The change in roosting habits of species 1 after species 2 became established is an example of which concept?

• A. Habitat modification
• B. Resource partitioning
• C. Mutualism
• D. Competitive exclusion

Answer: (B)

Resource partitioning occurs when species differentiate how they use a resource to avoid direct competition and allow coexistence. Here, after species 2 becomes established, species 1 changes its roosting habits—such as using different roost sites or timing—to reduce overlap with species 2. This behavioral adjustment reduces competition for the same roosting resources and demonstrates how niches can be partitioned in space or time.

Habitat modification would involve one species altering the environment to affect others, which isn’t described here. Mutualism would require both species to benefit from the interaction. Competitive exclusion would imply one species drives the other out entirely, rather than shifting behavior to share resources.