In an ecological pyramid, which level would typically have the least amount of energy?

In an ecological pyramid, the level that typically has the least amount of energy is the one at the top, which includes tertiary consumers. This occurs due to the principles of energy transfer within ecosystems, often described by the ten percent rule. At each trophic level, only a fraction (around 10%) of the energy from the previous level is passed on to the next.

Producers, such as plants, capture energy from the sun through photosynthesis and represent the highest energy level in the pyramid. The primary consumers, which feed on producers, receive less energy compared to the producers. Secondary consumers, which eat the primary consumers, further reduce the amount of energy available. By the time energy reaches the tertiary consumers, who are at the apex of the pyramid and primarily feed on secondary consumers, there is significantly less energy available to support them.

This energy reduction at each level explains why tertiary consumers, which often include top predators, typically have the least energy available to them in an ecological pyramid.