314 



ground. 199 in orchards. 115 in meadows, 71 on recently plowed 

 ground, and 46 of them on young wheat. Taking into account 

 the different acreages of these areas and computing the num- 

 ber of birds per square mile in each, we have 2726 per square 

 mile in orchards, 1551 in pastures, 1587 in meadows. 468 in corn 

 fields, 430 on plowed ground. 429 on stubble, and 192 on young 

 wheat. A square mile of swamp land, if we may judge by the 

 forty-seven acres examined, would have contained a population 

 of 1331 birds; and a square mile of farmyards, 6580. Com- 

 pared by percentages of all the birds in each crop, 47 per cent, 

 were in pastures. 20 per cent, in corn, and 9 per cent, in stubble, 

 the ratios in other crops and situations ranging from 4 per 

 cent. down. 



The above crops may be divided, from this point of view, 

 into four classes: young wheat, with less than 200 birds to the 

 square mile; corn, stubble, and plowed ground, with about 450 

 each; pastures and meadows with over 1500 each; and orchards, 

 with 2700 birds to the like area. The fact that birds are nearly as 

 common in old stubble fields as in corn, suggests that it is not 

 the grain in either case which attracts them there, but rather the 

 seeds of the weeds by which both kinds of fields are generally 

 covered in fall. Their preference for pasture-lands is probably 

 due to the amount of food found by them in the droppings of 

 stock, and to the greater abundance of insect life in such a situa- 

 tion. Other comparative conclusions may best be postponed 

 until the special assemblages of birds characterizing each of 

 these principal classes of situation are more fully discussed. 



The Principal Birds in each Crop. 



The next four tables give us the data of the distribution 

 and abundance of the principal species of birds as related to the 

 principal crops. In Table V. we have the numbers identified 

 of the twelve most abundant birds in each kind of crop, without 

 reference to differences in acreage. In Tables VI. -VIII. the list 

 of species is reduced to nine by dropping the three passing mi- 

 grants. In Table VI. the number of birds per section, or square 

 mile, of each crop is given for each of the species; in Table 



