By Dr. Hal Schramm

Big baits catch big bass. Biologically this makes sense. Fish live in a perpetual energy crisis, and they don’t survive in the long run by expending more energy chasing down a meal than they gain by eating it. Big prey equals more energy. Not so easy to understand is why a big bass will eat a diminutive drop shot worm. Appetizer?

Fish story: Ben Davis and I were catching post-spawn bass in a small pocket with greening water willow. Davis is making frequent catches with a 6-inch lizard; my fish are eating a spinnerbait. We change locations to small cove. The spinnerbait bite died, but Davis is getting bit almost every cast with the lizard. Strangely though, Davis can’t get a hook in the fish. Are they just little bass?

I pulled out a worm rod that still had a 10-inch Yum Ribbontail rigged from last fall. (Yeah, I need to work on tackle management.) Thinking I’ll throw the big worm a couple times before putting on a “more appropriate” offering, I immediately get bit, set the hook, and boat a good bass. In the next 45 minutes, the 10-inch worm put a dozen bass up to 5 pounds in the boat. Davis continued to get bites on the 6-inch lizard, but only a few of those fish ate the bait well enough for Davis to get a hook in them.

big bass
Enter the stickleback. The three-spine stickleback is an interesting little fish that captured the attention of Dr. Niko Tinbergen, one of the fathers of ethology--the study of animal behavior. The stickleback develops a bright red belly during the spawning season. The purpose of the red belly is to attract a ready-to-spawn female, but it also serves to alert other fish that it will defend its nesting territory. Tinbergen’s research proved that an elongate wooden object with a red underside would elicit attacks from male sticklebacks. Looking like a fish was not essential—long and red below triggered the attack.

Ethologists call this a releasing stimulus. But then Tinbergen made another discovery—sticklebacks would ignore a live red-bellied stickleback and attack the wooden dummy (a lure?) if its underside was brighter red than the stickleback. This over-emphasized releasing stimulus is called a supernormal stimulus. There are many other examples of supernormal stimuli throughout the animal world, including huge-eyed stuffed toys and (excuse me ladies) women’s make up that emphasizes eyes and lips.

According the ethological theory, feeding by a fish (or any animal) is a series of fixed action patterns, each triggered by a releasing stimulus. A prey triggers approach. If it “looks” (which may also include sounds and smells) right, then the fish attacks. If it still “looks” like food, the fish eats it. Although this all happens in a blink, each step is a separate fixed action pattern, and each is triggered by a releasing stimulus. Ethologists have demonstrated that releasing stimuli are simple characteristics, such as red underside. The wooden dummy didn’t even look like a stickleback except that it was elongate.

Fish use a variety of senses—sight, smell, sound, water movement—to detect prey and trigger the sequence of fixed action patterns that result in a strike and fish on. Keeping in mind that fish have been successfully selecting and consuming food for millions of years, I tend to give credence to ethological theory. As such, it follows that there is something about a lure that is catching fish that leads the fish through the entire approach-attack-consume series of fixed action patterns. Bear in mind that it may be different stimuli for each successive fixed action pattern.

Was the 10-inch worm a supernormal stimulus that triggered consume, whereas Davis’ 6-inch lizard was only triggering attack? Might a 10.5-inch Mighty Worm, an 8-inch flutter spoon, a giant crankbait or swimbait, or an oversized Super Rogue be a supernormal stimulus that rushes the fish to the final step of the series of feeding fixed action patterns? I’ve caught smallmouth on giant muskie plugs, and friend of mine catches smallmouth on big twin-blade buzzbaits in the upper Mississippi River.
I think there is a time to supersize.And it just might be one of those tough-bite days when “normal” isn’t working.