Predation - Wikipedia
Predator-prey relationship. From Biology-Online Dictionary | Biology-Online Dictionary. Jump to: navigation, search. Definition. noun. Predator–prey reversal is a biological interaction where an organism that is typically prey in the About 10% of predator–prey relationships have smaller organisms preying on larger ones. These are all active attacks though, unlike the Epomis. Predation is used here to include all "+/-" interactions in which one organism consumes all or part of another. This includes predator-prey, herbivore-plant, and .
For example, fossils dating back nearly million years have revealed evidence that extinct animals known as Hederellids were the prey of an as yet unknown creature that killed them by drilling holes through their tubular shells. As species developed and flourished, other species exploited them as their food. A species that has become a successful predator and has survived has developed a few or a number of strategies to acquire the prey.
The predator may use speed; stealth the ability to approach unnoticed by being quiet and deliberate in its movements, or by approaching from upwind ; camouflage; a highly developed sense of smell, sight, or hearing; tolerance to poison produced by the prey; production of its own prey-killing poison; or an anatomy that permits the prey to be eaten or digested.
Likewise, the prey has strategies to help it avoid being killed by a predator. A prey species can also use the aforementioned attributes listed for the predator to avoid being caught and killed.
The fitness of the prey population—the number of individuals in the population, chance of being able to reproduce, and chance of survival—is controlled by the predator population.
The ways in which predators stalk, kill, and feed on their prey can be used in a classification scheme. A so-called true predator kills the prey and then feeds on it.
True predation usually does not involve harm to the prey prior to death. For example, prior to being chased down and killed by a cheetah, a gazelle is healthy. Cattle that graze on grass are not considered a predator-prey relationship, as only a portion of the grass is eaten, with the intact roots permitting re-growth of the grassy stalk to occur. A predator and its prey can both be microscopic, as is the case with the bacterium Bdellovibrio and other Gram-negative bacteria. But, the size difference between predator and its prey can be immense.
Predator-prey relationships can be more complex than a simple one-to-one relationship, because a species that is the predator or the prey in one circumstance can be the opposite in a relationship with different species.
For example, birds such as the blue jay that prey on insects can become the prey for snakes, and the predatory snakes can be the prey of birds such as hawks. This pattern is known as a hierarchy or a food chain.
The hierarchy does not go on indefinitely, and ends at what is described as the top of the food chain. For example, in some ocean ecosystems, sharks are at the pinnacle of the food chain. Other than humans, such so-called apex predators are not prey to any other species.
This relationship applies only to the particular ecosystem that the apex predator is in. If transferred to a different ecosystem, an apex predator could become prey. For example, the wolf, which is at the top of the food chain in northern forests and tundra environments, could become the prey of lions and crocodiles if it were present in an African ecosystem.
Predator-prey relationships involve detection of the prey, pursuit and capture of the prey, and feeding. Adaptations such as camouflage can make a prey species better able to avoid detection. By blending into the background foliage or landscape and remaining motionless, an insect or animal offers no visual cue to a predator since it mimics its surroundings. There are many examples of mimicry in predator-prey relationships.
Predator–prey reversal - Wikipedia
Some moths have markings on their outer wings that resemble the eyes of an owl or that make the creature look larger in size. Insects popularly known as walking sticks appear similar to the twigs of the plants they inhabit. Another insect species called the praying mantis appears leaflike. The vertical stripes cause individual zebras in a herd to blend together when viewed for a distance. To a predator like a lion, the huge shape is not recognized as a potential source of food.
Camouflage can also be a strategy used by a predator to avoid detection by prey. An example is the polar bearwhose white color blends in with snow, reducing the likelihood that the bear will be detected as it approaches its prey. In this case, the same strategy and color can be utilized by young seals, since their color allows them to be invisible as they lie on the snowy surface.
The community of individuals and the physical components of the environment in a certain area. A sequence of organisms, each of which uses the next lower member of the sequence as a food source. An interconnected set of all the food chains in the same ecosystem. The natural location of an organism or a population. Factors that influence the evolution of an organism. An example is the overuse of antibiotics, which provides a selection pressure for the development of antibiotic resistance in bacteria.Predator Prey Relationship Examples and Their Role in the Ecosystem
The opposite of camouflage can occur. A prey can be vividly colored or have a pattern that is similar to another species that is poisonous or otherwise undesirable to the predator. A successful predator must judge when pursuit of a prey is worth continuing and when to abandon the chase.
This is because the pursuit requires energy. A predator that continually pursues prey without a successful kill will soon become exhausted and will be in danger of starvation.
Predatory species such as lions are typically inactive during the hot daytime hours, when prey is often also resting, but become active and hunt at night when conditions are less energy taxing and prey is more available. Similarly, bats emerge at night to engage in their sonar-assisted location of insects that have also emerged into the air. When supplied with food in a setting such as a zoo, predators will adopt a sedentary lifestyle.
Predation is an energy-consuming activity that is typically done only when the creature is hungry or to supply food for offspring. In settings such as an aquarium, predators and prey will even co-exist. Being a prey does not imply that the creature is completely helpless.
The prey may escape from the predator by strategies such as mimicry, or can simply outrun or hide from the predator. Some species act coordinately to repel a predator. For example, a flock of birds may collectively turn on a predator such as a larger bird or an animal such as a cat or dog to drive off the predator. This mobbing type of repulsion can be highly orchestrated. As well, some bird species use different calls, which are thought to be a specific signal to other birds in the vicinity to join the attack.
Even birds of a different species may respond to such a call. The interactions involved in attempting to eat and avoid being eaten have strong and wide-reaching influences across all facets of ecology, from behavioral, population, and community interactions to how we attempt to manage and conserve the natural world. As in many subfields of ecology, the science behind predator-prey investigations has been driven by theory, including important advances in generating and testing predictions. This article highlights the breadth of influence that predator-prey interactions have on ecology.
At the individual level, the predator-prey interaction will be arranged in two perspectives: The article also considers the less typical and more integrative aspects of predator-prey interactions, such as their physiological and neurological mechanisms and their relevance for questions associated with conservation. In addition, this article will consider the validity of including parasitism and herbivory within the broad definition of predation. A great deal of debate is ongoing as to whether these two ecological interactions possess similar enough qualities with predation to be characterized as one phenomenon.
Those sections of this article will cover this debate and provide the reader with resources with which to consider this question. General Overviews To acquire a broad overview of the field of predator-prey ecology, one should begin by examining several excellent reviews and general resources on the subject.
A great starting point for researchers interested in an introduction to predator-prey ecology is Barbosa and Castellanoswhich examines the subject from behavioral, population, and applied perspectives.
For a more detailed approach, Lima and Dill provides a readable synthesis of behavioral trade-offs involved in predator-prey interactions, one that is broadened in ecological scope in Lima and, written later, Chase, et al.
Dawkins and Krebs provides an introduction to the evolution of the predator-prey arms race, while Abrams provides a critical approach to the arms race using a largely theoretical background for the predator-prey interaction, especially in terms of its evolutionary stability. The evolution of predator-prey interactions: Annual Review of Ecology and Systematics Abrams supports his arguments with a strong theoretical background beginning with early Lokta-Volterra models and advancing through gaps in current models.
Barbosa Pedro, and Ignacio Castellanos, eds.