They are increasingly threatened by climate change. Humans have hunted many apex predators close to extinction, but in some parts of the world, these predators are now returning. Conservation The wolf is both an apex predator and a keystone species, affecting its prey's behaviour and the wider ecosystem.īecause apex predators have powerful effects on other predators, herbivores, and plants, they can be important in nature conservation. This effect, called mesopredator release, occurs in terrestrial and marine ecosystems for instance, in North America, the ranges of all apex carnivores have contracted whereas those of 60% of mesopredators have grown in the past two centuries. For example, a reduction in the population of sperm whales, apex predators with a fractional trophic level of 4.7, by hunting has caused an increase in the population of the large squid, with trophic level over 4 (carnivores that eat other carnivores). The removal of top-level predators, often through human agency, can cause or disrupt trophic cascades. Such wide-ranging effects on lower levels of an ecosystem are termed trophic cascades. When introduced to subarctic islands, for example, Arctic foxes' predation of seabirds has been shown to turn grassland into the tundra. They are central to the functioning of ecosystems, the regulation of disease, and the maintenance of biodiversity. Effects on ecosystem Īpex predators can have profound effects on ecosystems, as the consequences of both controlling prey density and restricting smaller predators, and may be capable of self-regulation. Predators that exert top-down control on organisms in their community are often considered keystone species.
#ARE WOLVES APEX PREDATORS TRIAL#
Removal of badgers (in a trial investigating bovine tuberculosis) caused hedgehog densities to more than double. 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. A lake manipulation study found that when the non-native smallmouth bass was removed, lake trout, the suppressed native apex predator, diversified its prey selection and increased its trophic level. Non-native predatory fish, for instance, have sometimes devastated formerly dominant predators. Īpex predators affect prey species' population dynamics and populations of other predators, both in aquatic and terrestrial ecosystems. These include interactions via ecotourism, such as with the tiger shark, and through rewilding efforts, such as the proposed reintroduction of the Iberian lynx.Įcological roles Effects on community The great skua is an aerial apex predator, both preying on other seabirds and bullying them for their catches.
More recently, humans have started interacting with apex predators in new ways.
Humans have for many centuries interacted with apex predators including the wolf, birds of prey, and cormorants to hunt game animals, birds, and fish respectively. The apex predator concept is applied in wildlife management, conservation, and ecotourism.Īpex predators have a long evolutionary history, dating at least to the Cambrian period when animals such as Anomalocaris dominated the seas. Food chains are often far shorter on land, usually limited to being secondary consumers – for example, wolves prey mostly upon large herbivores (primary consumers), which eat plants (primary producers). Īpex predators are usually defined in terms of trophic dynamics, meaning that they occupy the highest trophic levels. The great white shark (bottom) was originally considered an apex predator of the ocean however, the orca (killer whale, top) has proven to be a predator of the shark.Īn apex predator, also known as a top predator, is a predator at the top of a food chain, without natural predators of its own. The saltwater crocodile is the largest living reptile and the dominant predator throughout its range. The lion is the world's second-largest big cat and serves as an apex land predator in Africa. For other uses, see Apex predator (disambiguation).
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