SECOND ANNUAL EEPOET OP BIRD COUNTS IN THE U. S. 



The number of new reports received from this section in 1915 was 

 almost exactly the same as the total number received in 1914. This 

 new material has been treated with reference to the same points con- 

 sidered in 1914, and the comparison of the results of the two years 

 is given in the subjoined table. 



The average farm in the Northeastern States, according to the 

 1910 census, contains 108 acres, and a farm of this size was used as 

 the basis of the calculations for each year. 



Table I. — Results of counts in northeastern United States. 



1914 



1915 



Average 

 for 2 

 years. 



Average area covered by each count. 



Acres. 

 58 



Acres. 

 64 



Acres. 



Plowed land 



Hay land 



Orchard 



Woodland 



Land around buildings . 



Permanent meadow 



Pasture land 



Average bird population on each area covered 



Average bird population for each 100 acres of the area covered... 

 Average bird population on each 100 acres of isolated woodland . 



Average area not covered by the count in each farm . 



17 



21 



19 



8 



6 



7 



4 



5 



5 



3 



9 



6 



3 



3 



3 



8 



6 



7 



15 



14 



14 



Pairs. 



Pairs. 



Pairs. 



69 



80 



75 



119 



126 



122 



175 



199 



187 



Acres. 



Acres. 



Acres. 



50 



44 



47 



Plowed land 



Hay land 



Woodland 



Meadow and pasture. 



Probable average bird population in the woodland 



Probable bird population on the remainder of the area 



Probable bird population on each 108-acre farm (estimated from average of 

 count area and area not covered) 



15 

 7 

 18 

 10 



Pairs. 

 31 

 14 



Pairs. 

 32 

 12 



124 



Pairs. 



119 



The results of the counts of 1915 agree so very closely with those 

 of 1914 as to indicate the strong probability that each represents on 

 the average a close approximation to the truth. 



Some 25 persons who sent in reports of bird counts in 1914, taken 

 on farms in the Northeastern States, made reports the next year of 

 counts taken on the same areas. The average of these for 1914 is 

 117 pairs of native birds to each 100 acres of farm land, while the 

 average for 1915 is 122 pairs. 



Combining all the 1915 counts from farms in the Northeastern 

 States with those of 1914 which were not repeated in 1915 — that is, 

 combining the counts of all the different farms received in the two 

 years — gives the following results, expressed in the same terms as 

 those used in the report of the 1914 enumeration : 



The average enumeration area on farms in the Northeastern 

 States is 61 acres, i. e., it consists on the average of the farm build- 

 ings and the grounds surrounding them together with approximately 



