194 The Ruffed Grouse 



were seasons of low abundance, when these conditions could only 

 prolong the existing grouse depression. Both 1910 and 1912 were 

 preceded by mild winters. 



Very bad February or March snow conditions occurred in 1893, 

 1896, 1897, 1900, 1908, 1910, 1916, 1920, 1928, and 1932. Those not 

 happening in a period of declining or low abundance, 1893, 1900, 

 1910, 1920, and 1932, were all followed by favorable June weather. 

 Several of these periods of excessive snow were of short duration, 

 as for example in 1932. 



Every time severe February-March snow conditions and very low 

 temperatures, followed by a very cold June, occurred in two suc- 

 cessive years, a giouse decline followed. And every time there was 

 an important grouse decline, these weather conditions had prevailed. 



A close scrutiny of the details of this record shows that it was not 

 uniform each time. Each decline was unquestionably the product 

 of several conditions, each of which varied on different occasions. 

 Predation varies widely, even when conditioned by weather factors. 

 We believe that disease played a significant part in the 1927 decline. 

 Was this epidemic set up by weather factors? We don't know. It 

 hardly seems that a haK-century record of weather-grouse-trend 

 correlations could have so much in common, as appears to be the 

 case, unless there was actually a real functional connection. It is far 

 from a perfect record of cause and effect; but is so impressive that 

 the importance of climatic factors in relation to grouse population 

 trends can hardly be discounted lightly. Weather conditions play a 

 big part in grouse fluctuations both great and small. 



REFERENCES AND CITATION SOURCES ON WEATHER 

 CONDITIONS IN RELATION TO RUFFED GROUSE 



Allen, A. A. The Autobiography of a Mother Grouse, Bird Lore, Vol. XXIX, 



No. 6, December, 1927. 

 Bump, Gardiner. New York's RufiFed Grouse Survey, Game Breeder, Vol. 86, 



No. 2, Feb. 1932. 

 DeLury, R. E. Sunspots and Living Things, Trans. 17th Am. Game Conf., 



1930. 

 DeLury, R. E., and O'Connor, J. L. Regional Types of Response of Wildlife 



to the Sunspot Cycle, Trans. 1st N. A. Wildlife Conf., 1936. 

 Eaton, E. H. Birds of New York, 1910. 

 Forbush, E. H. Game Birds, Wild Fowl and Shore Birds of Massachusetts 



and Adjacent States, 1912. 



