28 THE GROUSE IN HEALTH AND IN DISEASE 



ments of the breeding season. It is probable that various 

 motives induce the birds to congregate in packs. Some of these 

 motives may be briefly mentioned, (a) To get on to the high 

 bare tops out of the wet it is observed that Grouse are always 

 more packed after wet weather, (b) To go down to feed on 

 the cornfields ; Grouse are seldom found feeding singly on the 

 stooks ; this may be due to the natural timidity of the wild 

 bird, which makes it fear to resort to the unwonted feeding- 

 ground unless supported by numbers. The same rule applies 

 with even greater force to the case of birds leaving their own 

 ground and wandering far afield in search of food ; such migra- 

 tions never take place except in large packs, (c) Owing probably 

 to the same cause, Grouse invariably tend to pack after they 

 have been much disturbed, especially by driving ; on moors 

 which for some reason have not been shot over for a season 

 the birds do not pack until late in the year, (d) In dry weather 

 small packs of two or three coveys are found at or near the 

 springs even on August 12th. 



Undoubtedly, the most common cause of packing is scarcity 

 of food. It has already been remarked that during the winter 

 months the feeding area on every moor is restricted to those 

 parts where the heather is of such a character as to resist the 

 effects of frost and cold ; hence the birds tend to concentrate 

 upon these food centres. 



The habit of packing is probably indirectly connected 

 with the question of disease. If we admit that the congestion 

 of a large number of birds upon small areas of moor is conducive 

 to the deposit in dangerous numbers of the larval worms which 

 cause disease on the favourite feeding-grounds of the birds, 

 then it follows that the pack formation is in itself a danger 

 to the health of the stock. This view is supported by the fact 

 that where packing is the exception rather than the rule, as 

 in the west coast of Scotland, disease is of rare occurrence. 

 It is obviously impracticable to induce the Grouse to abandon 

 this dangerous practice of congregating in packs ; but in another 

 chapter suggestions are offered for minimising the risk of disease 



