Energy availability decreases at higher trophic levels due to the inefficiencies of energy transfer in food chains. At each trophic level, organisms consume organic matter, but only a fraction of the energy is assimilated into their tissues through processes like digestion and metabolism. The remaining energy is lost as heat or in waste products. As energy moves up the food chain, these losses accumulate, resulting in a decrease in available energy.

Primary producers, such as plants, capture solar energy through photosynthesis and convert it into chemical energy. Herbivores, at the next trophic level, consume plants, but only a portion of the plant’s energy is transferred to them. Carnivores at higher trophic levels experience further energy losses. This pyramid of energy transfer explains why there are fewer individuals and less total biomass at higher trophic levels and emphasizes the ecological importance of maintaining balanced ecosystems for energy efficiency.