No. 4.] DECREASE OF BIRDS. 487 



The Natural Enemies of Birds. 



In the opinion of many correspondents, the natural ene- 

 mies of birds do no appreciable injury, while others consider 

 fEem 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 J) 

 it might seem that those most responsible for the decrease of/ 

 birds were trying to shift the blame ; but we must remember \ 

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



most likely to observe their destruction bv their natural \ 



" _J 



enemies. 



Under normal conditions, the natural enemies of birds are 

 alsqlJifii* friflnds7 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 appreciable effect on the^numbers of game birds. 



Hawks 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 Avell 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- 

 wise increase unduly, and become very destructive to egg* 

 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- 



