The difference between an animal’s fundamental niche and realized niche is that the fundamental niche encompasses the full range of environmental conditions and resources under which the animal can survive, grow, and reproduce without any competition or limiting factors. In contrast, the realized niche is the actual set of conditions and space the animal occupies in nature when biotic factors such as competition, predation, and interactions with other species limit its distribution and behavior.
Fundamental Niche
- It represents the potential or ideal conditions an animal can theoretically occupy to survive and reproduce.
- Includes all possible abiotic and biotic factors the species can tolerate in the absence of competitors or predators.
- It is a broader, theoretical niche that is often not fully realized in nature due to ecological interactions.
Realized Niche
- The actual environment and conditions where the animal is found living and reproducing in the presence of competitors, predators, and other limiting factors.
- It is usually smaller than the fundamental niche because of these biological and ecological constraints.
- Reflects where the species effectively “fits” in an ecosystem considering real-world pressures.
Summary Table
Aspect| Fundamental Niche| Realized Niche
---|---|---
Definition| The full range of conditions under which a species can survive and
reproduce without competition| The actual conditions occupied by a species due
to competition, predation, or other limiting factors
Size| Generally broader and theoretical| Usually narrower due to biotic
interactions
Influencing Factors| Abiotic factors (temperature, resources, habitat)| Biotic
factors like competition and predation
Ecological Role| Potential role and space available| Actual role and space the
species occupies
For example, the fundamental niche of a predator might include hunting prey at any time of day and across many habitats, but the realized niche could be restricted to hunting only at night or in certain territories due to competition or avoidance of predators themselves.
