172 THE GROUSE IN HEALTH AND IN DISEASE 



B. — Causes of Death and Damage restdting from Natural Conditions. 



Nearly all tlie causes of death and damage due to purely natural conditions 

 have from time to time been so well described that it will here suffice merely 

 to recapitulate them.^ 



1. Climatic extremes are well known and well recognised. They may 

 Climatic occur from the time the eggs are laid to the end of the bird's life, 

 extremes. ^^ every age, in every season, and every year, the welfare of the 

 bird is threatened by excess in one direction or another. 



Excessive heat and its usual accompaniment, water famine, are both somewhat 

 Heat and Uncommon at the time of year when they would be most dangerous 

 drought. ^Q Grouse life. They are referred to in chapter ii.^ 



The following abstracts sum up the harm done by wet and cold. Macdonald 

 in "Grouse Disease" has no doubt about the matter when he writes that 

 Wet and " Damp and cold never fail to produce diarrhcea, cramp, and disease " ; 

 '^°^^' and again, " Excessively cold or wet seasons are succeeded by great 



mortality among birds, and Grouse suffer more in wet than in dry seasons, how- 

 ever cold — this was strikingly demonstrated in the wet season of 1872-1873"; 

 and again, "Cold wet causes bad hatching seasons."' So also Macpherson in 

 the Fur and Feather Series says that young Grouse " do best in fairly dry 

 seasons." * And for the bad effect of cold and wet on the food supply Macdonald, 

 again, in "Grouse Disease," says: "We can also connect the disease with wet 

 seasons. The heather does not quite ripen, particularly the small tops on which 

 Grouse chiefly feed."' 



There seems, in fact, to be a consensus of opinion amongst those who have 

 had the best opportunities for judging, that the hatching season can hardly be 

 too dry so long as there are dewy nights. The chicks can supply their needs 

 by drinking dew in the morning, and beyond this they find sufficient moisture 

 in the insects and young succulent moss-cap.sules and heather shoots which form 

 their staple diet, and which contain something like 60 to 80 per cent, of water. 

 The sitting hens want water and must have it, and their bulky dropjiings may 



* In connection with the effect of weather conditions upon Grouse, much additional evidence has been 

 collected by the Coniniittce, and is summarised in Appendix G., vol. ii. In view of the information now 

 made available for the first time, it may become necessary to reconsider some of the opinions of recognised 

 authorities referred to in this chapter. 



^ Vule chap. ii. p. 16. 



^ Macdonald, " Grouse Disease," pp. 24, 40. 



■* Fur ajid Feather Series, " The (irouse," p. 24. 



' Macdonahi, " Grouse Disease," p. 40. 



