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Using and Making Models – Investigation 2 CAP


Using and Making Models: Investigation 2 – CAP


You have likely had experience thinking about how to model different animals or plants, whether through experiments or “playing pretend.” In this CAP we take a bit of a turn and describe to you how animals and even plants can change or modify their environment to suit the own needs. Animals and plants that change their environment for their own use are sometimes called ecosystem engineers. Man is the greatest ecosystem engineer alive today or has perhaps ever lived.


While many animals change the environment to meet their needs, we begin by observing the beaver. The picture on the left shows the beaver’s strong and sharp teeth. On the right, we can see the hundreds of bite marks left by the beaver who felled this tree. TAsk yourself, “Why do you think the beaver chops down trees?” You might think the beaver does this to eat the wood. However, this is not true, they use lumber to build lodges and dams. Now ask yourself, “What do you think the beaver is going to do with the wood it has chopped down?”

We will see the answer to this question on the next slide.


In this slide, we see that beavers use the logs and lumber they have harvested to build structures. On the left is a beaver lodge. Beavers use lodges for shelter. On the right is a beaver dam. Beavers dam streams which often cause the formation of a “beaver pond”. Fish can gather in the deep, slower-moving water and serve as a source of food for a beaver family. Beavers will also build their lodges in the ponds.


This slide and the following slide are simply to demonstrate that other animals change their environment to meet their needs. Here we see a prairie dog that has dug a hole or burrow, a spider’s web, and a hornet nest. The spider web serves as protection for the spider but also as a trap for catching insects for food. The hornet nest protects eggs and larvae until they mature.


This slide shows that birds change their environment by building nests from various materials. You will likely be most familiar with this form of environment modification by animals.


This slide shows that plants modify their environment to suit their needs as well. Also, you have probably seen how tree roots displace or crack concrete sidewalks. Plants change their environment in many other ways. 


This final slide shows just a few ways in which man, the ultimate ecosystem engineer, changes the environment to suit his needs. Can you think of other ways in which humans change their environment.