Final answer:
The use of various foraging microhabitats by different species leads to decreased competition, which can increase species fitness by allowing for more efficient use of resources and reducing niche overlap.
Step-by-step explanation:
The topic in question relates to the outcomes of interspecific competition and how different foraging microhabitats used by various species can influence their evolutionary fitness. The main answer to the student's question is option a, decreased competition. This is because when different species utilize various foraging behaviors and microhabitats, they reduce the overlap in their ecological niches, consequently minimizing the competition for resources. This specialized use of resources can increase the fitness of each species, as areas of the environment are more efficiently used without direct competition, aligning with the sampling-competition effect and competitive exclusion principle.
Furthermore, this specialization can lead to niche expression, where species adapt to exploit different resources or foraging times, as seen in the example of Darwin's Finches with various beak shapes suited to different food types. These adaptations and reduced competition can foster coexistence and diversification within an ecosystem.