246 The Ruffed Grouse 



Probably the most prevalent species is H. cinnabarina Koch 

 (1844), the common rabbit tick, found on numerous mammals, 

 gallinaceous biids, and man. It is a carrier of the dread disease, tula- 

 remia. Its range is wide and it is known to infest giouse in the east- 

 em United States and Canada from Minnesota and Alberta to New 

 England and Labrador. 



Another species attacking grouse over a wide range is H. leporis- 

 palustris. Gross (1930) reported it ". . . present in considerable 

 numbers on most of the biids collected and examined at Matamek 

 (in Labrador, eastern Canada) in 1929." Fisher (1939) recorded 

 1,172 specimens taken from thirty ruffed grouse from Michigan and 

 examined by Dr. R. G. Green of Minnesota. The average number of 

 ticks per grouse was one hundred and sixty-seven. This species also 

 carries tularemia. Fisher also reported one grouse from Michigan 

 examined by Dr. H. J. Stafseth that had the tick H. punctata punc- 

 tata, a species found on a number of mammals and birds. The fourth 

 species, H. chordeilis, was reported from New York in 1941 (IV. Y. S. 

 Cons. Dept. Ann. Rep., 1941). 



The heaviest infestations of ticks have been reported by Green 

 from Minnesota. The average number on all Minnesota grouse ex- 

 amined during September was six hundred and forty and in October 

 it was one hundred and eighty (Green and Shillinger, 1934). The 

 heaviest infestations were on two birds that yielded 2,985 and 2,468 

 ticks, respectively. The authors believed that the average figures 

 were lower than the actual owing to ticks escaping before the birds 

 were picked up and sealed in bags. 



Fisher (1939) quoted Green on the examinations of Michigan 

 grouse and their ticks: "Nineteen samples of a hundred ticks each 

 were injected into a corresponding number of guinea pigs. Two of 

 the nineteen guinea pigs died with lesions typical of tularemia, 

 showing that the samples of ticks obtained from grouse specimens 

 were infected with tularemia to the extent of ten per cent. This fig- 

 ure is probably to be considered a normal finding and does not 

 represent an unusual situation for the present stage of the game 

 cycle, as similar findings have been obtained in Minnesota." 



Infestation of ticks varies greatly in different years and probably 

 follows a rather well-marked cycle. However, there is often marked 

 variation in nearby localities at any given time. Numbers of ticks 

 present are, of course, correlated with grouse abundance, there be- 



