At each level of the food chain, about 90% of the energy is lost in the form of heat.

The total energy passed from one level to the next is only about one-tenth of the energy received from the previous organism.

Therefore, as you move up the food chain, there is less energy available.

1. The sun has one liter of rootbeer (energy) to give.

2. Of that, the plant gets one-tenth or 100 milliliters.

3. The mouse gets 10 milliliters from the plant.

4. The hawk gets 1 milliliter from the mouse.

5. When the hawk dies and is decomposed by the mushroom, the mushroom gets only one-tenth of a milliliter!

Rootbeer Activity

Sun has 1 liter (1000 ml) Plant receives -100 ml

Plant has 100 ml Mouse receives 10 ml

Mouse has 10 ml Hawk Receives 1 ml

Hawk dies has 1 ml Decomposers receive .1 ml

Energy Pyramids show the flow of energy through an ecosystem

Ecologists study energy pyramids

3rd level consumers mostly carnivores & some omnivores

2nd level consumer carnivores & omnivores

1st level consumer herbivores

Producers: green plants make their own energy from sunlight

10,000 Kcal

1000 Kcal

100 Kcal

10 Kcal

1 Kcal

An energy pyramid from the Andrews

10,000 Kcal

1000 Kcal

100 Kcal

10 Kcal 0.1%

1%

10%

100%

1 Kcal 0.01%

When an owl eats a flying squirrel it uses about 90% of the calories to live—

move, digest, produce body heat, reproduce and escape from predators.

When a frog eats a cricket or a cricket eats a plant, they use 90% of those calories to move, digest, produce

body heat, reproduce and escape from predators.