Being the scientific sort, I have occasionally sat by at family reunions quietly studying the eating habits of our collective teenage boys. Watching them eat can be an awesome experience and it takes on a whole new dimension when they eat hot dogs.
Most people through good breeding or common sense know enough not to cram the major part of a foot-long into their mouths. But somehow something apparently snaps in the eating center of a male adolescent's brain. The mere sight of a hot dog instantly challenges them to test anew the theory that a teenager's oral cavity evolved from a black hole!
Teenage bass must suffer from the same eating disorder. Many an eyewitness has reported finding a young bass in the wild with an oversized meal of bluegill hopelessly stuck in its throat. With the bass unable to open its mouth any further, and no room left for it to breathe, both the bass and the sunfish were doomed to die by suffocation.
I found a bass a 4 pounder with a fish, in this case a 3-pound bass, firmly lodged in its throat.
Despite these glaring exceptions, in the vast majority of cases bass regularly practice size selection in the meals they engulf. In fact, bass look to optimize the size of their meals, preying of food organisms that are neither too small nor too large but on those that fall within a preferred size range.
Targets that overload a bass's senses, such as an object that casts too large an image across the visual field or whose movements stimulate the later line system too strongly, are instinctively avoided. In contrast, small prey objects may be neglected simply because they escape detection.
As the fish gains experience, it gets more accurate at predicting which prey are likely to yield the biggest meal for the least effort the most bang for the buck, so to speak.
Fishermen have been sizing their baits accordingly since time immemorial. Most bass fishermen still relate lure size directly to the size bass they are stalking. Small lures are for small bass, big lures, like the swimbaits, are for big bass.
In a recent study here at the Berkley lab, we set out to learn what is the effect of lure size on 1 1/2-pound bass feeding responses. We noticed two things right off. First, the bass did indeed have a size, 7 centimeters in length, preferred above all the others. Second, the response to increasingly smaller lures fell off slowly, whereas the response to the larger lures fell off rapidly.
Larger bass 3 and larger for example respond better overall to larger lures. Since at any give time you don't know where you lure is relative to a bass's optimum choice, how do you know whether to upsize, downsize, or just stay put? The answer is, experiment.
First, try upsizing. If your catch rate drops off dramatically then you know you went too big. When upsizing slows the catch rates, downsize. If you are not catching bass at all, then almost certainly you want to downsize. If after two or more downsizings you still are not catching fish, then your problem probably has little to do with lure size.