INTERNAL MIGRATIONS 281 



been covered with snow, resort to the farmyards, and 

 even to villages and towns. Scores of similar instances 

 might be given ; and in some continental districts, where 

 the weather has been far more severe than with us, still 

 more extraordinary cases have occurred — of wild birds 

 visiting civilized places to seek for food. Now in the 

 first place let it be remarked that however unusual the 

 locality may be in which such species may appear under 

 these exceptional circumstances, it is always within the 

 normal area occupied by that species. A Nutcracker 

 will never come to an English cottage door for food, no 

 more than a Robin will ever appear at the threshold of 

 a Canadian settler. In the second place, the straying of 

 a species from its accustomed haunts is purely abnormal 

 — a struggle for life in fact of an individual — and such 

 an action in the majority of cases would not save the 

 species from extermination if it succeeded in saving that 

 individual. The conditions for successful reproduction, 

 found only in the normal haunts of the species, would be 

 wanting, and the inevitable result would be a more or 

 less rapid extinction throughout the area affected. 



No matter how an area may abound with food in 

 winter, it will not be visited normally by any species 

 whose area of distribution is beyond it. Vast numbers 

 of birds die during a severe winter in the British 

 Islands alone, if food fails in the local area of distribution. 

 I have known our flocks of Redwings, which used to 

 come to certain localities and remain in them the winter 

 through, be almost exterminated during an exceptionally 

 severe season, and not to regain their usual numbers for 

 years afterwards. And this, mind, in a locality where a 

 flight of a very few miles would have averted the disaster. 



