CHAPTER VII 



THE ENGLISH SPARROW QUESTION 



THE multiplication of the English sparrow should 

 serve as a warning to all people who would introduce 

 foreign birds to this continent. If North America 

 should be once more connected with Asia by a wide 

 isthmus, the plant and animal life of both countries 

 would be deeply affected. The Atlantic Ocean is an 

 impassable barrier to most birds, and has probably 

 existed as such a barrier since birds began to sing in 

 the primeval forests. When we take an animal or a 

 plant across this wide barrier, we introduce a disturb- 

 ing factor into nature's household on the continent 

 where the species is introduced. If the new species 

 finds favorable conditions, it will multiply and spread 

 rapidly until it meets a new impassable barrier. The 

 most remarkable illustrations are the English sparrow, 

 or house sparrow in this country and the rabbit in 

 Australia. 



The house sparrow affects European song birds in 

 much the same way that it influences our own. As 

 far as I know, it is not claimed that it has directly 

 caused a decrease of European birds. We need, there- 

 fore, not be alarmed that it will cause the disappearance 

 of our song birds. The enormous increase of the bird 

 in this country is due to the following causes : 

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