Interspecific Competition Exclusion and Niche Differentiation
Interspecific competition occurs when two different species consume exactly the same resources (food, shelter, etc.) and inhabit exactly the same place. For instance, when a lion and a tiger both inhabit in the same place, interspecific competition occurs. This is because both the animals depend on the same prey at the same time. Similarly, if there are a school of fish and aquatic plants in a lake, interspecific competition occurs as both require oxygen for their survival. If there are more aquatic plants in the lake, there are chances for the fishes to be deprived of oxygen and ultimately suffer.
Most of the time, this kind of competition between similar/different species is not direct. However, competition is an important factor that can ultimately alter the population and a species's structure in two ways.
Competitive Exclusion is also popularly known as The Gause Principle. According to this principle, when two species co-exist in the same place using the same limited resources, they cannot co-exist for long. One of the species will show to be superior to the other, and the superior species will have complete dominance over the limited resources.
Ultimately, the less superior species will be completely deprived of the resources and will move to a different place due to the drop in the population. Later, the inferior species will be replaced by another competitor, which may or may not be superior to the existing population in that habitat. This is a cycle that keeps repeating itself in nature. The inferior species will be forced to move to a different place altogether in order to survive. Gradually, these species will get accustomed to their new environment, if they survive.
In some cases, competitive exclusion might result in a situation where there are alterations in the resources used. In most of the cases, competitive exclusion will result in migration to a different niche where they can use different resources for their survival, thus avoiding future competition.
For example, let us say that both tigers and lions hunt the same prey. They try to avoid competition by choosing a different region for their hunt. For instance, the tigers might hunt in the west of the forest and lions might hunt in the south. This avoids competition and also help the species to make use of resources in a more comfortable manner.
But this will not be the case all the time. If species live in the same area, they tend to compete. This might lead to massive destruction of one kind and thus forces the inferior kind to choose alternate resources in order to avoid competition with the superior kind.