Predation

Solitary predator: a polar bear feeds on a bearded seal it has killed
Social predators: meat ants cooperate to feed on a cicada far larger than themselves

Predation is a biological interaction where a predator (a hunting animal) kills and eats its prey (the organism that is attacked). Predators are adapted and often highly specialized for hunting, with acute vision, hearing, and sense of smell. Many have sharp claws and jaws to grip, kill, and cut up their prey.

In ecology, predators are heterotrophic, getting all their energy from other organisms. This places them at high trophic levels in food webs. Many predators are carnivores; others include egg predators. Predation is one of a family of common feeding behaviours that includes parasitism and micropredation which usually do not kill the host, and parasitoidism which always does, eventually. All these are evolutionarily stable strategies.

Predator and prey adapt to each other in an evolutionary arms race, coevolving under natural selection to develop antipredator adaptations in the prey and adaptations such as stealth and aggressive mimicry that improve hunting efficiency in the predator.

Strategies

Heterotrophic animals such as predators that derive their energy from other organisms (prey or hosts) can be classified by their consumer-resource interactions with those organisms.[1] A perspective on the evolutionary options available to predators and parasites can be gained by considering four questions: the effect on the fitness of the prey or host; the number of prey or hosts they have per life stage; whether the prey or host is prevented from reproducing (by being killed, or by being castrated), reducing its evolutionary fitness to zero; and whether the effect depends on intensity. From this analysis, the major evolutionary strategies of predation and micropredation emerge, alongside parasitism and parasitoidism; social predators such as lion and wolf are distinguished from solitary predators like the cheetah.[2]

Evolutionary strategies in parasitism and predation[2]
(Intensity-dependent: green, roman;
       Intensity-independent: purple, italics)
Host fitness Single host, stays alive Single host, dies Multiple hosts
Able to
reproduce
(fitness > 0)
Conventional parasite
   Pathogen
Trophically transmitted parasite[a]
   Trophically transmitted pathogen
Micropredator
   Micropredator
Unable to
reproduce
(fitness = 0)
-----
   Parasitic castrator
Trophically transmitted parasitic castrator
   Parasitoid
Social predator[b]
   Solitary predator

Conventional predation

A conventional predator is one that kills and eats another living thing. Predators may hunt actively for prey in pursuit predation, or sit and wait for prey to approach within striking distance in ambush predation.[3][4] Some predators kill large prey and dismember or chew it prior to eating it, as do humans; others may eat their prey whole, as do bottlenose dolphins swallowing fish,[5][6] white storks swallowing frogs,[7] or baleen whales swallowing thousands of krill or small fish at once.[8] Some predators use venom to subdue their prey before the predator ingests it, as in the box jellyfish,[9] while the venom of rattlesnakes and some spiders also helps to digest the prey.[10][11] Seed and egg predation are true predation, as seeds and eggs are potential organisms.[12][13]

Grazing and micropredation

Grazing animals generally do not kill their prey, but like predators, they live by feeding on other organisms. While some herbivores like zooplankton live on unicellular phytoplankton and therefore inevitably kill what they eat, in a relationship sometimes called predation,[14] many others including cattle and sheep only eat a part of the plants that they graze.[15] Many species of plant are adapted to regrow after grazing damage. For example, the growing meristems of grasses are not at the tips as they are in most flowering plants, but at the base of the leaves.[16] Similarly, kelp is grazed in subtidal kelp forests, but continuously regrows from a meristem at the base of the blade where it joins the stipe.[17] Herbivore-plant interactions, as with predator-prey interactions, have driven plants to evolve defences such as thorns and chemicals to dissuade grazing.[4]

Animals may also be 'grazed' upon by blood-feeding micropredators. These include annelids such as leeches, crustaceans such as branchiurans and gnathiid isopods, dipterans such as mosquitoes and tsetse flies, other arthropods such as fleas and ticks, fish such as lampreys, and mammals such as vampire bats.[18][19][4]

Parasitism

Parasites, like predators, live by feeding on another organism, but differ in that they often do not kill their hosts. The entomologist E. O. Wilson has characterised parasites as "predators that eat prey in units of less than one".[20][4][1][18]

Parasitoidism

Parasitoids are insects living in or on their host and feeding directly upon it, eventually leading to its death, making their strategy comparable with predation. They are, however, much like parasites in their close associations with their hosts. Unlike typical parasites, they always kill their hosts, but often not instantly. Parasitoid wasps are solitary insects that live a free life as adults, laying eggs on or in other insects such as lepidopteran caterpillars. The wasp larvae feed on the growing host, eventually killing it. Parasitoids make up as much as 10% of all insect species.[21][22]

Social predation

In social predation, a group of predators cooperates to kill creatures larger than those they could overpower singly. Social predators such as lions, hyenas, and wolves collaborate to catch and kill large herbivores. By hunting socially chimpanzees can catch colobus monkeys that would readily escape an individual hunter, while cooperating Harris hawks can trap rabbits.[23][24][25]

Illustrations

Each predation-like strategy is illustrated for comparison.

Other Languages
Afrikaans: Predasie
العربية: افتراس
aragonés: Depredación
asturianu: Depredación
беларуская: Драпежніцтва
bosanski: Predacija
català: Depredació
dansk: Prædation
eesti: Kisklus
español: Depredación
Esperanto: Predado
euskara: Harraparitza
فارسی: درندگی
føroyskt: Predatión
Frysk: Predaasje
galego: Depredación
한국어: 포식
Ido: Predato
isiXhosa: I-Predator
íslenska: Afrán
italiano: Predazione
עברית: טריפה
ಕನ್ನಡ: ಭಕ್ಷಕ
latviešu: Plēsonība
Bahasa Melayu: Pemangsaan
Nederlands: Predatie
日本語: 捕食
norsk: Predasjon
norsk nynorsk: Predasjon
oʻzbekcha/ўзбекча: Yirtqichlik
português: Predação
русский: Хищничество
Scots: Predation
Simple English: Predation
slovenščina: Plenilstvo
српски / srpski: Predacija
srpskohrvatski / српскохрватски: Predacija
suomi: Saalistus
svenska: Predation
татарча/tatarça: Ерткычлык
тыва дыл: Шүүргедекчи
українська: Хижацтво
Tiếng Việt: Săn mồi
Zazaki: Seydwan
中文: 捕食