Answer:
any time a source of energy is obtain using natural means, the 10 % rule will apply. 10 % rule means when energy is passed in an ecosystem from one trophic level to next, only 10% of the energy will be passed on. A trophic level is the position of organism in the food chain.
So Quaternary consumers are at the top position in the food chain, they will receive less energy from the food as compared to the primary consumers which are at the bottom of the food chain. so when getting less food and less energy, Because of this, the populations of Quaternary consumers are usually the smallest out of the populations in the food chain.
