Category Zoology

Animals on the Move

When the cold days of winter come, many animals find it hard to find food. So they fly, march, scamper, or swim to warmer places. When spring comes, they fly, march, scamper, and swim back. This movement from place to place as the seasons change is called migration.

Barn swallows, monarch butterflies, ladybirds, caribou, whales, salmon, and lemmings are just a few of the animals that migrate.

When birds migrate, they often fly great distances. Sometimes they cross oceans and continents. In spring, they migrate back. Sometimes they return to the same nests they used the summer before.

In winter, caribou leave their summer home in northern North America and begin dangerous journey southwards in large herds. The following spring they journey northwards again.

Lemmings are small mammals that live in northern Europe. They migrate sometimes, too. When there is a lot of food, lemmings have many young. When the food runs out, they migrate. Sometimes they travel along roads and through towns looking for food.

Picture Credit : Google

Sleeping Through Winter

Every autumn, a woodchuck eats large amounts of food, curls up into a ball, and goes to sleep in its underground home. But the woodchuck’s sleep isn’t like your sleep. The woodchuck’s heart and breathing slow down and nearly stop. Its body changes. Most of the time, the woodchuck’s body is warm because it is a warm-blooded animal. But the woodchuck’s body grows cold before it goes into its long winter sleep. As it sleeps, its body lives off the energy from the extra food it ate in autumn.

The woodchuck’s sleep is called hibernation. Ground squirrels, bats, hamsters, hedgehogs, and other warm-blooded animals also hibernate.

Snakes, turtles, frogs, and toads hibernate in a different way. A snake is cold-blooded. Its body is just as warm or as cold as the air around it. So when the weather grows colder, a snake’s body grows colder. The snake tries to get warm by crawling into a hole. But as the weather becomes colder, the snake’s body becomes cold and stiff. Its heart and breathing nearly stop.

When spring comes, the woodchucks and other warm-blooded animals wake up. The snakes warm up, too, and crawl out of their holes. The world is alive again!

Picture Credit : Google

Animal Partners

Hungry crocodiles usually try to eat birds that come near them. But one kind of bird can walk among crocodiles safely. In fact, this bird can lay its eggs in crocodile nests!

A bird called the water dikkop eats insects that disturb crocodiles. The bird gets an easy meal and the crocodile becomes more comfortable. So the birds are really helping the crocodiles. Maybe that’s why the crocodiles don’t harm them.

Little fish called wrasses help many other bigger fish. Tiny worms often fasten themselves to a fish and make sores on its body. When this happens, the fish goes to a coral reef where a wrasse lives. The little wrasse hunts all over the fish’s body and eats the worms.

A European fish called a bitterling teams up with certain freshwater clams. The female bitterling lays her eggs in the clam. When the baby fish leave the shell, clam larvae are buried in their skin. After the clam larvae have grown a bit, they leave the fish and sink to the bottom of the pond or river. The clam provides a safe place for the fish to lay its eggs, and the fish helps spread baby clams along the pond bottom.

The water dikkop, the wrasse, and the bitterling all get something from the animals they help. Some get food as a reward for getting rid of annoying pests. Others help each other reproduce.

Warning!

Have you ever wondered what animals is “saying” when they tweet, squeak, mew, or bark?

Sometimes, animals make sounds to find a mate. But other sounds are calls for help or cries of danger. A dolphin that is hurt makes a high whistling noise to get the attention of other dolphins. The other dolphins use their backs and flippers to keep the injured dolphin near the top of the water so it can breathe.

Some animals “talk” without using any sounds. Deer and many other animals mark their territory by rubbing a special scent on trees or bushes. Glands in the faces of some male deer give off a scent that warns other males to stay away.

Other animals communicate by changing their body positions. Whenever two wolves in the same family meet, they use their bodies to show which wolf has a higher rank, or position. The high-ranking wolf stands straight, holds its tail high, and points its ears forwards. A low-ranking wolf crouches, holds its tail between its legs, and flattens its ears.

Song and Dance

Have you ever seen fireflies flashing on a summer night? If so, you’ve seen male fireflies looking for mates. The male firefly flashes his light to attract a female. Animals use all sorts of things—light, colourful feathers, and even food—to attract mates.

The male satin bowerbird of Australia builds a kind of house out of grass and twigs. It decorates the house with bright stones, flowers, and seeds. When a female comes near, the male spreads its wings and “dances”.

Other animals make “songs” to attract mates. Crickets and grasshoppers make a loud sound by rubbing their wings together, or by scraping a leg against a wing. Many frogs and toads blow up a large sac under their chin. This makes their croaking sound extra loud.

Some animals use “perfume” to attract a mate. Female silkworm moths release sweet-scented chemicals to attract males. For some females, food is a gift of love. A male tern catches a fish and offers it to the female. Male nursery-web spiders present the female with a captured fly before mating.

Safety in Numbers

A herd of baboons hunts for food at the edge of a grassy plain in Africa. Each baboon is looking and listening every second. There might be a lion creeping through the grass towards the herd!

If a baboon saw or heard something, it would give a loud grunt. Baboon grunts sound almost like someone yelling “Hah!” Then all the baboons would hurry to climb trees. Because of one baboon’s warning, all the baboons would be safe.

Some animals live together in herds. They are safer that way. An animal by itself may not see or hear the enemy that creeps towards it. But if there are many animals watching, there are many more chances that one animal will see or smell danger and warn the others.

Herds of baboons, zebras, antelopes, and deer run when they sense danger. But sometimes a whole herd of animals will fight an enemy.

Sometimes the safest place to be is in a herd. There is safety in numbers!

Animal Pretenders

Sometimes, in the world of animals, it’s eat or be eaten. To stay safe from predators, some animals hide in clever ways or pretend to be something else.

It’s hard to see a green grasshopper on a leaf, a striped tiger in tall grass, or a brown lizard on the bark of a tree. Their colour makes them hard to see in their habitats. Some insects are also experts at hide-and-seek. Their bodies are shaped like leaves or twigs, or even like bird droppings. These ways of blending into the background are called camouflage. It makes the animals hard to find, so they are safe from predators.

Other animals are actors they trick predators into leaving them alone. When the Australian frilled lizard is frightened, it unfolds a big flap of skin around its neck and opens its mouth wide. The small, harmless lizard suddenly looks big and dangerous. The opossum and the eastern hognose snake lie on their back and “play dead” when they feel threatened.

How well some animals can hide or act often decides whether they will be able to look for food or become food themselves!

Animal Armour

If you saw a pangolin you might say it looked like a pine cone with legs and a long tail.

A pangolin is one of the animals that is protected by armour. It’s covered with scales like those on pine cone, only bigger. When a pangolin is frightened, it rolls itself into ball. Then it tucks its head between its legs and covers its stomach with its tail. Its sharp-edged scales stick up. Not even a tiger would dare to bite through it.

The armadillo is another animal in armour. An armadillo is born with soft skin. But as it grows, its skin becomes covered with small, flat pieces of bone. This bony armour covers much of the armadillo’s body. The armadillo protects itself by rolling up into a hard, bony ball that even a wolf finds hard to bite.

Porcupines, hedgehogs, porcupine fish, and sea urchins wear a sort of armour, too. Their bodies are covered with sharp spines that keep other animals from biting them. These animals can’t run fast or fight well. But wearing armour helps they stay alive.

Amazing Animals

Do you know of a mammal that lays eggs? A bright blue lizard with stubby legs? Or a fish that can walk on land? There are millions of different animals, and some are truly fantastic.

The platypus and the echidna are mammals that seem to be part bird. The platypus looks like it has the body of a beaver and the bill and feet of a duck. The echidna looks like a porcupine with a pointy snout. Female platypuses and echidnas feed their young with milk, like all mammal females, but they also lay eggs, like all female birds.

The bright blue lizard called an ajolote looks like a worm with legs. It uses its two tiny front legs to crawl and dig holes.

The walking fish will drown if it stays underwater too long. It has to come to the top of the water to gulp air. Sometimes it even crawls out of the water. It pulls itself along with its fins.

Arthropod of the Sea

Many kinds of arthropods live in the sea. Lobsters, shrimps, crabs, and barnacles are all arthropods that live in the sea. They are called crustaceans. That means animals with crusts. Every part of a lobster’s body is covered with a crust of hard skin, like armour. Crustaceans have hard shells, 10 leg and 4 feelers, or antennae. Because they live mostly in the water, crustaceans breathe with gills, like fish.

Lobsters use eight of their ten legs for walking along ocean floor. The other two legs are used like arms. Each arm ends in a fierce-looking pincer, or claw. Shrimps look like tiny lobsters. Some kinds of shrimps are so small they can be seen only with a microscope.

Crabs have flat bodies. The tail is tucked forwards under the rest of the body. Instead of walking forwards, crabs scuttle sideways along the seashore or in shallow rock pools. Barnacles are crustaceans that fasten themselves to rocks or the bottoms of ships. They are closed up inside their shells, and only their legs stick out. They wiggle their legs to pull in food that floats past in the water.