NATURAL REGULATION
The natural regulation of wildlife may involve both an animal's internal physiology and its external environment. To varying degrees, wildlife populations exhibit "self regulation," which means their growth tends to slow down as the population becomes denser and to increase if their numbers decline - a biofeedback response. For example, as more elk inhabit the same range, the cows carry less fat and produce fewer calves, and the calves that are born weigh less and are therefore less likely to survive. As the northern Yellowstone elk population has grown, researchers have documented a decline in pregnancy rates and increases in the winter mortality of calves, yearlings, and older bulls.
Environmental factors such as climate and predation also play a large role in controlling an animal population. …