Apex predators have a long evolutionary history, dating at least to the Cambrian period when animals such as Anomalocaris and Timorebestia dominated the seas.
[9] As a terrestrial example, the badger, an apex predator, preys upon and also competes with the hedgehog, a mesopredator, for food such as insects, small mammals, reptiles, amphibians, and the eggs of ground-nesting birds.
Elk, the wolves' primary prey, became less abundant and changed their behavior, freeing riparian zones from constant grazing and allowing willows, aspens, and cottonwoods to flourish, creating habitats for beaver, moose, and scores of other species.
[27] Dozens of other species, including eagles, ravens, magpies, coyotes, and black bears have also been documented as scavenging from wolf kills within the park.
Roopnarine instead calculated the position of humans in two marine ecosystems, a Caribbean coral reef and the Benguela system near South Africa.
Using metrics as diverse as tool use and acidity of the stomach, they concluded that humans evolved as apex predators, diversifying their diets in response to the disappearance of most of the megafauna that had once been their primary source of food.
Extinct species cannot be directly determined to be apex predators as their behavior cannot be observed, and clues to ecological relationships, such as bite marks on bones or shells, do not form a complete picture.
[32] Carnivorous theropod dinosaurs including Allosaurus[33] and Tyrannosaurus[34] are theorized to have been apex predators, based on their size, morphology, and dietary needs.
[45][46] Tour operators may in consequence decide to intervene in ecosystems, for example by providing food to attract predators to areas that can conveniently be visited.
[46]In some densely populated areas like the British Isles, all the large native predators like the wolf, bear, wolverine and lynx have become extirpated, allowing herbivores such as deer to multiply unchecked except by hunting.
[47] In 2015, plans were made to reintroduce lynx to the counties of Norfolk, Cumbria, and Northumberland in England, and Aberdeenshire in Scotland as part of the rewilding movement.
[48] Conservationists such as Paul Lister propose instead to allow wolves and bears to hunt their prey in a "managed environment" on large fenced reserves; however, this undermines the objective of rewilding.