Third Grade Ecosystems UnitPasco School District #1

Created by Allen Hovland, Science TOSA

Third Grade Science Standards

Enduring Understanding: See how parts of objects, plants, and animals are connected and work together.

2-3 SYSA A system is a group of interacting parts that form a whole.2-3 SYSB A whole object, plant, or animal may not continue to function the same way if some of its parts are missing.2-3 SYSC A whole object, plant, or animal can do things that none of its parts can do by themselves.2-3 SYSD Some objects need to have their parts connected in a certain way if they are to function as a whole2-3 SYSE Similar parts may play different roles in different objects, plants, or animals.

Enduring Understanding: Carry out investigations by using instruments, observing, recording, and drawing evidence-based conclusions.

2-3 INQA Scientific investigations are designed to gain knowledge about the natural world.2-3 INQB A scientific investigation may include making and following a plan to accurately observe and describe objects, events, and organisms; make and record measurements, and predict outcomes.2-3 INQC Inferences are based on observations.2-3 INQD Simple instruments, such as magnifiers, thermometers, and rulers provide more information than scientists can obtain using only their unaided senses.2-3 INQE Models are useful for understanding systems that are too big, too small, or too dangerous to study directly.2-3 INQF Scientists develop explanations, using observations (evidence) and what they already know about the world. Explanations should be based on evidence from investigations.2-3 INQG Scientists make the results of their investigations public, even when the results contradict their expectations.

Enduring Understanding: Develop a solution to a problem by using a simplified technological design process. Investigate the use of tools.

2-3 APPA Simple problems can be solved through a technological design process that includes: defining the problem, gathering information, exploring ideas, making a plan, testing possible solutions to see which is best, and communicating the results. 2-3 APPB Scientific ideas and discoveries can be applied to solving problems.2-3 APPC People in all cultures around the world have always had problems and invented tools and techniques (ways of doing something) to solve problems.2-3APPD Tools help scientists see more, measure more accurately, and do things that they could not otherwise accomplish.2-3 APPE Successful solutions to problems often depend on selection of the best tools and materials and on previous experience.

Enduring Understanding: Changes in ecosystems affect living populations and non-living elements of a defined area. 2-3 LS2A Ecosystems support all life on the planet, including human life, by providing food, fresh water, and breathable air.

2-3 LS2B All ecosystems change over time as a result of natural causes (e.g., storms, floods, volcanic eruptions, fire). Some of these changes are beneficial for the plants and animals, some are harmful, and some have no effect.

2-3 LS2C Some changes in ecosystems occur slowly and others occur rapidly. Changes can affect life forms, including humans.

2-3 LS2D Humans impact ecosystems in both positive and negative ways. Humans can help improve the health of ecosystems so that they provide habitats for plants and animals and resources for humans over the long term. For example, if people use fewer resources and recycle waste, there will be fewer negative impacts on natural systems.

Third Grade - Science - Lesson 1 - Ecosystems

Objectives Describe how energy moves through a food chain. Create models of food chains in a pond ecosystem. Describe how environmental changes might affect a pond ecosystem.

Materials Pictures of pond plants and animals at end of unit. Sentence-strip tags with yarn loops to wear around the neck, marked producer, consumer 1, consumer 2, consumer 3, consumer 4, decomposer A sentence strip crown with the word energy printed on it Pond Food Web and worksheet for each student (found at end of unit)

Suggested Books

Butternut Hollow Pond: by Brian J. Heinz; Millbrook Press Minneapolis, MN 55401

Lake Critter Journal; by Diana Noonan (part of the Good Habits, Great readers series you have in your classroom).

Background Information Ecology is the study of the interconnectedness of living things. It comes from the Greek word, oikos which means household. Ecologists study natural households or communities to find out how plants and animals relate to each other and their surroundings. They study how inhabitants of a community provide food, shelter and other things for one another. An ecosystem is a natural community and its surroundings. A pond is an example of an ecosystem in which the web of life can be studied. Within the pond ecosystem, there are several habitats where plants and animals live: the pond edge, the bottom of the pond, open water and the surface of the pond. Mammals, fish, reptiles, amphibians, insects, birds and plants live in these habitats and play roles in the equilibrium of the pond ecosystem. Plants and animals in any ecosystem can be divided into three groups according to their roles. Green plants are producers. Through photosynthesis, they capture energy from the sun and change it into food. Animals are consumers. They eat plants (herbivores) or eat other animals (carnivores) and energy is transferred from the producers to the consumers. Decomposers (scavengers, bacteria and fungi) break down dead plants and animals and recycle nutrients that plants can use to grow and produce more food. This transfer and recycling of the sun's energy fuels the natural world. The natural world is dynamic, always changing. Due to changes in environmental conditions, both subtle and catastrophic, animal and plant populations grow and dwindle. Variations in supplies of food and cover, weather and climate, disease, enemies and natural disasters all can cause changes to an environment. Interdependence, adaptability, competition and grabbed opportunities determine what individuals and what species survive. Nature's equilibrium, or balance, is maintained by limiting factors. For example, when wolves were exterminated in Arizona, deer populations increased dramatically. With wolves eliminated as predators, more deer survived. The food resources for deer,

however, did not increase. The larger population of deer browsed not only on mature trees, but also on very young trees that could not survive their browsing. Before long, the forest had thinned and there was not enough food to support the deer population. Many deer starved to death. The limiting factor of food supply kept the deer population in check.

Teacher Procedure Remind the students that they learned about the five classes of vertebrates: fish, reptiles, amphibians, birds and mammals. Tell the students that there is something that all animals, both vertebrates and invertebrates do. They all eat. Ask: What do animals eat? (plants, other animals) Tell the students that animals eat, so they are consumers. Write consumer on the board. Remind the children that green plants make food. They capture energy from the sun and change it into food. Plants are called producers because they produce food. Write producer on the board. To get a plant's food energy, an animal eats it. Then energy moves from the plant to the animal. Draw an arrow from producer to consumer on the board. Tell the children that when the plant eater is eaten by another animal, the energy moves from that consumer to another consumer. Write consumer 2 on the board and draw an arrow from consumer to consumer 2. Ask: What do you think happens to the energy when consumer 2 dies? (Accept all answers.) Tell the students that plants and animals called decomposers break down the dead body and recycle its nutrients into the soil or water so plants can use it to grow and make more food. Write decomposer on the board. Draw an arrow from consumer 2 to decomposer and an arrow from decomposer back to producer, forming a cycle. (Great place to read “Butternut Hollow”.) Tell the students that this cycle is how energy moves through a food chain. Ask: What is a food chain? (plants and animals linked together because each one is food for the next) Tell the class that today they are going to create models of some food chains. Write producer, consumer 1(plant eater), consumer 2 (animal eater) and decomposer as headings on the board. Ask the students if they have ever visited a pond. Tell them a pond is not like a river or stream where the water is always moving. A pond is still and shallow and much smaller than a lake. Show the students pictures from Suggested Books of ponds and the plants and animals that live in or around a pond, for example, frog, tadpole, water strider, fish, dragonfly, turtle, duck, reeds and cattails, duckweed, snail, water boatman, water lilies, etc. Ask: What animals might visit a pond to hunt for prey? (snakes, herons, kingfishers, raccoons, maybe people with fishing rods) Brainstorm with the students and list on the board plants and animals that inhabit or visit a pond. Put them under the appropriate headings. Remind the students that there are several habitats or neighborhoods in a pond community. Some animals and plants live at the edges of a pond or visit it, some live on the muddy bottom, some in open water in the middle of a pond and others live on the surface of the pond (water strider and water spider). Suggest making a food chain from the list. For example, the food chain might begin with some floating green plants in a pond. Ask a student to come up and be a floating green plant in a pond. Have him or her wear the producer tag. Tell the students that this green plant has been floating in the sunshine, gathering the sun's energy (place the energy crown on the student's head) and changing it into food. Up swims a tadpole to nibble on the green plant. Have a student come up to be a tadpole and wear the consumer 1 tag. Tell the students that the tadpole nibbled on the green floating plant and food energy moved from the plant to the tadpole. Place the energy crown on "tadpole's" head. Tell the students that along came a big fish and swallowed the tadpole in one gulp. Have a student

come up, be a big fish and wear the consumer 2 tag. Place the energy crown on his or her head. Tell the students that the fish was a very old fish. Soon it died and its body fell to the bottom of the pond. There water beetles, worms and bacteria used the fish's body for food and broke it down into nutrients that floated in the water. Ask a student to come up, be a water beetle and wear the decomposer tag. Place the energy crown on the student's head. Tell the students that once the fish's body was decomposed, the nutrients in the water were used by floating plants to grow and make more food. Move the energy crown to floating plant-producer's head. Point out that energy has passed from floating plant to tadpole to fish to water beetle to floating plant. Read “Lake Critter Journal”Have the students devise other pond scenarios using different plants and animals listed on the board and perhaps creating longer food chains that use tags for consumers 3 and 4. For instance, suggest that if tadpole were eaten by a snake, a different food chain would be formed (perhaps tadpole-snake-heron). Suggest that if tadpole grows up and becomes a frog, it might eat a dragonfly and then become food for a raccoon, making a different food chain. Have students create 4 more Food Chains. May use the ones from Butternut Hollow Pond.Distribute the pond food web sheet (see attached). Point out how food chains connect in a pattern called a food web. All the animals and plants that live in a pond community are connected to each other through a food web. The food web is sometimes called the web of life. Ask: Looking at the pond food web, what do you think would happen if a pet store owner came to the pond and caught all the frogs, then took them back to his store to sell? (There would be no frogs in the pond.) Ask the students to put an X over the frog on the food web sheet. Have the students count how many kinds of animals that eat frogs would be hungry. (4) Suppose the frog eaters became so hungry that they died. Tell the students to draw X's over the frog eaters. Ask: If the frog eaters are gone, what happens to animals that eat the frog eaters? (They leave or starve.) Tell the students to draw an X over the animal that eats frog eaters (hawk). Remind the students that with no frogs to lay eggs, there won't be any tadpoles. Have the students draw X's over the frog eggs, tadpole, any frog egg eaters, tadpole eaters, and animals that eat tadpole eaters or frog egg eaters. Ask: Looking at the pond food web, what has happened to the pond community? (Many of the animals that live in the pond community have starved or left the pond.) Remind the students that plants and animals in a community are connected to each other. When something happens to one kind of animal, it can affect all the animals in that community and its web of life.

Possible Field Trip Visit a pond at a park, like the Burbank Wildlife Center. If possible, contact park staff or a naturalist to help the students safely explore the pond. Nature centers often provide materials to prepare the class for a visit and may help with dip nets and containers for examining pond inhabitants. Ecologists who study ponds are called limnologists. Contact a limnologist at a local university. He or she might be able to speak to the class or steer you to a good pond to visit in your area.

Long Term Project Introduce the idea of a long term project to the class. Explain that each student will be working throughout the month, putting together a project on an endangered animal. Each student will read books and collect information about the animal, about its habitat, what it looks like, what it eats and why it is endangered. At the end of the month each student

will write a letter to his or her Representative in Congress or U.S. Senator. In their letters, the students will tell their representatives in Washington why they care about endangered animals and why it is important to protect them. Distribute the Long Term Project info sheet/checklist (see attached). The students' first assignment is to find out the name of their representative in Congress or their U.S. Senator and address an envelope to that person. You might want to review how to write an address and show an example of a correctly addressed envelope. To find the names of representatives and senators, call the Federal Information Center at 800-688-9889. Students can find out their Congressional Districts by looking at their parents' voters.

Third Grade - Science - Lesson 2 - Ecosystems

Objectives Describe how changes in an environment can affect animal and plant populations. Recognize the primary concerns of an ecologist. Identify a variety of ecosystems.

Materials Pictures of wolves from Suggested Books Map of U.S. Laminated cut-outs of trees (six), deer (seven), a wolf and masking tape (pictures found at end of unit) and Student Science Notebook

Suggested Book

Godkin, Celia. Wolf Island. New York: W.H. Freeman, 1993. Tells the story of some island creatures who are affected by the disappearance of wolves on their island.

Teacher Notes Cut-outs can be laminated so they can be used from year to year. To save time during the lesson, write this list on a corner of the board: pond, forest, desert, stream, tropical rainforest, ocean, cave, mountaintop, underground, city.

Teacher Procedure Remind the students that last time they learned that plants and animals in a community are connected to each other. What happens to one kind of animal in a community can affect the others in its food web. Ask: What happened to the pond community when all the frogs were taken away? (Other animals that ate frogs and tadpoles had no food and left the pond or starved. This meant animals that ate frog eaters or tadpole eaters had no food and left the pond or starved also.) Tell the students that you are going to describe another example of what happens when a food web gets out of balance. This example starts with wolves. Ask: Are wolf’s carnivores or herbivores? (Wolves are carnivores. They hunt and eat meat.) Tell the students that wolves cooperate and hunt together in packs. Their packs are like families. When they work together, wolves can hunt and kill animals bigger than they are and get meat to feed the pack. Show the students pictures of wolves from Suggested Books. Tell the students that wolves are larger than a German Sheppard dog. Tell the students that in the last century, there were wolf packs in northern Arizona. Have

a student come up to the U.S. map and locate Arizona. Tell the students that in the forests and meadows of northern Arizona wolves once hunted deer. Put a wolf cut-out on the board. Below it put three deer cut-outs. Tell them that the deer found food in the forest, nibbling moss, leaves and twigs. Put seven tree cut-outs below the deer cut-outs. Try to arrange the cut-outs to form a pyramid shape. Point out that producers (the trees) fed the consumers (the deer) which fed other consumers (the wolves) making a food chain. Tell the students that people who lived in northern Arizona decided that wolves were a nuisance. They didn't like predators killing the deer they wanted to shoot as game. They thought the wolves threatened their cows and sheep. So they began hunting and shooting the wolves. The human hunters shot or poisoned every wolf in northern Arizona. Remove the wolf cut-out. Ask: With the wolves gone, what do you think happened to the number of deer? (Their numbers increased.) Tell the students that with no wolf predators, many more deer survived and the deer population grew and grew. Add four more deer cut-outs to the row on the board. Tell the students that population explosion is a way to describe the number of deer. Ask: What did the deer eat? (twigs and leaves from trees) Did the number of grown-up trees increase quickly? (no) Point out that trees grow slowly. The deer's food supply stayed the same, but the number of animals depending on it increased. Tell the students that the deer were so hungry that they began eating young trees that couldn't survive the nibbling. Those trees died. Before long, the forest had fewer trees. Remove some of the tree cut-outs. Ask: What do you think happened to the deer when their food supply dwindled? (They starved.) Tell the students that many of the deer died because there was not enough to eat. Remove all but two deer cut-outs. Ask: What was the result of killing all the wolves? (At first there were more deer, but then there were fewer trees and fewer deer.) Tell the students that the people who killed all the wolves did not understand that the web of life connects animals and plants together. What happens to wolves affects what happens to deer, trees and any other plants and animals in their food web. (Good time to read “Wolf Island”)Tell the students that scientists who study the connections between plants and animals in a community are called ecologists. Write this word on the board. Tell the students that what they have been learning about--how living things interact with their environments--is called ecology. Write this word on the board, too. Tell the students that ecologists study all kinds of natural communities. Some ecologists look for connections between the plants and animals that live in ponds, some study forest communities or desert communities, or the living things in streams or tropical rainforests, in the oceans, in caves, on mountaintops, underground or the living things in cities. As you mention these communities to the students, point to them on the board. Tell the students there are living things in communities all over the planet. Some communities are very, very small. For instance, there is a community of very tiny living things in the stomach of a termite! Ecologists call these communities that they study ecosystems. Write this on the board also. Tell the students that ecologists are like detectives. They investigate what part each animal and plant plays in the ecosystem and how it is connected to others in the web of life. As a writing opportunity, have the students write paragraphs to answer these questions: If you were an ecologist studying the web of life, what community or ecosystem would you want to study and why? What kinds of plants and animals might you find in that ecosystem? Describe what equipment you might take on your ecological expedition. Refer the students to the list of communities on the board for ideas. Some paragraphs will undoubtedly focus on adventures the young ecologists have studying an ecosystem. If

you want to offer a sample paragraph to your students:  

I would like to be a desert ecologist because I want to learn more about rattlesnakes and how they are connected to a desert food web. I'm going to watch rattlesnakes and find out what kinds of animals they eat. The desert is a hot, dry place, so I'm going fill my jeep with lots of water containers and a tent for shade. I will also take tall boots. If I accidentally get too near a rattlesnake, it won't be able to bite my ankle. The desert is full of cactus and scorpions.

If there is time, have the students share their paragraphs. Ask: If you were an ecologist studying ecosystems in northern Arizona, what advice would you have given the people that wanted to kill all the wolves? (Don't shoot the wolves. They are an important strand in the web of life.) Remind the students that when wolves were wiped out in Northern Arizona, the ecosystem went out of balance--it wobbled.

Additional Activity If available, read Wolf Island by Celia Godkin aloud. Ask: What animals were affected by the disappearance of wolves from the island? Put a wolf cut-out on the board and draw lines to the name of each animal affected.

Long Term Project Explain to the students that people in the western U.S. killed so many wolves during the past one hundred years that now gray wolves are endangered. Endangered means that a plant or animal is in danger of becoming extinct because there are so few of them left. Remind the students that when a plant or animal becomes extinct, it disappears from the Earth forever. Tell the students that during the next few weeks they will be learning about some of the reasons animals and plants are becoming endangered. These reasons include losing their habitats, pollution and acid rain, oil spills and, as with the wolves, over-hunting. Distribute a list of endangered animals to the students (see attached). Tell the students that to complete part two of their long term project, they should pick an animal from the list about which they are interested in learning more. Tell the students to go to the library and find at least two books with information about the animal they have chosen. Students may find books by looking up the name of an animal in the library's catalog, but are more likely to find information by looking under "endangered" or under the name of the animal's habitat such as "desert animals" or "wetlands." Articles from National Wildlife Magazine or Ranger Rick can also provide information.

Third Grade - Science - Lesson 3 - Ecosystems

Objectives Review the basic needs of all animals. Describe connections between animals and a saguaro cactus in a desert ecosystem and recognize the importance of a single species to the health of an ecosystem. Create an advertisement to persuade desert animals that a saguaro cactus meets their habitat needs.

Suggested Books

Bash, Barbara. Desert Giant. Boston: Little Brown, 1989. This Reading Rainbow selection is a compelling example of plant and animal interdependence. It is a popular book in ecology units throughout the U.S.

Guiberson, Brenda. Cactus Hotel. New York: Holt, 1991. Features the life cycle of a two- hundred-year-old saguaro cactus and the many animals that use it for food and shelter.

Teacher Procedure Review with the students the definition of an ecosystem: a community of living things and their environment. Remind them that animals and plants in an ecosystem are interconnected; they depend on each other. Remind the students that they have learned about food webs and how producers, consumers and decomposers depend on each other for food. Tell the students that plants and animals also depend on each other for other things they need to survive. Ask: What do all animals need to survive? (food, water, shelter, and a place to reproduce and raise young) List these on the board. Tell the students that today they will learn about a special plant that grows in a very harsh environment--the desert. This plant provides many desert animals with what they need to survive. Tell the students that this special plant, the saguaro (sa-WAHR-oh) cactus, provides animals in its environment with food, water, shelter and a place to reproduce and raise young. Ask: What do you think makes a place a desert? (very little rainfall) Tell the students that a dry climate is part of the desert ecosystem. Daytime in many deserts is so hot that any moisture evaporates quickly. Plants and animals in the desert have adapted to the lack of water. Ask the students to imagine that through magical means, a giant bird has snatched them up in its claws and flown them to a desert in southern Arizona. Plop! The bird has set them down on a broad desert plain. Say: It is high noon and hotter than blazes in the desert. You have only a piece of chewing gum in your pocket. How will you survive? (Accept all answers. It is important that the students visualize themselves in this harsh environment.) Tell the students that the number one rule for desert creatures is: Get out of the sun! Write this on the board. Tell the students that all around them in the desert, animals are hiding from the hot sun. Spadefoot toads have burrowed underground. Packrats have built spiny nests where they curl up in the shade. Rattlesnakes coil under rock ledges. Wild pigs have buried themselves in the sand. Elf owls, coyotes and scorpions come out only at night when it is much cooler. Ask the students if they agree that shelter is very, very important to survival in the desert. Show the students the cover of either Cactus Hotel by Brenda Guiberson or Desert Giant by Barbara Bash. Tell them that the book you are going to read to them describes the life cycle of this desert plant, the saguaro cactus. Saguaros can live nearly two hundred years. Write a subtraction problem on the board: 1997-200 years'. Ask a student to solve it. Point out to the students that some saguaro cacti that are alive today sprouted in 1797 when the president of the U.S. was George Washington. Ask the students to listen carefully as you read because when you have finished, you are going to

ask them to tell you about the animals that depend on the saguaro for food, shelter or a place to breed and raise young. Read aloud one of the books. Cactus Hotel requires at least five minutes to read; Desert Giant requires at least seven minutes of reading time. When you are finished reading, tell the students that you want to make a web on the board that shows the connections between plants and animals in the desert ecosystem portrayed in the book. Draw a large shape of the saguaro in the middle of the board. Ask: what animal was the first to make a shelter in the saguaro? (gila woodpecker) Show the students the illustration from the book if they cannot remember. Ask: What did the woodpecker use the shelter for? (To hatch and raise its babies) Draw a small hole in the saguaro and a line pointing to it. Write woodpecker at the other end of the line and under it raise babies. Ask: What other birds used the cactus for nesting? [Answers to following questions will vary according to which book was read] (Dove or hawk built nests on its arms) Draw a line from one of the arms and write dove or hawk at the end of the line and raise babies under that. Ask: What animals depended on the old woodpecker holes for shelter? (elf owls-shelter, bats-shelter, pack rats-raise babies) Draw a line to woodpecker and at the other end list the animals. Tell the students that without the woodpecker to make the holes with its sharp beak, these animals would not have a home in the cactus. Ask: What animals depended on the cactus for nectar? (birds, bees, butterflies and bats) Draw a small flower on the cactus shape. From the flower draw a line. At the end of the line write birds, bees, bats and under that write food. Remind the students that the birds, bees and bats that fed on the nectar also pollinated the flowers so fruit would grow. Ask: What animals ate the fruit of the cactus? (packrats, birds, ants, coyote, javalina, people) Draw a fruit shape on the cactus shape. Draw a line from it and on the other end write the animals' names (including people) and under them write food. Remind the students that the animals that ate the fruit also helped spread the cactus seeds inside the fruit so more cactus would grow. Ask: After the very old cactus fell to the ground, what animals found shelter inside its ribs? (ants, termites, scorpions, spiders, lizards, snakes, mouse) Write these animals' names on the board and write shelter beneath them. Draw a line from them to the middle of the cactus. Ask the students to take a look at all the animals that depend on the food, shelter and space to raise babies that this cactus hotel provides. Ask: Do you think the saguaro cactus is an important part of the desert ecosystem? (yes) Erase the cactus outline. Ask: What do you think would happen if the saguaro cactus disappeared? (Many animals would not survive.) Ask the students to pretend that desert animals can read. Tell the students that you want them to write an advertisement for a room in the saguaro cactus hotel. Ask them to try to persuade a bat, packrat, bird or insect that a saguaro cactus is the best place to live. How does the cactus fill their needs? Ask: What do advertisements do? (try to persuade a person to buy a product by telling how it will help the buyer ) Ask: What is the product you are trying to sell in this advertisement? (a room in the cactus hotel) Ask the students to create persuasive advertisements that sell the product to the animal they are trying to convince. Think about what that animal would want in a home.

Long Term Project Check to see that each student has correctly addressed an envelope and has found two books or sources of information about an animal. For homework, ask the students to answer in full sentences the questions on the checklist sheet about the endangered animal they have chosen. Remind them that they are to locate the area of the world where the animal lives on a world map.

Third Grade - Science - Lesson 4 – Ecosystems

Candle and chalk activities adapted from Pollution and Waste by Sally Morgan and Rosie Harlow

Objectives Identify sources of air pollution. Suggest ways to reduce air pollution and conserve energy. Describe the cause and some damaging effects of acid rain.

Materials Candle in a holder, matches, heatproof dish Bottle of white vinegar, clear glass dish or shallow bowl, a piece of chalk

Suggested Book

Jeffers, Susan. Brother Eagle, Sister Sky. New York: Dial, 1991. This Parents' Choice Award winner offers the speech given by Chief Seattle over a hundred years ago about the sacredness of our relationship with the Earth. Beautifully illustrated.

Teacher Note Chief Seattle's speech was made in 1854. The translator and subsequent anthologists took liberties with his actual words. The quote used in this lesson is from a version published in 1970.

Teacher Procedure Remind the students that last time they learned how just one kind of plant can be very important to the survival of animals in its ecosystem. Ask: What desert plant provides habitat and food for other animals? (saguaro cactus) Point out that the saguaro cactus is a part of the web of life in the desert ecosystem. If the cactus were taken out of the desert web of life, an important strand in the web would be broken. Animals that depend on the cactus would not have what they need to survive. Tell the students that they have learned about what animals need to survive. Ask: What do people need to survive? Write the students' responses on the board. The list should include air, water, food, shelter, space and love (infants need caring or nurturing). Ask the students to think about their place in the web of life as you read them something once said by a Native American named Chief Seattle. Read the following quote: "Whatever befalls the earth, befalls the sons of the earth. Man did not weave the web of life; he is merely a strand in it. Whatever he does to the web, he does to himself..." Ask: Are people part of the web of life? (yes) What do you think Chief Seattle meant when he said, "Whatever [man] does to the web, he does to himself."? (Accept all answers.) Read “Brother Eagle, Sister Sky” in its entirety. Write the word pollution on the board. Tell the students that pollution means something

harmful in the environment that does not belong. Tell them that today they are going to find out where air pollution comes from and come up with some ideas of their own to clean up the air. Tell the students that dirty air is polluted with two kinds of pollution--particles and gases. We can sometimes see the particles as smoke or soot, but the gases are invisible. Ask: Where do these pollutants come from? (Car, truck and bus exhaust, factory smoke stacks, power plants that burn fuel and make smoke and soot, etc.) List sources of air pollution on the board. Tell the students that the engines in cars, trucks and buses burn gasoline. When fuels are burned, gases and particles go into the air. Factories that make products and power plants that make electricity burn fuels, too and release pollution into the air. Incinerators that burn garbage also release soot and gases into the air. Light a candle and tell the students that wax is the fuel for this fire but gasoline, coal, oil and wood are burned to make energy for people. Carefully hold a heat-proof dish upside down over the yellow part of the flame for 30 seconds. Move the dish from side-to-side to spread the black carbon deposit. Show the students the carbon stain and tell them that usually this soot you have captured would have escaped into the air. Tell them the invisible gases from the burning wax candle are now in the air. Blow out the candle and point out the visible smoke also escaping into the air. Ask the students to imagine the number of cars in the Tri-Cities burning gasoline at this very moment. We might be able to see smoky exhaust coming out of the tailpipes of those cars, but most of the pollution is invisible, like the invisible gases from the candle. Ask the students to imagine all the lights, fans, heaters, air conditioners, refrigerators, T.V.s, washers and dryers, water heaters, toasters and other appliances in the Tri-Cities that need electricity to work. With all the homes and businesses in the Tri-Cities that need electricity, imagine how much fuel the Gas and Electric Company must burn to make that energy. Burning fuels makes pollution. Tell the students that really dirty air is called smog. It can make the sky look brown. Dirty air can smell bad, too. Gases from burning coal or oil can smell like rotten eggs. Ask: Do you think breathing dirty air is good for people? (no) Do you think it is healthy for plants and animals? (no) Do you think polluted air should be part of our city habitats and ecosystems? On the board write Problem: Burning fuels causes air pollution. Point out the list of pollution sources on the board. Ask: What can people do to reduce the amount of air pollution in our city? (Accept all answers.) Write the students' responses on the board. Some suggestions might include: Reduce the number of cars in the city. Have more people use the Metro, Light Rail, buses or bicycles instead of so many individual cars. One radical suggestion might be to ban cars in the city. Have all people use public transportation or bikes. Don't burn garbage in incinerators. Reduce the amount of electricity we use so power plants don't have to burn so much fuel. Discuss with the students ways they might be able to reduce the amount of electricity they use at home, for instance, turning off lights and/or T.V. when they are the last to leave a room or not keeping the refrigerator door open longer than necessary. Planting and tending trees in empty lots and city streets can offer shade and reduce the need for fans and air conditioning. A student might suggest making electricity another way, without burning fuels. If so, you might want to discuss clean, renewable forms of power such as solar energy or wind power. Another suggestion might be that cars and buses be powered by something other than gasoline engines (electric or solar-powered). After you have discussed ways to reduce air pollution in the Tri-Cities, tell the students that there is another problem about air pollution--it travels. Air currents carry air pollution made by car exhaust and power plants in other parts of the country to our air

space adding more pollution to our pollution. To clean up the air, every city has to do its part because we are all connected by air space--our atmosphere. Write the words acid rain on the board. Tell the students that there is something called acid rain that forms when two gases made by burning fuels mix together high up in rain clouds. The clouds travel and then drop acid rain on the land below. Acid rain can do a lot of damage. Trees and plants soak up the rain and then slowly die. Acid rain collects in rivers and lakes killing fish and plants. It runs down stone statues and buildings and dissolves the stone. Show the students a piece of chalk. Tell them that chalk is made of a kind of soft stone. Show them the bottle of vinegar and explain that vinegar is acidic like acid rain but is a stronger acid. Pour some of the vinegar into the glass dish. Ask: What do you think will happen when I put this chalk made of soft stone into this strong acidic vinegar? (Accept all answers.) Drop the chalk into the vinegar. In a few moments, remove what is left of the chalk from the vinegar. Ask: What happened to the chalk? (It is dissolved or eaten away by the acid in the vinegar.) Tell the students that acid rain is a weaker acid than vinegar and so would take more time to eat away the stone on buildings. Tell them that acid rain has destroyed acres and acres of forests in North America and in Europe and has caused the deaths of lake, river and stream ecosystems. Remind the students that they learned how an animal's or plant's survival depends on the health and balance of its ecosystem. Ask: Do you think people's health and survival depends on the health of our ecosystem, too? Ask the students to listen again to the words of Chief Seattle: "Whatever befalls the earth, befalls the sons of the earth. Man did not weave the web of life; he is merely a strand in it. Whatever he does to the web, he does to himself..."

Long Term Project Ask several students to identify the endangered animal they have chosen and locate where it lives on the world map. Have them read what they have written about their chosen endangered animals.

Third Grade - Science - Lesson 5 - Ecosystems

Objectives Simulate sources of pollution in a model mountain lake. Describe three ways to limit pollution of the Columbia River.

Materials Picture of a mountain lake (picture found at end of unit). A large, clear glass bowl full of water Nine simulated pollutants in labeled paper cups: DIRT-a few tablespoons of soil; TRASH- gum or candy wrapper; PAINT-small amount of water with a drop of red food coloring; GAS AND OIL-small amount vegetable oil; SEWAGE-teaspoon of soy sauce; FERTILIZER- small amount of water with a drop of blue food coloring; PESTICIDE-1/4 cup vinegar; ASHES-baking soda; CLEANERS-one drop of liquid detergent in small amount of water

Teacher Procedure Remind the students that last time they learned how burning fuels, such as gasoline, coal and oil, cause air pollution. Tell the students that today they will be learning how water gets polluted and what can be done to keep it clean. Show the students a picture of a mountain lake from a book or magazine. Tell them that this is a lake you are going to call Big Bear Lake and they are going to help you tell the story of how Big Bear Lake became polluted. Show the students the large glass bowl full of clean water. Ask them to imagine that this bowl of crystal clear mountain water is Big Bear Lake. Big Bear Lake is filled by many streams that tumble down the surrounding mountainsides in beautiful waterfalls and pour their clear, cold waters into the lake. The lake is home to many animals. Ask the students what animals they'd like to imagine living in and around Big Bear Lake (examples: fish, turtles, ducks, water snakes, snails, frogs, bear, deer, moose, wolves). Tell the students that one day some people came in a car to the shores of Big Bear Lake. "This is the perfect place to build a hotel and restaurant," said one man. "We'll call it Big Bear Lodge." "And we can build a pier out into the lake and make a marina for motor boats," said another man. "But first we should knock down some of this forest and build a wide road so people can get to Big Bear Lodge. Bring in the bulldozers!" When the bulldozers dug up the ground, a lot of dirt was washed into the lake. Have a student put DIRT into the lake to simulate the erosion from construction. Once the road was built, the men started on the hotel and restaurant. The workmen liked to eat their lunches next to the lake. They usually threw their trash into the water. Have a student throw TRASH into the bowl to simulate trash. When the painters finished painting the rooms in the hotel, they cleaned their painting equipment in the lake. Have a student put PAINT into the water. When the hotel was finished, people came to the lake to swim and boat and fish. They brought their motor boats and enjoyed speeding around the lake. Many of their boats leaked gasoline and oil into the lake. Have a student add GAS AND OIL to the lake. Meanwhile, each time the guests in the hotel flushed their toilets, the water went into an underground septic system. Unfortunately, the builders did not put in a very good septic system. Soon it began to leak and sewage began to seep into the lake's waters. Have a student pour SEWAGE into the lake. On a hillside near the lake, one of the owners of the hotel decided to plant a vineyard and grow grapes. He cleared the land and planted his vines. He also spread fertilizer on his land. When it rained, the fertilizer washed into the lake. Have a student add FERTILIZER to the lake. The hotel owner also decided to spray his grape vines with chemical pesticides to kill the bugs that might eat his plants. The pesticides washed into the lake, too. Have a student add PESTICIDES to the bowl. The hotel owners and staff found it was much easier to burn the big piles of trash from their guests than to drive it out to a dump, so they burned it and then dumped the ashes into the lake. Have a student dump ASHES in the lake. Meanwhile, boat owners did not like the oily water of the lake messing up their boats, so they washed the boat decks with detergent and other cleaners and rinsed the suds into the lake. Have a student add a CLEANERS to the lake. Ask: What has happened to crystal clear Big Bear Lake? Is this a healthy ecosystem? (No, the lake is polluted.) Would you want to swim or fish in this lake? (no) What do you think has happened to the animals that were living in and around the lake? (Many of them are probably dead from the poisonous pollution or have moved away.) Ask: Do you think the poisons from the pollution in the lake are in the food chain? Do you think any fish caught in the lake might have poison in them? What might happen to any animals or

people that eat the fish? (Poisons from the fish would be passed on to those that ate them.) Ask: Did the people pollute the lake on purpose? Discuss the fact that the people were probably unaware that what they were doing was polluting the Big Bear Lake. Tell the students that many of the things that polluted the lake are the same things that are polluting the Columbia River. Review the labels on the cups of pollutants. Point out that people around the Columbia River are more aware of what causes pollution in the river.. They know that building on the shoreline will cause lots of soil to wash into the river. Now there are laws that limit building on the shoreline. Tell the students that waste water treatment plants filter and treat the Tri-Cities sewage until it is nearly clean before releasing it into the river. Dumping garbage or chemicals from factories into the river is against the law. Tell the students that a big problem in cleaning up the rivers waters is a pollutant that comes from miles and miles away. Pick up the cup labeled FERTILIZER. Explain to the students that like the fertilizers that washed down into the lake from the hillside vineyard, fertilizers on farm fields here in Washington and way up in Canada wash down streams and rivers and into the river every time it rains. There is one kind of tiny plant in the river that thrives on all that fertilizer. Floating, green, slimy algae uses the fertilizer to grow and grow and grow. It blocks out the sunlight to plants and animals below. Then as it dies and decays, it uses up oxygen in the water so there isn't enough for fish to breathe. Ask: What do you think happens to the food web in the river when algae takes over? (fewer fish, not enough for fish eaters to eat) Tell the students that to protect the river, we have to find a way to keep fertilizer out of the water. Write Clean Up the Columbia River on the board and ask the students to help you list three ways to protect the river. (Don't build on the shoreline. Keep fertilizer from washing into the river. Don't dump garbage or chemicals into the river.)

Long Term Project Have students chose an endangered animal. Have students research and write a report to share with the class. Show where they live on a world map and read what they have written about them. Tell the students that you will be collecting their write-ups to include in a class book on Endangered Species.

Read Aloud

*Bash, Barbara. Desert Giant. Boston: Little Brown, 1989. (0-316-08307-0) *Godkin, Celia. Wolf Island. New York: W.H. Freeman, 1993. (0-71676-513-6) *Guiberson, Brenda. Cactus Hotel. New York: Holt, 1991. (0-80501-333-4) *Jeffers, Susan. Brother Eagle, Sister Sky. New York: Dial, 1991. (0-80370-969-2) Heinz,

*Brian J.. Butternut Hollow Pond. Minneapolis: Millbrook, 2000. (978-0-8225-5993-1)

For a list of national parks with links to pictures, maps and information on each one, visit http://www.yahoo.com/Recreation/Outdoors/Parks/United_States/National_Parks National Wildlife Federation for Kids Website (http://www.nwf.org/kids/).  

*Required or highly recommended for lessons  

Long Term Project Checklist

Put a check in the box when you have completed that part of the long term project.

PART 1 Find out the name of your representative in Congress or your U.S. Senator. Address an envelope to one of them. Below are the addresses.

For representative in Congress: The Honorable U.S. House of Representatives Washington, D.C. 20515

For U.S. Senator: The Honorable U.S. Senate Washington, D.C. 20510

PART 2 Choose an animal from the Endangered Animals list that you would like to know more about. Go to the library and find two books with information about that endangered animal.

PART 3 On a separate piece of paper, answer the following questions about the endangered animal you have chosen: 1. What is the name of the animal? 2. Where in the world can this animal be found? Be able to locate this place on a world map. 3. What type of habitat does this animal need? (Examples: tropical rainforest, ocean, desert) 4. What does this animal eat? Is it an herbivore, carnivore or omnivore? 5. What are the causes of it being endangered? (Examples: over-hunting, habitat loss, pollution) 6. Are people helping to save this animal from extinction? How are they helping? 7. If you wish, draw a picture of the animal.

PART 4 Write a letter to your representative in Congress or U.S. Senator. Tell him or her why you care about endangered animals and why it is important to protect them. Tell him or her about a particular endangered animal you are concerned about.    

Third Grade - Science - Ecosystems

Endangered Animals

Here are a few animals on the long list of endangered animals of the world. These animals are in immediate danger of becoming extinct.

Giant Panda Humpback Whale African Elephant Jaguar Whooping Crane Black Rhino Sea Otter Orangutan Black-footed Ferret Brown Pelican Chimpanzee Mountain Gorilla Bengal Tiger Desert Tortoise Blue Whale

Local Endangered Species

Burrowing Owl

Columbian White Tailed Deer

Bald Eagle

Northern Spotted Owl

Leatherback Sea turtle

Short Tailed Albatross

Western Snowy Plover

Gray Wolf

Lesson 2 Questions

With the wolves gone, what do you think happened to the number of deer?

What did the deer eat?

Did the number of grown-up trees increase quickly?

What do you think happened to the deer when their food supply dwindled?

What was the result of killing all the wolves?

Lesson 2 Writing Worksheet

If you were an ecologist studying the web of life, what community or ecosystem would you want to study and why?

What kinds of plants and animals might you find in that ecosystem?

Describe what equipment you might take on your ecological expedition.

Pond Food Web Worksheet Name: ________________________

Date: ____________

1. List the Producers: ______________________________________

______________________________________

______________________________________

______________________________________

2. List the Primary Consumers: ______________________________________

______________________________________

______________________________________

______________________________________

3. List the Secondary Consumers: ____________________________________

______________________________________

______________________________________

______________________________________

______________________________________

4. List the Tertiary and Quatenary Consumers:

______________________________________

______________________________________

______________________________________

5. List the Decomposers: ______________________________________

________________________________

Pond Food Web

Mountain Lake

Amoeba (Ameba)

The amoeba is a tiny, one-celled organism. You need a microscope to see most amoebas - the largest are only about 1 mm across. Amoebas live in fresh water (like puddles and ponds), in salt water, in wet soil, and in animals (including people). There are many different types of amoebas. The name amoeba comes from the Greek word amoibe, which means change. (Amoeba is sometimes spelled ameba.)

Anatomy: An amoeba consists of a single blobby cell surrounded by a porous cell membrane. The amoeba "breathes" using this membrane - oxygen gas from the water passes in to the amoeba through the cell membrane and carbon dioxide gas leaves through it. A complex, jelly-like series of folded membranes called cytoplasm fills most of the cell. A large, disk-shaped nucleus within the amoeba controls the growth and reproduction of the amoeba.

Diet: Amoebas eat algae, bacteria, plant cells, and microscopic protozoa and metazoa - some amoebas are parasites. They eat by surrounding tiny particles of food with pseudopods, forming a bubble-like food vacuole. The food vacuole digests the food. Wastes and excess water are transported outside the cell by contractile vacuoles.

Locomotion: Amoebas move by changing the shape of their body, forming pseudopods (temporary foot-like structures). The word pseudopod means "false foot."

Reproduction: Amoebas reproduce asexually by binary fission. A parent cell divides (the nucleus also divides in a process called fission) and produces two smaller copies of itself.

Classification: Eukaryota (organisms with nucleated cells), Kingdom Protista (flagellates, amoebae, algae, and parasitic protists), Phylum Protozoa (single-celled organisms), Class Sarcodina (having pseudopods).

ANTS

There are thousands of species of ants found all over the world and in just about every type of land environment. Many species are found in rain forests. The science of studying ants is called myrmecology.

These common social insects live in colonies (groups of related ants). Each colony consists of:

Queen - The queen begins her life with wings, which she uses while mating. After mating with a male ant (or many males), she flies to her nesting area. She then loses her wings and spends her life laying eggs.

Workers - Workers are the many sterile (non-reproducing), wingless female worker ants who are the daughters of the queen. These workers collect food and feed members of the colony, defend the colony, and enlarge the nest. Most of the ants in a colony are workers.

Soldiers - Soldiers are large workers (sterile females) who defend the colony and often raid other colonies, capturing slaves. .

Males - Males are small ants that have wings. They fly from the colony to mate with a queen. They die soon afterwards.

Ants exhibit complex behavior; some ants build intricate nests, some are fierce warriors, some collect and store seeds (harvester ants), some capture slaves, and some farm fungi (leaf-cutter ants).

Anatomy: Ants, like all insects, have jointed legs, three body parts (the head, thorax and abdomen), a pair of antennae, and a hard exoskeleton. The exoskeleton is made up of a material that is very similar to our fingernails. Ants range in color from yellow to brown to red to black.

Some ants have a stinger and some can even inject poisonous acid from the stinger (the stinger is at the tip of the abdomen, the rear body segment). Ants can also bite using their jaws (mandibles). Ants range in size from about 0.08 inch (2 mm) to up to about 1 inch (25 mm) long.

Life Cycle: The life cycle of the ant consists of four stages: egg, larva, pupa, and adult. Fertilized eggs produce female ants (queens, workers, or soldiers); unfertilized eggs produce male ants.

Egg: Ant eggs are oval shaped and tiny (they are on the order of 1 mm long, but the queen's egg is many times larger).

Larva: The worm-like larvae have no eyes and no legs; they eat food regurgitated by adult ants. The larvae molt (shed their skin) many times as they increase in size.

Pupa: After reaching a certain size, the larva spins a silk-like cocoon around itself (against a solid object, like the wall of the chamber) and pupates. During this time the body metamorphoses (changes) into its adult form.

Adult: The pupa emerges as an adult. The entire life cycle usually lasts from 6 to 10 weeks. Some queens can live over 15 years, and some workers can live for up to 7 years.

Classification: Class Insecta (insects), Order Hymenoptera (ants and wasps - insects with a waist), Family Formicidae (over 8,000 species of ants).

Beavers

The beaver is a large, semi-aquatic rodent with a large, flattened tail. It is a strong swimmer and can swim up to 5 miles per hour (8 kph). The beaver can swim underwater for up to 15 minutes. Young beavers are called kits. Beavers live in forests in North America and in parts of Europe and Asia. Beavers do not hibernate over winter, but they will stay in their lodge, where they have stored enough food to last until spring.

Beaver Lodges and Dams: Beavers build sophisticated lodges out of sticks and mud. The dome-shaped lodge is built in water and only has underwater entrances. If the local pond water isn't deep enough, the beaver will build a dam (or a series of dams) downstream from where the beaver wants to build a lodge. The dam forms a deep pond. Beavers cut down trees for the dam using their strong teeth. The water in the pond must be deep enough so that the pond bottom won't freeze in winter, blocking the lodge's entrance.

Anatomy: Beavers are about 3 ft (0.9 m) long; their flat, thick tail is about 1 ft (30 cm) long. They weigh 30-70 pounds (14-32 kg). Like all rodents, their teeth continue to grow their entire lives. Their ears and nostrils can close while the beaver is underwater. While swimming, transparent eyelids protect their eyes. Beavers can close their mouth by closing a flap located behind their teeth, allowing them to chew while holding their breath.

Diet: Beavers are herbivores (plant-eaters). They eat tree bark, leaves, roots, twigs, and water plants.

Predators: The beaver is hunted by many animals, including coyotes, wolves, bears, lynxes, and wolverines. Minks, owls and hawks prey upon young beavers. Beavers cannot move very quickly on land, so their best defense from predators is to retreat into the water and go into their lodge.

Black Swan

The black swan (Cygnus atratus) is an Australian native that has been introduced to other places, including New Zealand (where it is now considered a pest) and Sweden. The adult female is called a pen, the adult male is called a cob, and the baby is called a cygnet. Black swans are very territorial. They make honking and hissing noises. Black swans fly in a V-shaped formation and can fly at speeds of up to 50 miles per hour (80 kph). The black swan is the emblem of the State of Western Australia.

Anatomy: Black swans are long-necked black birds with a red beak tipped in white. The neck is longer than the body. Black swans have a wingspan of up to 6 feet (1.8 m) and are up to 4 feet (1.2 m) long. They weigh up to 13 pounds (6 kg). Males and females are similar in size.

Diet: The black swan eats mostly water plants and some grain. It reaches under the water with its long neck to get these plants, and it even eats the roots. Cygnets eat a lot of bugs and other small invertebrates, since they feed mostly from the water's surface.

Eggs and Nests: These graceful waterfowl mate for life. Black Swans build large nests located near the water; they are lined with swan down (delicate feathers). Females lay 4-8 pale green eggs in each clutch (a set of eggs laid at one time). Both parents care for the eggs and hatchlings.

Canada Goose

The Canada Goose is a common North American goose. It makes a loud, honking sound. There are many subspecies of this goose, and they range widely in size; the smallest of these (called "cackling geese" because of their high-pitched calls) are only 1/4 the size of the largest (called "honkers"). Many Canada Geese migrate seasonally, flying in a characteristic V-shaped formation.

Anatomy: The Canada Goose has a distinctive white "chinstrap" and a dark head and neck. They are generally brown above and white below. The young Canada Goose looks similar to the adult. The Canada Goose has a plump body, a long neck, and webbed feet. It ranges from 22 to 45 inches (56 to 115 cm) long.

Diet: The diet of the Canada Goose consists mainly of plants.

Eggs and Nests: The Canada Goose's nest is a simple depression in the ground that is lined with grass and feathers. Females lay 2-12 dull white eggs in each clutch (a set of eggs laid at one time).

Capybara

The capybara, Hydrochaeris hydrochaeris, is the biggest rodent in the world. This semi-aquatic rodent lives in swamps, in marshes, and also in forests (near ponds, lakes and rivers). It is found in Central and South America.

Capybaras gather near the water in groups of about 20 animals; they spend a lot of time wallowing in mud. These social animals communicate using whistles and barks; they also produce glandular scents. These mammals have a life span of 8 to 10 years in the wild.

Anatomy: Capybaras range from 40 to 52 inches (102-132 cm) long and weigh from 60 to 100 pounds (27-50 kg). They have thin brown hair that dries off quickly. Webbed toes help the capybara swim.

Diet: Capybaras are herbivores (plant-eaters); they eat water plants, grasses, fruit, and grains. Like all rodents, their two front teeth continue to grow throughout their lives, and the capybara must gnaw and chew to wear these teeth down.

Reproduction: Females give birth to a litter of one to six young. Newborns weigh about 2 pounds (1 kg); they have hair and can see at birth. Capybaras are mature at about 1 1/2 years old.

Predators: Hunters of the capybara include the jaguar, caiman, ocelot, harpy eagle, large snakes (like the anaconda), and people (who eat capybara). When in danger, the capybara goes into the water; it is a strong swimmer.

Common HouseflyMusca domestica

The common housefly is a flying insect that is found throughout the world. The genus and species of the housefly is Musca domestica.

Anatomy: Like all insects, the housefly has a body divided into three parts (head, thorax, and abdomen), a hard exoskeleton, and six jointed legs. Flies also have a pair of transparent wings. The Housefly can taste using its its feet and with its mouthparts. Adults are about 1/4 to 1/2 inch (6 - 12.5 mm) long with 13 - 15 mm wingspan. Houseflies are dark gray, with four dark stripes down the top of the thorax. They have sponging mouthparts (they cannot bite); houseflies can only eat liquids, but they can liquefy many solid foods with their saliva.

Reproduction: The complete life-cycle of a housefly takes from 10 to 21 days. On the average, 12 generations of houseflies can be produced in one year. Adult females lay 120-150 tiny white eggs, usually in manure or other warm, moist, decaying organic matter. A female lives for about 2 1/2 months and can lay up to 1,000 eggs in her short life. The eggs are only about 0.04 inch (1 mm) long and hatch into white, worm-like maggots in about 12 hours. The maggots grow to be about 1/2 inch (12.5 mm) long. When they are this big, they burrow into the ground to pupate. An adult will emerge in about 5 to 6 days (in warm weather) or about a month (in cold weather).

Disease Carrier: The housefly is often a carrier of diseases, such as typhoid fever, cholera, dysentery, and anthrax. The fly transmits diseases by carrying disease organisms onto food. It picks up disease organisms on its leg hairs or eats them and then regurgitates them onto food (in the process of liquefying solid food).

Classification: Kingdom Animalia; Phylum Arthropoda; Class Insecta; Order Diptera ("two wings"); Family Muscidae; genus Musca; Species domestica.

Common Snapping TurtleChelydra serpentina

The Common Snapping Turtle is an aggressive, freshwater turtle usually found in ponds, streams, and canals. It spends most of its life in the water. These nocturnal (active at night) turtles live in eastern North America. Snapping turtles are so fearless that they have been known to attack people. Snapping turtles have an average life span of about 30-40 years.

Anatomy: The Common Snapping Turtle has powerful jaws, a sharp beak, and no teeth. It has a long tail, and each webbed foot has five clawed toes. This turtle, like all turtles, has no vocal cords and can only make hissing and grunting sounds. It grows to be up to 18.5 inches (47 cm) long and weighs up to about 85 pounds (38.5 kg). Male snapping turtles are larger than the females. The color of the shell ranges from brown to olive green to black to tan. The color of its skin also varies and can be gray, brown, yellow, tan, or black.

Diet: Snapping Turtles are omnivores; they eat plants, small fish, frogs, insects, snakes, and even dead animals that they find (carrion).

Copepod

Copepods (meaning "oar feet") are small, shrimp-like crustaceans that swim in seas, lakes, and ponds. Copepods are very important in the food web since many animals eat them.

There are 10 orders of copepods and over 4500 species; a few orders are free-swimming, but many are parasites (of fish). The free-swimming copepods move through the water in jerky motions by moving their swimming legs.

Anatomy: Copepods have a hard exoskeleton, many legs (used for swimming and gathering food), a segmented body, and jointed appendages. Most copepods are under 1 mm long, but a few oceanic species are over 1/4 inch (1 cm) long. Although they lack compound eyes, these arthropods have a single simple eye in the middle of the head (sometimes it is only present in the larval stage); this simple eye can only differentiate between light and dark. There are two pairs of antennae; one pair is long and one pair is short. Like all crustaceans, copepods molt their exoskeleton as they grow.

Diet: Copepods eat bacteria, diatoms, and other tiny, single-celled organisms in the water. Maxillae, maxillipeds and antennae push food towards the mandibles (jaws), which process the food.

Predators: Free-swimming copepods are a component of zooplankton and are eaten by many organisms, including mussels, fish and fish larvae, squid, sea birds, and mammals (like baleen whales and some seals).

Reproduction: The female copepod produces clusters of eggs that she carries in one or two egg sacs that are attached to her adbdomen.

Crayfish

Crayfish are crustaceans that are also known as crawdads, crawfish, and freshwater lobsters; they are closely related to lobsters, crabs, and shrimp. There are about 150 crayfish species in North America, and over 540 species worldwide.

Crayfish live in streams, rivers, swamps, ponds, and other freshwater habitats. Most crayfish are strictly aquatic but some live in semi-aquatic environments. The semi-aquatic crayfish burrow into the soil to get to water (so that they can breathe).

Anatomy: This crustacean has a hard exoskeleton that protects and supports the body. The crayfish has 8 jointed walking legs, a segmented body, 2 pairs of sensory antennae, and compound eyes. It has 2 large pincers or claws called chelipeds. If a crayfish loses a leg, the leg will regenerate (regrow). The head and thorax are fused, forming the cephalothorax. Using gills, a crayfish breathes oxygen that is dissolved in water. Juvenile crawfish are light tan, but adults are deep red. Their color also depends on diet. As a crayfish grows, it often molts (loses its old shell and grows a new one). It eats the old shell. Crawfish in North America range from 2 to 6 inches (5-15 cm) long; Australian crawfish are larger.

Diet: Crayfish are omnivores; they eat plants, animals, and decaying organisms. They are nocturnal (most active at night) and eat fish, shrimp, water plants, worms, insects, snails, and plankton. Larval crayfish are very tiny; they eat plankton.

Predators: Many animals eat crayfish, including fish (like eel, trout, pike, chub, perch), herons, mink, otters, snakes, and people.

Dragonfly

The dragonfly is a flying insect that can hover in mid-air. It eats other insects, catching them while it is flying. There are many different species of dragonflies, and most of them are found near water. The earliest dragonflies appeared over 300 million years ago.

Like all insects, the dragonfly has a three-part body: a head, a thorax, and a long, thin, segmented abdomen. The dragonfly has 2 large compound eyes that take up most of the head. On the short thorax there are three pairs of jointed legs and two pairs of long, delicate, membranous wings. The dragonfly breathes through spiracles (tiny holes in the abdomen).

Life cycle: A dragonfly undergoes incomplete metamorphosis. The larva hatches from an egg which is laid in water, in plants near water, or even underwater. As this aquatic (living in the water) larva (called a nymph) grows, it molts (loses its old skin) many times. When fully-grown, it emerges from the water, using the claws on its feet to crawl onto a plant. The dragonfly flies away over land. It only returns to the water to reproduce and continue this cycle. The life span

ranges from about 6 months to over 7 years (most of it is spent in the nymph stage - the adult lives for only a few weeks).

Classification: Kingdom Animalia; Phylum Arthropoda (arthropods); Class Insecta (insects); Order Odonata (dragonflies and damselflies); Suborder Anisoptera (dragonflies), many families, including Family Libellulidae (skimmers or pond dragonflies).

EarthwormEarthworms (also called nightcrawlers) are very important animals that aerate the soil with their burrowing action and enrich the soil with their waste products (called castings). Good soil can have as many as as 1,000,000 (a million) worms per acre.

There are over 3,000 species of earthworms around the world. These invertebrates (animals without a backbone) range in color from brown to to red, and most have a soft body. Earthworms range in size from a few inches long to over 22 feet long. The largest earthworms live in South Africa and Australia.

Diet: Earthworms eat soil and the organic material in it - including plants, insect parts and bacteria.

Anatomy: The earthworm is a tube-shaped worm that is covered by a moist, protective cuticle. The body earthworm's body is divided into about 150 segments. Tiny bristles (plural setae, singular seta) appear in pairs on most segments of the earthworm's body. On one end is the the mouth (which is covered by a flap, called the prostomium, that helps the earthworm sense light and vibrations). On the other end is the anus (through which waste is excreted). The brain, hearts, and breathing organs are located in the first few segments of the worm. Earthworms breathe through their skin -- they have no lungs (if the skin dries out, they cannot breathe and will die). It has five pairs of hearts. The rest of the inside of an earthworm is filled with the intestines, which digest its food. Mature worms have a clitellum (the enlarged segments in the middle of the earthworm), the reproductive parts of this worm.

Reproduction: Although each earthworm is hermaphroditic (each worm has both male and female reproductive systems), it takes two worms to mate and reproduce. The reproductive organs are located in the clitellum. After mating, the clitellum forms an egg case/cocoon which protects the developing eggs. Newly-hatched earthworms look like tiny versions of adult earthworms.

Movement: When burrowing underground, earthworms move by having cycles of muscle contractions that alternatively lengthen and shorten the body. The bristles (setae) help hold the stationary part of the worm in place as it "launches" another part forward.

Classification: Kingdom: Animalia, Phylum Annelida: the "segmented worms" (in Latin, "annellus" means small ring), Class: Clitellata (worms having a clitellum), Subclass: Oligochaeta (meaning "few bristles").

FlamingoThe flamingo is a beautiful pink bird that lives in large flocks near alkali lakes in a variety of habitats.

When a flamingo flies, its long neck and legs make a nearly straight line. Flamingos live to be about 50 years old.

Feathers: The flamingo's bright pink color is due to its diet. The carotene from the shrimp or other shrimp-like crustaceans in its diet turns its feathers pink. If the diet is low in carotene, the feathers become white.

Anatomy: Flamingos have a very long neck and long, pink legs with big, pink, webbed feet. Adults grow to be about 4 feet (1.2 m) tall. Their long

bill turns downward in the middle; it is yellow/orange with a black tip. The large bill is used in filter feeding. The eyes are orange-yellow.

Habitat: Flamingos prefer alkaline (the opposite of acid) waters. Flamingos are native to South/Central America and Africa (flamingos are not native to the USA). They are found in warm, tropical areas, desert lakes (in East Africa), and cold mountain lakes (in the Andes mountains).

Diet: The flamingo eats insects, crustaceans (shrimp and other shrimp-like animals), and tiny plants like diatoms and algae. The flamingo eats by putting its head upside-down into the water looking backwards. It takes in water that is rich in tiny organisms and filters nutrients from the water with a comb-like organ on its tongue.

Frogs

Frogs are amphibians, animals that spend part of their lives under water and the remainder on land. They have long, powerful jumping legs and a very short backbone. Most frogs have teeth (in the upper jaws only) but toads do not have any teeth.

Life cycle: Like all amphibians, frogs spend their lives near water because they must return to the water to lay their eggs. Frog eggs are laid in the water. When they hatch into tadpoles, they breathe with gills and swim using a tail. As they mature, they lose their tail, and they develop lungs for breathing air. In harsh climates, frogs bury themselves in sand and mud and hibernate (sleep very deeply) through the cold winter.

Diet: Frogs eat insects, catching them with their long, sticky tongue. They also eat small fish and worms.

Classification and Evolution: Kingdom Animalia (animals), Phylum Chordata, Class Amphibia (amphibians), Order Anura (Frogs and toads). The first true frogs evolved during the early Jurassic period, about 200 million years ago (during the time of the dinosaurs).

Great Blue Heron

The Great Blue Heron is a majestic wading bird from North America. The largest of the American herons, it lives in swamps, marshes, shores, and tide flats. The Great Blue Heron flies with slow wing beats. It has a deep, raspy call that sounds like "frahnk, frahnk, frahnk." The scientific name of the Great Blue Heron is Ardea herodias (genus and species).

Anatomy: The Great Blue Heron is about 4 ft (1.3 m) tall and has a wingspan of up to 6 ft (1.8 m). Its body has gray feathers, the neck is brown, and the thighs are reddish brown. The cheeks,

throat, and crown (the front of crest) are white, but the rest of the crest is bluish-black. The bill is dull yellow and the long legs are pale brown.

Diet: The Great Blue Heron eats fish, lizards, frogs, crawfish, rodents, and insects. It hunts in shallow water, usually impaling the prey on its long, sharp bill. It then tosses the dead prey into the air, and catches it with its mouth.

Eggs and Nests: The Great Blue Heron's nest is a platform of twigs and sticks that is built in trees, on cliffs, or on the ground. These birds nest in colonies called rookeries. Females lay 3-7 pale green eggs in each clutch (a set of eggs laid at one time).

Great Egret

The Great Egret (also known an the Common Egret) is a large wading bird found worldwide. It is the second-largest member of the heron family in America (second only to the Great Blue Heron). It lives in mudflats, tidal shallows and marshes. It winters in the south down to Colombia. The Great Egret flies with slow wing beats and has a deep, croaking call. The scientific name of the Great Egret is Casmerodius albus (genus and species).

Anatomy: The Great Egret is over 3 ft (1 m) tall and has a wingspan of up to 55

inches (140 cm). Its body has white feathers, the neck is S-shaped, the bill is bright yellow, and the long legs and the feet are black. Males and females are similar in appearance.

Diet: The Great Egret eats fish, lizards, frogs, crayfish, small rodents, and insects. It often hunts in shallow water, usually impaling the prey on its long, sharp bill.

Eggs and Nests: The Great Egret's nest is a platform of twigs and sticks that is built in trees or on the ground. Females lay 3-5 pale blue-green eggs in each clutch (a set of eggs laid at one time). The incubation period of the eggs is 23-26 days. Both parents care for the young, feeding them frogs, fish, and snakes.

Lake Trout

The Lake Trout, Salvelinus namaycush, is also known as the gray trout, mackinaw, laker, and salmon trout. It is a large, fast-swimming fresh-water fish that is native to Alaska, Canada, and the Great Lakes area. This solitary fish has been introduced in other deep-water lakes, and is now widely distributed in North America. It has a life span of about 20 years and is slow-growing. Lake Trout are commercially valuable fish that are prized for their meat.

Anatomy: The Lake Trout is torpedo-shaped and has a deeply-forked tail. It has a large head with well-developed teeth on the jaws, tongue, and the roof of mouth. The Lake Trout grows to be about 50 inches (1.25 m), but is usually 17 to 27 inches (43-68 cm). Most weigh from 3 to 9 pounds (1.3-4 kg), but it can weigh up to 120 pounds (55 kg).

Diet: The Lake Trout is a carnivore (meat-eater), eating small crustaceans (like shrimp), insects, fish (including Whitefish and Cisco), and even some tiny mammals. Young lake trout eat plankton, insects, shrimp, and small aquatic invertebrates.

Mallard Duck

Mallard Ducks are common wild ducks that live in Northern Hemisphere wetlands. Most domestic (tame) ducks were bred from mallards. The female is called a hen, the male is called a drake, and the young are called ducklings.

Anatomy: Males are brightly colored, having a green head, a white collar, and a bright yellow bill. Females are mottled brown with a brown bill. Mallards are about 20-23 inches (51-59 cm) long.

Diet: Mallard ducks have a varied diet. They eat insects, worms, frogs, snails, slugs, small shellfish, grasses, and other plants that grow near shore.

Eggs and Nests: Mallards build cup-like nests made of grass and leaves; they are lined with duck down (delicate feathers). Nests are usually on the ground in dense undergrowth. Females lay 5-14 greenish-white eggs in each clutch (a set of eggs laid at one time). The female cares for the young.

MosquitoThe mosquito is a common flying insect that is found around the world. There are about 2,700 species of mosquitoes. Mosquitoes can fly about 1 to 1.5 miles per hour (1.6-2.4 kph).

Mosquito Bites:Females drink blood and the nectar of plants; the males only sip plant nectar. When a female bites, she also injects an anticoagulant (anti-clotting chemical) into the prey to keep the victim's blood flowing. She finds her victims by sight and smell, and also by detecting their warmth. Not all mosquito species bite humans.

Disease Carrier:The mosquito is often a carrier of diseases, such as malaria, encephalitis, yellow fever, dengue fever, dog heartworm, West Nile virus, and many others. The females, who drink blood, can carry disease from one animal to another as they feed.

Anatomy:Like all insects, the mosquito has a body divided into three parts (head, thorax, and abdomen), a hard exoskeleton, and six long, jointed legs. Mosquitoes also have a pair of veined wings. They have a straw-like proboscis and can only eat liquids.

Life Cycle:Mosquitoes undergo complete metamorphosis; they go through four distinct stages of development during a lifetime. The four stages are egg, pupa, larva, and adult. The full life-cycle of a mosquito takes about a month.

Eggs: After drinking blood, adult females lay a raft of 40 to 400 tiny white eggs in standing water or very slow-moving water.

Larvae: Within a week, the eggs hatch into larvae (sometimes called wrigglers) that breathe air through tubes which they poke above the surface of the water. Larvae eat bits of floating organic matter and each other. Larvae molt four times as they grow; after the fourth molt, they are called pupae.

Pupae: Pupae (also called tumblers) also live near the surface of the water, breathing through two horn-like tubes (called siphons) on their back. Pupae do not eat.

Adult: An adult emerges from a pupa when the skin splits after a few days. The adult lives for only a few weeks.

Muskrat

Muskrats are rodents that live in freshwater and saltwater marshes, lakes, ponds, and streams. Muskrats often build dome-shaped houses in marshes. These houses, made of plants, protect the muskrat from predators, since the only entrance is underwater. Some muskrats live in

burrows on the water banks. Muskrats are excellent swimmers but are slow on land.

Muskrats are native to North America, but have been brought to Europe and Asia, where they now live in the wild. Muskrats got their name because they have musk glands that produce a strong scent.

Anatomy: Muskrats are about 12 inches (30 cm) long. They weigh roughly 2 to 4 pounds (1 to 2 kg). Muskrats are covered with thick, insulating brown fur. They paddle in the water with their partly-webbed hind feet and steer with their scaly tail.

Diet: Muskrats eat water plants and shellfish.

Predators: Muskrats are hunted by many animals, including foxes and raccoons. Muskrats cannot move very quickly on land, so their best defense is to retreat into the water or into their burrow or house.

Newts

Newts are brightly colored salamanders. These small amphibians are found in moist, wooded areas in North America, Europe, and Asia.

Anatomy: On average, newts are about 3 to 4 inches (7.5 to 10 cm) long. They have four legs; there are four fingers on each of the front legs and five toes on each of the hind legs. The adult's color varies from deep green to brown on top, and the underbelly is usually yellow with dark spots. Many newts have red spots along their sides.

Life cycle: Like all amphibians, newts spend their lives near water because they must return to the water to lay their eggs. Newt eggs are laid in the water. When they hatch, they breathe with gills and swim. As they mature, they develop lungs for breathing air. Some newts leave the water at this time and are known as red efts. They are red-orange, but over about 2 to 3 years, they turn green. Then, they return to the water to lay eggs and the cycle starts over again. Some newts do not go onto the land, but remain in the water.

Diet: Newts eat insects, worms, snails, and small fish.

Painted Turtle (Painted Terrapin)

The painted turtle, Chrysemys picta, is a common turtle in North America; it is also called the painted terrapin. This reptile lives in ponds, lakes, marshes,and slow-moving rivers that have soft, muddy bottoms. In the wild, this turtle lives from 5 to 10 years; in captivity it can live over 20 years. Behavior: Although it spends most of its time in the water, the painted turtle often suns itself while lying on a log, a rock, or the shore. These turtles are often seen in large groups. Hibernation: During very cold weather, northern painted turtles hibernate, burying themselves for months in the mud beneath streams and ponds. Anatomy: The are many subspecies of painted turtles which vary in size, coloration and plastron pattern (the plastron is the lower shell). The painted turtle has a hard upper shell (the carapace), which is from 4 to 7 inches (10-18 cm) long. The webbed feet are used for swimming. Diet: The painted turtle is an omnivore (it eats both meat and plants). The young eat mostly meat. Adults eat both animals (including insects, snails, slugs, crayfish, leeches, mussels, tadpoles, frogs, fish eggs, small fish, and dead animals that it finds) and plants (including duckweed, algae, and lily pads). Predators: Raccoons, skunks, opossums, birds, snakes, and some other large turtles prey upon the painted turtle; the young are especially vulnerable to predators. Reproduction: The female lays 5 to 10 eggs in each clutch. The eggs are laid in a shallow pit that she digs with her hind legs. She covers the eggs with sand or dirt, and then abandons them. The eggs hatch in about 10 to 11 weeks. Classification: Kingdom Animalia (animals), phylum Chordata, class Reptilia (reptiles), order Testudines (terrapins and tortoises), family Emydidae, genus Pseudomys, species P. picta.

Plankton

Plankton are microscopic organisms that float freely with oceanic currents and in other bodies of water. Plankton is made up of tiny plants (called phytoplankton) and tiny animals (called zooplankton). The word plankton comes from the Greek word "planktos" which means "drifting."

Phytoplankton: Phytoplankton are primary producers (also called autotrophs). As the base of the oceanic food web, phytoplankton use chlorophyll to convert energy (from sunlight), inorganic chemicals (like nitrogen), and dissolved carbon dioxide gas into carbohydrates.

Zooplankton: Zooplankton are microscopic animals that eat other plankton.

Some zooplankton are larval or very immature stages of larger animals, including mollusks (like snails and squid), crustaceans (like crabs and lobsters), fish, jellyfish, sea cucumbers, and seastars (these are called meroplankton).

Some zooplankton are single-celled animals, like foraminifera and radiolarians. Other zooplankton are tiny crustaceans, like Daphnia. (If you include krill and copepods,

which can swim, this group constitutes about 70 percent of all plankton)

Food Web: Plankton is the first link in the marine food chain; it is eaten by many organisms, including mussels, fish, birds, and mammals (for example, baleen whales).

Pupfish

The Pupfish, genus Cyprinodon, is a tiny fish that lives in springs, ponds, marshes, and slow-flowing streams in the deserts of southwestern North America. Pupfish are found in the Mojave and Sonoran Deserts (in northwestern Mexico, southern California, USA, and Arizona, USA).

Many types of pupfish are endangered species due to a loss of habitat and to competition from exotic species of fish that have been introduced to their habitat.

Lifecycle: Towards the end of summer, most desert pools and other desert waters dry up, killing most pupfish. Only a few bodies of water do not dry up completely, so very few pupfish survive. During the coldest parts of winter, pupfish burrow into the muddy bottom and become dormant until the weather warms up. They then mate and reproduce quickly. Most pupfish have a life span of less than one year.

Diet: Pupfish eat diatoms (microscopic unicellular algae with a hard cell wall), algae, and small aquatic invertebrates (like amphipods, gastropods, and ostracods).

Some pupfish engage in "pit digging," in which the fish rests at the water's bottom and wiggles its body in order to to churn up the mud and sand. No one is sure exactly why they do this, but it may be to dislodge food from the mud.

Anatomy: The Pupfish is a tiny fish, about 2 to 2 1/2 inches (5-6.5 cm) long. Pupfish range in color from silvery-brown to silvery-blue.

River Otter

River otters are sleek, furry, streamlined aquatic mammals that live in rivers, streams, ponds, and marshes in Canada and the USA. They are a large type of weasel (a member of the mustelid family). Their scientific name is Lutra canadensis (Genus, species). The river otter is an endangered species because of overhunting (it was hunted for its beautiful, dense fur).

River otters are nocturnal (most active at night). During the day, they rest in underground dens.

Anatomy: River otters are from 3 to 4 feet (0.9-1.3 meters) long and weigh about 44-82 pounds (20-37 kg). The tail is 1 to 1 1/2 feet (30-45 cm) long. Webbed feet help the otter swim. These sleek mammals have short legs and semi-retractible claws. Both the ears and the nostrils close when the animal is under water.

Fur: River otters are kept warm by their dense fur and high metabolism. They are active all year long, even through very cold winters. Careful grooming with their forepaws keeps the fur waterproof.

Diet: River otters are carnivores (meat-eaters). They eat crustaceans (like crayfish), slow-swimming fish (like trout), amphibians, insects, small mammals and birds. They hunt for their prey in the water and on the land. These intelligent mammals have a keen sense of smell; they use their sensitive whiskers to help find prey in muddy water.

Predators: River otters are preyed upon by the bald eagle, some bears and coyotes.

Classification: kingdom Animalia, Phylum Chordata, Class Mammalia (mammals), Order Carnivora, Family Mustelidae (weasels, ferrets, minks, skunks, otters, badgers), Genus Lutra.

Shrimp

Shrimp are small animals that live on the floor of oceans and lakes. There are over 2,000 different species of shrimp worldwide. Shrimp are invertebrates (animals lacking a backbone) that have a tough exoskeleton.

Anatomy: Shrimp range from a small fraction of an inch to 9 inches (a few mm to 23 cm) long. These crustaceans have a thin, smooth, hard, and almost transparent exoskeleton. Shrimp vary widely in color; tropical varieties are often brightly colored. Shrimp have 5 pairs of jointed walking legs on the thorax, and they have 5 pairs of swimming legs (swimmerets) and 3 pairs of maxillae (feeding appendages) on the abdomen. The body, legs, swimmerets, and other appendages are segmented. Shrimp have two pairs of segmented sensory antennae, a tail fan, and compound eyes.

Diet: Shrimp are omnivores; they eat plants and small animals. The unusual pistol shrimp kills or stuns its prey by making a very loud sound with a huge claw with a moveable, snapping appendage.

Life Cycle: Female shrimp lay over a thousand eggs, which are attached to her swimming legs. The shrimp emerge as tiny, floating organisms, a component of zooplankton. After growing, they sink to the bottom, where they will live. As a shrimp grows, it often molts (losing its old shell and growing a new one).

Predators: Shrimp are eaten by many animals, including many fish, many birds (including flamingos and loons), octopi, squid, cuttlefish, and people.

Classification: Kingdom Animalia, Phylum Arthropoda, Class Crustacea (crustaceans), Subclass Malacostraca, Order Decapoda, Suborder Natantia.

Snails

The Snail is a gastropod, a soft-bodied type of mollusk that is basically a head with a flattened foot. The soft body is protected by a hard shell, which the snail retreats into when alarmed. These invertebrates (animals with no backbone) are found worldwide in the seas, in fresh water, and in moist areas on land.

Locomotion: Snails move by crawling, swimming, or floating with currents. Land snails crawl on the ground, creeping along on their large, flat foot; a special gland in the foot secretes mucus (a slimy fluid) that helps the snail move. The common garden snail is the slowest moving animal; it can travel about 0.03 mph (0.05 kph).

Anatomy: Snails range in size from 0.02 inch (less than a millimeter) long (Ammonicera rota) to over 30 inches (77 cm) long (the marine Australian Trumpet (Syrinx aruanus). The largest land snail is the Giant African Snail; it is over 15.5 inches (39 cm) long and weighs about 2 pounds (900 g).

Snails have two pairs of tentacles on the head. Land snails have a light-sensitive eyespot located on each of the larger tentacles; water-dwelling snail eyespots are at the base of the tentacles. The smaller pair of tentacles is used for the sense of smell and the sense of touch.

Diet: Most snails eat living and decaying plants, but some are scavengers and some are predators. They eat using a radula, a rough tongue-like organ that has thousands of tiny denticles (tooth-like protrusions).

Predators of the Snail: Many animals eat snails, including birds, fish, frogs, snakes, turtles, beetles (and other insects), and people.

Toads

Toads are amphibians, animals that spend the early part of their lives under water (as eggs and tadpoles) and the remainder on land. These nocturnal animals hunt at night and spend the day sheltered in a cool spot. Toads spend less time in the water than frogs. Toads are found all over the world except polar environments and Australia.

Anatomy: Toads have poison glands (called parotids) behind their eyes, a chubby body, and shorter legs than frogs. Toads have no teeth, and most toads have warty skin. The largest toads are over 8 inches (20 cm) long. Females are larger than males.

Life cycle: Like all amphibians, toads must return to the water to lay their eggs. Toad eggs are laid in the water. When they hatch into tadpoles, they breathe with gills and swim using a tail. As they mature, they lose their tail, and they develop lungs for breathing air.

Diet: Toads eat insects and other small animals, catching them with their long, sticky tongue.

Trumpeter Swan

Trumpeter Swans are loud, migratory birds that live in North America. The adult female is called a pen, the adult male is called a cob, and the baby is called a cygnet. They live about 12 years in the wild, and about 35 years in captivity. These birds almost went extinct about 100 years ago; they are now protected and are recovering.

Anatomy: Trumpeter Swans are long-necked white birds with a black beak. They have black legs and black webbed feet. Their thick feathers protect them from extreme cold weather. The Trumpeter is the largest swan in the world, with a wingspan up to 9 feet (3 m).

Diet: Trumpeter Swan eat mostly water plants, like cattails, pondweeds, and others. They reach under the water with their long neck to get these plants, and even eat the roots. Cygnets eat a lot of bugs and other small invertebrates, since they feed mostly from the water's surface.

Eggs and Nests: These beautiful birds mate for life. Trumpeter Swans build large nests made of grass, roots, and reeds; they are lined with swan down (delicate feathers). These nests are often built on top of a muskrat's den. Females lay 5-6 white eggs in each clutch (a set of eggs laid at one time).

Water Strider

The water strider (also known as the pond skater) is a true bug that can run across the surface of water. It lives on ponds and slow-running streams. It rarely goes underwater. The underside of the body is covered with water-repellent hair.

Anatomy: Like all insects, the water striders have a three-part body (head, thorax and abdomen), six jointed legs, and two antennae. It has a long, dark, narrow body. Some water striders have wings, others do not. Most water striders are over 0.2 inch (5 mm) long.

The Legs: The long, middle legs move this bug across the surface on the water like paddles. The long hind legs steer them and act as brakes. The short front legs are used to catch prey.

Diet and Predators: Water striders eat small insects that fall on the water's surface and also larvae (immature insects). Water striders are very sensitive to motion and vibrations on the water's surface. It uses this ability in order to locate prey. It pushes its mouth into its prey and sucks the insect dry. Water striders do not bite people. Predators of the water strider, like birds and fish, take advantage of the fact that water striders cannot detect motion above or below the water's surface.

White-Tailed Deer

The White-Tailed Deer is a long-legged, fast-moving mammal. The genus and species of the White-Tailed Deer are Odocoileus virginianus. This deer is found over most of North and Central America and northern parts of South America. It lives in deciduous forests, conifer forests, rainforests, grasslands, farm land, marshes, and even deserts. It has a life span of about 9 to 12 years.

Anatomy: White-Tailed Deer are about 3 to 3 1/2 feet (0.9 to 1 m) tall at shoulder. Bucks (males) weight up to 400 pounds (180 kg), does (females) weigh up to 200 pounds (90 kg).

Fawns (babies) are usually born in May or June. Only bucks have antlers, which are branched; the antlers are shed each year, and later regrow.

Behavior: Deer are shy herbivores (plant-eaters) who spend most of the day eating leaves, grass, bark, acorns, and other plant material. Does often travel in small herds with their fawns.