What is the difference between Fundamental and Realized Niche?

When you say fundamental niche, you mean to say that there are different conditions that are available so that animals will have the ability to reproduce. This will increase the chances of the animal surviving whatever it is going through. When you say realized niche, this is also another set of conditions for animals.

This time, the conditions are set depending on the other animals that the animals have interacted with. There are various animal relationships that should be considered, such as competition and predation, that will determine what may transpire.

Both fundamental and realized niche refers to the environmental conditions or positions of different species in an ecosystem. These two niches refer to the conditions necessary for perpetuating different species and their ecological roles in the system. A fundamental niche focuses on the various functions of the species. On the other hand, the realized niche focuses on what the species is capable.

The fundamental niche describes a plethora of conditions, roles, and resources under which a species grows, reproduces, and survives. The niche involves the experiences of the species and how it endures a particular condition. The fundamental niche is more impressive in size compared to the realized niche.

The realized niche can be labeled a subset of the primary niche. When the species comes across various interactions and demands of others, they are forced to become a narrower niche. Thus, the realized niche is formed.