CHAPTER V 

 THE GAME CYCLE IN THE NORTH CENTRAL STATES 



A 



"BACKGROUND. Certain game species in the north central region and 

 |J elsewhere are subject to extreme fluctuations in abundance. 



It has only recently been generally realized that these fluctuations take place 

 more or less simultaneously over large areas, and that they have a more or less uni- 

 form period or length. This fluctuation is common to all cyclic game, and is 

 now coming to be known as the game cycle. 



It is necessary, before an analysis of the separate species can be attempted, to 

 first describe the cycle which affects all of them. This chapter describes their 

 common cycle. Subsequent chapters will describe the several species. 



Very little is known about the behavior of the game cycle, and still less about 

 its mechanism and causes. An investigation of the causes of fluctuation in ruffed 

 grouse was started by the American Game Protective Association in 1924. This 

 investigation dealt mainly with parasites. An astonishing variety of parasites 

 was found in ruffed grouse, but which of them cause the cycle, or whether all of 

 them merely accompany weakness induced by some other cause, still remains an 

 unanswered question. Several additional investigations dealing with diseases, 

 habitat, and history of cyclic species are now under way. 



When the game survey was started in 1928, it was apparent that it could 

 not undertake to add anything to these detailed scientific studies of possible causes. 

 Such studies require highly specialized experts, working through long periods of 

 time. It seemed probable, however, that the experts could make a better guess as 

 to what to look for, and could better interpret the meaning of what they found, 

 if the game survey compiled the available evidence on the general behavioi of 

 cycles with regard to species, geography, and time. It was believed that many 

 observing sportsmen and game wardens would recollect certain facts and dates 

 concerning behavior in their respective localities, which when compiled and 

 analyzed, might enable administrators to predict recurrences, and also enable 

 scientists to eliminate certain causes as inconsistent with behavior, and thus con- 

 centrate their labors on the remainder. Until science discovers the cause and 

 mechanism of the cycle, all efforts to manage and conserve the cyclic species must 

 necessarily grope in darkness. 



The detailed study of behavior of the game cycle was confined to Wiscon- 

 sin. It is hoped that similar studies of behavior will be made in other States. 



The greater part of the Wisconsin information appears on Charts 7, 8, 9, 

 and Map 12. The principal findings of the survey will be given first, and then 

 the methods whereby the information was collected and interpreted, and an ex- 



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