<span>It is false that energy in higher trophic levels is greater than energy at lower trophic levels. In the first trophic level you find the producers, in the second the primary consumers in the level following that the secondary consumers and in the last level the tertiary consumers. And only 10% of energy at one level is available to the next level. </span>
Answer
The main reason being the amount of food available.
Explanation:
Think of it this way:
If an animal is trying to find food but another species is looking for the same prey then its going to be increasingly difficult for the species to find prey and if there's not enough of the prey species then the population of the predator to go down.
That is why its considered a limiting factor.
