Answer:
Fundamental niche is the maximum theoretical inhabited hypervolume which a species can occupy in the absence of interactions with other species on the other hand the portion of fundamental niche that a species actually exploits as a result of interactions with other species is called as realized niche.
Explanation:
In, fundamental niche the full range of environmental variables and resources that a species can possibly tolerate and use in the absence of competitors and predators, i.e free from any sort of interference from other species.Thus, fundamental niche is hypothetical.
Where as,realized niche is the actual smaller hypervolume which a species occupies under interference and predation from the other species.Because of interspecific interactions,the realized niche of a species is often smaller then fundamental niche.
