Many animals embark on annual migrations that have evolved into epic journeys. Scientists are not certain what triggers these mass movements, nor do they know how the animals manage to unerringly arrive at their destinations, some thousands of miles from the point of departure. Reader's Digest: Nature's Great Events -- Great Journeys documents some of these migrations, including those of the humpbacked whale, who heads north in search of plentiful food. The film features footage of seldom-seen occurrences in the lives of wild creatures. ~ Alice Day, All Movie Guide