Final answer:
A type II functional response is a feeding response observed in predators where the rate of predation levels off at higher prey densities, preventing the predator from controlling a large prey population.
Step-by-step explanation:
A type II functional response is a feeding response observed in predators, where the rate of predation does not increase linearly with an increase in prey density. Instead, the predation rate levels off at higher prey densities, indicating a saturation point. This type of functional response can prevent a predator from controlling a large prey population because it limits the predator's ability to have a significant impact on prey numbers, especially when prey density is high.
For example, let's consider a population of birds as the predators and a population of insects as the prey. If the birds exhibit a type II functional response, they will consume a certain number of insects per unit of time, regardless of how many insects are present. As the insect population increases, the bird predation rate will initially increase, but it will eventually reach a point where it levels off, and the prey population can continue to increase unchecked.
In this way, a type II functional response hinders a predator's ability to control a large prey population by limiting the predation rate and allowing the prey population to persist at high densities.