Final answer:
When a third species of herbivore finches moves into the same ecosystem, there will likely be increased competition for limited food resources. This may result in one of the original finch species losing the competition and either dying off or migrating to another region.
Step-by-step explanation:
Interspecific competition happens when individuals of different species strive for a limited resource in the same area. One species will be better adapted to its environment and out-compete the other. The species that loses will either die off or migrate to another region. When a third species of herbivore finches moves into the area, there will likely be increased competition for limited food resources. This may result in one of the original finch species losing the competition and either dying off or migrating to another region.