Behavior Patterns 239 



As water temperatures drop below 18.3°C (65°F) warm-water fishes be- 

 come slow-moving and sluggish and their rate of digestion becomes 

 proportionately slowed.''^ However, the fact that most species of warm- 

 water fishes may be caught in winter through the ice suggests that they 

 do not stop feeding, even though the digestion of any food material 

 ingested mav require days. Because of a sluggishness of movement and a 

 tendency to congregate in deep water, the fish may be difficult for the 

 winter angler to find. Once a concentration of fish is located, they are 

 often caught at a relatively high rate and fishermen tend to congregate 

 at points where a few good strings of fish have been taken. 



For some unknown reason the catch of fish through tlie ice is usually 

 more rewarding in fish per man-hour during late January and February 

 than during the early part of winter. It has been conjectured that fat 

 stored during fall may be reduced by the latter part of winter so that 

 the fish become more interested in taking food. 



Of all the warm-water fishes, the crappies are more associated with 

 early spring fishing than any other kinds. Hansen ^^ showed that the 

 larger white crappies in Lake Decatur ( Illinois ) reached peak weight in 

 fall, winter, or early spring and lost weight during the spring months. 

 The period of good crappie fishing was usually correlated with the 

 period of weight decline. 



Largemouth and smallmouth bass will begin to feed actively in early 

 spring when the water is at a temperature below 15.6°C (60°F) but their 

 movements are so sluggish that an artificial lure moved at "normal" speed 

 for summer bass fishing is too "fast" for the bass to capture. This is also 

 true for various pan fish— bluegills, red-ears, pumpkinseeds, and war- 

 mouths. Yellow perch and yellow bass are often taken in numbers in early 

 spring, and they are active at colder water temperatures than are most 

 sunfish. 



Walleyes, northern pike, and muskellunge are quite active during early 

 spring when the water is still relatively cold. 



Except for the high rate of catch sometimes recorded for ice fishing the 

 catch rate for most anglers' species is highest in the spring months, begin- 

 ning in March in tlie south, in late April and early May in the mid-states, 

 and in late May and early June in the northernmost states and southern 

 Canada. The phenomenon of good spring fishing is probably due to a 

 combination of factors including a warming of waters, a sex stimulus, and 

 a scarcity of small fish upon which to feed. This high catch rate may 

 continue until spawning is completed and summer weatlier temperatures 

 are attained. At this time a maximum of foods is available both in quantity 

 and variety and surface water temperatures that exceed 23.9 to 26.9° C 

 (75 to 80°F) cause fish to seek locations where they may find cooler 

 temperatures and adequate oxygen. 



