Niche basically is the lifelihood of a species that involves feeding on what, drinking from what....
If both species are competing for the same resources, they would compete until a certain species is eradicated. (think of it as 2 species of ants in 2 colonies that are close to each other, take the same leaves, prey and stuff. They would fight with each other in other until one colony is eradicated.) hence, unless a species and adapt and change its niche, both species would fight until one is eliminated. Thus, the principle states that 2 species cannot continue to occupy the same niche, not living environment.
