Lesson Session – Weave a Food Web

Weave a Food Web

Subject – Science, Art

Grade Level – 4-6

Skills Used:

Predicting; Collecting, Recording and Interpreting Data; Identifying and Controlling Variables; Defining Operationally

Key Vocabulary:

Food Chain, Food Web

Lesson Time:

30 minutes

Conceptual Objective:

Students will understand that food chains overlap to form a web of multiple energy paths.

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Process Objective:

Students will create a model of a food web.

Materials

* construction paper
* markers
* scissors
* bulletin boards
* pushpins
* tape
* string
food web handout – click to download

Procedure

1. Introduce and explain the terms ‘food chain’ and ‘food web’ to students.

2. View, explain, and answer questions about an example food web.

3. Pass out handouts and explain how the information is set up on the chart.

4. Put children into groups of five, giving each group the necessary supplies.

5. Instruct children to draw and label all of the different woodland organisms listed. Also draw a picture of the sun. Cut out drawings and attach them to bulletin boards with pushpins. Leave space between the drawings.

6. Students should tape one end of the piece of string to any one of the drawings. Using the table, connect the other end of the string to the proper organism.

7. Students should draw and cut out an arrow, taping it on the string to indicate in which direction the energy is flowing.

8. Students should repeat these steps to connect all of the organisms.

9. Announce clean-up time, and display finished food webs around the room.

Lecture

What is the food chain?

Energy flows through an ecosystem as one animal eats another animal or plant. A food chain shows “who eats who” in an ecosystem.

For example:

An owl – eats a mouse who – eats a beetle who – eats leaves.

Each part of the food chain has a name:

Plants make (produce) their own food using water, sunlight and carbon dioxide (photosynthesis). Plant start the food chain. There are more plants than any other living thing because they are the bottom of the food chain. They provide the energy for everything else. They are the PRODUCERS.

The animals (insects, mice, chipmunks, squirrels, rabbits, deer) that mostly eat plants are called the herbivores. There are fewer herbivores than there are plants because each herbivore needs a lot of plant matter to live. Herbivores feed directly on the producers. They are the PRIMARY CONSUMERS.

Animals (spiders, birds, snakes) who eat the primary consumers (herbivores) are the SECONDARY CONSUMERS. There are fewer secondary consumers than there are primary consumers because each secondary consumers needs to eat a lot of primary consumers to live.

Animals (fox, coyotes, eagles, owls) who eat the 1st & 2nd consumers are carnivores (they eat meat). They are the TERTIARY CONSUMERS. There are fewer tertiary consumers than there are secondary consumers because each tertiary consumers needs to eat a lot of secondary consumers to live. Because there are fewer animals as you move up the food chain, it is really a food pyramid with the big carniores needing to eat the most and so being the rarest of the animal kingdom.

Because animals eat so many things, the food chain has many overlapping parts, so is really a FOOD WEB.

Last but not least, the DECOMPOSERS eat and so recycle dead animals and plants (mushrooms, fungi, insects, bacteria). They are then consumed themselves by other parts of the food web so nothing is wasted.

Something to think about:

In a food web, if an important animal is taken out, and there are no other animals to take its place, it can affect all the other animals in the food web. This animal is called a KEYSTONE SPECIES.

An example of this is the American alligator. Thirty years ago it was hunted so much in the everglades that it all but disappeared. What people didn’t realize was that the American alligator’s main food is the gar, a big everglade fish. The gar in turn eats a lot of the same fish people like (referred to as game fish).

When the American alligator disappeared, the gar (with no other predator) became very plentiful. All the extra gar ate all the game fish. Suddenly fisherman noticed that all the game fish had disappeared and there were gar everywhere.

The food web was out of balance. Once the American alligator was protected from hunting, its numbers rose quickly. In turn the number of gar decreased. Soon the game fish returned. The balance was restored.

Evaluation

1. Did students make and use a model that allowed them to make inferences about food chains? Assess the neatness and the accuracy of the food webs.

Troubleshooting

1. Students may argue about who will do what in the group. If this happens, the teacher should assign roles to students.

Reptiles Alive wowed Linton Hall School

Linton Hall students squirmed at Reptiles Alive

“edu-tainment” event.

the BULL RUN OBSERVER March 6, 2009
by GRETCHEN L.H. O’BRIEN

The visitors to Linton Hall School in Bristow were rather cold to the students.  They didn’t shake hands or even make eye contact. Of course, they were reptiles.

The students – kindergartners to eighth-graders didn’t care that the creatures weren’t into shaking their hands.  In fact, some of the students looked relieved to be sitting more than a few feet from the reptilian visitors.

When the energetic young woman from the zoo on wheels started talking to the students, she kept their attention well-no small feat, when students range from ages 5 to 13.  However, she told them she brought “some of the best” reptiles for the youngsters to see.cvsunshine18

Vader the [Bull]snake started out the show to many ooohs and aaaahhhs from the crowd.  Vader, the presenter told the children, was similar to them in at least two ways: snakes and people both are vertebrates with backbones and snakes’ skin is made of a similar protein; keratin.  Human hair and fingernails have a great deal of keratin in them, she noted.

The students sat raptly for the full 45 – minute program as the presenter brought out reptile after reptile.  However, she did throw in one amphibian: Jeremiah, who was a bullfrog and was a very good friend of the presenter’s. The frog, she said, did have wet and slimy skin, which is much different from the smooth skin of snakes and many other reptiles.

It was the bearded dragon that breathed fiery life into the students.  They got even more excited about seeing and discussing reptiles and human similarities.

But when Janice the Leopard Tortoise looked as if she were going to walk off the table, the younger audience members erupted with excited comments.  There were concerned for her safety.
Safety was obviously important to the presenter: she made sure the students kept their distance from the reptiles.  The students definitely complied: they sat at attention as the creatures that came out of the plastic crates got bigger and bigger.

The eyes and responses of the older students got bigger in tandem with the animals.  Dean Martin, the alligator, didn’t dance, but he definitely entertained the crowd.

It was Sunshine the albino Burmese Python that brought down the house and acted as the Reptiles Alive grand finale for this show.  The 12-foot snake roped across the table at the front of the school’s gym.  The middle-schoolers were definitely wowed by the snake, who simply wanted to slither back into her crate.

Christina Ashworth, 13, was one of those who thought Sunshine was the brightest spot in the show.  Christina’s favorite animal is the snake, so she adored seeing the huge snake at her school.
Her brothers, Thomas, 7, and Bobby, 10, also rated Sunshine as the star attraction at the show.  Thomas like the crocodile too.  Bobby said he’s not too afraid of snakes.

The presenter repeatedly noted that many people are afraid of sakes but reminded the audience members that snakes are very afraid of people.

Jerry Barrett, director of development, was impressed with how well the Reptiles Alive presenter wove facts and teachable moments into her presentation to the students.  He  was thrilled the show combined fun with “a good educational value.” He enjoyed it as well and was also impressed by Sunshine the albino Burmese Python.
The python and other creatures held all the children’s attention, which was what Libby Robinson, who as head of the school’s parent guild helped plan the presentation, had hoped.  Robinson thought the show was terrific.

Elizabeth Poole, Linton Hall principal, agreed the show was terrific.  She was glad to see all her students’ enthralled by the show that ended with an appropriate, if corny, “Ssssssssssssseee you later alligator.”

Herpetological Spring

Officially, spring does not actually begin until the Vernal Equinox on March 20.  However, there are many signs of spring popping up all over the Washington DC region.  The cheery blooms of the forsythia, crocus, and daffodils  can be seen in neighborhoods across our area.  But what gets me excited is the beginning of herpetological spring – when the spotted salamanders, wood frogs, and spring peepers begin to emerge.

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Spring Peeper

Most of the year, spotted salamanders and wood frogs remain hidden from view buried under ground or hiding under fallen leaves in the forest floor.  But once a year in late February, March, and early April, we have a chance to actually see these awesome amphibians – and not just one or two, but lots of them all at once!

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Vernal Pool

Thousands of spotted salamanders, wood frogs, and spring peepers all head for vernal pools at the same time.  Vernal pools are ponds of water that dry out in the summer, so no fish can survive in them.  These pools are crucial to the survival of many species of insects and animals, including many amphibians.

The salamanders and frogs lay millions of jelly-like eggs in the vernal pools.  Within a few weeks or so, the eggs hatch into larvae, or tadpoles.  The tadpoles go through metamorphosis fairly quickly so they can leave the water before the pool dries up.  The froglets and tiny salamanders emerge from the water and almost immediately disappear into the surrounding woodlands – not to be seen again until next year.

So, last weekend I convinced my friend Jon Kerr to head out with me to some of my FAVORITE froggy places.  A very strange vernal pool can be found in Fairfax County at Scott’s Run Nature Preserve.  This “vernal pool” is actually an abandoned swimming pool that was built using a natural spring as a source of water.  Even though humans have long since abandoned it, the pool is now used by hundreds of wood frogs and spotted salamanders every year.

would-frog

Wood Frog

When we arrived, the place was hopping! With wood frogs that is! But there were no spotted salamanders to be found. They were probably still on their way – they just needed a rainy night to really get them going. We did, however, find a pinchy crayfish in the nearby spring seep.

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Mr. Pinchy – the Crayfish

Next, we headed for Eakin Park – one of my favorite places to be.  You can sit and listen the amazing loud songs of the teeny Spring Peepers.  This is my most favorite sound of spring – I LOVE this time of year!

Happy Herpetological Spring Everyone!

Creature Feature – Spotted Turtle

Spotted Turtle

Clemmys guttata

Reptiles Alive Name: Spot

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Hissstory: Spot was donated to us from a nature center.

RA Diet: Earthworms, crickets, meal worms and  zoo aquatic turtle food.

Natural Diet: Spotted turtles are omnivorous – meaning they eat both plants and meat.  Algae, leaves of soft aquatic plants water lily seeds, worms, mollusks, crustaceans, insects, amphibian eggs, tadpoles, and carrion are all eaten by spotted turtles.

Range: Eastern Canada south through the eastern United States including the Washington D.C. region.

Habitat: Small ponds, vernal pools, marshes, swamps and wet woodlands

Size: Grows 3.5 – 4.5 inches, with a record of 5 inches

Lifespan: Can live over 20 years

Reproduction: Spotted turtles breed March – May. Females lay 3-5 eggs in June. The eggs hatch in the fall and sometimes the hatchling turtles overwinter in the nest.

Conservation Issues: Spotted turtles are threatened in many areas due to habitat loss, pollution and the pet trade.

Cool Facts: Spotted turtles emerge from hibernation earlier than most other turtles.  They can function at lower temperatures than most other reptiles species.