320 The Ruffed Grouse 



portance. Predators may not cause major grouse declines but in 

 most areas they play a part in implementing them. 



10. Sunspot Cycles are Correlated with the Die-off in Grouse. 



Among the first to suggest that sunspots might be correlated with 

 wdld life population fluctuations was DeLury (1930). The concept 

 of some direct action from the sun affecting animal hfe so fitted the 

 need for an all-pervading, mysterious something to explain the 

 newly recognized animal population cycles that it was grasped 

 quickly by many workers in the field. To make the solution complete 

 it was even felt ( or possibly hoped ) that in some unexplained man- 

 ner the recurring intensities of sunspots, with their effect upon the 

 ultraviolet and possibly other vitally important rays from the sun, 

 directly resulted in the decimation of vast miJtitudes of susceptible 

 animals. Such a theory is generally discounted today. 



As the meteorological and biological specialists working in this 

 field progressed with their studies, it was evident that sunspot 

 cycles actually do affect Iffe on the earth but little agreement was 

 reached as to their relation to animal cycles. Effects upon the 

 weather, which in turn greatly affects animal survival, seem to be 

 clearly demonstrated. It is conceivable that the changes In the sun's 

 rays accompanying the sunspot phenomenon may alter the quality 

 in vegetable foods developed through photosynthesis. Braestrup 

 ( 1940 ) gives evidence that mineral deficiencies may thus be caused, 

 deficiencies that may be vital to life. Wing ( 1935 ) , in studying wild- 

 Iffe cycles, came to the conclusion that "the sun is the dominating 

 factor in wild life," logical enough but not unveiling the modus 

 operandi of cyclic behavior. Clarke ( 1936 ) is among those who dis- 

 count any connection between the sunspot and wild-life numbers 

 cycles, as are also MacLulich (1936) and Cross (1940), Canadian 

 associates all. MacLulich, with convincing evidence, thoroughly lays 

 the ghost and concludes: ". . . the fluctuation in numbers of neither 

 lynx (Lynx canadensis) nor varying hare (Lepus americanus) are 

 correlated with sunspots. . . ." Elton (1942) likewise discounts 

 this theory, concluding ". . . There can be httle doubt that it is 

 wrong. . . ." 



The shortcomings of the sunspot theory are many. In the first 

 place, the cycles do not always check by any means. The grouse 

 fluctuations are too erratic geographically to be guided by such an 

 all-pervading force. The geographical lag does not fit into the 



