Competition occurs in virtually every ecosystem in nature. This type of relationship develops when more than one organism in an environment requires the same thing in order to survive. When food and shelter are plentiful, there is no competition--it only takes place when there is not enough to go around. Competition often results in the survival of the fittest.
Competition often occurs between members of the same species. This is known as intraspecific competition. It is a common type of competition because animals of the same species often live in great numbers in a particular area. These individuals compete for limited resources like food, shelter and mates.
This type of competition acts to keep the population under control. If there is a limited amount of food to go around, the environment can only feed so many individuals of the same species. This results in the survival of those most capable of competing and winning. Similar regulation occurs when individuals compete over shelter, especially dens necessary for raising young. In some cases (e.g., in the case of young male lions), animals that lose this type of competition are driven from the group and from the area.
Interspecific competition occurs when members of more than one species compete for the same resource. For example, woodpeckers and squirrels compete for nesting rights in the same holes and spaces in trees, while the lions and cheetahs of the African savanna compete for the same antelope and gazelle prey.
Even though individual animals are competing for the same shelter or food, interspecific competition is usually less critical than intraspecific competition. For example, the antelope is not the lion's only prey. Because of this, the lion can choose whether to compete for antelope or to look elsewhere. Animals of different species typically compete with each other only for food, water and shelter. However, they may compete with members of their own species for mates and territory as well.
Competition Among Plants
Plants also compete for space, nutrients and resources such as water and sunlight. This competition can shape the appearance of the ecosystem. For example, the floor of a deciduous forest is not as full of plant life as might be thought. The taller trees shield the forest understory from sunlight, making it possible for the growth of mainly shade-tolerant plants. The life cycles of some plants are also impacted because many shorter plants flower and bear seeds before the leaves of the taller trees are fully developed, which makes it possible for shorter plants to receive sunlight.
Desert plants have developed shallow, far-reaching roots systems in order to successfully compete for valuable water resources, which is an example of how competition can affect the evolution of a species.
Competitive relationships are thought to be at least partially responsible for the evolutionary process. In natural selection, the individuals of a species that are best adapted to the environment around them survive to reproduce and pass on the genetics that make them well adapted. This can be seen in the development of the giraffe when the giraffe competes with other grazing herbivores such as zebras and antelope for food. Giraffes with longer necks are able to reach the leaves of high tree branches, giving them access to more food and a better chance of passing their genetics on to their offspring.
Exploitative competition, which is the use of resources that make it impossible for others to use them, can result in the extinction of a species or an evolution that allows that species to find another route of survival. This can include finding another food source or adapting nests to suit another type of shelter.