What is Predation? – Predation Definition

• Predation is the interaction between a prey and a predator in which energy is transferred from one creature to the other. Predator is the organism that preys on other organisms, also known as prey.
• Predation occurs when a predator creature consumes one or more prey organisms.
• The predator always reduces the fitness of the prey.
• This is accomplished by preventing prey from surviving, reproducing, or both.
• Relationships between predators and prey are vital for preserving ecological balance.
• There are both carnivorous and omnivorous predators. The lion, the tiger, the shark, and the snake are all predators.
• Depending on their position in the food chain, predators may potentially fall prey to other large animals. A snake, for instance, is a predator to a mouse but prey to a hawk.

Characteristics of Predators

1. Physical adaptations

• Predators have developed numerous physical adaptations for locating, capturing, killing, and digesting prey as a result of natural selection.
• These characteristics include swiftness, dexterity, stealth, keen senses, claws, fangs, filters, and efficient digestive systems.
• Predators have highly developed vision, smell, or hearing to detect prey.
• Diverse predators, including as owls and jumping spiders, have forward-facing eyes that provide binocular vision over a relatively restricted field of view, whereas prey species often have less acute all-around vision.
• Foxes can detect their prey even when it is buried in 2 feet (60 cm) of snow or soil.
• Numerous predators possess acute hearing, and some, such as echolocating bats, hunt solely through the use of active or passive sound.

2. Diet and behaviour

• The Eurasian lynx, for instance, hunts exclusively tiny ungulates.
• Others, like leopards, are more opportunistic generalists, feeding on at least one hundred different species.
• The specialists may be highly adapted to capturing their particular prey, while the generalists may be better equipped to move to other species when their preferred target becomes rare.
• When prey have a clumped (uneven) distribution, the optimal approach for the predator is projected to be more specialised since the prey are more prominent and can be identified more rapidly; this appears to be true for predators of static prey, but it is questionable for predators of mobile prey.
• In size-selective predation, predators choose victims based on their size. Large prey may be problematic for a predator, whereas little prey may be difficult to locate and yield a smaller reward.
• This has led to a link between predator and prey size. Size may also provide protection for large prey. For instance, adult elephants are reasonably protected from lion predation, whereas adolescents are susceptible.

3. Camouflage and mimicry

• Members of the cat family, like the snow leopard (which lives in treeless highlands), the tiger (which lives in grassy plains and reed swamps), the ocelot (which lives in forests), the fishing cat (which lives in thickets near water), and the lion (which lives in open plains), hide themselves with colours and patterns that match their environments.

4. Venom

• Many small predators, like the box jellyfish, use venom to stun and kill their prey. Venom can also help break down food (as is the case for rattlesnakes and some spiders).
• The marbled sea snake that has learned to eat eggs has venom glands that have shrunk and a mutation (the deletion of two nucleotides) in the gene for its three-finger toxin that makes it inactive. Because its prey doesn’t need to be tamed, it has changed in these ways.

5. Electric fields

• Several types of predatory fish are able to find, track, and sometimes even kill their prey, like the electric ray, by detecting and creating electric fields around their prey.
• The electric organ is made from nerve or muscle tissue that has been changed.

6. Physiology

• As part of their physiology, bacteria that eat other bacteria can break down the complex peptidoglycan polymer in the cell walls of the bacteria they eat.
• All five major classes of carnivorous vertebrates (fishes, amphibians, reptiles, birds, and mammals) have lower relative rates of sugar to amino acid transport than either herbivores or omnivores. This is likely because they get enough amino acids from the animal proteins they eat.

Types of Predators

Predation comes in four main forms:

1. Carnivory

• Predators that are carnivorous kill and consume their victim.
• Each carnivore has a unique eating strategy, ranging from sea otters dining on sea stars to blue whales feeding on zooplankton and small marine creatures.
• The usual conception of carnivory is a huge animal, such as a shark, tiger, or wolf, hunting rabbits or deer.
• However, carnivorous predation is common in the animal kingdom, and carnivores come in a variety of sizes – from sea otters hunting sea stars to blue whales ingesting zooplankton, each carnivore is specialised to its manner of feeding.

Example of Carnivorous Predation

• Wolves are huge canines that hunt mostly large herbivores, including deer, elk, and sheep. With their strong jaws, heightened senses, and robust bodies, they can recognise prey and pursue it at great speeds.
• Additionally, carnivorous predation might involve the interaction of two groups of species. While the majority of carnivores seek animals considerably smaller than themselves, some collaborate with other members of their species to capture larger prey.
• Lions, for instance, work in groups to ambush and kill huge herbivores such as zebras and rhinos. A pack of Asiatic wild dogs is capable of pursuing and hunting huge bison that are around 10 times the size and weight of a wild dog.
• In the plant kingdom, insectivores such as pitcher plants and Venus flytraps engage in carnivorous predation. In places with poor soil nutrition content, insectivores are commonly found.
• Cannibalism is an extreme and uncommon kind of carnivorous predation in which members of the same species are consumed.

2. Herbivory

• When a predator is herbivorous, it feeds mostly on autotrophs like plants and algae.
• Unlike carnivory, not all herbivorous interactions result in plant death.
• Occasionally, herbivory can also be advantageous to the plant. As the herbivore moves, it disperses fruit seeds across a large area.
• In the herbivore’s digestive tract, tough seed coverings are removed, and the herbivore’s excrement fertilises the soil, creating an optimal condition for seed germination.

Example of Herbivorous Predation

• Herbivory has many forms, including grazing, in which the plant regrows its components after being consumed. Herbivores have evolved to their feeding habits. Elephants, for instance, have big, flat teeth for grinding thick plant material. In addition, they have microbes in their intestines that help them digest plant-based carbohydrates.
• It is known that plants evolve defences against grazing. When giraffes consume the leaves of acacia trees, the trees secrete a toxic chemical into their leaves, causing the giraffes to flee. In addition, acacias emit ethylene gas, which signals surrounding trees to pump toxins into their own leaves. To continue eating, herbivores often go approximately 300 feet (91 metres) away.
• In marine habitats, krill are little crustaceans that feed on phytoplankton, the ocean’s principal photosynthetic organism. Krill are essential to the ecology since they are the primary natural food supply for numerous species and huge mammals such as blue whales.

3. Parasitism

• Parasitism is a sort of predation in which the host provides critical nutrients for the parasite’s continued existence and reproduction.
• In many successful parasite relationships, the host experiences a loss of energy, feels unwell, or loses access to resources.
• Unlike carnivory, however, the host is not invariably killed. Typically, the parasite is significantly smaller than the host.

Examples of Parasitic Predation

• Plasmodium, the parasite that causes malaria, infects numerous animal hosts, including reptiles, birds, and mammals. The illness produces recurrent bouts of high fever and chills, and can possibly be fatal to the person.
• Tapeworms are widespread parasites that can result in malnutrition, particularly in young infants. These parasitic worms cause skin, eye, and lymphatic system illnesses.
• Parasitism occurs in the plant kingdom as well. Common tropical plants that behave like parasites are strangler figs. Many are members of the genus Ficus. Their seeds develop in the fissures of other trees, and they obtain nourishment by sending their roots into the bark of the host tree, as opposed to the soil. The host tree eventually dies, and the strangler fig appears as a tree with a central column that is hollow.

4. Mutualism

• Mutualism is the interaction between two organisms in which one organism provides food and space for the growth and reproduction of another.
• However, the host is not harmed, and the interaction benefits both parties.

Examples of Mutualism

• Human connection with their gut flora is a famous example of mutualism. The bacteria aid in digestion and defend against harmful bacteria invasion. Recent study indicates that a person’s entire assortment of gut bacteria can have far-reaching effects on the host’s metabolism, immunity, and well-being.
• Similarly, nitrogen-fixing bacteria inhabit the root nodules of leguminous plants, such as chickpea and soybean. The bacteria fix air nitrogen, enhancing the plant’s accessibility to nutrients. In return, the plant gives the bacterium with a sugar-rich fluid.

Adaptations

• The premise underlying evolution is the survival of the fittest.
• Both the fitness of the prey and the fitness of the predators are affected by predation. Both predators and prey must develop adaptations that allow them to consume and prevent them from being eaten in order to survive and propagate their respective species.
• Survival mechanisms are transmitted through genetically defined qualities. Natural selection is the basis for the improvement of predator predation and the avoidance of predation by prey.

Predators adaptations

• This modification facilitates the capturing of prey by predators. Predators typically possess characteristics, such as sharp claws, fangs, body structure, and venom, that enhance their ability to seize prey.
• In addition to these characteristics, a predator need highly sensitive sensory organs to identify and observe its target.
• The adaptation produced heightened senses of smell, hearing, and sight.
• For instance, birds of prey (raptors) can identify their prey from a mile away. Likewise, the owl captures mice by locating their sounds. Pit viper snakes can detect heat from their prey, which aids in their pursuit. Bats and dolphins utilise sound waves to navigate and locate prey.

Prey adaptations

• In nature, prey adaptability helps the prey evade notice or capture. Certain animals employ colour and camouflage to evade detection. These include insects that feed on leaves, small lizards, moths, frogs, and other herbivores. The prey freezes in place upon detecting the predator.
• The lack of movement makes visual searching harder for a predator. There are times when predators approach too closely; when this occurs, the victim flees abruptly. The predator may initiate the pursuit.
• Prey will avoid capture by moving away from the predator or by hiding in an inconspicuous location. However, such strategies are not always effective. Some prey animals confound or surprise predators in order to gain additional time to escape. Lizards shed their tails to mislead predators.
• The predator captures the lizard’s tail as it flees. Similar to butterflies, moths can use their colourful hindwings to confound and intimidate predators. The vividly coloured species are regarded as poisonous by predators.
• Not all species with bright colours are poisonous, but those that are mimic to avoid being eaten. Instances of such mimicry include the swallowtail butterfly, which imitates the repulsive Amauris and Danaeus species.

Chemical adaptations

• Predators and prey have both demonstrated chemical adaptability. The predators utilise chemicals to assault their prey, while the prey uses the same chemicals to defend itself or to escape being eaten.
• Prey use venom, poisons, and toxins as a defence mechanism. The venomous snakes kill their prey with their poisonous venom.
• These snakes can kill a larger animal by injecting their venom into the bloodstream of their target while biting. A few moments later, the animal will perish.
• Instead of chewing, the snakes swallow their prayers. Larger snakes have been observed devouring whole goats and deer.
• Certain prey possess systems that make them less appetising to their predators. For instance, caterpillars and monarch butterflies can consume milkweed, a plant that is toxic to the majority of omnivores and herbivores. By consuming this plant, the butterflies consume the toxins as well. This renders them unappealing to predators.

Hunting techniques of Predators

• Predators hunt, evaluate, pursue, and ultimately kill their victim. These actions are known as the foraging cycle of a predator.
• The quest involves locating the proper prey. For instance, a wolf will not seek out a really large mammal such as a buffalo, preferring instead a smaller species such as a moose.
• Similarly, a “mantid” insect would prefer to capture little prey. This is due to the fact that it uses its forelegs to grab and consume prey, and its forelegs are not very huge or robust.
• Therefore, there is a positive association between prey size and predator species.
• Once the prey has been discovered, the predator must decide whether to wait for it or pursue it. It also depends on the characteristics of the predator and the prey population density.
• Obviously, a plant will not chase after a fly. However, certain predators, such as tigers and lions, might wait for their prey to enter their territory before pursuing it.
• Different predators have diverse hunting strategies. One of the approaches is capturing prey. Different predators employ a variety of capture strategies.
• The strategies include ambush (used by lions, panthers, and other carnivores), ballistic interception (as when a frog captures a passing fly with a quick twitch of its sticky tongue), and pursuit (chasing).

Ambush

• In ambush, the animal analyses the environment and waits for prey in a more concealed position while remaining silent.
• The objective of an ambush is to launch a surprise attack on the prey, hence reducing its survival prospects.
• Both vertebrate (such as frogs and angel sharks) and invertebrate (such as spiders and snakes) predators use ambush tactics (mantis shrimps, trapdoor spiders, etc.)

Ballistic interception

• Ballistic interception is the approach in which the predator first watches and predicts the movement of its prey, and then intercepts by attacking the animal with the predator’s natural instrument.
• Vertebrates like chameleons and invertebrates like dragonflies are examples of predators that employ ballistic attacks.

Pursuit 

• Another tactic employed by predators is pursuit, in which they pursue escaping prey. Predators require mobility and expertise when pursuing prey.
• If prey goes in a single direction, the predator’s speed will determine whether it captures it.
• Whoever has the greater speed will win. However, prey typically does not move in a straight line (for example chasing a deer).
• In such a scenario, the predator must act quickly by estimating and pursuing the intercept path.

A predator that mindlessly pursues erratically moving prey will eventually lose it. The most effective approach employed by the predator is parallel navigation, in which each movement of the prey brings it closer to the predator. Some predators disguise themselves before to the actual pursuit. This allows them to get as near as possible to their prey. Consequently, less effort may be necessary.

In contrast to the high-speed pursuit performed by lions, tigers, cats, etc., there exists a pursuit that demands extraordinary endurance and perseverance. In such pursuits, the predator moves slowly over great distances in pursuit of the prey. The pursuit might last for hours.

The African dog is the best example of a predator of this type. It follows its victim at a somewhat moderate speed over many kilometres. Group chase predators are predators who hunt as a pack. Both lions and wolves exhibit this behaviour. This pursuit can assist in capturing and handling larger prey.

Defense mechanisms against predation

• Studying a community requires taking into account the evolutionary forces that have acted (and are acting!) on its various populations. Natural selection drives evolutionary change within species over time scales of generations.
• Adaptations, or favourable features that arise as a result of natural selection, help both predator and prey species thrive in their respective ecological niches. For example, prey species often develop strategies to ward off predators. Mechanical, chemical, physical, and behavioural defences are all possible examples.
• Mechanical defences, such as thorns on plants or a turtle’s hard shell, deter animal predation and herbivory by causing pain to the predator or preventing it from eating the prey. Foxglove is one example of a plant that uses chemical defences; if ingested, it can cause severe illness or death. The millipede in the bottom panel can defend itself both chemically and mechanically by rolling into a tight ball and secreting a noxious substance that causes skin and eye irritation when it comes in contact with a predator.
• The body plan and colouring of many species help them to hide from potential predators. The crab spider, for instance, is almost impossible to spot when it is still because its body coloration and shape mimic that of a flower petal. Do you think it’s even visible in this image? It actually took me that long! The chameleon is another well-known example because of its ability to alter its appearance to blend in with its natural habitat. Camouflage, or the practise of hiding by making one’s target appear to be a part of the background, is evident in both cases.
• Different species use coloration in a different way to send a message to potential predators: they are not edible. In the case of the strawberry poison dart frog shown below, its vivid colouring alerts potential predators to the fact that it is poisonous. Similarly, the striped skunk, Mephitis mephitis, uses the pattern of its stripes to alert potential prey to the unpleasant odour it emits.
• Many species, not just those two, use vivid or eye-catching colouring to warn of unpleasant odours, toxic chemicals, or the ability to sting or bite. Those predators who choose to ignore the warning coloration and eat the organism anyway may be deterred by the unpleasant aftertaste or toxic chemicals. Aposematic coloration, also known as warning coloration, is a type of defence used by animals.
• In order to survive, some species have evolved to imitate the aposematic coloration of other species, even if they do not share those traits. Batesian mimicry occurs when a species that poses no threat adopts the warning colours of a potentially dangerous species. This camouflage helps the harmless species avoid being eaten by the same predators as the dangerous species even though the harmless species lacks the biological mechanisms that protect the target species. Many species of nonvenomous, nonstinging insects, for instance, have evolved to look like wasps or bees.
• It is important to note that all of the species engaging in Müllerian mimicry actually do possess defence mechanisms, despite their use of the same warning coloration. The pair of foul-tasting butterflies shown in the figure below are an example. If a predator tries one of these species and doesn’t like the way it tastes, it will likely avoid the other. This resemblance may have been selected for during evolution because it would have benefited both species by reducing the likelihood of predation from a predator that had learned to distinguish between them.
• These are merely a few examples of the many ways in which prey species have adapted to protect themselves from predators. Of course, predators also have adaptations to maximise the capture of prey, such as sharp claws and teeth, fast running speed, and colouring that provides camouflage, allowing the predator to lie in wait for the prey. This could be seen as an evolutionary arms race in which both sides must constantly raise their game to maintain any sort of competitive advantage.

Facts of Predation

• One organism, the predator, consumes another, the prey, in its entirety or in part as part of an interaction known as predation.
• The practise of feeding on plants, known as herbivory, is a form of predatory behaviour.
• The dynamics of predator and prey populations are intertwined. Predator and prey populations tend to increase and decrease in tandem.
• Adaptations, or favourable features that arise as a result of natural selection, are common among both predators and prey that are based on their interactions with one another. Prey have a variety of defences and warning signals, such as vivid colouring, to help them avoid being caught.

Examples of Predation

Large Predators

• The large predators have evolved unique strategies for killing their prey. A few examples of large predators on Earth are polar bears, killer whales, and great white sharks.
• Seals make up the bulk of the polar bear’s diet. Killer whales feed on marine mammals and fish. The great white shark is the ocean’s most lethal predator and a voracious eater.

Small Predators

• Generally speaking, smaller predators are not responsible for widespread destruction. Some marine animals, like sea stars, rely heavily on shellfish for sustenance. When it comes to eating aphids, the ladybug is the tiniest predator there is.
• Lions, tigers, bears, wolves, leopards, dogs, snakes, crocodiles, etc. are just some of the other predators out there.

References

• Minelli, A. (2008). Predation. Encyclopedia of Ecology, 2923–2929. doi:10.1016/b978-008045405-4.00287-1 
• https://www.sciencedirect.com/science/article/pii/B9780128191668000165
• https://www.nature.com/scitable/knowledge/library/predation-herbivory-and-parasitism-13261134/
• https://en.wikipedia.org/wiki/Predation
• https://www.khanacademy.org/science/biology/ecology/community-ecosystem-ecology/a/predation-herbivory
• https://biologydictionary.net/predation/
• https://www.biologyonline.com/dictionary/predation
• https://flexbooks.ck12.org/cbook/ck-12-middle-school-life-science-2.0/section/12.8/primary/lesson/predation-ms-ls/