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Bird feathers

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Have you ever heard the old saying, " Birds of a feather flock together "? But what if birds had fur? Would they flock togeth...ur? No, that doesn't sound right! We guess it's a good thing birds have feathers.

Birds seem to think so, too. Their feathers are unique. In fact, you might say they're one of the bird's characteristics . If it's got feathers, it's a bird. If it's a bird, it's got feathers. And those feathers aren't just there for show! Scientists and bird lovers alike can tell you that feathers are very important.

Feathers allow birds to do one of their favorite things: fly. Without their aerodynamically -designed feathers, birds would be around on the ground like the rest of us!

However, even flightless birds need their feathers. For example, penguins rely on their feathers to keep them warm and dry in cold climates. Birds are warm-blooded creatures. That means their bodies maintain a healthy temperature to keep them alive. As insulators , feathers help with this. In this way, they're a bit like clothes for birds.

Birds aren't known to keep up with the latest fashion trends, though. Still, the colors of a bird's feathers can affect its ability to find a mate. In many species, male and female birds have differently colored feathers. This helps them tell each other apart. More brightly-colored birds may also find mates more easily.

Some birds use their coloring to attract other birds. But other feathers help make birds invisible...to predators, at least. In this way, feathers can serve as camouflage . For example, the winter feathers of the Willow Ptarmigan are pure white. This helps the bird to blend in with its snowy surroundings.

How did birds get their feathers? Scientists think they may have evolved from scales like you'd find on a reptile. This view is supported by the fact that some birds still have scales on their lower legs and feet. As feathers began to develop, they took on a few different forms.

The largest feathers on a bird are called feathers. These include the flight feathers and the tail feathers. They give birds their shape and color.

Underneath the feathers are soft, fluffy down feathers. They provide most of the insulation birds need to stay warm. They're so good at this that humans have used them for many years in down jackets and feather pillows.

A few other types of feathers found on many birds include semiplumes, filoplumes, and powder feathers. Semiplumes are like a cross between down and feathers. They provide insulation while helping to maintain a bird's shape.

Filoplumes are the simplest feathers. These sit under the feathers. They're hair-like and usually stiff. They also have receptors that help birds understand what's going on with their feathers.

Powder feathers can be found on certain birds, such as pigeons and herons. They grow continuously and disintegrate at their tips into a fine powder. The of this powder is not completely understood, but some scientists believe it may help with waterproofing.

Do you have a favorite species of bird? Maybe you like to look at flamingos or peacocks. Many of the world's birds have very colorful feathers. What about the birds where you live? The next time you're outside, try bird watching! You may just find a species you've never seen before.

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Why Do Birds Wear Feathers Instead of Fur?

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Have you ever heard the old saying, " Birds of a feather flock together "? But what if birds had fur? Would they flock togeth...ur? No, that doesn't sound right! We guess it's a good thing birds have feathers. Birds seem to think so, too. Their feathers are unique.

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Would you like to hear a joke? Okay, here it is: Why can't penguins fly?

Any ideas?

It's because they don't have enough money to buy plane tickets!

Okay, so that's an old joke, but we still like it! And it made us WONDER...why can't penguins fly? After all, they are birds, aren't they?

Yes, penguins are , flightless birds that live in the Southern Hemisphere --especially Antarctica. Unlike the wings of other birds, penguins' wings are more like that make them well- for life in the water.

In fact, penguins swimming through water looks quite similar to birds flying through the sky. Their feathers trap air, which makes them more in the water and them from the cold water.

Penguins spend about half their time in the water and half their time on land. And their don't just help them swim! When they're on land, their and their tails help them keep their and walk .

Have you ever seen a penguin walk? Their walk looks more like a waddle, and they don't move very fast. If a penguin wants to move quickly, it slides on its belly! This is a movement called " tobogganing " after a northern method of sledding.

Okay, so a penguin's help them a lot. Still, why can't they fly? Scientists believe penguins can't fly because they likely had little or no threat from predators in their past. That means they never evolved to fly because they didn't have anything to fly away from. Instead, these birds evolved to become more to better survive in their habitat. They relied on the oceans for food, so developing to swim well was more important than growing wings to fly.

As they exist today, it's easy to see why penguins can't fly. Their , adapted for life in the water, simply cannot get their cute, chunky bodies into the sky. This is especially true for the largest species of penguin, the Emperor Penguin. Emperor Penguins stand over three feet tall and can weigh 75 pounds or more. They'd need some pretty strong wings to fly through the air!

It's easy to see why penguins would choose advanced swimming ability over flying. How about you? Would you rather glide gracefully through water or through the air? There are definitely advantages to both, as we can see from all our bird friends!

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Would you like to hear a joke? Okay, here it is: Why can't penguins fly? Any ideas? It's because they don't have enough money to buy plane tickets! Okay, so that's an old joke, but we still like it! And it made us WONDER...why can't penguins fly?

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Emperor penguins are the largest penguins on Earth. At almost 4 feet tall and weighing 50 to 90 pounds, these penguins grow to be the same size as many elementary school students!

Emperor penguins live in Antarctica , the coldest on Earth. Temperatures in Antarctica can drop as low as -140° F. The shape of its body helps the emperor penguin survive life in these temperatures.

The emperor penguin 's body has a thick layer of by a thick layer of covered by feathers. These three layers provide triple protection from harsh conditions and extreme cold. In addition to trapping body heat in, the feathers also keep cold air and water out.

The emperor penguin 's diet consists mostly of fish, squid and crustaceans . It catches its dinner by diving into the sea.

Although humans can't stay underwater very long before they need to come up for a breath, emperor penguins can remain for up to 18 minutes at a time!

This is possible thanks to specialized body systems. The emperor penguin 's blood allows it to function even with very low oxygen levels. In order to use as little oxygen as possible while diving, the emperor penguin can also slow its metabolism and stop any nonessential organ functions.

Each winter, the emperor penguin walks 30 to 75 miles over ice to . A single breeding can include thousands of penguins.

When a female emperor lays an egg, she immediately rolls it onto the father penguin's feet. Male penguins care for the eggs until it is hatching time. During this time, male penguins can lose up to half of their body weight because they stay on shore caring for the egg and do not return to the sea to eat.

About seven weeks after birth, emperor penguin chicks form groups called " creches." The penguins in a huddle together for protection and warmth, but they continue to be fed by their parents. Emperor penguin chicks can identify their parents from the group of adult penguins by the sound of their call.

At six months of age, emperor penguin chicks are fully grown. At this time, the adult penguins and all the chicks return to the open sea together. In the wild, emperor penguins live to be about 20, although some have lived to be 50 years old.

The emperor penguin , along with nine other species of penguins, may soon be included under the United States Endangered Species Act. Warming seas and industrial fishing have begun to change fish populations, making it more difficult for penguins to find enough food. The emperor's habit and breeding colonies are also becoming disrupted by .

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Emperor penguins are the largest penguins on Earth. At almost 4 feet tall and weighing 50 to 90 pounds, these penguins grow to be the same size as many elementary school students! Emperor penguins live in Antarctica , the coldest on Earth. Temperatures in Antarctica can drop as low as -140° F.

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As you your ship at the of the floating of , you scan the for signs of life. You can't wait to hit the and get started exploring this cold, world. Suddenly your binoculars focus in on movement.

What could it be? As your eyes strain to make sense of the blurry motion, you realize you've found a large group of flightless birds that are all dressed up and ready to greet you. What are we talking about? Penguins, of course!

Wouldn't it be cool to explore the edges of the world and spend some time with penguins? They're super cute, especially since their coloring makes them look like they're wearing tuxedos.

In addition to their appearance, you can also recognize penguins immediately by their tell-tale . As they make their way across the , they along, seeming to take their time without a care in the world.

If you've ever watched a , you may have WONDERed: do penguins have knees? After all, if you didn't have knees, you'd probably , too!

If you were to x-ray a 's legs, you would discover that penguins do indeed have knees! In fact, a 's leg is made up of four parts: a , knee, tibia, and - the same bones you have in your leg!

Why do their legs look so short then? It's a bit of an illusion, because a 's upper legs are hidden by their feathers.

So penguins do have knees. And their legs are longer than they look, because the upper parts are hidden by feathers. Why would they then, if they have knees?

That question puzzled scientists for quite a while. Most scientists today believe that penguins because their legs were designed to help them faster.

If you look closely at a 's legs, you'll notice that they're set far back on the body. This makes it more difficult to walk on land, as it requires more energy to move quickly. Also, penguins walk on the soles of their feet instead of their toes like other birds. As a result, waddling helps penguins to maximize their momentum while using the least amount of energy.

Since penguins spend as much as 75% of their time in the water, their bodies have evolved to be able to move quickly through the water. They use their tails and feet as rudders, and their flippers act much like wings do on other birds - essentially, penguins "fly" through the water!

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As you your ship at the of the floating of , you scan the for signs of life. You can't wait to hit the and get started exploring this cold, world. Suddenly your binoculars focus in on movement. What could it be?

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Use your Google login to listen and read!

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ReadWorks | Award-Winning, EdTech Nonprofit Organization

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ReadWorks is an edtech nonprofit organization that is committed to helping to solve America's reading comprehension crisis.

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Use your Google login to listen and read!

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ReadWorks | Award-Winning, EdTech Nonprofit Organization

# data[].attributes.attachment_link.description
ReadWorks is an edtech nonprofit organization that is committed to helping to solve America's reading comprehension crisis.

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Use your Google login to listen and read!

# data[].attributes.attachment_link.title
ReadWorks | Award-Winning, EdTech Nonprofit Organization

# data[].attributes.attachment_link.description
ReadWorks is an edtech nonprofit organization that is committed to helping to solve America’s reading comprehension crisis.

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Have you ever felt like, no matter how hard you try, there's someone after you? You build a house of straw and what happens? He blows it down. You build a house of sticks. Guess what? Same result.

If this sounds familiar, you're not alone. We all feel like the Three Little Pigs every now and then. Every time we turn around, there's the Big Bad ready to blow things down. Wouldn't it be great if we could just him, so we could control him?

After all, a is just a big dog, right? And dogs are man's best friend. So couldn't we train the Big Bad to be our friend? Maybe not...

Certain of animals are easily domesticated, while others tend to remain all their lives. Today, we'll take a look at wolves and whether it's possible to them.

Scientifically, wolves are known as Canis lupus. Canis is what gives us our common name for domesticated dogs: canines. So wolves are indeed part of the dog family. In fact, they're the largest members of the family.

Throughout history, wolves have had an adversarial relationship with humans. They've been portrayed as beasts with spine-tingling howls. Although they rarely attack humans, most people consider them one of the most feared villains in all of . Perhaps it's because they do regularly attack animals, such as pets and .

Although many types of wolves were once commonplace all around the United States, their numbers have dwindled considerably. Due to hunting and loss of , wolves struggle to survive in today's world.

Because of the of some of wolves, some scientists have tried to their numbers by breeding them in in zoos or animal reserves. This has led some to WONDER whether these creatures could be domesticated like the dogs we're all familiar with.

It seems , right? They're animals from the same family. Scientists have confirmed through testing that wolves and dogs are remarkably similar. Despite their similarities, though, wolves are very difficult to domesticate.

With such a similar background, scientists have long wondered why wolves tend to stay while dogs will gladly assume the role of man's best friend. New research has given them some hints as to the answer to this mysterious riddle.

Kathryn Lord, an evolutionary at the University of Massachusetts Amherst, believes the difference between wolves and dogs stems from their first experiences and how they're socialized. Each animal goes through a short period of time called a socialization window.

During this time, they can be introduced to things, such as other animals, sights, smells, and experiences, that they will be comfortable with all their lives. After the socialization window closes, however, new things will elicit a response.

The key to the difference between wolves and dogs may be when they experience the socialization window. Researchers believe wolves may experience the socialization window much earlier than dogs. Why does this make a difference?

When wolves and dogs are very young, their sense of develops first. Afterward, their sense of hearing develops, followed by their sense of sight. When wolves experience their socialization window, they may only be able to . As they try to their new world, they probably can't hear or see much at all.

As their socialization window closes and they subsequently develop their hearing and sight, those new sounds and sights will elicit responses. This may explain why it's extremely hard to domesticate wolves.

Dogs, on the other hand, enter their socialization window after their hearing and sight have developed. Thus, they do not most of what they hear and see early in life, leading to their ability to get along with and not humans and a variety of other animals.

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Have you ever felt like, no matter how hard you try, there's someone after you? You build a house of straw and what happens? He blows it down. You build a house of sticks. Guess what? Same result. If this sounds familiar, you're not alone.

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Blue whales are the largest animal ever known to have lived, even larger than the dinosaurs who once roamed the Earth. In fact, the longest blue whale ever measured was 111 feet long - approximately the length of three school buses parked end to end.

Scientists have determined two causes for the blue whale's size. First, the blue whale lives in the ocean. Since the ocean covers more than 70 percent of the Earth's surface, whales have plenty of room to grow and swim.

Another contributor to the blue whale's size is that weightless feeling you've probably noticed if you've ever floated in a swimming pool. It's similar to the weightlessness astronauts feel when they're in a low gravity situation in outer space!

Unlike humans, the blue whale does not rely on its skeleton to support its huge body. Instead, the whale relies on the of the water around it to keep its body afloat.

Despite its huge size, the blue whale's diet consists almost entirely of - small shrimp-like crustaceans. The whale gathers thousands of at a time by sucking enormous mouthfuls of seawater through a special mouth filter called a "." As the whale closes its mouth, seawater is flushed out, leaving and small fish behind for the whale to swallow.

Coming across such a giant creature in the ocean may seem scary, but blue whales are harmless to humans. In fact, they even have some things in common with us!

Blue whales are warm-blooded mammals. Unlike fish, they must breathe air.

Research also indicates that blue whales are highly social and very intelligent. They even have their own form of language used to communicate with other whales. Listen to what they have to say!

Here are some other fun facts about blue whales:

The heart of an adult blue whale is the largest of any .

A blue whale heart can weigh up to 1,300 pounds and is the size of a Volkswagen Beetle.

The tongue of an adult blue whale is approximately the same weight as an adult elephant.

What about baby blue whales? Here are some fun facts about blue whales' "little" ones:

At birth, a blue whale calf is about the size of a hippopotamus.

A baby whale can drink up to 100 gallons of milk every day during its first seven months of life.

With that kind of diet, it should come as no surprise that a baby whale can gain up to 200 pounds a day.

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Blue whales are the largest animal ever known to have lived, even larger than the dinosaurs who once roamed the Earth. In fact, the longest blue whale ever measured was 111 feet long - approximately the length of three school buses parked end to end. Scientists have determined two causes for the blue whale's size.

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If you love sea creatures, you're probably fascinated by whales. These swimmers amaze us with their size and moves. Whales aren't like other fish, though.

In fact, they're not fish at all! You may already know that whales are mammals. Like dolphins and porpoises, whales are mammals that share some common characteristics with other mammals, like humans.

For example, mammals are warm-blooded and they breathe from the air. They also give birth to live young and have hair.

If you're thinking, "Hmm...I've never seen a hairy whale before," you're not alone. Many people don't realize that whales have hair. After all, you never see a whale with a comb, do you?

Since whales aren't furry, you're probably WONDERing where they have hair. If you've ever seen a whale up close, you've probably noticed that their skin seems rather smooth and not at all hairy.

Of the over 80 species of whales in the world, only a few have visible hair. Many whales have hair on their bodies before they're born, but it often goes away shortly after birth.

A few whales have visible hair as adults. For example, the whale has unique bumps on its head. The bumps, which are the size of golf balls, are called and they contain hair .

Right whales have hair on their chins and upper jaws. whales often have hair on their lips, chins, snouts and blowholes. Since whales don't need hair to keep warm (they have for that!), scientists believe whale hair may serve another purpose, such as sensing things around them or communicating a need to nurse in their young.

Hair isn't the only thing that can make whale skin bumpy from time to time, though. Normally-smooth whale skin can become bumpy from scratches caused by interactions with other marine animals while feeding.

Marine parasites can also cause skin bumps and discoloration in whales. For example, whales are often seen with whale lice and attached to their skin. Both whale lice and are skin parasites. Whale lice are related to skeleton shrimp, while are related to crabs and lobsters.

If whales rub up against something that removes these creatures, scars on their skin are often left behind. That's why some whales have a spotted or "" look to their skin. As if these problems weren't enough, scientists now also believe it's possible for whales to get sunburned. Due to ozone depletion, whales are being exposed to the sun's harmful ultraviolet rays when they surface to breathe, leading to sunburn and other skin problems!

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If you love sea creatures, you're probably fascinated by whales. These swimmers amaze us with their size and moves. Whales aren't like other fish, though. In fact, they're not fish at all! You may already know that whales are mammals. Like dolphins and porpoises, whales are mammals that share some common characteristics with other mammals, like humans.

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The oceans of the world are with . From the cold Arctic seas to the warm waters of the tropics, the number and variety of species that live in the world's oceans boggles the mind.

Since we live on land, humans are often of the constant -and-death battles waged below the waves. Complex chains exist in the oceans with microscopic algae and plankton at the bottom of the chain and the world's largest fishes and mammals at the top.

In fact, the oceans are home to perhaps the most fierce predator on Earth. It's a killing machine with no natural predators that feeds on most anything that comes across its path, including , sea birds, seals, and even whales and sharks. If you've ever seen an awesome black-and-white beast with long, sharp teeth, then you already know what we're talking about: killer whales!

Killer whales are also known as orcas, a name that comes from their scientific name: Orcinus orca. Although they're not considered a danger to humans in the , killer whales will eat just about anything else that crosses their path.

They have a huge range, living anywhere from the Arctic to waters near the . In addition to , killer whales will hunt other animals in coastal waters, such as seals and sea birds. They're also not afraid to take on the other large creatures they share the oceans with, including squid, octopuses, sea turtles, sharks, and other whales.

The to take on other whales is where their terrifying name comes from. Long ago, sailors referred to these massive creatures as "whale killers." Eventually that nickname changed to killer whale. In Spanish, they're referred to as ballena asesina, which means " whale."

The name killer whale is still a bit deceptive, though. Scientifically, they're classified as a toothed whale that's actually a member of the dolphin family ( Delphinidae). They're the largest member of the oceanic dolphin family, which also includes dolphins and pilot whales.

Killer whales rule the sea thanks to their impressive physical characteristics. They can grow to be nearly as long as a school bus and weigh up to 12,000 pounds. They also possess a mouth full of sharp teeth that can grow to be four inches long.

Killer whales are very animals that live in groups called pods. Pods can have as many as 40 members that stick together to hunt for . Like the dolphins they're related to, killer whales use echolocation to communicate with each other.

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The oceans of the world are with . From the cold Arctic seas to the warm waters of the tropics, the number and variety of species that live in the world's oceans boggles the mind. Since we live on land, humans are often of the constant -and-death battles waged below the waves.

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Are whales mammals?

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A man walked into a movie theater and picked a prime seat. As he was starting to on his popcorn, he noticed what looked like a whale sitting a few seats over. Flabbergasted , the man asked, "Are you a whale?"

"Yes, of course," said the whale. "Umm...what are you doing at the movies?" asked the man. "Well," said the whale. "I really liked the book." "Ha! You're a funny !" exclaimed the man.

OK, so that's a bad joke, but do you know what's wrong with it? If you said whales don't go to the movies, you're on the wrong track. If you said whales aren't , then you were paying close attention!

Even though they live in the ocean, whales are mammals. That means they've got something in with you and me, because human beings are mammals, too. But what exactly does it mean to be a ?

Mammals are the animals that make up the scientific class Mammalia. Throughout the entire Earth, there are over 5,000 different species of mammals. That sounds like a lot, doesn't it? Compared to the over 21,000 kinds of and over 800,000 kinds of insects in the world, though, mammals make up a fairly small group of animals.

Mammals range from the very tiny Kitti's hog-nosed bat that weighs less than an ounce to the extremely huge blue whale that can weigh as much as 150 tons. If you put a hog-nosed bat, a human being, and a whale in the same room, you'd need a very large room, but you'd also notice how different these creatures are.

Despite their differences, though, all mammals share some characteristics. For example, all mammals are vertebrates. That means that they have a backbone. They also have three middle bones.

All mammals have of some sort, as well as glands. In female mammals, the glands produce that they use to feed their . Mammals are also warm-blooded, which means they regulate their own body temperature via a region in the brain called the neocortex.

Mammals come in all sorts of shapes and sizes. They can also live just about anywhere on Earth. From whales and dolphins in the sea to elephants and primates on land, mammals have found homes in a variety of places, including in trees and in the air.

There is one other characteristic shared by nearly all mammals with just a few exceptions: nearly all mammals give to live . The exceptions to this rule are monotremes, such as the echidna and , which lay eggs instead of giving to live .

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Join us in Wonderopolis today to find out what you have in common with some of your favorite animals!

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Do you know why it takes elephants so long to find their at the ? All their trunks look the same!

OK, so that wasn't the , but it does underscore the misperception that all elephants are the same. Although all elephants may share some similarities, there are actually two types of elephants: African elephants and Asian elephants. Asian elephants, known by their scientific name Elephas maximus, belong to a different genus than African elephants, which belong to the genus Loxodonta.

Given their names, you've probably already figured out one of the primary differences between these two types of elephants: their habitats. Since African elephants can be found in Africa and Asian elephants stick to Asia, these elephants don't run across each other in the wild.

If you see these two types of elephants, it's usually in pictures and they can look very similar. If you saw them in the flesh next to each other, though, you'd be able to spot a few key differences between them.

For example, African elephants tend to be much larger than Asian elephants. On average, African elephants their Asian counterparts by a or more! Weight can be hard to , though, so one feature experts look at first is the size of an elephant's ears.

African elephants have proportionally larger ears than Asian elephants. Some people think the ears of African elephants are shaped a bit like the continent of Africa. These larger ears help keep African elephants cooler in the African heat. Asian elephants, on the other hand, tend to spend more time in cooler jungles. As a result, their ears tend to be smaller.

You can also see a difference between the two types of elephants when they move. African elephants appear to have their heads down when they walk. This is because they have a sloped back that makes their shoulders their highest part. Asian elephants have a flatter back, and they carry their heads higher than their backs and shoulders.

There are a few other smaller differences that can also help tell African and Asian elephants apart. In Asian elephants, only the males grow (but not all of them do). In African elephants, both males and females will usually (but not always) grow .

African elephants also have a full, rounded head that consists of a single dome. Asian elephants, in contrast, have heads that consist of two domes with an indentation in the middle.

Although both types of elephants have skin color ranging from dark gray to brown, as Asian elephants get older, they develop patches of pinkish-peach skin on their trunks, ears, and faces.

For years, scientists thought that African elephants were a single species. Thanks to DNA testing capabilities, scientists have now learned that African elephants can actually be divided into two species: African forest elephants and African bush elephants. As their names indicate, they live in different environments and have started to develop unique characteristics that help each thrive in its particular environment.

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Do you know why it takes elephants so long to find their at the ? All their trunks look the same! OK, so that wasn't the , but it does underscore the misperception that all elephants are the same. Although all elephants may share some similarities, there are actually two types of elephants: African elephants and Asian elephants.

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"An elephant never forgets!" Have you ever heard that saying before?

It's a common saying, and people have believed that elephants have incredible memories for a long time. But is it true?

In reality, "an elephant never forgets" is a generalization that's not true all the time because all elephants forget things from time to time. However, scientists have proven that elephants do have incredible memories.

Researchers who studied African elephants in the wild learned that older, female elephants (called "matriarchs") often lead herds. These matriarchs build up a strong memory over time that allows them to remember friends and enemies.

They can also remember places where the has found food and water in the past. Researchers believe elephants' good memories are a big part of how elephants survive and why so many live so long (50 to 60 years or more on average).

Those who work closely with elephants also have noticed that elephants remember injuries and can hold grudges against those who have them. For example, a study of African elephants showed that the elephants would react negatively to the smell or sight of certain clothing.

They discovered that the elephants reacted this way because the clothing resembled that worn by Maasai tribesmen. These tribesmen often threw spears at elephants to prove their manhood.

So why do elephants have such great memories? Scientists believe it probably has something to do with their large brains. An average adult elephant's brain weighs in at approximately 11 pounds - the largest of all the land mammals!

In comparison, the brains of humans and bottlenose dolphins - two other "smart" mammals - weigh about three pounds. Of course, a large brain doesn't necessarily mean an animal will be smart.

Studies have shown, though, that elephants are among the smartest in the animal kingdom. In fact, some scientists believe elephants are as smart as dolphins and chimpanzees.

An elephant's brain is like a human's brain in both and complexity . Researchers have found that elephants exhibit many behaviors that reveal substantial intelligence, including , , , play, art, use of tools, and self-awareness .

For example, most elephants live in family groups that can only be separated by death or capture. Amazingly, elephants show signs of when they the remains of other elephants that have died. It's not uncommon for them to touch the dead bodies or bones with their feet or trunks.

Elephants have shown "" (selfless concern for the welfare of others) by their willingness to help other , even humans, in distress. Elephants can also be observed playing and mimicking sounds they hear.

When they use their trunks like arms, elephants demonstrate an unusual ability to use tools. One such use that has amazed people at zoos across the world is when an elephant uses its trunk to hold a brush to create abstract art.

Perhaps one of the greatest signs of elephants' intelligence, though, is the ability to recognize their reflection in a mirror. This ability exhibits self-awareness . This is something that only a few of the most intelligent can claim.

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"An elephant never forgets!" Have you ever heard that saying before? It's a common saying, and people have believed that elephants have incredible memories for a long time. But is it true? In reality, "an elephant never forgets" is a generalization that's not true all the time because all elephants forget things from time to time.

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Today's Wonder of the Day was inspired by james. james Wonders, " How much does a elefant weigh " Thanks for WONDERing with us, james!

Have you ever given much thought to the relationships human beings have with animals? Some animals we and make our pets. Some examples of these animals include dogs, cats, guinea pigs, turtles, and fish.

Other animals we for . Animals such as cows, pigs, and chickens are responsible for much of the that we eat on a regular basis.

There are still other animals that might us for if we should find ourselves in the in their . For example, lions, tigers, and bears might have us shouting "Oh my!" were we to them in the .

For the most part, we humans tend to be bigger than most of the animals we . From badgers and squirrels to beavers and sheep, we usually maintain a size over most animals.

Of course, that's not the case when we larger animals, such as horses and cows. If we into certain parts of the world, we might actually feel small for a change. For example, it's an perspective when you find yourself looking up at a giraffe.

Humans probably feel the smallest, however, when they come face to face with an elephant. Why? The African elephant is the largest living land on Earth!

Exactly how big are elephants? Really big! Asian elephants, which tend to be smaller than their African counterparts, can weigh between 5,000 and 11,000 pounds (2,268 and 4,989 kilograms).

African elephants can range from 5,000 pounds to more than 14,000 pounds (6,350 kilograms). According to the World Wildlife Fund, an average African elephant weighs about 12,000 pounds (5,443 kilograms). Even a baby African elephant can weigh between 200-300 pounds (90.7-136 kilograms) at birth!

The largest African elephants can stand in excess of 13 feet (4 meters) tall at the shoulder. How does an African elephant grow to be 13 feet tall and weigh over 14,000 pounds? By eating a lot! Scientists estimate that the largest elephants can eat more than 300 pounds of in a single day.

Despite their huge size, African elephants are still smaller than the heaviest animal in the world. To find that animal, you'll have to look to the sea. The water in the oceans of the world helps to support the incredible weight of the blue whale. With a length of up to 100 feet (30 meters) from head to tail, the largest blue whales can weigh in excess of 400,000 pounds (181,437 kilograms)! Just imagine how small you'd feel swimming next to that creature!

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Today's Wonder of the Day was inspired by james. james Wonders, " How much does a elefant weigh " Thanks for WONDERing with us, james! Have you ever given much thought to the relationships human beings have with animals? Some animals we and make our pets.

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We were sitting alongside a stream in Wonderopolis the other day when we heard a squirrel, a badger, and a moose having an odd conversation:

Squirrel: Hey! Look at that swimming in the over there.

Badger: You mean the sunbathing on the shoreline?

Moose: No, I think he means that doing the backstroke.

Squirrel: You guys are nuts!

Turtles? Tortoises? Terrapins? What's going on here? Are these completely different animals or are the squirrel, badger, and moose just using nicknames for the same animal?

, , and are all names for the hard-shelled, egg-laying reptiles in the order Chelonia. Basically, they're all turtles. The exact name used for a particular type of , though, can vary depending upon where they live or where YOU live.

People in different parts of the world use different names depending upon the type of they're talking about. For example, the name "" is used most widely and usually refers to those turtles that spend most of their lives in or near the .

is often used to refer to turtles that rarely leave the ocean. Of course, can also refer to the many types of turtles that live in fresh , such as lakes or ponds.

The word "," on the other hand, is usually used to refer to turtles that spend most of their time on , eating shrubs and grasses. Unlike their relatives, tortoises don't have feet, since they don't spend much, if any, time in the .

So what about "terrapins"? Terrapins are turtles that spend time both on and in , . The word "" comes from an Algonquian Indian word meaning "a little ."

Of course, these are all just generalizations and, depending upon where you live, these terms may be interchanged or used in different ways. Do you know what these animals are called where you live? If not, ask around. You might be surprised to learn what words different people use for different types of turtles!

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What's the Difference Between Turtles, Tortoises, and Terrapins?

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We were sitting alongside a stream in Wonderopolis the other day when we heard a squirrel, a badger, and a moose having an odd conversation: Squirrel: Hey! Look at that swimming in the over there. Badger: You mean the sunbathing on the shoreline? Moose: No, I think he means that doing the backstroke.

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Today's Wonder of the Day was inspired by Taryn. Taryn Wonders, " How does a turtle's shell stay on if they are in a really fast current? " Thanks for WONDERing with us, Taryn!

Have you ever been told to come out of your shell? People sometimes use this to refer to kids who are . If you're , sometimes you keep to yourself and don't much with others.

Keeping to yourself is kind of like a hiding inside its shell. Turtles feel safe inside their shells. Likewise, you might feel safe from the outside world when you keep your thoughts and feelings to yourself.

However, we believe most turtles would tell you - if they could talk - that you need to come out of your shell every once in a while. When you do, you the world and meet new friends that make life more . Let's take a closer look at the to see what the world is like for them when they peek out of their shells.

Turtles are reptiles that are known for the hard shell on their backs. The shell acts as a that helps turtles defend themselves from predators. When threatened, turtles will retreat into their shell for protection.

Turtles have been around for over 200 million years. This makes them one of the oldest groups on Earth. Unfortunately, some species of turtles today are endangered.

Turtles can live on land or in water. Some of the largest turtles in the world are . For example, the largest - the leatherback sea - lives in water. It can grow to almost 7 feet long and weigh over 2,000 pounds!

The largest in North America is the alligator snapping . It can grow to almost three feet long and weigh as much as 250 pounds. That's big, but it's a far cry from the size of the leatherback sea !

Did you know that the parts of a 's shell have different names? The upper shell is called the . The lower shell that covers the belly is called the . The two pieces are joined together by pieces of bone called bridges.

Part of the inner layer of a 's shell consists of bones that are part of the 's backbone and ribs. That means the shell is an integrated part of the 's body. If a wanted to leave its shell, it couldn't!

CCRA.R.1, CCRA.R.2, CCRA.R.4, CCRA.SL.1, CCRA.L.1, CCRA.L.4, CCRA.L.6

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You may need to coax today's Wonder of the Day out of hiding!

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We were walking along the Wonderopolis the other day when we heard a little voice yell, "Let's make a run for it, !" We looked around and realized it was said by a baby in the sand. Suddenly, dozens of baby turtles came scrambling down the and headed quickly towards the water. "We made it!" they cheered, as waves carried them off to the sea.

Before we knew it, all the baby turtles were gone from the and it made us to investigate what kind of we saw.

Known to scientists as Dermochelys coriacea, the leatherback sea is the largest on Earth. The largest leatherbacks can grow to be as much as ten feet (three meters) long and weigh more than 2,000 pounds (907 kilograms). Most leatherbacks grow to be between four and six feet (1.2 and 1.8 meters) long and 650-1,100 pounds (295-499 kilograms).

Leatherbacks get their name from the look and feel of their , which is the section of their exoskeleton that covers the back. Unlike other sea turtles that have a hard, bony shell, the dark-colored of the leatherback is made up of a thin but tough layer of skin that feels .

The leatherback's also looks a bit like leather because of the thousands of tiny bone plates that exist under the surface. Unique ridges along the also give leatherbacks a hydrodynamic structure that allows them to move more easily in the water.

Despite their impressive size, leatherbacks aren't fierce predators. Their delicate jaws only allow them to survive on a diet of soft-bodied animals. That's why most leatherbacks eat only jellyfish.

Leatherbacks can be found in oceans all over the world. They're more widely distributed than any other . They can be found as far north as Alaska and as far south as the coast of South Africa. With their powerful front , they can swim thousands of miles across open seas.

Unfortunately, leatherback numbers have been in recent years. In most areas, they're listed as a vulnerable species. In the United States, they're listed as an endangered species. Scientists point to pollution as a major to leatherbacks. In particular, plastic bags can often be mistaken for jellyfish and harm leatherbacks when they eat them.

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We were walking along the Wonderopolis the other day when we heard a little voice yell, "Let's make a run for it, !" We looked around and realized it was said by a baby in the sand. Suddenly, dozens of baby turtles came scrambling down the and headed quickly towards the water.

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Orca facts and pictures

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Six tons of pure power whacks an ice floe floating in cold Arctic waters. The seal lying on top of the ice doesn't stand a chance. Knocked into the sea, the seal becomes a meal for one of the ocean's top predators-the huge orca, or killer whale.

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Beluga Whale information

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Unlike most other whales, the beluga has a very flexible neck that enables it to nod and turn its head in all directions.

Belugas generally live together in small groups known as pods. They are social animals and vocal communicators using a diversified language of clicks, whistles, and clangs. Belugas can also copy a variety of other sounds.

These whales are common in the Arctic Ocean's coastal waters, though they are found in subarctic waters as well. Arctic belugas migrate southward in large herds when the sea freezes over.

Belugas feed on fish, crustaceans, and worms.

The whale is related to the tusked "unicorn" whale known as the narwhal.

The beluga is not related to the sturgeon of the same name, which has been heavily fished for its famous caviar.

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The beluga, or white whale, is one of the smallest species of whale. Their distinctive color and prominent foreheads make them easily identifiable. Unlike most other whales, the beluga has a very flexible neck that enables it to nod and turn its head in all directions.

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Blue Whale facts and pictures

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Narwhal facts and pictures

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Get narwhal facts and pictures from National Geographic Kids.

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Emperor penguin facts and pictures

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Emperor penguins spend their entire lives on Antarctic ice and in its waters. They survive-breeding, raising young, and eating-by relying on a number of clever adaptations.

These flightless birds breed in the winter. After a courtship of several weeks, a female emperor penguin lays one single egg then leaves! Each penguin egg's father balances it on his feet and covers it with his brood pouch, a very warm layer of feathered skin designed to keep the egg cozy. There the males stand, for about 65 days, through icy temperatures, cruel winds, and blinding storms.

Finally, after about two months, the females return from the sea, bringing food they regurgitate, or bring up, to feed the now hatched chicks. The males eagerly leave for their own fishing session at sea, and the mothers take over care of the chicks for a while.

As the young penguins grow, adults leave them in groups of chicks called crèches while they leave to fish. There is a reason for the timing of emperor penguins' hatching. By December, when the Antarctic weather has warmed somewhat, the ice the penguins occupy begins to break up, bringing open waters closer to the nesting sites. Now the chicks are old enough to take to the seas and fish for their own food.

Check out the book Penguins vs. Puffins for more about these amazing birds!

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Emperor penguins spend their entire lives on Antarctic ice and in its waters. They survive-breeding, raising young, and eating-by relying on a number of clever adaptations. These flightless birds breed in the winter. After a courtship of several weeks, a female emperor penguin lays one single egg then leaves!

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Humboldt penguin facts and pictures

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Adelie penguin facts and pictures

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Asian elephant facts and pictures

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THE BIGGER THE BETTER

Asian elephants live in the tropical forests and grasslands of Southeast Asia. They're a little smaller than African elephants but can grow nine feet tall and weigh nearly six tons. That's heavier than two medium-size cars! Even newborns are on the hefty side, weighing some 200 pounds. Given their size it's no surprise that these guys are big on food. Adults can eat 300 pounds in one day, nearly 75 times what the average human eats! An Asian elephant's ideal meal includes roots, grasses, fruit, and bark.

Much of an Asian elephant's time is spent searching for grub. In fact the animal may travel 50 miles a day to find food. Asian elephants also enjoy taking dips in the water. To cool down their backsides, the animals will fill their trunks with water and spray it over themselves like a hose.

SOCIAL NETWORK

Asian elephants are gentle and super-social. Related females live with their young in herds. (Adult males go off on their own.) To communicate with each other they use rumbles, bellows, growls, and moans. Some of their vocalizations can be heard more than a mile away. Talk about a long-distance call!

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A three-foot-deep watering hole in northeast India hums with buzzing insects and chirping birds. Suddenly seven Asian elephants stomp through the grass surrounding the pool and splash into the water. It's bath time for the herd. THE BIGGER THE BETTER Asian elephants live in the tropical forests and grasslands of Southeast Asia.

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African elephant facts and pictures

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When an elephant drinks, it sucks as much as 2 gallons (7.5 liters) of water into its trunk at a time. Then it curls its trunk under, sticks the tip of its trunk into its mouth, and blows. Out comes the water, right down the elephant's throat.

Since African elephants live where the sun is usually blazing hot, they use their trunks to help them keep cool. First they squirt a trunkful of cool water over their bodies. Then they often follow that with a sprinkling of dust to create a protective layer of dirt on their skin. Elephants pick up and spray dust the same way they do water-with their trunks.

Elephants also use their trunks as snorkels when they wade in deep water. An elephant's trunk is controlled by many muscles. Two fingerlike parts on the tip of the trunk allow the elephant to perform delicate maneuvers such as picking a berry from the ground or plucking a single leaf off a tree. Elephants can also use its trunk to grasp an entire tree branch and pull it down to its mouth and to yank up clumps of grasses and shove the greenery into their mouths.

When an elephant gets a whiff of something interesting, it sniffs the air with its trunk raised up like a submarine periscope. If threatened, an elephant will also use its trunk to make loud trumpeting noises as a warning.

Elephants are social creatures. They sometimes hug by wrapping their trunks together in displays of greeting and affection. Elephants also use their trunks to help lift or nudge an elephant calf over an obstacle, to rescue a fellow elephant stuck in mud, or to gently raise a newborn elephant to its feet. And just as a human baby sucks its thumb, an elephant calf often sucks its trunk for comfort. One elephant can eat 300 pounds (136 kilograms) of food in one day.

People hunt elephants mainly for their ivory tusks. Adult females and young travel in herds, while adult males generally travel alone or in groups of their own.

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When an elephant drinks, it sucks as much as 2 gallons (7.5 liters) of water into its trunk at a time. Then it curls its trunk under, sticks the tip of its trunk into its mouth, and blows. Out comes the water, right down the elephant's throat.

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Gray wolf facts and pictures

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Wolves work together to hunt, raise their young, and protect their territory. Wolves communicate with more than howls. They whimper and whine, growl and bark, yelp and snarl. They also use scents produced by their bodies to communicate. A wolf's sense of smell is 100 times stronger than a human's. One source of scent is urine, which they use to mark territory and to tell other wolves in their own pack where they are. Another way wolves communicate is through body language. If a wolf feels confident, it will approach another wolf with its head and tail held high and ears perked up. If you saw a wolf slinking toward another with its body lowered, its tail between its legs, and its ears flattened, you'd know it was approaching a dominant animal.

( Find out how these canines are making a comeback.)

When a pack of wolves does howl, it can be heard from ten miles away. The howl is used as a way to call to another pack or warn of danger. Each pack has a unique howl, and while they don't howl at the moon, wolves howl more when the moon is full and bright.

When a wolf wants to play, it prances about happily and bows-lowering the front of its body while its rump stays up in the air with its tail wagging. When its angry, a wolf may furrow its forehead, show its fangs, or growl. A wolf's body language may remind you of another animal: a pet dog. Wolves and dogs are closely related, and the ways they communicate are similar.

Young wolves stay in their parents' pack for at least two years before some of them take off to join other packs or to start their own. They may stay close to their parents or go far away. Wolf pups play a lot as they're growing. They leap and pounce, chase and wrestle, play hide-and-seek and tag-a lot like you do!

A new wolf couple will produce one litter of pups every year. Just like a human older brother or sister looks after its younger sibling, the older wolf offspring care for their younger brothers and sisters by finding them food.

In some areas, gray wolfs are classified as endangered, but in most places, they are seen to have healthy population numbers.

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Wolves live in groups called packs. A pack is a family of 7-8 wolves with a mom, dad, and offspring. The wolves' communication skills are very important to the pack's survival. Wolves work together to hunt, raise their young, and protect their territory. Wolves communicate with more than howls.

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Green Sea turtle facts and pictures

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Green sea turtles are the world’s largest species of hard-shelled sea turtle. While most individuals weigh about 300 to 400 pounds (136 to 181 kilograms), some can be as heavy as 440 pounds (204 kilograms). These turtles are found nesting along the coastline of more than 80 countries, with the large…

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Leatherback Sea Turtle facts and pictures

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Leatherback sea turtles are the biggest turtles on Earth. An adult leatherback sea turtle is generally longer than an average-size man is tall. Unlike other species of sea turtles, which have hard shells, the leatherback’s shell is leathery; it feels almost rubbery. The shell is black, often speckle…

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Loggerhead sea turtle facts and pictures

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Watch a sea turtle swim and eat!

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Wolf adaptations

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Wolf communication

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How do wolves keep warm? What is their prey?

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Wolf facts and photos

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All about gray wolves

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All About Wolves - Gray Wolves of Yellowstone

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Observe wolves in their natural habitat with wildlife experts

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Wolf facts and articles

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There's so much to know about wolves - where they live, how they communicate, what they eat. Whether you study wolves, pretend to be a wolf or watch wolf movies

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Watch an orca at an aquarium breathe

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Humpback whales come up for air (video taken from a boat)

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Elephant flapping its ears

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Cute Large Elephant Bull Flapping His Ears To Stay Cool Stock Footage

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Wolf-pack running and playing

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Wolf howling

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The Wolf's Howl Gives You Chills. The Good Kind.

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Arctic wolf pups

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Gray wolf pack protects its pups.

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Wolves Defend Pups from a Bear | BBC Earth

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Emperor chicks and Adelie adult penguins.

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Penguin chicks rescued by unlikely hero | Spy In The Snow | BBC Earth

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How does a penguin launch itself from the sea? - The Wonder of Animals | BBC

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Three kinds of whales hunt at the same time!

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Whales and Orcas Feed Together | BBC Earth

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Elephant baby on an elephant reserve takes its first bath.

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Baby Elephant's Adorable First Bath | BBC Earth

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Elephants swimming!

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Swimming Elephant by Real Freedom Productions