Why is it that most top predators (e.g., lions, tigers, bears, and wolves) have extremely large ...

The second law of thermodynamics, as it applies to ecological pyramids of biomass, means that a substantially higher amount of ecosystem productivity is required to provide sufficient energy for organisms that feed on a third or fourth trophic level. This results in a need for a large ecological territory to provide sufficient autotrophic surface area to convert enough solar energy to provide for the energy required to be passed through three trophic levels. As a result, an ecosystem can only support a very few of these top predators.