2 BULLETIN 187, U. S. DEPAETMENT OF AGEICULTUEE. 



PREVIOUS BIRD CENSUSES. 



The first publication of the results of a bird census on a large 

 scale in the United States was in 1901, at Berwyn, Pa., where F. L. 

 Burns reported 588 pairs of native birds breeding on 640 acres.^ 

 This is in very close agreement with the 583 pairs found to be the 

 average for the present census under comparable conditions. There 

 was no such agreement, however, in regard to the English sparrow, 

 Mr. Burns finding 106 pairs to the square mile as compared with 

 about 60 pairs as the average for the 1914 census. 



In the summer of 1907 the University of Illinois conducted a 

 series of statistical bird studies,^ and during the month of June 

 found 600 native birds per square mile as the average for southern 

 Illinois, or less than half the number found to be the average in the 

 national census. The method of conducting the Illinois census, 

 however, was so radically different from that used by the Biological 

 Survey that the two sets of figures are scarcely comparable. The 

 Illinois census finds for the whole State 114 English sparrows to the 

 square mile as compared with about 120 sparrows per square mile 

 for the national census; but here, again, the differences are really 

 greater than the above figures would indicate, for in the Illinois cen- 

 sus a large number of the English sparrows counted were young birds. 

 ■ The differences between these three censuses are most noticeable in 

 the case of the EngUsh sparrow. For every 100 native birds enumer- 

 ated in the bureau's census of typical farms of northeastern United 

 States, seven EngUsh sparrows were found. The Berwyn census and 

 the Illinois census showed 18 Enghsh sparrows per 100 native birds, 

 but, as abeady stated, many of these in the latter census were young 

 birds. 



PLANS FOR THE 1914 CENSUS. 



The first season's work must necessarily be regarded as largely pre- 

 liminary, and the present pubhcation, which may be considered in the 

 nature of a report of progress, is issued for the double purpose of 

 giving information as to the actual accomphshment in the prelimi- 

 nary survey and of increasing pubhc interest in the matter so that 

 next season the work may be greatly extended. 



A bird census of a tract of land near Washington, D. C, had been 

 taken for several years and the experience thus gained was used as a 

 basis for the following circular of instructions : 



1 Bums, F. L. A Sectional Bird Census Taken at Berwyn, Chester County, Pa., During the Seasons of 

 1899, 1900, and 1901. Wilson Bulletin, No. 37, 1901, pp. 84-103. 



- Forbes, S. A. The Mid-summer Bird Life of Illinois: A Statistical Study. American Naturalist, 

 XLH, 1908, pp. 505-519. 



