The three ecological pyramids are a Pyramid of Numbers, a Pyramid of Biomass and a Pyramid of Energy Flow. All three ecological pyramids illustrate the reduction in energy when moving through each feeding level in an ecosystem.
A Pyramid of Numbers counts all of the organisms at each specific feeding level. This can be difficult in some ecosystems, as it is not always possible to count how many of each species is present.
A Pyramid of Biomass collects the organisms from each feeding level, then dries and weighs them. The dried weight shows the amount of organic matter of the organisms.
A Pyramid of Energy Flow measures the caloric value of the organisms at every feeding level.