Once energy is captured as glucose it becomes available for organisms to use. This energy moves through the ecosystem through a system called the FOOD WEB.
Food Webs are graphic models of how energy flows from producers (plants) to primary consumers ( herbivores) and then to secondary and tertiary consumers (omnivores and carnivores). The Food Web below shows how energy flows through the African Savanna.
It takes a lot of energy to keep an organism alive so that amount of available energy decreases as you move up the food web. An energy pyramid is one way to visualize this reduction of energy at each level.
An Energy Pyramid
I will let the Amoeba Sisters explain it.
We looked at some data about predator and prey population numbers. This is an example of that data below. Note that a healthy ecosystem always has a much larger number of prey than predator. Predators require a large population of prey in order to get the energy that they need to survive.