572 FLUCTUATIONS / V GROUSE ABUNDANCE 



the loss occurred has varied on different occasions. On Connecticut Hill losses during the 

 breeding and nesting season have averaged proportionately greater than those during the 

 brood period. In 1940 high nest mortality caused a sharp drop in the fall population level. 

 On the other hand, in those years when failure of the crop was most severe (1933, 1935 and 

 1942), unusually high brood mortality always occurred. On the Adirondack area very high 

 brood losses were responsible for the poor crops in 1933 and 1935. Although breeding fail- 

 ure apparently occurred its significance is not clear. Unfortunately there was no opportu- 

 nity to observe conditions associated with a real scarcity throughout the State. 



Evidence that failure of the ainnial increment has frequently been the chief cause of major 

 declines in the general abundance of grouse is also found in the observations of others. 

 Among the first to report this were Woodruff*"' and Forbush'" with reference to the scarcity 

 of 1907. As a result of his investigations in New York. Woodruff noted that "with only one 

 exception the observers state that all or nearly all the birds shot in 1907 were old birds, 

 and most of them cocks. Scarcely any young birds of the year were seen." The same author 

 also quotes similar reports from Connecticut. Massachusetts and Michigan. Speaking of 

 New England, Forbush stated "I had been much in the field during the spring and summer 

 of 1907, and had noted that very few young birds were reared in the region with which I 

 was familiar." Also applying to the 1907 decline the following statement appeared in the 

 Annual Report of the Pennsylvania Game Coramission™" "Game birds have not been as plen- 

 tiful during the last season as heretofore, notwithstanding the promised increase because of 

 the many birds left over the year before." 



Regarding the decline of the following decade Minnesota stated"" "In 1915 all hunters re- 

 ported finding few coveys of young birds and the few found were small. Much the same 

 condition prevailed in 1916." Similarly Pennsylvania's Annual Report for 1916"™ commented 

 that most of the grouse killed in the fall were old birds. 



Again in the next decade an official report for Minnesota"*' contains the following state- 

 ment, "During . . . 1923. the increase in partridge, or ruffed grouse, in many districts 

 of the state was almost unbelievable, these birds abounding in great numbers in suitable lo- 

 calities. So far as it has been possible to ascertain the birds wititered well during the winter 

 of 1923 and 1921 but for some unaccountable reason at the close of the nesting season in 

 1924 the decrease in numbers of these birds was so enormous that the closing of the tKirnial 

 shooting season was being seriously considered." In northern Michigan, too. a large crop 

 was said to have hatched in 1924 but most of the young died before the hunting season"'. 

 Similarly Brewster" called attention to "the well known fact that every now and then almost 

 no young grouse arrive at maturity in Now England during seasons when very many are 

 successfully hatched". McDonald'", speaking of eastern Canada, reported a great abundance 

 in the spring of 1924 and a good hatch but few at the end of the summer and also com- 

 mented "In fifty years with the grouse I fiii<l that they change in numbers greatK and always 

 in the summer". 



After his stud) of llni tualions in Canada, with parliinlar reference to Ontario from 1932 

 to 1935, Clarke" slated that his field studies at the time of the diniinulion showed that the 

 dying-ofT was the result of a condition "affecting chicllv \oung grouse and taking ])lace 



during the sununer". With res|)e(t to 1936 Massachusetts re]>i)rte<l" HulTc<l grouse had a 



good breeding season, and the young and (dd iiirds alike came liiroi];.:h llic sununer. but by 

 the lime the season opened their numbers were badlv depleted mi much so that, in order 

 to [)roti'ct the brood slock, it appeared to be the best policy to dose the season. ' 



