238 The Ruffed Grouse 



BrachtjJaemus fiiscattis. This fluke was reported in one grouse from 

 Minnesota by Erickson (1944). 



In the autopsies of Michigan grouse reported by Fisher (1939), 

 trematodes were found only one year, 1933. Of seventy-three speci- 

 mens, two and fifty-nine one hundredths per cent contained cysts of 

 intestinal flukes. 



Of aU the hundreds of grouse examined by the New York study 

 {N. Y. S. Cons. Dept. Atin. Reports, 1932-42) only one bird was 

 found to have a fluke infection. In 1938, one bird of 69 had "cecal 

 trematodes." However, it seems quite likely that in these studies 

 these obscure worms may have been commonly overlooked. In no 

 instance, however, has their presence given rise to serious pathogenic 

 effects so far as is known. 



The Protozoa. Protozoans are single-celled, microscopic animals, 

 the parasitic forms of which are found in several parts of the body. 

 Some of these parasites cause serious disease in gallinaceous birds. 

 At least nine species are known to infect the ruffed grouse. 



Eimeria angusta E. A. Allen, 1934 



Eimeria honasae E. A. AUen, 1934 



Eimeria dispersa Tyzzer, 1929 



These protozoans are known as coccidia, and the disease they 

 cause is coccidiosis. Allen and Gross (1926) reported one wild 

 grouse as having a few coccidia but they found these organisms to 

 be a serious cause of loss in young grouse in captivity. A few years 

 later Tyzzer (1929) described E. dispersa from wild ruffed grouse. 

 This species is found in the small intestine. It ". . . is differentiated 

 from any other species of coccidia in gallinaceous birds by the ab- 

 sence of any well-defined polar inclusions in the oocyst" ( Boughton, 

 1937). This author reports finding it in twenty-four Minnesota 

 ruffed grouse, six and five-tentlis per cent of those examined. 



Two new species of coccidia in ruffed grouse were described by 

 E. A. Allen (1934), as E. angusta and E. honasae. The former lives 

 in the ceca and has been recovered from grouse taken in Labrador, 

 Alaska, and Minnesota. Allen says that "quite a number of the 

 birds examined had heavy infections . . ." Boughton ( 1937 ) found 

 it present in four ruffed grouse, or one and one-tenth per cent of 

 those examined and in one sharp-tailed grouse. 



