The best example of competition in a forest ecosystem from the options given is:
Blue jays and finches nest in the same oak trees.
This scenario illustrates competition because both bird species are vying for the same resource (nesting sites) within the same habitat. The other options describe different interactions, such as mutualism (bees and hive), parasitism (ticks and deer), and predation (wolves and rabbits), but they do not exemplify competition for resources.