We know dolphins love to jump. And we've all seen the pictures of salmon jumping right into the jaws of a waiting bear. But did you know that even a tame goldfish can jump a good foot?  It's not unusual for fish to escape their aquariums (some experts suggest it's because their water is contaminated), which is why a cover is recommended.

Fish jump because they're hungry, scared or in a bad mood.
Or need to get somewhere fast. Mostly, they jump because ...

Between the birds and the fish, when you live on or near the water, nature can keep you entertained for hours.  

At our house, we call it “the show.” Just pull up a chair on the deck and before you know it, birds are dive-bombing into the water headfirst and fish are leaping in and out of the water so fast that you just might think you were imagining things.  

Around our home on Lake Erie, walleye, yellow perch and pickerel are the most common fish. And judging by their darker colouring, it seems the pickerel jump the most.  

Why are they jumping?   

According to a posting on MadSci Network by John Franklin Rawls, then a graduate student in developmental biology at Washington University, my pickerel are a tad hungry. One of the main food sources for many freshwater fish is insects, he says, and since most flying insects spend most of their time hovering on or just above the water, they are a ready snack for fish with a bad case of the munchies.  

Jumping out of the water at the wrong time, however, can spell trouble for unsuspecting fish. Many a cunning fisherman has been known to create the perfect jumping conditions by shining a spotlight onto the surface of a dark lake while banging the side of the boat. The light and racket excite both fish and insects, with some sources claiming this method has resulted in fish jumping right into the boat! 

Chased by predators

But feeding is not the only reason fish jump. For salmon, jumping is an important skill that allows the fish to travel upstream to spawn. For other fish, especially the smaller variety, jumping is a way of staying clear of predator species.  

No fish is better at escaping predators than the flying fish (from the exocoetidae family), which comes equipped with a torpedo-shaped body that allows it to swim along the surface of the water. Found in our oceans, especially in the warmer tropical and subtropical waters, the flying fish will jump to escape predators — shooting straight out of the water at speeds up to 50 km/h!  

Flying fish have also been known to jump as high as 36 feet into the air, an ability my pickerel have yet to master. It should be said that pickerel are not the nicest hunters, so no need to feel sorry for them. They are known to lunge at their prey, using their very sharp teeth to hold their newfound dinner tight in their jaws. Not only do they jump out of water to lunge at passing insects, they are also known to snap at dangling fish lures.  
There is a joke in the fishing world that answers the question “Why do fish jump?” with “Because they don’t have fingers.” In other words, they like to give frustrated anglers the “fin” — the fish version of giving someone the finger.  

But are fish really that rude?  

My favourite “show” occurred early last summer, when two anglers cast their nets into the lake from their small boat. As they were close enough to shore that I could clearly see them from my deck without having to resort to my binoculars, I sat back to watch, curious to see how long it would take them to land the catch of the day.  
No sooner had they cast their lines than the fish started jumping. Unfortunately for our anglers, who were sitting one behind the other in the boat facing west, the fish always jumped out of the water behind them. Had they known the fish were so close at hand, the anglers could have turned around and caught the leaping fish in their net! 

This pickerel is no fisherman's friend

Alas, all they saw of our jumping fish was the wake from the splash as dinner dived back safely into the lake. This routine went on for a good 20 minutes, leaving me in stitches on the deck as I cheered for the fish and its taunting fins.  

It wasn’t long before our fishermen, without anything to show for their time, and unaware they had been one-upped by fish, coaxed the boat’s motor into life and headed back to the marina.  

Dennis Dobson, a writer and hunting and fishing guide, whose essay Why Fish Jump is found on the LandBigFish website, would have appreciated my pickerel show that day.  

Here is Dobson’s answer to the age-old questions: Why Do Fish Jump?  

“Have you ever watched from a deer stand or on a nature show as deer frolic? Have you ever seen chimpanzes chase each other just for the joy of it? Have you ever seen bear cubs tumble and rough house? Did you watch as your youngster, in that never-never land between toddler and teen, ran pell-mell at the speed of light playing with friends simply because it felt good? If you have, then you already know why fish jump.  

“I am convinced that Mother Nature sees to it that every organism above a certain point in the food chain is blessed with enough sense of self to enjoy being what they are. One universal expression of this joy is the exuberance of physical activity.  

“The whole-body rush as adrenaline and endorphins flood the system. The invigorating flush of heat and motion. The stretch and play of supple muscles, the dynamic tension between skin and ligament, bone and tendon as we each discover our physical limits.  

“The range of emotions your face undergoes as you fight a fish leads us to the same conclusion. First surprise, followed in short order by confusion, concentration, determination and finally pride and joy as you bring the fish to net, all point to the same reason.  

“Fish jump because they can. Because it feels good. It’s that simple.”  

Sounds right to me.

After all, did I not see my pickerel smile as they played hide-and-seek with those two fishermen that day? I know it felt good watching them.