what is predation theory?

Answer 1

predation describes a biological interaction where a predator organism feeds on another living organism or organisms known as prey.Predators may or may not kill their prey prior to feeding on them. The other main category of consumption is detritivory, the consumption of dead organic material (detritus). It can at times be difficult to separate the two feeding behaviors, for example where parasitic species prey on a host organism and then lay their eggs on it for their offspring to feed on its decaying corpse. The key characteristic of predation however is the predator's direct impact on the prey population.

Answer 2

Visual Predation Theory

Answer 3

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 parasite-host interactions. These linkages are the prime movers of energy through food chains. They are an important factor in the ecology of populations, determining mortality of prey and birth of new predators. Predation is an important evolutionary force: natural selection favors more effective predators and more evasive prey. "Arms races" have been recorded in some snails, which over time become more heavily armored prey, and their predators, crabs, which over time develop more massive claws with greater crushing power. Predation is widespread and easy to observe. Neither its existence nor its importance is in doubt.

Mathematical models of predation are amongst the oldest in ecology. The Italian mathematician Volterra is said to have developed his ideas about predation from watching the rise and fall of Adriatic fishing fleets. When fishing was good, the number of fishermen increased, drawn by the success of others. After a time, the fish declined, perhaps due to over-harvest, and then the number of fishermen also declined. After some time, the cycle repeated.

The idea that a coupled system of predator and prey would cycle gained further support from analyses of fur trapping records of the Hudson's Bay Company. The number of furs purchased at the Company's forts was meticulously recorded, for well over 100 years. An analysis of the numbers of snowshoe hares, and one of their main predators, the lynx, provides a remarkable record of a predator-prey cycle. Peaks and valleys can be easily observed at roughly 8-10 year intervals. Logic and mathematical theory suggest that when prey are numerous their predators increase in numbers, reducing the prey population, which in turn causes predator number to decline. The prey population eventually recovers, starting a new cycle (Figure 1).

Paramecium, which also proved useful in test-tube studies of competition, was placed in culture with a predaceous protozoan. These laboratory studies found that cycles were short-lived, and the system soon collapsed. However, if one added more paramecium every few days, the expected cycle was observed. These results suggested that the predator-prey system was inherently self-annihilating without some outside immigration.

Answer 4

http://www.globalchange.umich.edu/globalchange1/current/lectures/predation/predation.html