An interactive introduction to working with animals
Zoology for Kids invites the next generation of zoologists to discover the animal kingdom through clear, entertaining information and anecdotes, lush color photos, hands-on activities, and peer-reviewed research. Young minds are introduced to zoology as a science by discussing animals’ forms, functions, and behaviors as well as the history behind zoos and aquariums. Related activities include baking edible animal cells, playing a dolphin-echolocation game, and practicing designing an exhibit. Young readers can peek into the world of zookeepers and aquarists, veterinarians, wildlife researchers, and conservationists as they “train” their friends, mold a tiger’s jawbone, and perform field research in their own backyard. This engaging resource provides readers with new knowledge, a healthy respect for the animal kingdom, and the idea that they can pursue animal-related careers and make a difference to preserve and protect the natural world.
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Zoology for Kids
Understanding and Working With Animals: With 21 Activities
By Josh Hestermann, Bethanie Hestermann
Chicago Review Press IncorporatedCopyright © 2015 Josh Hestermann and Bethanie Hestermann
All rights reserved.
ANIMALS-FORM AND FUNCTION
It's late spring off the coast of Australia. A crab scuffles along the sandy seafloor surrounding a vibrant coral-reef community. It must be on guard. In the ocean, there are predators in every corner, looking for their next meal. A giant Australian cuttlefish lurks nearby. Its normally smooth skin has become textured, almost spiky. Its special skin cells have shifted to blue-gray and greenish-gold, mimicking the pattern of the reef over which the cuttlefish hungrily hovers. It has transformed itself into a near-perfect copy of the reef to its left and right. If you look closely enough, you might see two W-shaped pupils, watching ... waiting.
Whoosh! Suddenly, the crab is snatched from behind. It wiggles and squirms, but two suctioned tentacles have exploded from the cuttlefish's beak, latching onto the crab and pulling it into its mouth. This time around, the crab has been outwitted. It walked right into the cuttlefish's trap.
The giant Australian cuttlefish is a magnificent creature, but so is the crab that ended up on its menu. Each animal is unique and valuable to its ecosystem, which makes studying zoology full of delights and surprises.
What Is an Animal?
If you have a sheet of paper nearby, make a list of the first 10 animals that come to mind. Now take a look at your list and try to answer this question: What is an animal? For instance, what makes a house cat an animal? Is it the fact that it has four legs, a fuzzy coat of fur, whiskers, and a tail? Not all animals can be described the same way. A hummingbird is an animal, but it has wings, feathers, and a beak. Now take a look in a mirror. Humans are part of the animal kingdom, but we are quite different from hummingbirds and house cats.
So what do humans, house cats, and hummingbirds have in common that makes us different from, say, an oak tree or a tulip? It's not the fact that we're alive, because not all living things are animals. For instance, plants are living things, but plants are not animals. How do scientists know? Plants are producers; they create their own energy. Animals, on the other hand, like you and me and house cats, are consumers. Consumers can't make their own energy; they have to consume it. Humans are consumers because we get energy by eating producers (plants like fruits and veggies) and other consumers (animals like cows, pigs, and chickens).
Mobility, the ability to move around freely, is another characteristic of most animals. Whether they walk, hop, fly, slither, or swim, animals can typically travel from one place to another without any help. But when was the last time you saw an oak tree hop around the park? While some plants can move, like when a sunflower bends toward the sun, a plant can't get up and walk to the other end of the garden.
Some underwater animals are not mobile, such as adult sea squirts, but this is not the norm. Once they grow up, sea squirts permanently latch on to surfaces such as an ocean pier, a ship's hull, a rock, or even a large crab.
Animals' cells, the basic building blocks of life, are another distinguishing feature. Animal cells are made up of three basic parts: the plasma membrane (the thin border around a cell), the nucleus (the control center of a cell), and the cytoplasm (the "stuff" or matter within a cell). Plant cells are different because they have an extra part, a more rigid border called a cell wall.
Cells vary in size, but each one is so small, you can only see it with the help of a microscope. If you were to take a really close-up look, you'd see how complex and impressive a tiny animal cell really is.
When similar cells group together, they form tissues. Tissues make up organs like the heart, brain, and lungs. All animals have similar cells, but not all animals have the same types of tissues. For instance, some animals that live in the sea, such as fish, have gills — organs that make it possible for them to breathe oxygen underwater. Other animals, such as land animals and marine mammals, have lungs — organs that make it possible for them to breathe oxygen from the air.
Organs help an animal's body perform basic functions that keep it alive. Gills and lungs allow animals to inhale oxygen and exhale carbon dioxide. Organs like the stomach are part of an animal's digestive system, which is how animals get energy from their food. Other organs, such as the liver and kidneys, also work behind the scenes to support animal life.
Structural tissues help define the shape of an animal's body. These types of tissues include muscle, cartilage, and bone. Some animals, such as humans, have all three types. If you flex your arm, you can feel muscle tissue beneath your skin responding to the flex. If you touch your nose or ear, you can feel cartilage, a more flexible type of tissue that also makes up shark skeletons. Bone is a third type of structural tissue that makes up many animal skeletons, including yours.
When you think about skeletons, you may assume they always exist inside the body like human skeletons do. In reality, you can find three different types of skeletons within the animal kingdom. Humans have endoskeletons that support the body from the inside. Endoskeletons are usually made of bone or cartilage.
A second type of skeleton is called an exoskeleton, which exists outside an animal's body. Exoskeletons are strong structures that enclose the body of animals such as beetles and lobsters. Unlike endoskeletons, exoskeletons do not grow with the animal and must often be shed and regrown as the animal gets bigger.
A hydrostatic skeleton relies on internal pressure from body fluids for support. An earthworm has no bones, and yet it's strong enough to burrow through the earth. Animals with hydrostatic skeletons, such as earthworms, have special muscles that control internal pressure and keep their bodies inflated, kind of like a water balloon.
When it comes to animals' forms, there is some amazing diversity. But more often than not, animals have something in common: symmetry. If you were to draw an imaginary line down the center of a butterfly, you'd notice that the shapes, patterns, and colors you see on the right side are the same as the shapes, patterns, and colors on the left side. Other animals' bodies form a circle, such as sea anemones. Animals with this type of symmetry resemble a wheel, often with a mouth at the center.
Surviving in the Wild
Animals have many tools in their biological tool kit when it comes to survival. In fact, one of the most interesting reasons to study zoology is to learn how animals' forms help them survive against extreme temperatures, fierce predators, and other hurdles they face in their daily lives. Whether they have dense, waterproof fur or the ability to see in the dark, many animals simply wouldn't make it without their bodies' natural survival kits.
Your body has a natural survival kit, too. Have you ever noticed the ways your body reacts to outside temperatures? If it's hot, you might start sweating, which is your body's attempt to cool itself down. If it's cold, you might shiver, which is your body's attempt to warm itself up. Your body goes to this trouble because maintaining the right internal temperature is very important to an animal's survival.
Most birds and mammals (including humans) are warm blooded, which means their bodies can stay at a stable temperature even when the temperature outside changes. Cold-blooded animals such as reptiles and insects, on the other hand, cannot do this. These animals' body temperatures change along with the temperature of their environments.
Most animals have help managing their body temperatures thanks to feathers, fur, or body fat that slows escaping heat. A bird with feathers will fluff itself up on a chilly day, creating air pockets that hold in heat. Animals that live in cold climates often depend on coats of fur to keep their bodies warm. These animals may even put on some extra body fat to help them survive a long, cold winter. Marine mammals such as whales and seals have blubber — a layer of fat-like tissue beneath the skin. Blubber can be as thick as 12 inches in large animals like whales.
Along with the ability to regulate body temperature, animals' senses help them survive. Raptors such as eagles, hawks, and vultures are known for their keen eyesight. Andean condors and other raptor species soar thousands of feet in the air while searching for food way down on the ground.
Other animals rely on their sense of smell. The great white shark can smell a tiny drop of blood from miles away. Many fish can sense vibrations and electrical impulses, along with small changes in water currents and pressure. Still other animals depend on a well-developed sense of hearing. Nocturnal animals that sleep during the day and become active at night, like many owl species, rely on their hearing and eyesight to track down prey.
Echolocation is a bonus sense found in animals such as bottlenose dolphins and horseshoe bats. To echolocate, animals make a sound, then listen for how long it takes for that sound to bounce off an object and return to them. By listening for echoes, animals can figure out how far they are from predators, prey, or obstacles. They can even determine how large an object is and whether it's moving or staying still. For animals that live in the ocean or in dark caves, this can be a crucial tool for survival.
Animals' unique forms sometimes function as built-in defenses that help them survive in the wild. The African crested porcupine, for instance, has a body full of barbed quills. When a predator is nearby, a porcupine sticks up its quills, kind of like the hair on your arms when you get goose bumps. While it wouldn't be wise to sneak up on a porcupine, the myth that says these spiky creatures can shoot their quills at attackers isn't true. Porcupine quills detach pretty easily, so a quill or two may fall off when a porcupine bustles up. But that doesn't mean it can aim and shoot!
Spines and scutes are two more built-in defenses within the animal kingdom. Some puffer fish species have spines covering their bodies that can help shoo away predators. When threatened, a puffer fish will suck in water to become big, round, and sharp.
Other dazzling defenders, such as the nine-banded armadillo, have tough, bony plates called scutes covering their bodies. These plates are like a coat of armor that helps protect an armadillo from becoming a snack.
Hoofed mammals such as white-tailed deer, moose, bison, and oryx have antlers or horns that help them defend their territory. During certain seasons, male bighorn sheep ram into each other with their tough, curled horns. These competitions often last for several hours until the weaker rival gives up and leaves. The winner earns territory and access to mates. Unlike deer species that shed their antlers every year and regrow them, species in the bovid family, like bighorn sheep and gazelles, have permanent horns.
Large animals such as bighorn sheep may be the first to come to mind when you think of horns, but not all horned animals are big. Male rhinoceros beetles have front-facing horns that come in handy when charging rivals during fights for territory, just like bighorns.
Claws or talons can also be great defenses in nature. One impressive bird, the cassowary, kicks and slices at attackers with the two sharp talons attached to the cassowary's middle toes. A tiger's curved claws can be equally deadly as it swipes at rivals and prey. Like house cats, most big cat species can retract their claws when they are not in use.
Other defenses include beaks, stingers, and teeth. Male and female walruses have formidable teeth called tusks that can grow to be three feet long. While walruses usually use their tusks for boring holes in the ice and lugging their heavy bodies out of the water, males may also use them as a weapon to scare enemies away or to spar with other males.
Many animals defend themselves with harmful substances called toxins. Did you know there's a difference between venomous animals and poisonous animals? Venomous animals inject toxins through a bite or a sting. Some venomous animals include black widow spiders, rattlesnakes, scorpions, and stingrays. Poisonous animals, on the other hand, do not inject toxins; they secrete them. Poisonous animals, such as certain species of toads, newts, and salamanders, produce a toxic substance on their skin that can be deadly when touched or swallowed.
Camouflage is another way animals' forms function as a defense. Some animals, like zebras, are naturally camouflaged with designs or patterns. The black-and-white-striped pattern on a zebra's body is called disruptive coloration. When there is a group of zebras, their patterns make it more difficult for predators like lions to pick out one zebra from the rest of the group.
When an animal's coloring resembles its environment, it's called concealing coloration or background matching. Cuttlefish are masters of this type of camouflage. The pigment-filled cells in a cuttlefish's skin allow it to change color to match its surroundings. This helps it hide from predators and sneak up on prey.
Arctic foxes also benefit from concealing coloration. During the winter, an arctic fox grows a thick, white coat of fur that blends in with the snowy terrain. When the snow melts, the fox sheds its white coat for a brown-gray coat that matches the color of the ground.
Have you ever heard of an insect that looks so much like a stick that predators mistake it for something far less tasty than it actually is? These insects are called walking sticks, and they display a type of camouflage called disguise. The Solomon Island leaf frog uses disguise to look like a dead leaf on the forest floor. Thanks to its unique head shape, its dead-leaf coloring, and its dead-leaf texture, a predator might look right past a little leaf frog without even realizing it's missing out on something scrumptious.
Some creatures are copycats; they have camouflage that mimics another animal. For example, the nonvenomous milk snake looks just like the venomous coral snake. By copying a coral snake's coloring, the milk snake appears to be more dangerous than it actually is. As a result, it's less likely to be eaten. Well played, milk snake.
Animals have some things in common, like their cells and the ability to move, but they really do come in all shapes and sizes. Whether it has gills to breathe underwater, a layer of blubber to keep warm, scutes that act as armor, or some tricky coloration, each animal must make the most of its unique characteristics to survive. In many cases, an animal must also adopt certain behaviors to take advantage of its special form.CHAPTER 2
UNDERSTANDING ANIMAL BEHAVIOR
On the island of Madagascar, an aye-aye sits perched in a forest tree. It's nighttime, but the nocturnal primate is well suited to work in the dark. It has large oval eyes, oversized ears, sharp claws, and toes that can grab on to tree branches. After spending most of the day balled up in its tree nest, the aye-aye is well rested and ready for some grub. But first, it must find some.
Using its extra-long middle finger, the aye-aye begins to tap the tree. As it taps, it listens. Inside the tree's trunk, wood-boring insects have carved channels through the wood. The aye-aye uses the sound of its tapping to figure out whether there is a meal to be had inside this tree. Tonight it's in luck; the aye-aye likes what it hears. With its long, skinny finger, the aye-aye digs into the tree, scoops out the insects, and eats them.
The aye-aye's unique foraging technique is just one example of a cool animal behavior. Whether it's foraging, hunting, grooming, or looking for a mate, animal behavior includes anything and everything an animal does. The study of animal behavior helps zoologists understand all kinds of things, such as why some animals live in groups while others live alone. It has even shown us that some animals can learn and that most have special ways of communicating.
Zoologists often refer to animal behaviors as innate, learned, or complex. Animals are born with a basic set of survival knowledge and/or skills. This knowledge is innate, which means it is not taught or learned and it can be performed the first time without practice. When a baby bird reaches up to its parent's beak for food, the behavior is automatic and unlearned — in other words, it is innate.
Learned behaviors are those an animal develops as it gains life experience. Just like human toddlers who learn how to be human by watching their siblings, classmates, and parents, animals often learn by watching members of their own species and imitating the behaviors they see. In some cases, animals learn by practice. Lion cubs practice stalking and pouncing by roughhousing with their brothers and sisters. Later in life, lions use these skills to hunt or to defend their group.
Excerpted from Zoology for Kids by Josh Hestermann, Bethanie Hestermann. Copyright © 2015 Josh Hestermann and Bethanie Hestermann. Excerpted by permission of Chicago Review Press Incorporated.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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Table of Contents
ContentsForeword by the Kratt Brothers,
Introduction: What is Zoology?,
Part 1 ZOOLOGY FOR BEGINNERS,
1 Animals — Form and Function,
2 Understanding Animal Behavior,
3 Animals and Their Environments,
Part 2 WORKING ON THE WILD SIDE-ZOOLOGY IN REAL LIFE,
4 Zookeepers, Aquarists, and Other Zoo Crew,
5 Call the Doctor! Veterinarians,
6 Wildlife Researchers,
7 Conservation Warriors,