APPENDIX G 129 



always a possibility that these losses may be repaired by means of second broods, and 

 where the parent stock is healthy there is more chance of these second broods being 

 successful. The case is different where the stock is unhealthy, for then the nests contain 

 fewer eggs, the eggs are less fertile and the parent birds have not sufficient stamina to 

 produce successful second broods. This seems to be a reasonable explanation of the rather 

 puzzling fact that it is only where the parent birds are unhealthy that the young stock 

 seems to be seriously reduced by bad weather in the breeding season. Another possible 

 explanation is that the weather does not affect the case at all, and that the only reason 

 for the failure of the young stock is that the parent birds are unhealthy, and therefore not 

 prolific. But this explanation would entail the discarding of the unanimous evidence of 

 the reporters on the subject, and we think that the evidence goes far to establish the 

 following points. 



(a) Eggs may be destroyed by (1) snow; (2) frost; (3) wet ; their liability to destruction 



depends upon the stage of development they have reached. If they have not yet 

 been sat on probably none of these agencies will destroy them, provided the hen 

 does not desert or lose the nest. We know of cases when eggs have been buried 

 in snow for many days, 1 or have been covered to a depth of several inches with water 

 without suffering any harm. On one occasion (May 14th, 1911) a sitting hen 

 was driven off her nest by flooding ; the eggs were covered with water and their 

 colour washed off, nevertheless the hen returned, and on May 25th the whole clutch 

 hatched out. Frost, unless very severe, is probably less destructive than rain or 

 even snow, for while the hen is sitting the eggs are safe, and before she has begun 

 to sit it is doubtful if they are damaged unless the frost is hard enough to split them. 



(b) Young chicks may be destroyed by drowning, but are seldom killed by frost, snow, 



or extreme cold. 



(c) Very hot, dry weather after hatching has sometimes been associated with loss of 



chicks ; a possible solution is suggested on p. 264 vol. i. 



4. Relation of Weather Conditions to Health of Stock. If the stock is healthy bad 

 weather in the breeding season does little harm ; if the stock is unhealthy bad weather 

 at nesting and hatching time will result in a failure of young birds. 



The effects of a good breeding season upon a healthy and unhealthy stock respectively 

 cannot be stated with certainty, for during the three years under review there was no 

 really good breeding season. The nearest approach to favourable conditions occurred in 

 the east of Scotland in 1908, and then the results seemed to indicate that even where the 

 weather conditions are favourable an unhealthy stock will not be prolific. 2 



In the light of the foregoing remarks we may now with some confidence attempt to 

 answer the list of queries with which this chapter opened. 



(1) The weather during the winter appears to be immaterial, provided the food supply 

 is good. The winter food supply depends on (a) good spring growth ; (b) good 

 summer bloom ; (c) good autumn seed in the preceding year. The first-named 



1 Vide vol. i. chap. ii. p. 10. 



2 firfepp. 119-120. 



VOL. II. I 



