I have an ecology question.

Question

Explain why adaptations of particular organisms to interspecific competition may not necessarily represent instances of characterdisplacement. What would a researcher have to demonstrate about two competing species to make a convincing case for character displacement?

Answer 1

Character displacement requires that for whatever trait you're examining, the differences between the two species is greater in areas where they coexist.  

So, let's say you're looking at two species of birds and their beak size.  In areas thwere they coexist, Species A has a significantly shorter, stouter beak than members of Species A do where Species B does not exist.  Likewise for Species B.  In areas where the two coexist, they have a longer, thinner beak than members of Species B in areas where there are none of Species A.

So, to demonstrate character displacement, you have to find areas where each species occurs by itself and there has to be a difference in the trait within the species between the populations with and without the other species.