Predators can help maintain the quality of their prey population if the two species have lived for a long time in the same ecosystem. Under such conditions, the prey species learns to deal with the predators.

Therefore, predators mostly kill the weakest and least desirable members of the prey population. The prey population thus stays in a healthy state other wise if they have no choice they can go for the health once. Mostly the strongest pray survive.

Disease and parasites can reduce or even wipe out a population Eg Of the parasite that almost wipe down the lions of the NgoroNgoro Crater and the Serengeti in Late 1960s and early 1970s.But most pathogens (diseases and parasites) have been present throughout history.

Most host (infected) species have become adapted to living with their pathogens. Disease and parasites serve as important population controls primarily in the presence of other factors, such as competition for food or cover.

Behavior Three behavioral factors may be important: (1) territoriality, (2) dominance hierarchy, and (3) stress.
Territoriality occurs among animals that require a certain minimum amount of space, regardless of the available food and cover. Among such species, one animal or a group of animals establishes a territory. No other members of the species are allowed in this area, and breeding is usually restricted to the animals with territories. Such behavior ensures that the strongest members of the population-the animals with territories-survive and produce offspring. A territory contains resources that the animal needs to survive and reproduce.

These resources may include shelter, food, and water; places where mates can be found; and places where animals can escape from their enemies.The size of a territory varies, depending on the effort required to defend the area and the resources available. Animals may establish small territories in the immediate vicinity of nesting sites or in areas of abundant food. They may claim large territories when resources are widely scattered. The period a territory is held may vary from less than a day to many years or a lifetime.Animals may defend a territory by being openly aggressive, such as by chasing and fighting intruders. They also may defend the territory through signals of potential aggression.The scent of urine warns intruders of the Predators presence and the risk of an encounter. The more aggressive forms of defense generally are used when the intruder is especially persistent.

Dominance hierarchies, often called “pecking orders,” occur among many types of social animals. Within populations of such animals, the stronger individuals dominate the weaker ones. These dominant animals get the best food, cover, and breeding places. Weaker individuals are forced into areas with poorer food and cover, and some do not survive. The offspring of dominant parents also have the best chance to survive. The traits of the strongest individuals thus are passed on to the next generation of the species.

In a group, a particular individual may be dominant to some members and subordinate to others. This results in adominance hierarchy–that is, a ranking of individuals by their dominance in relation to each other. In many cases, an individual is subordinate to all those ranked above it and dominant to those below it. This type of ranking is calledlinear dominance hierarchy.Encounters that establish dominance only occasionally include actual fighting. In most cases, these encounters involve only signals that indicate an individual’s willingness or ability to win a potential fight.
Stress occurs among crowded populations of animals. Stressed animals become aggressive and irritable, and they often fight with one another. Some individuals do not breed, and those that do breed produce small litters. Many females do not take care of their young. Diseases and parasites spread rapidly among crowded animals, further reducing their number. That can be coursed by the lack of habitats Hunting, or loose of the territory and other many factors. For more info or question please do not hesitate to contact us