Episode 281: The Humpback Whale
b"Thanks to Clay for suggesting the topic of this week's episode, the humpback whale!\\n\\nHappy birthday to Emry!\\n\\nFurther reading:\\n\\nHow humpback whales catch prey with bubble nets\\n\\nStudy: Humpback whales aren't learning their songs from one another\\n\\nStanford researchers observe unexpected flipper flapping in humpback whales\\n\\nAncient baleen whales had a mouthful\\n\\nThe humpback's long, thin flippers help it maneuver:\\n\\n\\n\\nHumpbacks are active, jumpy whales:\\n\\n \\n\\nA humpback whale's big mouth:\\n\\n\\n\\nShow transcript:\\n\\nWelcome to Strange Animals Podcast. I\\u2019m your host, Kate Shaw.\\n\\nThanks to Clay for suggesting this week\\u2019s topic, the humpback whale!\\n\\nBut first, we have a birthday shout-out! A great big happy birthday to Emry! I hope your birthday is so epic that in the future, when people look up birthday in the dictionary, your name is listed there.\\n\\nI\\u2019m amazed we haven\\u2019t talked about the humpback whale before because when I was little, it was my favorite whale until I learned about the narwhal. Sorry, humpback, you\\u2019re now my second favorite whale.\\n\\nThe humpback is a baleen whale, specifically a rorqual, which is a group of related baleen whales. I don\\u2019t think I\\u2019ve mentioned the term rorqual before because I find it really hard to pronounce. Rorquals are long, slender whales with throat pleats that allow them to expand their mouths when they gulp water in. We talked about this in episode 211 about the fin whale, which is another rorqual. I\\u2019ll quote from that episode to explain again what the throat pleats are.\\n\\nA baleen whale eats tiny animals that it filters out of the water through its baleen plates, which are keratin structures in its mouth that take the place of teeth. The baleen is tough but thin and hangs down from the upper jaw. It\\u2019s white and looks sort of like a bunch of bristles at the end of a broom. The whale opens its mouth wide while lunging forward or downward, which fills its huge mouth with astounding amounts of water. As water enters the mouth, the skin stretches to hold even more, until the grooves completely flatten out.\\n\\nAfter the whale fills its mouth with water, it closes its jaws, pushing its enormous tongue up, and forces all that water out through the baleen. Any tiny animals like krill, copepods, small squid, small fish, and so on, get trapped in the baleen. It can then swallow all that food and open its mouth to do it again. This whole operation, from opening its mouth to swallowing its food, only takes six to ten seconds.\\n\\nThe humpback mostly eats tiny crustaceans called krill, and little fish. Since gulp feeding takes a lot of energy, finding a lot of food in a relatively small space is important to the whale. Many little fish that live in schools will form what are called bait balls when they feel threatened, where the fish swim closer together and keep moving around. Any given individual fish has a good chance of avoiding being eaten when behaving this way. Think about last week\\u2019s episode, where the spinner shark swims straight up through a bait ball, biting biting biting. It eats some fish, but most are fine. But a big filter feeder like the humpback can gulp a whole lot of fish at once, so it really likes bait balls.\\n\\nTo help maneuver prey animals into a small area, groups of humpbacks sometimes employ a strategy called bubble-net feeding. The whales will dive below the fish or krill and swim in a ring, blowing bubbles the whole time. The bubbles startle the animals, who move away from them. But since the bubbles are all around them, and the whales swim closer and closer together so that the ring of bubbles shrinks, eventually the fish or krill are all clustered in a small space as though they\\u2019re caught in a net. Then the whales open their mouths and gulp in lots of food. This is actually a simplified explanation of how bubble-net feeding works, which requires several different types of bubbles and various actions by the whales to make it work right."