The Diseases and Parasites of Wild Ruffed Grouse 237 



Harmostomum sp. 



The fluke, H. pellucidum, is found in the ceca. It is about one- 

 twentieth to one-tenth inch in length and one-fiftieth inch wide. 

 Its life history is unknown. Boughton (1937) found it present in 

 ten Minnesota grouse, or two and eight-hundredths per cent of the 

 birds examined. The average number of parasites per bird was five 

 and two-tenths and the maximum eighteen. This fluke has also been 

 reported from New Hampshire grouse by Mueller (1941). 



Another fluke of the genus Harmostomum, species not identified, 

 was found in four young giouse in two locations in Ontario by 

 Clarke ( 1936 ) . The parasites were found in the anterior extremity 

 of the rectum. 



Leucochloridium pricei Mcintosh, 1932. This fluke, first described 

 from spruce grouse taken in Alaska, was first found in the ruffed 

 grouse by Mueller ( 1941 ) . It was present in over half the grouse 

 he examined from New Hampshire (forty-six birds), and charac- 

 terized one of the most frequently encountered parasitisms. The 

 worms were located "... in the bursa Fabricii, cloaca, and lower 

 rectum . . . Heavy infections were commoner in young birds, with 

 as many as a hundred or more worms present in a single host." The 

 individuals were about one thirty-sixth of an inch long. The author 

 does not mention any pathogenic effects. 



Prosthogonimus mucrorchis Macy, 1934. This parasite was described 

 from the lake states and had not been reported either outside that 

 area or at all in ruffed grouse previous to the single case found by 

 Mueller ( 1941 ) in New Hampshire. It is about one-fifth of an inch 

 long and lives in the cloaca. The bird from which it was recovered 

 was a male weighing two hundred and thirty-three grams, indicat- 

 ing it to be an immature. 



Agamodistomum sp. Larval forms of these flukes were found en- 

 cysted in the subcutaneous tissue of the bird's breast, imbedded in 

 the chest muscles, or occasionally on the outer surface of the crop 

 (Boughton, 1937). Its cysts were pearly white and about one- 

 fiftieth of an inch in diameter. They were in eighty Minnesota 

 grouse, or sixteen per cent of the birds examined, and were also 

 found in one sharp-tafled grouse. The known range is from Minne- 

 sota east to Michigan. 



