244 Fish Behavior and Angling 



is). The fish has the choice of striking or ignoring the bait. Whether or 

 not he strikes depends upon the behavior of the fish. 



Laboratory experiments at the Ilhnois Natural History Survey, Urbana 

 demonstrated that fish were quite capable of learning and that certain 

 species were more easily taught than others. Mr. Lynn Hutchens and later 

 Dr. Arthur Witt ^'^^ tested the ability of common warm-water fish to learn 

 to avoid an earthworm impaled upon a hook; at the same time these fish 

 were being fed on free earthworms. Largemouth bass learned quickly, 

 but were sometimes somewhat brash when they evidently realized they 

 would be hooked. Bluegills learned quickly and were much less bold 

 than were the bass. Warmouths were difficult to impress with the danger 

 of being hooked and learned very slowly. Even an electric shock applied 

 to the warmouth when it bit the hooked worm did not always deter 

 it from biting the next one presented. The fish that "learned" to avoid 

 being caught retained this learning for several days. 



Lagler and DeRoth ^^ discovered that the bass in Lower Lach Alpine 

 (Michigan) could not be "fished out." When the population of this lake 

 had been reduced to 6 legal bass per acre the rate of catch was 0.04 legal 

 fish per hour ( 25 hours to catch one legal fish ) . At this time the fishermen 

 had the impression that the lake was "fished out." 



Westman, Smith, and Harrocks ^^ describe a "die-away curve" in fishing 

 success for largemouth bass which was the same when the fish 'were 

 returned to the water as when the fish were removed from the water. 



The largemouth bass of Ridge Lake (Illinois) always exhibited re- 

 sistance to being caught (Figure 7.3).'^ In 1949, for example, tlie lake 

 contained 1027 marked bass large enough to catch. These fish were re- 

 turned to the lake basin after the lake was drained in March and a small 

 amount of water had collected behind the dam. By June 1, when the lake 

 was opened to fishing, it had refilled only to the 11-acre contour (lake 

 area at spillway crest about 18 acres). Thus, all of the larger bass that 

 had developed in 18 acres were concentrated in a much smaller volume 

 of water supporting subnormal populations of small fish and crayfish 

 ( because they had been removed or lost on the March drainage ) . In spite 

 of these adverse conditions for bass, after 220 hours of angling per acre, 

 fishermen were only able to catch 595 bass or only 67.1 per cent of the 

 weight of bass returned. 



The experience at Onized Lake ( Illinois ) where 275 bass were present 

 in a 2-acre pond after more than 3000 hours of angling points up the 

 futility of fishing for bass after they have become "conditioned" to 

 angling.^* 



Aldrich ^ describes some observations made on largemouth bass at 

 Spavinaw Lake ( Oklahoma ) : By sitting quietly and flipping pebbles into 

 the water dozens of bass were attracted to the boat. Minnows flipped 



