Mac Arthur showed that five species of warbler birds co-exist in the same habitat due to

MacArthur showed that five closely related species of warblers living on the same tree were able to avoid competition and co-exist due to behavioral differences in their foraging activities.

Competitive release occurs when one of two species competing for the same resource disappears, thereby allowing the remaining competitor to utilize the resource more fully than it could in the presence of the first species.

The competitive exclusion principle says that two species can't coexist if they occupy exactly the same niche (competing for identical resources), eventually one will be eliminated.

Niche overlap refers to the partial or complete sharing of resources or other ecological factors (predators, foraging space, soil type, and so on) by two or more species.