SECOND ANNUAL REPORT OF BIRD COUNTS IN THE U. S. 13 



100 pairs of native birds, while the Biological Survey's estimate is 

 5 pairs. Based on his count, Mr. Burns estimates 165,000,000 individ- 

 ual English sparrows in the United States east of the Mississippi 

 Eiver, but this may be somewhat too high for the whole area, since 

 the English sparrow is especially partial to human society and the 

 square mile worked on by Mr. Burns contained more than one person 

 to the acre, or a human population thirty times as dense as the 

 average for farm land in the United States east of the Mississippi 

 River, and several times the average density for the whole land in- 

 cluding cities. 



SOME NOTABLE REPORTS. 



The most elaborate report to the Biological Survey in 1915 was 

 that of the campus of Cornell University, at Ithaca, N. Y. Its 256 

 acres was divided into six blocks, and the survey of each was made by 

 a different person, the whole being in charge of Prof. Arthur A. Allen, 

 of the university. Following is a description of each of the six 

 blocks : 



Block A, 22 acres, hillside pasture with a few trees; block B, 34 

 acres, hillside planted with scattered groups of trees and shade trees 

 about residences, with very little shrubbery; block C, 87 acres, con- 

 taining lawns, shade trees, a little shrubbery, and most of the uni- 

 versity buildings; block D, 24 acres, about one-third woodland, con- 

 taining residences with shade trees and some shrubbery ; block E, 64 

 acres, a clover field, a small nursery, a little woodland, and many new 

 buildings; block F, 25 acres, a hillside pasture covered with a 

 thicket of thorn apple and containing a stream. 



It is interesting to note the wide variations in the bird popula- 

 tion of the various sections. Block C, which contains the university 

 buildings and therefore has the largest human population, hundreds 

 of students passing and repassing all day, has less than the average 

 of native birds but swarms with English sparrows, in numbers al- 

 most equal to the total of the native birds. Block D, containing 

 residences, with their shade trees and shrubbery, has the greatest 

 density of native bird population — 84 pairs on 24 acres; and blocks 

 A and F, hillside pastures, though supporting a population of native 

 birds considerably above the average for the State, are almost free 

 from English sparrows. (See Table II.) 



Another count, representing great and painstaking work, was 

 made by M. S. Crosby on Grasmere Farms, near Ehinebeck, N. Y. 

 A 210-acre section containing 92 acres of woodland, 38 acres of 

 plowed land, 25 acres of meadow, 40 acres of orchard, and 15 acres 

 of lawns, drives, gardens, and buildings, was found to have a bird 

 population of 54 different kinds represented by 366 pairs, or an 

 average of 174 pairs of native birds to 100 acres, nearly the same 

 as on the Cornell University campus. 



