How do overlapping niches lead to competition?
Overlapping niches mean that two species niches have somes ressources in common.
A niches is a combinaison of variable that correspond to the needs of a specie. If two niches are overlapping that mean that two species have a ressource in common.
This ressources could be food, spaces or anything that they both need to survive and reproduce. If that ressources is limited, that there is not enough for the two species, there will be competition between the two.