6 BULLETIN 1165, U. S. DEPARTMENT OF AGRICULTURE. 



truck. Such supplementary information sometimes explains the 

 presence of unusual numbers or species of birds on the tract surveyed. 



MORE REPORTS NEEDED ON CERTAIN AREAS. 



The most important phase of bird life concerns its relation to man 

 and especially as it helps the farmer in destroying the enemies of his 

 crops. It is more important therefore to ascertain how many birds 

 inhabit the trees and shrubbery on the part of the farm actually 

 devoted to crops and in the fields immediately contiguous to it thru 

 on land not devoted to agriculture; this should be borne in mind in 

 all investigations along this line. 



Another matter worthy of careful attention concerns the number 

 of birds inhabiting certain areas which, while not devoted to agricul- 

 ture, are important because of their nearness to centers of human 

 occupation. Among such places are city parks, cemeteries, etc., 

 where the presence of a large population of native birds is most 

 desirable. That birds are quick to recognize the advantages of 

 these sanctuaries, as they may be termed, where they find pro- 

 tection with food and shelter in plenty, is evidenced by reports that 

 have been received of censuses made on areas that included such land. 



In 1916 two tracts of 40 acres each in Golden Gate Park, San 

 Francisco, averaged nearly 9 pairs of birds to the acre. At Omaha 

 12 acres of city park in 1916 had 33 pairs of native birds, representing 

 21 species, and 2 pairs of English sparrows; and in 1917 15 acres 

 sheltered 70 pairs of 20 species, all native birds. Two years' counts 

 made in the 44 acres of Woollen's Gardens, at Indianapolis, showed an 

 average bird population of 320 pairs to 100 acres. In 1920, 80 acres 

 of the campus of Wellesley College had 111 pairs of 34 species of 

 native birds and 4 pairs of English sparrows. Five years' counts 

 made on 95 acres in Highland Park, at Rochester, N. Y., show an 

 average of 205 nesting pairs, with a maximum of 214 pairs in 1917. 



RESULTS OF BIRD CENSUSES NORTH OF MARYLAND AND EAST OF THE 



PLAINS. 



For the part of the country north of Maryland and the Ohio River J 

 and east of the Great Plains enough counts have been made (see v^ 

 Fig. 1) to make possible some deductions regarding the average bird 

 population of the farm land. This territory was studied in con- 

 siderable detail in 1915; but for the five years under discussion the 

 material at hand is not sufficient to make practicable quite so de- 

 tailed a study. The land surveyed has been classified, therefore, 

 simply as fields, woodland, orchard, and plowed land. The last 

 term, designating land in crops other than hay, is especially impor- 

 tant in a study of the distribution of bird life, for very few birds 

 nest on it: yet this is one of the types of land on which they are 

 greatly needed. 



In all reports and comparisons, and especially in the tables of 

 averages, the character of the land surveyed, judged on the basis 

 of averages or percentages, is of primar}^ importance, since this is 

 the principal factor determining the number and kinds of birds 

 that will be found nesting there. Two adjacent farms of the same 

 size may support the same number of pairs of breeding birds and 

 yet have few species in common, because one farm is upland and 



