What could an ecologist do to find out if a species is occupying its fundamental or its realized niche?

• A. Remove a species it consumes & measure the effect.
• B. Observe how its use of resources changes upon the introduction of a competitive species.
• C. Take half the population out the community and observe the species' use of resources.
• D. Observe changes in the species' range of resources used after removal of a competitor.

Answer: (D)

Verified step by step guidance

1. Understand the concept of a niche: A niche refers to the role a species plays in its ecosystem, including how it gets its energy and nutrients, where it lives, and how it interacts with other organisms. The fundamental niche is the full range of conditions and resources a species can theoretically use without competition, while the realized niche is the actual conditions and resources it uses when competition is present.
2. Identify the role of competition: Competition occurs when two or more species vie for the same resources, such as food, space, or mates. This competition can limit a species to a smaller range of resources than it could potentially use, thus occupying its realized niche.
3. Design an experiment to test niche occupation: To determine if a species is occupying its fundamental or realized niche, an ecologist can remove a competitor species from the environment and observe any changes in the range of resources used by the species in question.
4. Measure changes in resource use: After removing the competitor, the ecologist should measure how the species' use of resources changes. If the species begins to use a wider range of resources, it indicates that the species was previously occupying its realized niche due to competition.
5. Analyze the results: Compare the resource use before and after the removal of the competitor. If the species expands its resource use, it suggests that the species was limited by competition and was occupying its realized niche. If there is no change, the species might already be occupying its fundamental niche.