4 THE GROUSE IN HEALTH AND IN DISEASE 



for these reference may be made to the late Professor Newton's 

 "Dictionary of Birds." 1 



No precise date can be given at which Grouse begin to 

 pair, for this depends more upon the climatic conditions than 

 upon anything else. In a mild winter Grouse will pair as early 

 as December or January ; but if, after they are paired, the 

 weather becomes rough and stormy, they will again congregate 

 in packs, even after the usual date of nesting has arrived. 



The time at which they select their nesting ground (March 

 and April) is also, to a limited extent, influenced by climatic 

 conditions. On high moors, where the snow lies in late seasons 

 till far into spring, it sometimes happens that during the whole 

 winter, and even up to the month of April, there is hardly a 

 bird upon the hill, the whole stock being congregated on the 

 lower-lying moors where there is " black ground " on which 

 food can be obtained. In such seasons it is interesting to 

 observe the return of the stock to the higher parts as soon as 

 the snow begins to melt. As a rule the birds do not pair upon 

 the low ground, but congregate in packs upon the edge of the 

 snow, waiting for an opportunity of returning to breed on 

 their native hill. A good example of this was furnished in 

 the spring of 1908 on a high-lying moor in Inverness-shire. 

 During the preceding winter there had been a heavy fall of 

 snow which lay for many months on the higher ranges, and 

 drove the Grouse down in vast numbers to the lower levels. 

 On the moor referred to there was not a Grouse to be seen 

 until the snow began to melt about the end of April. But at 

 the first sign of thaw the stock began to return, and as each patch 

 of bare ground came into sight a pair of birds arrived as if guided 

 by instinct and commenced to nest. That year the shooting 

 season turned out to be a record one, for upwards of five thousand 

 brace were killed upon an area of 20,000 acres, and many more 

 might have been shot without unduly reducing the stock. 



While heavy snow during the winter may do little harm 

 though it lies till far into the spring, a loss of stock may result 



1 " Dictionary of Birds," p. 391. 



