Pyramids of biomass
The dry mass of an organism is called its biomass. The total biomass at a particular step in a food chain is always less than the total biomass at the step before it. Let's look again at the food chain:
grass → vole → barn owl
The biomass of all the grass plants is the greatest in the chain, and the biomass of all the barn owls is the least. We can show information like this using a pyramid of biomass.
oak tree → caterpillar → blue *** → sparrow hawk