Did you know that right now you are sitting on top of a pyramid? That's the shape with four triangle sides and a square bottom. It's like the big ones you see in Egypt. The top is very pointy. Sounds uncomfortable, right? However, being at the top is exactly where you want to be. Not only do you get the best view, but the rest of the pyramid has to do all the work to hold you up. Oh, did I tell you that this is a pyramid made of all the living things in the world? Every plant and animal? No, this is not a circus act. Let me explain . . .
One thing is for sure. I'm not eating that.
Now if you are all the way at the top, what's at the bottom of this pyramid? In order for it to stand, it has to have a strong base. So at the very bottom, we have the living things that can hold themselves up on their own with nothing beneath them. These are plants that are able to make their own energy from sun, gas, and water. They do not need much help from other living things. Energy can be passed up to the rest of the pyramid from plants.
are living things that are able to make their own food. Most of them use the sun's light to make their food. They use most of the food they make to grow and stay alive, then store the rest in their bodies. Have you ever pulled a carrot up out of the ground? The orange part is the plant's stored energy. This is a great way to grow and still keep some energy for later. That is, of course, until a hungry rabbit hops along.
Yummy carrots, may I have some more please?
Plants on land and in the water are among the few living things that can make their own energy, so they make a great base for our pyramid. Now we can start adding more layers on top of it. This next layer is made of living things that eat plants for food, and also make good food for the animals above them. Bugs cannot make their own energy, so they need to eat plants. Above them we can put frogs and lizards, who love to eat bugs. Then above them, we can have birds, who love to eat frogs and lizards. Consumers
are the living things that cannot make their own energy and need to eat other living things to get energy. These include everything above plants on the pyramid: bugs, frogs, birds, rabbits, foxes, even you and your friends at the top. This may seem like a lot of animals hunting, killing and eating each other, but at the end of the day, we are all sharing energy and making life in the world work. Human bodies are very complicated and need a lot of energy. We are the highest consumers, sharing the top spot with hunters like eagles and tigers. I would not try to make friends with those tigers just yet, though.
I'm sly, how do you think I stay this high on the food pyramid.
We have now built the base of the pyramid with producers like plants and started to stack consumers, like birds, rabbits and foxes, on top of each other. We keep building up until we reach the pointy top where you are sitting. The energy pyramid
shows how energy starts with plants and is passed along to other living things as they eat each other. Each level is a new group of animals, and together they make a food chain. And lucky you, you get to sit at the top! You do not need to worry about anything sneaking up to eat you. Unless you go for a walk in the jungle . . . Then I can't make any promises.
You may notice that each layer is smaller than the one below it. Why is that? In Egypt, they built pyramids that way because the wide bottom can only hold up something smaller and lighter than itself. The largest number of stones make up the bottom, and then there's less and less on each row as we move up the pyramid. As we move up our energy pyramid, we also have to get smaller. Each new level of animal needs to eat more things than the last. It turns out that every time a living thing is eaten by another living thing, most of that energy is lost.
Look at it this way. When a plant makes food, it gets 100% of that food's energy. However, when a rabbit eats the plant, it will only get 10% of the energy. The rest of the plant's energy went into staying alive and building its cells. When a fox eats that rabbit, it will only get 1%, since the rabbit used the food it ate to live and build its own body. There is energy loss
when there is less and less energy in each organism as you move up the energy pyramid. Each living thing burns the energy it gets from food to grow and move, so the thing that eats it will be getting less. That's why each new level needs more carrots and more rabbits below it! That's also why your parents tell you to eat your vegetables.
We have made it to you, sitting all the way at the top. Sure it might be pointy up there, but this pyramid is not such a bad place to sit. Even though you may not be able to make your own energy with sunlight, you have plenty of living things below to eat. It's good to be king or queen, but remember that this means you are in charge of a lot of life. Think about what you put into your body and where it comes from. If you can only eat the healthy things you need, the stronger the pyramid will remain and the longer you will have this lovely view.Resources:
Annenberg Learner. "Life Science: Session 7 -- Energy Pyramids." Annenberg Learner, 2013. <http://www.learner.org/courses/essential/life/session7/closer5.html
Make Me Genius. "Food Chains, Energy Pyramid." Make Me Genius, 2010. <http://www.makemegenius.com/video_play.php?id=116