The Energy Pyramid

In a food web, the producer has the greatest amount of energy. At the consumer level, only 10% of absorbed nutrients are used to make a new body tissues. This represents the food available for the following level. The rest of the energy is lost as heat. Thus, the amount of usuable energy per unti mass decreases as the feeding level goes higher.

Herbivores, primary consumers, acquires only 10% of the total energy of the producers. Only 10% of the hervivores' energy goes to the animal in the next trophic level, so that the latter acquires 1/100th of the total producer's energy.