National Geographic Documentary - The Greatest Apex Predators on Earth - New Documentary HD 2018
An apex predator, also known as an alpha predator or apical predator, is a predator residing at the top of a food chain upon which no other creatures prey. Apex predators are usually defined in terms of trophic dynamics, meaning that apex-predator species occupy the highest trophic level or levels and play a crucial role in maintaining the health of their ecosystems. One study of marine food webs defined apex predators as greater than trophic level four. The apex predator concept is commonly applied in wildlife management, conservation and ecotourism.
Food chains are often far shorter on land, with their apices usually limited to the third trophic level – for example, giant constrictor snakes, crocodilians, Theropods, hyenas, Varanids, wolves, Great Apes, or big cats preying mostly upon large herbivores. Apex predators do not need to be hypercarnivores.
Apex predators affect prey species' population dynamics. Where two competing species are in an ecologically unstable relationship, apex predators tend to create stability if they prey upon both. Inter-predator relationships are also affected by apex status. Non-native fish, for example, have been known to devastate formerly dominant predators. One 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