238 Fish Behavior and Angling 



natural function of that fish (the fish engulfs an insect larva containing 

 a hook and is caught, or strikes an artificial lure that imitates some natural 

 food, and is hooked). This seems like a method of predation that is fool 

 proof, i.e., the fish does not know that it is being attacked until it is 

 on the hook and therefore has less than the usual warning that a predator 

 is attacking. 



Why then are not all fish of desirable kinds and sizes removed from 

 heavily fished waters? 



In part, the answer lies in the ability of all living organisms to develop 

 greater or lesser resistance to forces in their environment that would 

 cause their death. Thus, in spite of the fact that angling is a "refined" 

 mortality factor in fishes, many of the fishes subjected to angling are 

 able to adjust to this factor and avoid being caught. 



Why do fish attempt to capture a natural or artificial bait or lure? No 

 one except a fish can know exactly, but we fishermen assume that they 

 bite because they are hungry or because they become "angry," or they 

 are inquisitive, or they are protecting a home territory, a nest, or a 

 hierarchy that is broken by the audacious action of a plug. 



Why then do fish refuse to bite? They may fail to come within striking 

 distance of the bait, may be unconvinced that the bait is a natural food 

 organism, or be frightened by unusual noises made by the fisherman or 

 by the bait. There is evidence also that fish may become conditioned to 

 avoid a bait through seeing one of their members being caught,-^ much as 

 minnows are observed to give a fear reaction to pike after one of their 

 members has been captured and eaten. 



In this chapter I have attempted to describe the limits of sensory 

 perception in some freshwater fishes and a few behavior patterns related 

 to their success as animals inhabiting an aquatic environment. In the 

 next few pages I will attempt to establish a relationship between fisher- 

 men and certain factors that are believed to influence the rate of catch 

 of fish. 



Factors that Influence Biting 



Factors that influence the angler's rate of catch can be conveniently 

 divided into several categories: (1) physical— those such as climate, 

 season, time of day, etc., that influence the general and nonspecific be- 

 havior of fish in their contacts with fishermen; (2) human— those, such 

 as degree of care in presenting baits, that are controlled almost entirely 

 by the fisherman; ( 3 ) fish response— factors controlled almost entirely by 

 specific fish behavior patterns; and (4) combinations of two or more of 

 these categories. 



Water Temperatures. Changes in water temperature associated with 

 the cycle of seasons affect the response of fish to the feeding stimulus. 



