An ecological pyramid is a diagram that shows the relationships among the different parts of a food chain. It can show

• the number of organisms at each level (pyramid of numbers) (ex. 1 hawk)
  
• the amount of available food (biomass) (pyramid of biomass) at each level (ex. 5 kg of hawks)
  
• the energy lost at each level (pyramid of energy) (ex. 10 kcal)
  
  The largest amount of available food is found in the base of the food pyramid. The available amount of food decreases at each higher level of the pyramid.
  
  Notice that only a small percentage (approximately 10 percent) of the food energy is available to the next level of a food chain.

Food pyramids are excellent ways to show numbers and the energy gained or lost at various consumer levels.