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Nature Pyramid: Third Grade Fall Unit
Revised September 21, 2012

Unit Goals

In second grade students learned that nature consists of millions of plants and animals interacting with each other. Each differs in size, shape, texture, and behavior. In this unit students will learn that plants and animals can be grouped by similar characteristics (mammals have hair, birds have feathers) and their feeding preferences (producer, consumer, carnivore, etc.) The goal of this unit is to help the students to better understand each living thing's place in nature, their relative abundance, and the notion that nature is sustained through food chains as the Nature Pyramid.

This unit is specifically designed to address appropriate AAAS Project 2061 benchmarks as well as third grade Minnesota Academic Science Standards. Please email us for more information.

Summary

Before your visit, please review with your students:

  • Discuss the concept of the nature pyramid and understand the categories of producers, consumers, and decomposers
  • Review the differences between plants and animals
  • Discuss the characteristics of plants and animals that fit into the categories of "producer", "consumer", and "decomposer" and why each is important
  • Review similarities and differences in prairie, forest, and pond habitats

At River Bend:
Students will be divided into 3 groups and students will work with a partner in their group.

  • During the introduction we will review the above material
  • Teams will survey the prairie, the forest, and a water body to count components of the pyramid using Nature Pyramid worksheets (download sample).
    • weather conditions
    • decomposer search
    • insect collection
    • plant survey
    • animal signs
  • Compare the data collected as the group moves between sites
  • Each class will play the River Bend Nature Pyramid Game

In closing we will:

  • Inquire about students' results
  • Compile data collected to create large group Nature Pyramids
  • Remind the students of their next visit
  • Talk of upcoming events at River Bend
  • Invite the students to return on their own with family and friends.

 

 

Nature Pyramid

Vocabulary

Organism - any living thing

Adaptation - something that an organism has or does that helps it to live in its habitat

Decomposer - organism that decays or rots plants and animals in place, returning the nutrients to the soil (fungus, mold, bacteria, etc.). For our purposes, also will include "shredders" which aren't truly decomposers but assist the decomposition process (worm, pill bug, millipede, sow bug, some other creepy crawly creatures) See another web page of River Bend's for more on decomposers!

Producer - organism capable of making its own food from sunlight, water, and nutrients and chlorophyll (green plants)

Primary Consumer - organism which gets its food from plants (rabbit, squirrel, deer, mouse, honey bee, aphid, grasshopper, tadpole, duck, black bear (sometimes), mosquito, or humpback whale)

Secondary Consumer - organism which gets its food mainly by eating primary consumers, but may also eat producers and be prey itself. (weasel, shrew, mole, merganser, snake, spider, frog, most fish, other animals at times).

Top Level Consumer - organism which gets its food mainly by eating other consumers, but rarely becomes prey itself. (hawk, wolf, shark, fox, dragonfly, orca, human).

Carnivore - organism that consumes mainly meat (weasel, wolf, walleye, owl)

Herbivore - organism that consumes mainly plants (deer, rabbits, woodchuck, duck)

Omnivore - organism that consumes both meat and plants (skunk, raccoon, human)

What is a plant?

A plant is an organism that is almost always rooted to one place. It makes its own food and it "breathes" in carbon dioxide and "breathes" out oxygen. There are many different groups of plants. Some examples are trees, flowers, or grasses.

What is an animal?

An animal is able to move around on by walking, jumping, flying, etc. It gets its food from other living or once-living things. It breathes in oxygen and breathes out carbon dioxide.

How can we tell the different animals apart?

Each group of animals have "things" that are different from other groups. We call these "things" characteristics or adaptations. By comparing these characteristics, we can put everything into groups.

Within each group we look for the special habits different animals have. Some of the habits we look at include:

  • What does the animal eat?
    • If the animal eats other animals (meat), it is called a carnivore.
    • If the animal eats plants, it is called a herbivore.
    • If the animal eats anything, it is called an omnivore.
  • When does the animal eat?
    • If it eats primarily during the day it is called diurnal
    • If it eats primarily during the night it is called nocturnal
    • If it eats primarily at sunrise and sunset it is called crepuscular
  • Where does the animal live?
  • What are some of the specializations of the the body parts?
  • When does the animal have babies and how to they eat?
  • What does the animal look like?
    • size
    • color
    • exterior covering i.e. furs, feathers, scales
How can we tell different plants apart?

Just as animals are divided into groups by their different characteristics, so are plants. The special characteristics we look at include:

  • When does it replace its leaves?
    • If a plant does lose its leaves, it is called a deciduous plant.
    • If a plant doesn't lose its leaves, it is called a coniferous plant.
  • What is the size of the plant?
  • When does the plant bloom and release its seed?
  • Does it grow a woody stem or a green one?
  • Does it have many leaves, stems or flowers on each individual plant, or just one?
  • What type of habitat does it prefer?
    • wetlands
    • forest
    • prairie
    • desert
    • oceans
    • mountains
Why are plants and animals important?

Every type of plant and animal is a critical building block of the nature pyramid. Listed below are the major groups that are important to recognize.

mammals
hair, live birth,
milk from mother
deer bat rabbit dog whale skunk cow bear
consumers
birds
feathers, beak, hollow bones
duck robin owl hawk cardinal pheasant
consumers
reptiles
dry scales, lay eggs on land
snake lizard turtle
alligator crocodile
consumers
amphibians
moist skin, lay eggs in water, have tadpole stage
newt toad frog salamander
consumers
fish
slimy scales, fins
walleye sunfish trout northern bass salmon
consumers
insects/spiders
six legs (spiders eight)
butterfly bee ant
tick mite spider scorpion
consumers
trees
usually one trunk, tall
oak willow birch pine maple cottonwood spruce
producers
shrubs
several trunks, short honeysuckle rose dogwood prickly ash buckthorn
producers
grasses
thin blades, tiny flowers
bluestem timothy corn wheat brome lawn
producers
herbs
no wood noticeable flowers
tulips violets aster flowers vegetables most weeds
producers
fungi
no leaves rot things
mushrooms mold mildew yeast
decomposers
creepy crawlers
many or no legs,
worms centipedes crayfish snails clams slugs etc.
decomposers,
consumers

Why do plants and animals "eat?"

All forms of life burn up energy throughout their existence and this energy must be replaced, much like adding wood to a campfire. That energy comes from the food we eat, as well as other nutrients and compounds to replenish those we use up in our activities and lose in our waste.

Green plants, as producers, make their own food out of water, air, sunlight, nutrients, and a special chemical called chlorophyll that plants have and makes them green. They make sugar, which they use up to stay alive and is also passed on to whatever animal eats them.

The Nature Pyramid

Producers (green plants) are the only things on Earth that can make their own food. Every other living thing depends on this food, either by directly eating plants or by eating other animals that ate the plants, and so on.

Nature Pyramid

Click here to download a printable PDF version of the image above.

Plants and animals use other plants and animals as food or shelter in order to survive. If a plant or animal suddenly disappeared, other things that needed it to survive might also die. So plants and animals are important to each other. Why are non-living things needed?

Non-living things in the nature pyramid:
A nature pyramid also contains some non-living things that are needed to help the living things survive. Those non-living things are:

  • air
  • water
  • rocks and soil (although most soil has organic material)
  • sunlight
Discussion questions:
  • What would happen if there weren't any decomposers?
  • Do plants really need animals?
  • What would happen if there were more animals than plants?

What do we need to remember when we visit River Bend?

  1. The more quiet we are the more we will see
  2. Listen to your leader or whomever's turn it is to talk
  3. Raise your hand if you have something to say.
  4. Do not pick anything unless given permission.
  5. Stay with your group and follow your leader's directions.
  6. Be respectful of nature - and of each other!

 


Some suggested pre- or post-visit activities

Send us your ideas by email!

  • After completing the pyramid at River Bend, use the second side of your worksheet to create another pyramid, using either an exotic or fictional habitat, to demonstrate each student's understanding.

 


Interesting links

The following links contain some interesting information food chains/webs and the energy pyramid. Send us your ideas by email!

Watch a Food Chain movie and play a game along the way!
http://s2.brainpop.com/science/ecologyandbehavior/foodchains/preview.weml

Here's a colorful page on food chains
http://www.planetpals.com/foodchain.html

Here's a game that you might be interested in buying-
http://www.cajungames.com/foodchain/

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PO Box 186, 1000 Rustad Rd, Faribault, MN 55021-0186 USA
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