CHAPTER VI 



INFLUENCE OF WEATHER 



by Walter F. Crissey 



WEATHER AS A DIRECT DECIMATING AGENT 

 WEATHER AS AN INDIRECT INFLUENCE 



During the Nest Period — During the Brood Period — During the Adult Period 



COVER TYPE USE AS AFFECTED BY WEATHER 

 WEATHER AND FLUCTUATIONS IN GROUSE POPULATIONS 



^ 



Summary 



Weather is a basic influence on grouse and other wildlife species through its effect on the 

 environment in which they live. (p. 300). 



Its effect is largely indirect and specific relationships are therefore difficult to determine. 



(p. 300). 

 Direct losses from weather conditions seem negligible in New York, but on one occasion a 



severe cloudburst and flood before the chicks were six weeks old apparently took a heavy 



toU. (p. 301). 

 Although the onset of the reproductive season is primarily controlled by the progressively 



increasing length of daylight in the spring, minor variations in nesting dates from year 



to year seem related to the average minimum temperature during early April, (p. 303). 



There is apparent correlation between temperature and precipitation during the three weeks 

 immediately following hatching and the brood mortalitv occurring during the latter part 

 of the summer, (p. 303). 



The degree of over-winter loss among adult grouse seems to be affected to some extent by the 

 severity of the weather during March, (p. 304). 



There appears to be some degree of agreement between the occurrence of low temperatures 

 during March and June and periods of grouse scarcity which have been recorded in the 

 past. (p. 306). 



