Connell’s results led him to conclude that Chthamalus’ realized niche is smaller than its fundamental niche because of interspecific competition with Balanus. But what if competitive exclusion were not the explanation? What if Chthamalus’ and Balanus’ respective niches were a result of niche differentiation instead? Niche differentiation occurs when two species with overlapping niches change over time in a way that reduces their niche overlap, and thus reduces their competition for resources.