No. 4.] DECREASE OF BIRDS. 487 



The Natural Enemiefi of Birds. 



In the opinion of many correspondents, the natural ene- 

 mies of bu-ds do no appreciable injury, while others consider 

 them the chief cause of the decrease of birds. It is notice- 

 able that some sportsmen and gunners complain particularly 

 of hawks, foxes, crows, skunks and weasels. At first sight 

 it might seem that those most responsible for the decrease of 

 birds were trying to shift the blame ; but w^e must remember 

 that those who are most in the woods with the birds are 

 most likely to observe their destruction by their natural 

 enemies. 



Under normal conditions, the natural enemies of birds are 

 also their friends. There is no better proof of this than the 

 statements made by the early settlers at a time when game 

 birds were here in great abundance. Eagles and hawks were 

 then far more numerous than they are now. Evidently they 

 produced no a})[)reciable effect on the numbers of game birds. 



HaAvks which feed on birds will overtake the crippled, 

 sickly, least active or most conspicuous birds. This results 

 in a survival of the wariest, strongest, most active and least 

 conspicuous individuals, — in a word, the fittest. It pre- 

 vents the spread of disease and the propagation of weakness 

 and unfitness ; it preserves the race. This is true to a much 

 less extent of the effect of shooting, for a charge of shot 

 will overtake the strongest as well as* the weakest, — the fit 

 as well as the unfit. Hawks, owls, foxes and other so-called 

 enemies of birds also protect birds in another way. The 

 horned owl, no doubt, now and then kills a grouse ; but it also 

 kills the skunk and crow, which destroy the grouse eggs or 

 young. Hawks may kill game birds as well as other birds ; 

 but they also kill squirrels, crows, jays and weasels, the 

 enemies of these birds. All this may be true of the hunter 

 also ; but hawks, owls, foxes and weasels kill, in addition, 

 field-mice, deer-mice and shrews, all of which might other- 

 Avise increase unduly, and become very destructive to eggs 

 and young birds. No one knows how often the nests of 

 birds are broken up by deer-mice. They climb trees like 

 squirrels, nest in hollow trees, and may be as great a dan- 



