416 PARASITISM AND DISEASE IN RUFFED GROUSE 



Parasites of Other Wild Birds 



In considering the relation of other wild birds to parasitism and disease in grouse, the 

 factors which come to mind are the probabilities of association of grouse with other species 

 and the comparative susceptibilities of the birds. Some observations made during the Investi- 

 gation will illustrate the situation. The intestinal worms ( Ascaridia bonasae), gizzard worms 

 (Cheilospirura spinosa), cecal worms (Helerakis bonasae) and crop worms (Capillaria annu- 

 lata) found in ruffed grouse in New York have not been found in ring-necked pheasants, Hun- 

 garian partridge or bobwhite quail in this State. Stomach worms ( Dispharynx spiralis) which 

 are frequently found in grouse have been occasionally encountered in Hungarian partridge 

 and once identified in a wild bobwhite. Gape worms f Syiiiiamits trachea) are rare in 

 grouse but not uncommon in pheasant chicks in certain areas. 



These observations may be taken to indicate that in this State grouse are unimportant 

 factors in the distribution of parasites to other game birds and that the latter are of minor 

 importance in relation to parasites of grouse. The very few cases of aspergillosis which have 

 been reported in ducks have been unrelated to the cases of this disease observed in grouse 

 and in both birds the instances were so few as to be negligible. 



Avian tuberculosis has been encountered once in a wild pheasant and once in a crow but 

 was not found in wild grouse during the Investigation, although it has been observed in 

 captive birds. Gross"' reported this disease from grouse in JSew England. Though gape 

 worms have been reported from about forty species of birds, the difficulty experienced by 

 Ripple'"" in infecting chickens with eggs from the gapeworm found in the robin may indicate 

 that wild birds are not as important a factor in the dissemination of this parasite as has been 

 previously supposed. 



Green and Shillinger'"" reported a single case of "quail disease" in a wild grouse in Min- 

 nesota, but neither this disease nor blackhead, which ranks with it as a destroyer of grouse 

 in captivity, have been observed in wild grouse during the hnestigation. There seems to be 

 nothing to indicate that these maladies occur in the wild to any extent. 



Diseases of Wild Mammals 



Relatively few diseases are common to both mammals and birds, liul it so happens that 

 one of the most serious diseases of game mammals, tularemia, is transmissible to ruffed 

 grouse, sharptailed grouse, quail and sage hens. This disease is found most frequently in 

 cottontails though it also occurs in a number of other mammals. Transmission in the wild is 

 chiefly by the medium of deerflies and ticks, the most important being the rabbit tick (Haema- 

 physalis leporis-paUislris) . According to Shillinger and Morley'"' '"tularemia as yet has not 

 been found to be the cause of widespread losses among game birds." 



The potential danger of tularemia in ruffed grouse in New \iirk Stale i> cniulilioned consid- 

 erably by factors concerning relative tick populations on grouse and cottontails and the species 

 of ticks involved. In Minnesota where tularemia lias been reported as naturally occurring in 

 game birds, it is common to find several hundred licks on a grouse, cottontail or varying hare, 

 while in New York the average and the maximum infestations are much lower. Cottontails in 

 May have been found to carry from one to 184 licks I average U)). The maximum number of 

 ticks found on grouse in the summer was 300 in ihe Adirondacks (average 38) and 26 in the 

 rest of the State (average 5). A large percentage of the ticks found on grouse in New York 

 are the bird ticks (H. chordcilis). Up to 87 rabbit licks have been found on varying hares. 



