1. Competitive Exclusion:
* The stronger competitor will outcompete the weaker one, driving the weaker species out of the niche or even to extinction.
* This is based on the principle of competitive exclusion, where two species cannot coexist indefinitely if they rely on the same limited resources.
2. Resource Partitioning:
* Both species may evolve to specialize on slightly different resources within the niche, reducing competition.
* This could involve changes in diet, foraging behavior, or activity times.
* This allows both species to coexist, but their niches become more distinct.
3. Character Displacement:
* One or both species may evolve physical or behavioral traits that reduce competition.
* This could involve changes in beak size (for birds), body size, or mating times.
* This allows both species to access different resources and reduces competition.
4. Coexistence with Reduced Fitness:
* Both species may be able to coexist, but their fitness (ability to survive and reproduce) is reduced compared to if they had the niche to themselves.
* This can happen when competition is not too intense or if the environment fluctuates, preventing one species from completely dominating the other.
5. Competition for Limited Resources:
* This can lead to a decrease in population size for both species as they struggle to access sufficient resources.
* This can also impact the overall community structure, as the availability of resources for other species may also be affected.
Example:
* Two species of birds, the warbler and the sparrow, may initially compete for the same food sources (insects).
* Over time, the warbler may evolve to specialize on smaller insects found higher in trees, while the sparrow may specialize on larger insects found on the ground.
* This resource partitioning allows both species to coexist, reducing competition.
In summary:
When two organisms try to occupy the same niche, interspecific competition occurs. The outcome can vary, but it often leads to:
* Competitive exclusion of one species
* Resource partitioning and specialization
* Character displacement to reduce competition
* Coexistence with reduced fitness for both species
* Competition for limited resources, potentially impacting both species and the community.
