line. Then you simply have to ask 10 more members of your extended family to lay down too. Only now can you truly appreciate how long a blue whale is. But their length isn't even the most impressive thing about blue whales when it comes to their sheer size. One of the largest ever found weighed over 190,000 kilograms. Sticking with the family reunion metaphor, that's the equivalent of all the family you just asked to lay on the ground, plus another 2,480 people. To put that into perspective, that's the weight of you, your parents, your four grandparents, your eight great-grandparents, your 16 great-great-grandparents, your 32 great-great-great-grandparents, your 64 great-great-great-great-grandparents, your 128 great-great-great-great-great-grandparents, your 256 great-great-great-great-great-great-grandparents, Your 512 great-great-great-great-great-great-great-great-grandparents and your 1024 great-great-great-great-great-great-great-great-great-grandparents. That's like every direct relative you've had since the year 1700. Plus another 450 people. This blue human group would equal just a single blue whale. The scale of these creatures is really quite dizzying. The flippers, for example, are around 3 meters long, or about the length of an SUV. While this is certainly enormous, the blue whale's flippers are considered small because they only represent about 12% of their body length. The longest flippers relative to body length in cetaceans goes to the humpback whale, which sports flippers that are a third of their overall body length. While we're on flippers, did you know that flippers are essentially just modified hands? If you were to x-ray a flipper, you would see the distinctive bones that make up these appendages. But let's keep going with our body scan of the big blue. The eyes of the blue whale are about the size of a mini soccer ball. Compare that to our eyeballs, which are slightly smaller than a golf ball. Although the blue whale is the biggest creature on Earth, it doesn't have the biggest eyeballs either. That honour goes to the giant squid, which has peepers the size of a basketball. They need those humongous eyes in order to see in extremely low light conditions of the deep sea. But the blue whale makes do with a relatively smaller eye by foraging closer to the surface and singing songs to communicate with each other. It would be incredible to see them in person. And who knows, maybe one day we will. My favourite thing about doing this show is that it takes us to wild places in search of animals. From looking for the largest land predator on Earth, the polar bear, to one of the smallest, the water bear. We get into nature in search of the perfect shot. And when you're in nature for days, being comfortable is a must. That's why I wear Vessi shoes. For city wildlife, I love these Vessi Pacific sneakers. They're lightweight, waterproof and have amazing light cushioning. The soles have great grip. And also, they're slip-ons, which makes them easier to put on and also prevents the dreaded wet shoelace situation when you're outside. For practical purposes, it's everything you want in a shoe. And environmentally, they're vegan and free of forever chemicals. Combined with the new, super soft, moisture-wicking Vessi socks, they make the perfect combo to brave the city. Even our trusty producer wears Vessi shoes and socks. Whether I'm on a shoot, or grabbing a coffee, or simply going to work, these are comfortable shoes for any occasion. They're so durable that they give you a one-year warranty and 30-day refunds and exchanges, no questions asked. Scan this QR code or click on the link in the description to get 15% off your first pair of Vessis. And now, back to the larger-than-life blue whale. There is so much lore surrounding the size of blue whales, including that you could park a Volkswagen Beetle in a blue whale's heart and swim through its arteries. Let's examine that whale of a tail. While not the size of a compact car, the heart of the blue whale is still about 180 kilograms, and a meter and a half tall. That's about the size of 640 human hearts. While their arteries are large, they definitely aren't big enough to swim through. You could definitely send a volleyball through one of them with room to spare, though. Or if you're, say, an Olympic gymnast, you might be able to squeeze through the largest arteries. Just as expected from an animal of their size, these huge mammals are also capable of producing the loudest sounds of any animal. They are as loud as a jet engine. Blue whales don't have vocal cords like we do. Instead, their U-shaped voice box presses up against a specialized cushion of fat and muscle to produce these extremely loud sounds that can be heard up to thousands of kilometers away. Some of the sounds they produce, called infrasonic sounds, are so low that we humans aren't even capable of hearing them. But if we were close enough, we would certainly feel the vibrations in our bellies. With anatomy this large, you would think that everything on a blue whale would be enormous. But one part is actually surprisingly small. I am, of course, talking about its throat. The throat of a blue whale is actually only 10 to 20 centimeters wide. To compare, a human throat is about 2 centimeters wide, meaning that it's not even 10 times larger than a human's, despite the entire animal itself being 2,500 times heavier. The reason their throat is so small is simple. It's because these whales have adapted to eat very small prey. Blue whales are what are called baleen whales, meaning that they have baleen plates, moustache-looking structures made of the same substance that our hair is made of, that filters out the tiny krill that they eat. It seems unlikely that the largest animal would eat one of the smallest. But when there's a krill, there's a whale. To feed, the blue whale will charge at a group of krill, opening its massive jaws. The pleats on the underside of its lower jaw allow it to take in up to 70 tons of water and krill in a single mouthful. The whale will then press its tongue upwards to the roof of its mouth, forcing the water out, with their baleen plates keeping the krill in. The only thing left to do is swallow the krill, which presents no problem because the 1 to 2 centimeter krill will go right down that 10 to 20 centimeter hatch. It's kind of like when kids at the pool spit water through their teeth. Only in their case, they're keeping millions of prey animals in their cavernous mouths. It takes a lot of krill to power a body of that size, with blue whales eating upwards of 14,500 kilograms daily. That's like eating the equivalent weight of three elephants every single day. Considering that blue whales are estimated to live 80 to 90 years, that's like eating close to 100,000 elephants worth of krill in a lifetime. But with around 700 trillion Antarctic krill, weighing about 400 million tons, swimming around at any given time in the Southern Ocean alone, at least we know their food is in good supply. For now, at least. For a comparison, that's about how much all the humans on Earth weigh too. Keeping krill in good supply is, as you can imagine, krilledical. We talked to our friend Diane, who's been studying blue whales in the Gulf of California for over 30 years, to learn more. The whales are very good gardeners of their own ecosystem. So the whales feed down below the ptotic zone, where the phytoplankton is, and then edificate at surface. And we also did experiments with the feces, looking at, you know, in three different big bottles, at sea, close to where the whales are, without just the normal water with the phytoplankton there, same water with a little bit of feces, and the same water with double the feces. And the productivity, after the first bottle, after a couple of days, went down. There was not enough nutrient. The phytoplankton just went down. In the second bottle, it went up after two, three days. And the other one went way up. So what happened is that in the feces, there's a lot of nutriment. They spend one month and a half in the same place. They're not going and coming, and they stay there. So if they stay there a month and a half, two months, maybe what they do by feeding and edificating enhance so they can continue to feed. In other words, whales eat krill in deep water. Then they poop at the surface. Bacteria turn the feces into food for microscopic plants. And their numbers explode. The plants feed krill, and they also multiply. And then the whale eats the krill. So the whales actively make the surface more productive by bringing nutrients from the bottom of the ocean to the surface. But eventually, it's time to move on. So where did these whales go? To find out, we asked our friend Dr. John Ryan, who listens to blue whale songs to track their numbers. Blue whales, they just simply have to search farther and wider to find the krill. We can hear when they migrate. That's because they change how they sing. So we can hear when they're migrating, and therefore we can listen and know how that migration changes from year to year. And that's where we learned that blue whales will change the timing of their migration by up to a third of the year, which is the full length of a migration period sometimes. And that's because they have to adapt. They have to always take advantage of when an ecosystem allows them to pack on energy stores. So if there's food, they'll stick around. But if not, they'll go look for it elsewhere. It sounds simple at first, until you start wondering how the heck whales find krill in the vastness of the ocean. In an environment where the physical features defined by different water masses can be very small scale, the whales are finding them persistently and consistently with precision that is just mind-blowing. And what's important about that is that's the only way they can survive. If they can't navigate a complex environment that's changing continuously and find those dense krill swarms, they won't persist as a species. Because they need to consume so much food every day just to sustain that massive body. So the precision of a giant has blown my mind. Another problem blue whales face is that, like everyone, they have some very annoying relatives. Another day, there was that whale that was accompanied by terseops, a bottlenose dolphin. And at the beginning, we thought, oh, that's cool. Because the dolphin, when they follow the whales, they come at surface before the whales. So it's easy to follow the whale, let's say, especially if it's traveling. And that whale was kind of traveling. It was not making circles or anything. These dolphins were a group of maybe 25. They followed that whale the whole day. The whale was so, so upset. You have no idea. She really tried. It was a male, actually. It really tried to get away, but there was no point. I mean, they were always on her head, on his head. I felt that nobody has ever reported that maybe it would make. But, you know, like the frigate birds that follow gulls or other birds so they regurgitate, they still regurgitate the fish they have. I had the feeling that these dolphins wanted that whale to regurgitate. It's crazy. Who knew dolphins were that into krill tartare? And the worst part is that blue whales evolved from toothed whales, similar to dolphins. We know this from the fossil record. But what is harder to determine is just when these baleen structures started evolving. Unlike teeth, which are made of bone, baleen are more akin to hair or fingernails, meaning that they don't fossilize as well. Regardless of when it occurred, it's the evolution of the baleen that seems to be the key to becoming so massive. According to a recent paper, researchers used advanced trackers attached to the whales, analyzing over 10,000 feeding events of both toothed and baleen whales. They discovered that the cap for size for toothed whales is about the size of a sperm whale because of the tradeoff between calories it takes to hunt and the calories gained from eating the krill. Baleen whales, like blue whales on the flip side, can take in as much as 10 million calories in a single enormous gulp, meaning that they can expend a lot less energy to intake nutrition, thereby allowing them to grow to such epic proportions. But becoming so humongous is actually pretty recent for whales, at least in evolutionary terms, happening in the last few million years. And it all seems to be linked to the ice ages. As nutrients run off in times of melt, prey for baleen whales became super abundant. It's the same reason these whales today still travel long distances to their summer feeding grounds in polar climates. And it's these oscillations in food availability caused by the ice ages that are likely limiting them from becoming even larger. Getting that large for a whale is kind of cheating anyway. Let me explain. Animals that live exclusively in water have an easier time of existing as behemoths, since their every movement and ounce of mass doesn't need to fight against gravity. Whales in general lack the skeletal and muscular structure to hold their shape outside of water. This is part of the reason why beached whales are doomed to die. In addition to dehydration and overheating, just like a human lost in the desert, stranded whales will suffer what are called crush injuries. Crush injuries are just what they sound like, injuries sustained by a massive cetacean's organs being crushed internally by its own weight on land. Even if humans manage to intervene and get the whale back into the water, they can die a few hours later anyway as a result of these crush injuries. That's because being back in the water with the pressure off releases toxic products from their crushed organs into the whale's body. All that to say, it is only because they grow and evolve in an environment in which gravity has little effect are they free to balloon to sizes that would be difficult or impossible to reach or maintain on land. So when we think all the way back to the biggest dinosaurs that ever lived, like Patagotitan, it actually makes the enormous feat of growing so enormous on land even more impressive. It stands to reason that if you're the biggest around, your babies are going to be the biggest around too. Blue whale newborns win the award for chunkiest babies on earth. Once out of the womb, like all mammals, they rely on mama's milk to stay chubby. Blue whale babies will drink around 200 litres of their mama's extra fatty milk per day. While human milk is around 4% fat, the milk of the blue whale is about 50% fat to help the babies bulk up and gain 200 pounds a day. The thick, fatty consistency here is key for underwater feeding, since blue whale babies don't suckle like other mammals. Instead, the mama whale releases milk in a stream that the baby can drink without also chugging too much seawater. Some of the research we've been most excited to learn about is whale tagging, which is basically a GoPro with extra sensors and a GPS tracker. Thanks to the work of groups like Cascadia Research, we get to know where they go, what they do, who they hang out with, and how long they stay out at night. We're finally getting to see life from a whale's point of view. That data will help us understand them better and protect them more efficiently. We're also getting better at slowing down for whales. There are amazing initiatives, like Blue Whales, Blue Skies, that work with shipping companies to move at a speed safe for whales, to give them time to dive out of the way. Vessel strikes and entanglement in commercial fishing nets are a big problem. But pollution, habitat degradation, climate change, and even ocean noise can severely negatively impact these wonders of nature. If we act now, we can save these amazing creatures from becoming just more gigantic bones in our museums. But for now, if you can, support conservation organizations, sustainable ecotourism, and tell everyone about how lucky we are to live at the same time as the literally greatest animal to ever exist. So, what should we talk about next? Please let me know in the comments and don't forget to subscribe for new episodes every week. Thanks for watching and see ya!