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.Ī predator and its prey can both be microscopic, as is the case with the bacterium Bdellovibrio and other Gram-negative bacteria. For example, prior to being chased down and killed by a cheetah, a gazelle is healthy. True predation usually does not involve harm to the prey prior to death. A so-called true predator kills the prey and then feeds on it.

The ways in which predators stalk, kill, and feed on their prey can be used in a classification scheme. 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. A prey species can also use the aforementioned attributes listed for the predator to avoid being caught and killed. Likewise, the prey has strategies to help it avoid being killed by a predator.

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. A species that has become a successful predator and has survived has developed a few or a number of strategies to acquire the prey. For example, fossils dating back nearly 400 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.Īs species developed and flourished, other species exploited them as their food. Predators and prey have evolved together, and their relationship is ancient. Historical Background and Scientific Foundations The key aspect of a predator-prey relationship is the direct effect that the predation has on numbers of their prey. In contrast, fish and seals that are the prey of some species of shark are examples of prey that is fed on while still alive. For example, a cheetah will stalk, run down, and kill its prey (examples include the gazelle, wildebeest, springbok, impala, and zebra). In many higher organisms, the prey can be killed by the predator prior to feeding. Over time, the two populations cycle up and down in number. If the rabbit population is over-exploited or drops due to disease or some other calamity, the predator population will soon decline. When the numbers of a prey such as rabbits explode, the abundance at this level of the food chain supports higher numbers of predator populations such as foxes. Predator and prey populations respond dynamically to one another. Indeed, the study of Bdellovibrio predation has revealed a great deal of the mechanics of predation and how the predator and prey populations fluctuate in number over time in a related fashion.

The bacteria Bdellovibrio feed on other bacteria that are bioluminescent (they produce internal light due to a chemical reaction). Predators and prey exist among even the simplest life forms on Earth, single-celled organisms called bacteria. Bears, for example, feed on berries, a rabbit feeds on lettuce, and a grasshopper feeds on leaves. A few of them are the lion-zebra, bear-salmon, and fox-rabbit. There are literally hundreds of examples of predator-prey relations. The organism that feeds is called the predator and the organism that is fed upon is the prey. Predator-prey relations refer to the interactions between two species where one species is the hunted food source for the other.

Predator vs prey for kids