On our regular visits to Longboat Key, I routinely spend a few evenings sitting along the edge of Sarasota Bay. There, in the hour before sunset, squadrons of pelicans, gulls, terns and wading birds drift above the calm waters of the bay, returning to their nightly roosts. Other than the occasional squawk from a night heron, natural sound is limited to the numerous and regular splashes of jumping fish, scattered across the inlet.
Why do these fish jump? This question has surely been posed since the dawn of man. While science has offered several explanations for such behaviour, ranging from attempts to evade predators to zealous attacks on surface insects, it seems to me that, in most cases, a less functional trigger is involved. I suspect that, in most instances, fish jump from the water for the same reason that humans dive into it: it's a pleasurable experience.
While the natural imperative of genetics-driven life is to survive and reproduce, all creatures are equipped with certain traits and talents which, on the surface, appear to be used for other purposes; these include pleasurable activities that might play a vital role in stress reduction. Usually more evident in young animals than in adults, playful activity serves to hone physical skills and strengthen muscles; however, it might also be essential to the neurologic health of individuals, even those with primitive brains. Perhaps the pleasure of jumping has produced secondary benefits for fish and, over countless generations, that behavior has been sustained and reinforced by natural selection.
