When mosquitoes are abundant, purple martins flock to the area and feed exclusively on them. When mosquito populations are not large, purple martins are similarly scarce and feed on other insects. This is an example of A) density-independent regulation. B) density-dependent regulation. C) ecosystem carrying capacity. D) community carrying capacity.

Density-dependent regulation

Explanation:

density-dependent processes takes place when the density of a population population regulate growth rates.

Some factors that affect density-dependent factors could be biotic (biological in nature), such as; disease, predation, intraspecific competition, accumulation of waste, and interspecific compitition.

For instance, in interspecific competition or intraspecific compitition, reproductive rates of the individuals will definitely reduced, which results to reduce in population's growth rate. When the prey density is low, the mortality of its predator is increased.

Therefore, when mosquitoes are abundant and purple martins flock to the area and feed exclusively on them, since the mosquito populations are not large, purple martins are similarly scarce and feed on other insects, this is reffered to as Density-dependent regulation.