Third Grade Ecosystems Unit
Pasco 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
whole
2-3 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 nonliving 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, overhunting. 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 twohundred-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 domeshaped 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 Housefly
Musca 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 Turtle
Chelydra 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).
Earthworm
Earthworms (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").
Flamingo
The 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 orangeyellow.
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 secondlargest 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 2326 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.
Mosquito
The 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.
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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 slowflowing 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), slowswimming 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.