224 The Ruffed Grouse 



conclusive on this subject. Those who answered the Commission's 

 questiomiaire are convinced that these agencies (i.e. diseases and 

 parasites ) are playing little or no part in the present grouse shortage 

 —'disease' being placed last on the list of causes . . ." 



It was not long though before the matter of grouse disease again 

 received considerable attention. Following the secondary grouse 

 decline in 1924, the American Game Association arranged a study 

 of the grouse which from the start gave primary emphasis to the dis- 

 ease factor. Led by two eminent ornithologists, A. A. Allen and 

 A. O. Gross, this study inaugurated an era of research in the field of 

 wild life ecology and management. In their first report Allen and 

 Gross ( 1926), after a year's work including examination of nine hun- 

 dred and twenty-three birds, stated that ". . . no definite conclu- 

 sions or recommendations can yet be advanced." Nevertheless, con- 

 siderable progress was made. "The common belief is that there is 

 one disease responsible for the disappearance of the grouse. The 

 investigation this year uncovered no evidence to support the belief. 

 On the contrary over twenty different parasites and diseases were 

 found, any one of which may prove to be important in different lo- 

 calities. Some are abundant and of general distribution, others seem 

 to be of only local importance as yet." Later, evidence indicated that 

 the stomach worm {Dispharynx spiralis) might be the cause of local 

 grouse declines. Gross (1930) found that "this parasite was respon- 

 sible for the death of a large proportion of the birds found dead in 

 Massachusetts and Connecticut and sent to us . . ." No other dis- 

 eases or parasites of the wild birds showed any likelihood of causing 

 serious mortality. When Gross reported again a year later (Gross, 

 1931) he said that "not a single bird was received (during the past 

 year) which had met death through diseases or parasites." 



Thus was indicated the periodic nature of grouse disease as a 

 lethal agent. In the early years of the New York study, 1930-32, not 

 a bird found gave any indication of having serious trouble arising 

 from disease. Then, in 1933, the first indications of possible trouble 

 showed up at Connecticut Hill. The author found two grouse dead 

 and in full flesh which proved to have died from Dispharynx infec- 

 tion. Soon another bird was found which, while killed and decapi- 

 tated by a predator, was found to have been severely affected with 

 aspergillosis, which very likely had weakened it before the predator 

 attack. The grouse population was high and the incidence of para- 

 sitic infections was much higher than during the previous year. The 



