Difference Between Fundamental and Realized Niche

Fundamental vs Realized Niche

To know the difference between fundamental and realized niche, we first need to grasp the concept of niche. The word niche comes from a French word meaning nest. The term was first coined by Joseph Grinnell, a naturalist in 1917, to refer to the habitat of a species in which it lives. One can call a niche, sum total of all the ecological requirements that allow a species to mate and produce offspring, thus surviving and flourishing with any undue pressures. A fundamental niche of a species is the habitat that is natural for it while a realized niche is the result of many factors, such as human activities, presence of predators, and availability of its natural food resources. There are many differences between a fundamental niche and a realized niche that will be talked about in this article.

We all know that theoretically a rat can eat anything it pounces upon as it is an omnivore, and this is called his fundamental niche, but because of the presence of predators like cats, also because humans do not like them in their environment, rats are not able to eat everything they like, and have to make do with what they get because of these factors. This is his realized niche.

For any species to survive, and maintain its population the environmental conditions must not be too harsh, and individual members must be able to tolerate the environment, also be able to mate and reproduce. They must be able to have food to get nutrients and energy, also have means to avoid predators. If the total requirements of a species to survive and then thrive are present, it is termed as its fundamental niche. Realized niche is a subset of this fundamental niche as it describes ecological conditions that are actually available, and occupied by the species.

Fundamental niche is thus, the maximum possible a species can have and utilize. This is a niche, where he does not have to worry about the limited nature of food resources or about predators. This niche provides him with a comfortable environment in which, the species can mate and reproduce without any stress. Let us take up the example of raccoons that live in the forest, where they get a plenty of food in the form of bugs, fruits and small creatures like insects for their energy requirements, and where they can easily hide from their predators. However, raccoon today finds itself forced to live in a realized niche because of many limiting factors, such as industrialization, urbanization and deforestation. It is forced to live in an urban environment, where it has to feed upon waste and trash rather than insects and fruits that it used to eat when it was in its fundamental niche.

In brief:

Difference between Fundamental and Realized Niche

• Fundamental niche is the natural habitat of a species, where it can easily get food for its energy requirements, and can mate and reproduce without the fear of predators

• Realized niche is the environment that a species finally gets because of many limiting factors

• Realized niche is a subset of fundamental niche, and forces a species to live and adapt to the present conditions.

• Raccoons that lived in forests are today forced to live in urban environment, and eat garbage. Thus, forests are their fundamental niche, whereas urban environment is their realized niche.

  • Jenny Pilarski

    Thank you so much we went over this so fast in IPM class and I did not understand it, that example you gave is great! Thanks again!