Whales have been on the earth for a very long time. Some scientists think that the whales might have started out about 60 million years ago as mammals that lived in swamps and on shores. There were probably a lot of food under the water, so the animals might have started going into the water to look for this food, and they needed to hold their breath. Maybe after thousands of years the animals didn't ever need to come back to land again, because they had changed a great deal, and were like the whales we know today. Some scientists believe that the modern land mammal that's the closest relative to the whale is the hippopotamus.
The biggest difference between whales and fish is that whales are mammals. Because they are mammals, whales are warm blooded, which means that a whale's body always stays the same warm temperture. This is possible because whales have a thick layer of fat beneath their skin called blubber. Fish aren't mammals. They're coldblooded, and this means their body always has the same temperture as the water.
The other main difference between whales and fish is that whales give birth to live baby whales called calves, but fish lay eggs.
Whales and fish have different tails. A whale's tail sticks out horizontally or sideways and moves up and down. The parts of the tail that move are called flukes. A fish's tail grows straight up and down, and moves from side to side.
Whales and fish don't breathe in the same way. Fish have gills and breathe underwater through their gills. Because whales are mammals they have to breathe air, and they can only breathe air when they are out of the water. This means that they have to come up for air often.
There are about 76 different kinds of whales, and they can be divided into two main groups called baleen whales and toothed whales.
Baleen whales don't have any teeth, but instead they have long, flat plates that are like a comb. The whales fill their mouth up with water and then they push the water out through the baleen, and it keeps the food in their mouths. Toothed whales have teeth to catch and eat their food. They make special sounds and use echoes to locate food.
A killer whale is a toothed whale. It has about 40 to 56 teeth and are two inches long.
Whales are mammals, but they do look like fish. They have different shaped heads, and many different sizes and colors. The shape of a killer whale's head is very smooth and oblong.
Adult whales can range in size from 10ft to 100ft.
The smallest whale is the harbor porpoise and the biggest whale is the blue whale. The average size for an adult killer whale is about 30ft.
The coloring of the killer whale is very handsome. The whales are black with white markings. The markings for each killer whale are very special, so that scientists can identify and track indiviual whales.
Whales have tails with two halves called flukes, that they move up and down to propel themselves through the water. Whales have flippers too, so that they can turn and balance.
Most whales have a fin on their back called a dorsal fin that is used to help keep their balance. Killer whales have these dorsal fins, and their shape is just as special and indiviual as their white markings, so scientists also can use these dorsal fins to help track killer whales.
A whale has a huge skull and a huge jaw. The whales' flukes are also huge, but it's surprising that there aren't any bones in these flukes. There are bones in their flippers, and they look a lot like human fingers bones.
Whales have very long backbones, with about 41 to 64 vertabrae. Whales have ribs too, and most whales have 12 or 14 pairs of ribs.
Whales have a blowhole on top of their head for breathing. They push their heads up out of the water to take a breath. Then they close their blowhole, and hold air in their lungs, and go under water for one to twenty minutes. Then they have to get fresh air into their lungs, so they come up to the surface again and shoot the stale air out of their blowhole. This shooting out of air mixed with some water is spouting.
Female killer whales have calves every four to six years. They can start having calves when they are about 14 years old, and still have calves until they're about 40 years old. A pregnant whale carries her calf from 9 to 16 months. Usually she only has one calf at a time.
The whale calves are born underwater, and can swim right away. They have to come up for air imeditatly. Killer whales calves are big. They can weigh 300 pounds and be seven feet long.
Killer whale calves have the same markings as their parents, but instead of white patches, they have yellow, and then the yellow gradually changes to white as they grow up.
Killer whales use their blowholes to make clicking sounds. Sound moves much faster in the water than in the air. When the clicking sounds hit some object like a fish, they bounce back quickly and create an echo. The echo helps the whales learn about the location and the size and shape of the object. Scientists call this echolocation.
When killer whales are eating they keep in touch with each other by making sounds. Some times a killer whale gets lost from its group, and then it makes its special clicks to find its family.
Whales make another kind of sound too. It sounds a little like talking or singing. Scientists call this vocalization.
Migration means to move from one place to another and usually at the same time each year. Killer whales migrate from Alaska to Mexico. They go up to cool waters in Alaska in the summer, and they go to warm waters in California and Mexico in the winter. Killer whale calves are born while the whales are in warm waters. This protects the babies because they only have a small layer of blubber.
Baleen whales live for as long as 80 years, but most toothed whales don't live quite that long. Small toothed whales live about 30 years, and killer whales and other large toothed whales live maybe up to 70 - 75 years. Whales can die early from diseases or injuries or being hunted by whalers, or even killer whale sharks.
Killer whales eat so many different things. Sometimes killer whales are called the "wolves of the sea" because they are such powerful hunters and they hunt in groups. They hunt and eat seals, and sea lions, different kinds of seafood like salmon, squid, octopus, and even sea turtles, and birds. They can even eat other whales. However, even though the name killer whale might seem like these whales are dangerous to himans, scientists don't believe killer whales have ever harmed a human being.
A whale doesn't have a sense of smell, but a marine guide at a zoo I went to said some whales in zoos or marine shows have food they seem to especially like, so they must be able to taste something.
Whales have eyes on the side of their heads so they can't look straight ahead, but instead they have to look to the sides.
Whales can see under water, but the question is how well killer whales can really see. One source says they can see just as well under water as a cat can see on the land. But another author says their hearing is much better than their eyesight under water.
Scientists agree that killer whales can see really well above the water. They poke their heads out of the water and look around. This is called "spy hopping."
Killer whales have ears that are all inside their heads. They use echoes to find out about food and enemies and where they are located.
Some whales like to touch each other, like mother killer whales and their calves, and killer whales that are playing. Maybe they like people to pet them too, though we don't know for sure.
One Native American tale is that killer whales and wolves are related because they are both such excellent hunters. They story is that once some killer whales became bored in the water and decided to climb up onto the land, and once they were on the land, they turned into wolves.
Some Native American Indian tribes thought killer whales had special spirits, and they used their images for totem poles and carvings. Some tribes believed killer whales were humans who had been sent into the sea as punishment, so it would bring bad luck to kill them.
A very long time ago people called killer whales "whale killers" because they hunted other whales. Then, some people started calling the whales "killer whales". Another name for killer whales that you hear a lot today is orca, from the scientific name for Orcinus Orca.
Killer whales can be very large and weigh up to 9 tons. That's equal to the weight of about 140 people. Killer whales can move through the water at a speed of up to 25 - 35 miles per hour.
Killer whales have different shapes of dorsal fins and patterns on their white saddle patches. Scientists like to take pictures of these so they can identify the whales, and even name the whales.
Killer whales travel in groups. These groups are their families, and they are called pods. Pods are made up of mother whales and their children and their daughters children. But scientists don't yet know what happens to the fathers. Most pods have 3 - 25 whales, but other pods have up to 40 or 50 killer whales.
All About The Orca