The following food chain represents the biomass of organisms at each trophic level in a grassland ecosystem:
Ryegrass (780 g m−2)⟶Grasshoppers (115 g m−2)⟶Songbirds (39 g m−2)⟶Sparrowhawks (3.2 g m−2)\text{Ryegrass } (780\text{ g m}^{-2}) \longrightarrow \text{Grasshoppers } (115\text{ g m}^{-2}) \longrightarrow \text{Songbirds } (39\text{ g m}^{-2}) \longrightarrow \text{Sparrowhawks } (3.2\text{ g m}^{-2})Ryegrass (780 g m−2)⟶Grasshoppers (115 g m−2)⟶Songbirds (39 g m−2)⟶Sparrowhawks (3.2 g m−2)
Calculate the percentage of the biomass lost between the ryegrass and the songbirds. Give your answer to 2 significant figures.
State two ways in which biomass is lost between trophic levels.