Do bass remember then ignore popular lures?
Pittsburgh — Bass anglers have pondered this question for decades: Do bass remember?
More specifically, can the fish identify lures that previously led them to be hooked? If so, do they then avoid them?
About a week before the opening of the state’s traditional bass-fishing season, on June 14, it’s a good time to take a fresh look at the issue.
One scientist who has tried to answer the question says he thinks bass can remember lures – maybe for up to three months or longer.
Studies by Keith Jones, director of research at the Berkley Fish Research Center, suggests that largemouth bass are “conditioned” in various ways. Along with memory research, Jones took a look at whether a fish becomes conditioned to avoid certain lures it might see swimming by over and over.
“There are certainly trends on the bass tours that would seem to suggest that,” Jones said of his study. “For example, spinnerbaits, once a dominant presentation for top pros, seem a useless bait today. Swim baits, frogs and other newer trends have replaced old lures.”
Jones, widely regarded as one of the world’s foremost bass experts, writes about that in his book “Knowing Bass: The Scientific Approach To Catching More Fish.”
Four types of learning
According to Jones, the four main methods of learning are associated learning, habitation, spatial, and prey images.
He says to think of associated learning as “trial-and-error” learning.
“The fact that bass are capable of associative learning is proved by laboratory experiments where the animal is taught to link two types of stimuli, such as a certain colored light with an ensuing electric shock,” Jones writes. “Bass readily learn these associations, both in the lab and in the field, although not as fast as some other species.”
Spatial learning involves bass learning to move around their environments, recognize landmarks or objects, and stake out their territories. According to Jones, bass in his studies have been able to find their way through an underwater maze to reach a desired point.
Habituation learning involves bass gradually becoming less sensitive to specific stimulations. Jones said examples of this learning would include fish in an aquarium that no longer shy from people who walk by, or bass that learn to ignore boat traffic on a busy lake.
The fourth type of bass learning, prey images, is the ability to develop and recognize a shad or crawfish as prey.
“Given enough positive experience with a certain prey type, a bass will gradually come to actively seek out that specific prey,” Jones noted. “Prey species, for their part, often counter the bass’ efforts by changing their signature stimuli, often through the use of camouflage.”
Like humans, bass are capable of different types of learning, and individual bass learn at different rates.
Jones even cited a four-year study by the University of Illinois that documented recapture rates of largemouth bass. The average bass was caught twice each season, but some bass were caught up to 16 times in a single season.
Jones meticulously tested bass memory for lures, and his study suggests that indeed, bass do remember.
In the study, bass were allowed to strike a minnow lure for a five-minute test period. In the beginning, most strikes came in the first one to three minutes.
By the end of the five-minute period, the bass had learned to ignore the lure because it provided no positive reward – meaning there was no food to be had by striking the lure.
The bass were then divided into two groups, with no additional testing, for different lengths of time.
After two weeks, the bass in one group were re-exposed to the same lure, again for five minutes. The response of those bass was about one-tenth of what it was in the initial exposure.
According to Jones, that indicated that the bass had retained a strong memory of the lure during the two-week interval. And it was a negative memory.
After two months, the second group of bass still tested below the original response level.