THE ENGLISH SPARROW 3 ( .t) 



nies at Salt Lake City, San Francisco, and other outlying 

 regions ; and tlirough(jut this territory it occurred in great 

 abundance. Since then it has penetrated Vi'est to the Roclvy 

 Mountains, and south to Texas. This extraordinary spread 

 has been due to several causes. As already suggested, the 

 bird can adapt itself to various climatic conditions and its 

 fecundity is very great. Thus in our Southern cities there 

 are from five to six broods a j^ear, and from four to six young 

 in each brood. Assuming that twenty-four young, half of them 

 females, are produced by a pair each year, and that all the 

 females breed when one year old, and successivelj' for ten years, 

 and that there are no deaths, then in the tenth j'ear 1.36 billion 

 individuals will have been produced from the original pair. 

 To the realization of the possible maximum of reproduction 

 there are, however, manj^ checks, especially the destruction 

 of birds by accidents, disease, and beasts and l)irds of prey. 



Food of English Sparrow. — The house-sparrow was intro- 

 duced for the purpose of destroying or holding in check the 

 " canker-worm " and the various other caterpillars which 

 destroy our fruit, forest, and shade trees. There is much doubt, 

 however, whether the house-sparrow is at all efficient in the way 

 of destroying insect pests, while it is quite certain that it fights 

 with and drives awaj' our native insect-eating birds. More 

 important still, it destro^-s large quantities of grain in the field 

 as well as man}' kinds of garden produce, so that, on the whole, 

 the English sparrow must be reckoned destructive to agri- 

 culture. Of late years it has come into our Southern markets 

 as a substitute for the rice-bird, and it is to be hoped that there 

 will be a widespread demand for it in the market. 



Increase of Exotic Species. — The extraordinary spread of 

 the English sparrow after importation to this country is not 



