Desert Food Web (page 2)
Creating a Food Web
Life in the desert is more complicated than this, of course. You eat a lot of different foods during your day, and each of those foods comes from a different place. In other words, you have a polyphagous diet. The same thing is true of many organisms in the desert! Each herbivore, or plant-eater, eats a number of different plants, and the carnivores, or meat-eaters, eat a number of different kinds of animals. A pocket mouse sometimes eats seeds from grasses instead of nuts from a mesquite tree. An owl, instead of a hawk, could eat the mouse. Adding more complexity to your food chain turns it into a food web.
- Label two more push pins with the labels “grass” and “owl”. Place them into the cardboard as well.
- Connect the grass and the mouse, and the owl and the mouse.
- Connect the hawk directly with the mouse as well.
- Can you see a pattern forming? This pattern looks more like a web than a chain. Can you think of other animals that might eat mesquite or grass? Add them to push pins and continue building your web.
Creating a Food Pyramid
A food pyramid is different from a food chain or web. How is it different? Well, think about your mouse. How many seeds does it take to feed your mouse? Probably hundreds. How many mice does it take to feed your snake? One every day or two? How many snakes would a hawk eat in a week?
As you move up the food chain, each level can support fewer animals. Each level of the pyramid is called a trophic level, the position an organism occupies in a food chain. A single hawk (ultimate consumer) can eat many snakes (secondary consumer), and a single snake can eat many mice (primary consumer). Each mouse eats hundreds of mesquite seeds, which we call producers because plants produce food through photosynthesis (getting energy from the sun). This means that thousands and thousands of seeds end up indirectly feeding that hawk at the top of the food chain. A food pyramid shows the different numbers of organisms that are necessary at each level of the food chain. At the bottom of your desert food chain, you might draw many different seeds, but there will be only one hawk in the small triangle at the top.
- Have you decided what animals and plants you’d like to have in your desert food pyramid? Let’s build it! Print out this worksheet (preferably on cardstock paper) and let’s get started.
- First, cut out the template.
- Now, start folding. Fold the paper diagonally, unfold it, and fold it again in the opposite direction.
- From bottom to top, label the four parts of one triangle with the following names: producer, primary consumer, secondary consumer, ultimate consumer.
- From bottom to top, label the four parts of the second triangle with the names of the plants and animals you used in your food chain. You’ll begin with the plants at the bottom and put the name of the top predator at the top.
- Remember: The mesquite seeds are the producers, the mouse is the primary consumer, the snake is the secondary consumer, and the hawk is the ultimate consumer.
- On a third triangle, draw a picture of each plant or animal.
- To complete your desert food pyramid, tape the tab on your first triangle to the underside of your third triangle. You’ve made a food pyramid!
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