Nature Bulletin No. 338-A   March 29, 1969
Forest Preserve District of Cook County
George W. Dunne, President
Roland F. Eisenbeis, Supt. of Conservation

****:BLACK BASS BEHAVIOR

There are some peculiar expressions in our American Slang. We admire 
"a smart cookie" but "a poor fish" is held in contempt, as if fishes were 
the dumbest creatures on earth. They may seem dumb, and some kinds 
probably are, but -- to expert fishermen and scientists who study the 
behavior of fish -- the black basses, for instance, appear to be as alert 
and intelligent as many of the so-called higher animals. In Illinois, 
where there are three species of them, they are the Number One fish for 
most anglers. The Largemouth black bass thrives in lakes and the more 
sluggish streams throughout the state. The smallmouth bass and the 
spotted bass prefer faster moving streams, the former being restricted to 
the northern half of Illinois and the latter to the southern part.

Black bass strike best in waters which are fished very little, or, in more 
popular spots, when the season first opens. As more and more people 
come to try their luck, the time between bites rapidly becomes longer 
and longer until even the experts may go home empty-handed. Contrary 
to popular belief, this does not mean that most of the bass have been 
caught out. It merely demonstrates that the fish have become "smart" 
and wary; they have learned to avoid those gaudy artificial flies or 
plugs, and even tempting live baits on the end of a line.

This was strikingly shown in a lake near Charleston, Illinois, operated 
experimentally by the State Natural History Survey for a study of bass 
fishing and how to improve it. In 1949, with 1027 marked bass in the 
lake, it took an average of only 24 minutes, each, to catch the first 50 
but, by the end of that first day of fishing, it took over two hours to 
catch a bass. On the second day it took from 5 to 6 hours, and from 10 
to 15 hours on the next three days. In other words, although most of 
them were still in the lake, it took -- about thirty times as long to fool a 
bass as it did at first. The memory of an escape from the hook, or 
perhaps the sight of a fellow bass caught and struggling, was apparently 
enough warning for the others to beware of those colorful gadgets.

Largemouth black bass really see color as color and not as shades of 
gray -- which is the way most mammals see it. In another series of 
experiments by the Survey, young bass, each in a separate aquarium, 
were shown a red medicine dropper and, after they came close for a 
good look, rewarded by a water flea or a mosquito wiggler squirted 
from it. Then they were shown droppers colored yellow, blue or green, 
respectively, but were punished with a small electric shock if they came 
too close. After only 5 to 10 such training trials, the fish would hover 
close to the red dropper, waiting for food, but would back away to the 
far side of the tank if any other color was shown. Similarly, other fish 
were trained to come to yellow, green or blue droppers. They were able 
to distinguish most of these colors from a confusing series of gray 
droppers ranging from white to black. They had trouble telling yellow 
from pale gray, and blue from dark gray or black. Surprisingly, it was 
proved that bass see colors about as well as a human being wearing 
yellowish sun glasses.

Further, the Survey has found that each smallmouth black bass seems to 
have a favorite home, usually a shaded pool, where it spends most of its 
life. And that most of them are able to find their way back home after 
being caught, tagged and hauled to another part of the stream, or even 
another stream in the same river system.