14 Wyoming Birds. 



been very destructive to pear orchards in Maryland and 

 New Jersey. I learned that the birds had been visiting 

 these trees for about two weeks. At the time of my return, 

 they had evidently disposed of most of the last brood of the 

 season, for although they were still finding a good many on 

 the day of my return, they found very few afterwards, 

 though they visited the trees daily for a week longer. These 

 insects hibernate on the trees by hiding in the crevices be- 

 tween the twigs and are thus exposed to the attacks of birds 

 all winter." 



4. From Special Bulletin No. 3, University of Nebraska, 

 by Bruner, I take the following interesting computations : 



"In nearly every case where the food habits of our birds 

 have been carefully studied, we find that the good done far 

 exceeds the possible harm that might be inflicted by our 

 birds. Allowing- twenty-five insects per day as an average 

 diet for each individual bird, and estimating that we have 

 about one and one-half birds to the acre, or in round num- 

 bers; 75,000,000 birds in Nebraska, there would be required 

 1,875,000,000 insects for each day's rations. Again, esti- 

 mating the number of insects required to fill a bushel at 

 120,000, it would take 15,625 bushels of insects to feed our 

 birds for a single day, or 937,500 bushels for sixty days, or 

 2,343,750 bushels for one hundred and fifty days." 



When put in this way, the economic value of the birds is 

 easily comprehended as a real fact. 



5. From an article by Dr. Sylvester Judd, of the U. S. 

 Department of Agriculture, these figures are taken to show 

 the amount of weed seeds destroyed by seed-eating birds: 



"Prof. F. E. L- Beal, who has carefully studied this sub- 

 ject in the Upper Mississippi Valley, has estimated the 

 amount of weed seed eaten by the Tree Sparrow (Spisella 

 monticola) , Junco (Junco hyemalis), and other Sparrows 



