Although these animals were roughly the same size, there is some evidence of niche differentiation between the two.

In most cases, niche differentiation has created a relationship between two species where current competition is small or non-existent.

It is important to keep in mind that niche differentiation and inter-specific competition cannot always be considered linked.

Several theories exist for how niche differentiation arises or evolves given these two possible outcomes.

Another way by which niche differentiation can arise is via the previous elimination of species without realized niches.

Also, because no species is out-competing any other species in the final community, the presence of niche differentiation will be difficult or impossible to detect.

Finally, niche differentiation can arise as an evolutionary effect of competition.

This example illustrates that the evidence for niche differentiation is by no means universal.

There is some degree of niche differentiation between the sexes.

In the previous example, niche differentiation resulted in spatial displacement.