The Diseases and Parasites of Wild Ruffed Grouse 239 



E. honasae occurs in the ceca, or rarely in the small intestine. It 

 was reported by Allen (1934) from birds taken in Massachusetts, 

 Quebec, Labrador, and Alaska. Few of the birds examined were 

 found to harbor this species. 



Coccidia were found in seventy-nine, or three and eight-tenths per 

 cent, of the adult grouse examined during the New York study, as 

 noted in their annual reports, but all were found between 1932 and 

 1937, none from 1938 to 1942. The highest rate of infection was ten 

 and seven-tenths per cent in 1936, but this figure may have been 

 affected by inclusion of some captive birds. Of the young grouse 

 examined, forty, or four and three-tenths per cent, had coccidia. 

 Again the record is erratic, varying from zero (three years out of 

 eight ) to seventeen per cent in 1934 and thirty-seven and five-tenths 

 per cent in 1932 ( three out of eight birds ) . 



Infections of coccidia in wild grouse have not been proved to be 

 of significance as a mortality factor. However, the possibilities of 

 this disease assuming importance at times are real, especially among 

 the young birds. Boughton (1937) concluded that it ". . . is un- 

 doubtedly a dangerous parasite. It is an intracellular parasite, de- 

 veloping chiefly in the epithelial cells of the small intestine, and 

 when present in large numbers may give rise to acute enteritis, caus- 

 ing denudation of the intestinal epithelium, consequent digestive 

 derangements and malnutrition, and the bird becomes emaciated 

 and anemic." Coccidiosis has caused considerable trouble to grouse 

 in captivity (Allen and Gross, 1926; Bump, 1935) although it does 

 not necessarily follow that similar infections can occur in wild 

 populations. The most that can be said is that these organisms are 

 potentially dangerous to wild grouse, but are not yet proved to 

 be so. 



Leucocytozoon honasae Clarke, 1935. This species is a blood para- 

 site that causes a malaria-like disease. It is found in both adults 

 and young but seems to be particularly pathogenic to the young. 

 So far it has been found and identified only from Ontario, Minne- 

 sota, and Michigan. 



So impressively did its occurrence correlate with the dying-off 

 of grouse in Ontario in 1933 and 1934 that Clarke concluded it 

 ". . . is most probably the organism responsible for the dying-off 

 of grouse." It is quite possible that epizootics of this disease might 



