LOCAL CONDITIONS AND HEALTH OF GROUSE 303 



striking, for example, on many shootings the percentage of 

 mortality among young birds was much higher than the average 

 for the county, in some cases amounting to 60 per cent, or 

 80 per cent. On the other hand, in some cases the mortality 

 among the young birds was nil, and when this occurred the 

 bags in the shooting season were abnormally large. 



No accurate information was obtained as to the age at 

 which young Grouse were most susceptible to coccidiosis, few 

 chicks were picked up dead, but of the specimens obtained some 

 were reported as living a few days old, some a few weeks old, 

 and some half-grown. From observations upon birds received 

 in captivity it would seem that the younger the Grouse the 

 more vulnerable it is. 



The figures throw a sidelight upon the normal mortality 

 which may be expected among young Grouse, even in a good 

 season. They indicate that provided there is no serious mortality 

 among the adult birds the deaths among chicks may amount 

 to as much as 25 per cent, without unduly reducing the bags. 

 On the other hand, if the mortality among the chicks amounts 

 to more than 30 per cent, the bags tend to fall below the average. 

 This observation is confirmed in practice, for experience has 

 shown that the average yield of a moor is about two birds 

 for every bird left as breeding stock ; in other words, if a pair 

 of birds produces a brood of seven chicks it is found that of the 

 total number (nine) only about four come to the gun, two are left 

 as breeding stock, and the balance of three goes to make up the 

 wastage caused by disease or misadventure. Little wonder 

 that few survive to die of old age. 



The foregoing table does not bring out any marked con- 

 nexion between overstocking and mortality among the chicks, 

 for although the districts where mortality occurred were in 

 the majority of cases very heavily stocked, the same condition 

 existed in many districts where there was little or no mortality. 

 On the other hand, it is significant that a more detailed examina- 

 tion of the separate reports showed that in no case where there 

 was less than an average stock was there any serious mortality. 



