<P> The term niche differentiation (synonymous with niche segregation, niche separation and niche partitioning), as it applies to the field of ecology, refers to the process by which competing species use the environment differently in a way that helps them to coexist . The competitive exclusion principle states that if two species with identical niches (i.e., ecological roles) compete, then one will inevitably drive the other to extinction . When two species differentiate their niches, they tend to compete less strongly, and are thus more likely to coexist . Species can differentiate their niches in many ways, such as by consuming different foods, or using different parts of the environment . </P> <P> As an example of niche partitioning, several Anolis lizards in the Caribbean islands share common food needs--mainly insects . They avoid competition by occupying different physical locations . For example, some live on the leaf litter floor while others live on branches . Species who live in different areas compete less for food and other resources, which minimizes competition between species . However, species who live in similar areas compete strongly . </P>

States that two species cannot coexist in the same niche indefinitely