Friday, April 25, 2008

News; On The Move

All animals move. Big or small, fast or slow, animals walk, run, creep, crawl, fly, and swim. Some animals move in surprising ways. Let’s take a look at how animals move about. We’ll start by looking at sky animals.

FANTASTIC FLIERS

Many birds and bugs are famous fliers. It’s easy to get airborne when you don’t weigh much. Bugs are perfect fliers. They are small, and they are lightweight.

Bugs might be little, but they can handle some major flying feats. The painted lady butterfly migrates from North Africa to Iceland. That’s 6,000 kilometers (4,000 miles)!

Birds may not be as light as a feather, but they still manage to get off the ground. Their hollow bones make them light enough to soar into the sky. Larger birds stay in the air by gliding on air currents. They don’t need to flap their wings as often as smaller birds.

Hummingbirds, on the other hand, like to hang around. They hover, beating their wings quickly to stay in one spot in the air.

Hummingbirds hover as they feed on flower nectar. The smallest hummingbirds can beat their wings as fast as 80 times a second!

WINGING IT

Bats are the only mammals that truly fly. They are not birds. They don’t build nests. They don’t lay eggs. And they don’t have feathers.

Instead, bats have fur or hair. They give birth to babies. They make milk for their babies. In fact, bats are related to primates. Monkeys and apes are primates.

Bats are made for flight. They have short necks. They have wide chests. They also have narrow stomachs. These help them glide easily through the air.

Bats move through the air by flapping their wings. These are made of skin stretched over long bones similar to your fingers. Wing skin is amazingly thin. You can see light through it.

The thin skin makes it easy for a bat to change the shape of its wings while in flight. That lets it zigzag and dive to catch flying bugs. When they are not flying, bats use their thumbs for climbing.

WINGLESS WONDERS

Birds, bugs, and bats all have wings. That’s not true for all airborne animals. A few wingless daredevils manage to soar too.

Take the flying squirrel. It has flaps of skin that stretch along the sides of its body. The flaps act like sails, catching breezes. This lets it glide from tree to tree. It can glide about the length of a football field!

A few reptiles also glide between trees. The paradise tree snake leaps from a branch. It flattens its body. Then it wiggles from side to side to soar across the sky.

Some baby spiders make parachutes from bits of silk called gossamer. Breezes then pick up the parachutes and spiderlings, blowing them to new places.

SUPER SWIMMERS

The oceans brim with millions of different sea creatures. From tiny worms to enormous whales, they all have their own ways of getting around in the sea.

Take rays, for example. They are the birds of the sea. They have long, wing-like fins. The Pacific manta ray has fins that span 7.6 meters (25 feet). Their diamond-shaped bodies help them cut through the water.

Fish are also shaped to speed through the water. They have a cool trick to help them move up and down. Inside most fish is a sac called a swim bladder. When a fish wants to rise, it fills its swim bladder with air, and up it floats! When it swims into deeper waters, it lets out the air and sinks.

A squid goes from place to place by sucking water into its body. Then it squeezes the water out. As the water squirts out, it shoots the animal forward. A jetting squid scoots along at 40 kilometers (25 miles) an hour!

LIMBER LEGS

Back on land, animals move by running, jumping, walking, and wiggling. Most land animals have legs. As you know, legs are good for moving around.

Different animals use legs in different ways. Humans use their two legs to walk. Kangaroos use two legs to hop. Take the red kangaroo. It has big, powerful back legs. They are perfect for jumping around.

It also has a big, long tail. A kangaroo uses its tail for balance as it hops on its back legs. Kangaroos can jump more than 6 meters (20 feet) in one bounce.

Unlike people and kangaroos, most other mammals—rats and rhinos, monkeys and moose—use four legs for walking. There are lots of ways to use four legs.

Look at horses, for instance. They can change the patterns in the steps they take. They can walk, trot, or gallop. An animal’s walking rhythm is called its gait.

SLITHERING AND SLIDING

Unlike many land animals, snakes have to get around with no feet. Snakes do have strong muscles. They squeeze those muscles to wiggle their bodies forward in a series of curves. As a snake slithers, the scales, or plates, on its belly grip the ground.

Some critters have come up with even wackier ways to get from place to place. Lizards called geckos can walk upside down across a ceiling. They have tiny, invisible hairs on their feet. The hairs work like Velcro, keeping the lizards stuck to the ceiling.

Insects called water striders have hairy feet too. They don’t walk on ceilings. They walk on water! The hairs on their feet let them walk on the surface of the water without falling in.

Some lizards even run across water. If a basilisk lizard sees a predator, it drops from its tree to the water. Then it runs over the surface on its hind legs. It can go 4.5 meters (15 feet) before stopping to swim instead.

GOING TO SURVIVE

The trap-jaw ant is another bug that moves in an unusual way. Sure, it usually walks. When danger is near, though, it snaps into action.

This ant snaps its jaws shut 2,300 times faster than the blink of an eye. The jaws move up to 233 kilometers (145 miles) per hour. The force of the lightning-fast snap sends the ant hurtling through the air.

Too bad the ant isn’t as good at landing. It crashes to the ground in a tangled mess. No worries. The ant untangles its legs and gets up.

From ants and bats to whales and zebras, animals move in many different ways. Yet they have similar reasons to get a move on. They look for food. They also escape from predators.

Whether they’re running, jumping, flying, or swimming, animals are trying to survive in the fast-paced world of the wild.

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