If competing species are removed from an area, a population's realized niche would most closely resemble its

• A. Realized niche
• B. Preferred niche
• C. Climatic niche
• D. Fundamental niche

Answer: (D)

The question hinges on the difference between a species’ realized niche and its fundamental niche. The realized niche is the actual set of conditions and resources a population uses in the presence of biotic interactions like competition. The fundamental niche is the full range of abiotic conditions and resources the species could use if those interactions were absent.

If competing species are removed, those biotic constraints vanish, so the population can exploit a broader set of resources and tolerate a wider range of environmental conditions. In that situation, the realized niche expands toward the fundamental niche, making it resemble the fundamental niche more closely.

Climatic niche refers to climate-related conditions and wouldn’t capture the whole abiotic tolerance, and a “preferred niche” isn’t a standard term in this context.