Six areas of recent ecological research—extinction dynamics, island biogeography, metapopulation theory, natural disturbance ecology, top-down regulation by large carnivores, and landscape-scale ecological restoration—are the foundation for all informed protected area design.

They are brought together in the idea and scientific approach of rewilding, developed by Michael Soulè in the mid-1990s.

Three major scientific arguments constitute the rewilding argument and justify the emphasis on large predators.

First, the structure, resilience, and diversity of ecosystems is often maintained by “top-down” ecological (trophic) interactions that are initiated by top predators.

Second, wide-ranging predators usually require large cores of protected landscape for foraging, seasonal movements, and other needs; they justify bigness.

Third, connectivity is also required because core reserves are typically not large enough in most regions; they must be linked to insure long-term viability of wide-ranging species.…In short, the rewilding argument posits that large predators are often instrumental in maintaining the integrity of ecosystems. In turn, the large predators require extensive space and connectivity.