If you put on a scuba diving outfit right now and jumped into the sea, you might be surprised to learn you're not the only one who can't breathe under water! Whales, dolphins, seals and a lot of other animals that spend their time underwater need to come up for air. That's because they're mammals, just like you and me. If you're not sure what a mammal is, here's a quick test you can do on yourself:
Are you warm-blooded?
Do you have some hair on your body?
Do you use lungs to breathe?
Do you need to come up for air when you're swimming under water?
If you answered yes to these questions, then CONGRATULATIONS! You are a mammal! And believe it or not, so are some of the largest animals on earth: The Whales!
WHALES: There are over 80 different kinds of whales and they can be put into two groups: those with teeth (called toothed whales) and those without teeth (called baleen whales). Baleen is a wall of bristles in the front of a whale's mouth that catches and filters food. Baleen is made of the same stuff as our fingernails. It's easy to spot a baleen whale because they look like they're wearing moustaches. The biggest baleen whale - and the biggest animal in the world - is the blue whale. Bigger than a brontosaurus, the blue whale has a heart the size of a small car and probably weighs more than all the kids in your school put together. A blue whale is so huge, it would hardly fit on a full size basketball court!
When you think of whales, you might be surprised to learn that dolphins, porpoises and Orcas (killer whales) are also included in the same family as whales. That family is called the Cetaceans (pronounced sih-TAY-shuns). No matter which kind of whale you're learning about, you can be sure of a few facts:
Whales always travel together in groups called pods.
The males are called bulls, the females are called cows and the babies are called calves.
Whales talk to each other.
TALK?? Yes, talk! Whales don't have vocal chords like we do, but they send out vibrations that sound like creaky doors, whistles, squeaks and clicks. Scientists call this talking "echolocation". This may seem like an awfully big word, but let's break it down. The first word is "echo". Just think of yourself standing in a large canyon. You shout, "HELLO?" and an echo of your voice bounces through the canyon walls. "Hellooo? helloooooo?" And the second part of the word is "location", meaning "the place where something or someone is."
Through echolocation, whales can tell each other where they are, where food is, and even warn each other of danger. Whales can call out to other pods that are traveling miles away. Fin whales can talk even if they're 2,000 miles away from each other. That means two fin whales can keep in touch when they're on opposite ends of the Pacific Ocean! Since whales have eyes on the side of their heads and ocean water can sometimes be dark and murky, they use echolocation to help them see as they bounce their sounds around. Submarines also use a kind of echolocation called "sonar" to find their way through the dark waters of the ocean.
So, what do these huge creatures do all day? Well, when they're not feeding, taking care of their young, or migrating (moving) to warmer waters in the winter, they have all sorts of amazing behaviors. One is called "spy hopping." No, this isn't when a bunch of whales jump up and down on spies. Spy hopping is when a whale pokes its head straight out of the water to have a look around. Another behavior is called "breaching." This is where whales jump completely out of the water and splash down, kind of like when you do a belly flop in a swimming pool. Scientists think whales breach to scratch their skin when it's itchy. Think about it. If you lived in the water and didn't have hands to scratch an itch, you might take care of an itch doing the same thing! "Tail slapping" is another cool behavior. Whales put their heads and bodies underwater so that only their tails stick out in the air. Then they slap the waves, sending huge sprays of salty seawater. Some scientists think this is another way for whales to talk to each other. But the best behavior of all is definitely their "singing." Wait a minute. Singing??? Yep, you betcha! Whales can sing. Maybe not in the opera, but if you ever get a chance to hear a recording of a whale song, you'll be listening to some of the most calm, beautiful and amazing music you've ever heard!
Back in 1985, (maybe before you were born), a whale named Humphrey the Humpback Whale did something that puzzled scientists: he swam straight into the San Francisco Bay and then traveled 53 miles up the Sacramento River! The river was fresh water and Humphrey was used to living in salt water, so after 25 days of swimming around the river his skin started to peel. The scientists who were watching him feared he would die, so they gathered recordings of humpback whales talking and played them underwater. Humphrey followed the sounds all the way back to the Pacific Ocean! For years Humphrey would return to the San Francisco Bay, and in 1990, he swam on shore and got stuck in the mud. Wildlife experts rescued him and returned him once again to the ocean. Scientists think something may have been wrong with Humphrey's echolocation system but whatever the reason for Humphrey's confusion, Humphrey needed human help. There are many people who work hard to help whales all over the world. Who knows? Maybe someday you'll be one, too.
