A limiting factor refers to any condition that is required by a species which becomes insufficient or absent in a habitat. When particular needs are not met individuals of the population start to die off or fertility becomes inhibited. Some common examples of limiting factors are food, water, predation or lack thereof, water, shelter, gases i.e. oxygen, and organic chemical compounds. In some cases, a limiting factor can refer to a condition that is too abundant such as excessive sunlight for a particular species of plant. It works as a control that prevents unchecked growth in a population or can be one that causes a population to decline and disappear from a habitat.
Most of the time, a limiting factor is beneficial to an ecosystem. For example, one that controls one species, such as a predator, can in turn benefit another such as its prey. If the predatory species were not controlled, then the prey species would become severely depleted. In addition, the success of the predatory species would eventually result in their overpopulation which would ultimately result in a number of limiting factors for that group. We have seen this in the case of over hunting where people were responsible for the extinction of the dodo bird as well as other animals.
Sometimes, a predatory species is unchecked by a limiting factor and as such becomes such a condition for another species. Likewise, the lack of predators in a habit can limit a species. Both instances are especially true in the case of introduced or invasive species. An invasive species that has no natural prey can quickly establish large populations that result in competition with native species for food and habitat.
For example in the north east United States, people have become an extreme limiting factor regarding native wolves. One of the wolves’ native prey is deer whose population boomed due to the disappearance of their predator. The lack of predation becomes a limiting factor because their unchecked population growth results in additional factors such as food shortages and disease. In addition, people have experienced problems with the overpopulation when road bound deer become a driving hazard or garden pest.