REPOKT OF THE ORNITHOLOGIST AND MAMMALOGIST. 



237 



Table showing the annual increase and the total number of English Sparrows, the 

 progeny of a single pair, in successive seasons for ten years, assuming that all 

 lived. 



Years. 



Fii-st. . . . 

 Second . 

 Third . . . 

 roiirth . 

 Fifth . . . 

 Sixth . . . 

 Seventh 

 Eighth , 

 Ninth... 

 Tenth ., 



Number of pah's 

 breeding. 



1 



13 



169 



2,197 



28,561 



371,293 



4, 820, 809 



62,748,517 



815,730,721 



10,604,499,373 



Number of pairs 

 of young. 



12 



1.50 



2,028 



26,3(>1 



342,732 



4, 455. .516 



57,921,708 



754, 982, 204 



9,7'88,768,652 



127,253,992.476 



Total number of Total number 

 pairs. of birds. 



10, 

 137, 



ss: 

 S7i: 



4,826: 

 62,748: 

 815,730 

 604,499 

 858.491 



26 



338 



4,394 



57, 122 



742,586 



9,653,618 



12,5,497,034 



631,461,443 



208,998,746 



716,983,698 



Method of diffusion of the Spart^ow. 



" As the towns and villages become filled to repletion the overflow movQS off into 

 tlie countiy, and the Sparrow'.s range is thus gradually extended. Occasionally, 

 however, it is suddenly transported to considerable distances by going to roost in 

 empty box-cars and ti-aveling hundreds of miles. "When let out again it is quite as 

 much at home as in its native town. In this way it reached St. John, New 

 Brunswick, in 1883, on board the raih-oad trains from the west. ±n like manner 

 another colony arrived March 1, 1884, in grain cars from Montreal. Similarly it 

 appeared at Moncton, Frederickton. and Saint Stephen, in Canada, and in a number 

 of towns in the United States." (Hoadley MS.) 



Aside from this accidental means of wide dispersion, small colonies 

 have been purposely carried from time to time to various localities 

 beyond the limit of its regular advance, and these in turn have be- 

 come centers of diffusion. Prominent examples of this sort may be 

 seen in the large colonies now inhabiting California, the basin of the 

 Great Salt Lake, and the region bordering the Lower Mississippi, in 

 Louisiana; 



The method by which the Sparrows spread without the aid of man 

 is peculiar. They first invade the larger cities, then the smaller cities 

 and towns, then the villages and hamlets, and finally the populous 

 farming districts. 



Bate of ST>read of the Sparroiv, and extent of area occiwied at the 

 close of the year 1886. 



In the year 1886 the English Sparrow was found to have established 

 itself in thirty-five States and five Territories. Of these it occupies 

 the whole or large parts of the following thirty-three States and two 

 Territories: Alabama, Arkansas, California, Connecticut, Delaware, 

 District of Columbia, Georgia, Illinois, Indiana, Iowa, Kansas, Ken- 

 tucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Min- 

 nesota, Mississippi, Missouri, Nebraska, Xew Hampshire, New Jer- 

 sey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, 

 South Carolina, Tennessee, Utah, Vermont, Virginia, West Virginia, 

 and Wisconsin, and is found in a few towns in Florida, Texas, Wy- 

 oming, Idaho, and Arizona. Small, isolated colonies may exist in a 

 few other Territories, but if so they have escaped the searching in- 

 quiry of the Department In the United States the total area occu- 

 pied at the close of the year 1886 is 885,000 square miles; in Canada 

 it is not quite 148,000 square miles; in all, 1,033,000 square miles.* 



* The data on wliich the computation of the Canadian area is based are insufH- 

 cient, consequently the size of the area here given must be regarded as approximate 

 only. The United States area, however, may be looked upon as very nearly exact. 



