As the National Environmental Education Foundation observed, the predators help to maintain natural balance by keeping prey species numbers under control. Otters also help to improve water quality ...

However, the requirements for dominating the ocean's food chain include hunting skills, a big appetite, few predators, and often, sharp teeth. Killer whales are apex predators with no natural enemies.

One reason raccoons have multiplied so extensively is that many of their natural predators have been hunted down to keep them away from populated areas. This has allowed raccoon numbers to rise ...