Each level of the energy pyramid is smaller than the level directly below it because energy is lost as it moves up the food chain. This is due to the inefficiency of energy transfer between trophic levels. Only a fraction of the energy from one trophic level is transferred to the next level, with the rest being lost as heat or used for metabolic processes. As a result, there is less energy available at higher trophic levels, leading to a decrease in the biomass and number of organisms at each successive level of the pyramid.
