178 ANNUAL REPORT OF THE Off. Doc. 



It has been calculated that there are about 7U0 to 1,0UU individual 

 birds to be found in every sciuare mile of rural district. Suppose 

 each bird consumes about 50 insects during the day (a very mod- 

 erate estimate, because parent birds visiting their young do so a 

 hundred times a day, and each time bring an insect or some article 

 of food, according to the nature of the bird); at this rate of figuring, 

 75U birds to a square mile, with 50 insects per bird per day — in the 

 State of Pennsylvania in a day there will be consumed one billion 

 seven hundred and sixty millions insects; or, in the course of six 

 months, 316,800,000,000 insects. Though probably a very moderate es- 

 timate, this will ■alf ord some idea of the immense benefit man derives 

 from birds agriculturally. Many birds considered injurious to man 

 will, on careful examination, tell a diherent story. The common 

 crow — blackbird, common in this vicinity, arrives from its winter 

 grounds in numbers about the first of March, gradually increasing 

 in numbers, and occurring all through the Middle, New England and 

 Southern States. This bird has a bad name among the farmers, 

 because it pulls up the seed corn, and later on feeds on the mature 

 corn, and to a certain extent on fruits. Therefore the farmers every- 

 where are down on the blackbirds. Some years ago, however, a 

 Government Bureau in Washington, D. C, was directed to investi- 

 gate the food habits of birds; and an immense number of bird stom- 

 achs were secured and then bottled in alcohol and studied under the 

 microscope, and the proportion of animal and vegetable material, 

 also the exact species of plants and insects that were contained, in 

 a great many cases has been ascertained. It was found in the case 

 of the blackbird that fullv one-half of its food consisted of insects. 

 In the case of the young blackbirds, they for several weeks are fed 

 entirely on insects. The digestive organs of the young blackbird 

 do not develop the heavy, thick coating of the adult blackbird for 

 quite a time, and it would be impossible to digest corn and w^heat 

 until it becomes almost an adult bird. The first food of the young 

 blackbird is almost invariably spiders," then larger soft insects, 

 finally, the several kinds of beetles. Hawks and owls have been 

 badly misjudged. Farmers shoot them on sight, because they 

 do a great amount of mischief. Investigation by the Department of 

 Agriculture shows that out of 73 species of hawks and owls in the 

 United States, there are only five really injurious to agriculture. 

 In all the others the proportion of noxious insects in their food is 

 very much in excess of a lot of our common hawks, there were 2,212 

 stomachs examined, and these contained in their food supply 5(> per 

 cent, of field mice (very injuiious to all sorts of crops), 27 per cent of 

 noxious insects, and 3i per cent, consisted of poultry'. The chicken 

 hawk is a great friend, instead of an enemy, to the farmer, rarely car- 

 rying off any chickens, but feeding almost exclusively on field mice 



