62 



months, from dry goods boxes obtained in town. Thirteen of the 21 

 houses were inhabited during the following summer, 6 by wrens, 4 by 

 bluebirds, and 3 by colonies of purple martins. The grasshoppers that 

 summer made a rich living for the birds, and when the fall came that farmer 

 had the satisfaction of gathering 23 bushels of corn from the three rows 

 that grew next to the fence, right where there had been no corn at all the 

 year before. With corn selling at 55 cents per bushel, it represented a 

 saving of $12.65 for that year alone, and with the same insurance for the 

 following year with no outlay at all. x 



The most recent investigation regarding the cash value of a 

 bird is that of Dr. Gross, who makes the following estimates in 

 regard to the dickcissel or black-throated bunting. He has 

 studied the food of the young of the dickcissel and also the food 

 of the adults. He noticed that from the fifth day until the 

 young left the nest their food was practically all grasshoppers. 

 These grasshoppers were taken from a near-by clover field 

 which was overrun with them. During the last days spent by 

 the young in the nest, grasshoppers were fed to them at the rate 

 of one every three or four minutes. A conservative estimate 

 indicates that about 200 grasshoppers were eaten each day by 

 the two adult birds and their four young. Dr. Gross says that 

 if each dickcissel family averages as well as these birds, then 

 the more than a million dickcissels in Illinois destroy about 

 100,000,000 grasshoppers in a day during this period of the 

 nesting season. Since each grasshopper, according to an esti- 

 mate made by Professor Lawrence Bruner, entomologist of the 

 Nebraska Experiment Station, consumes about one and one-half 

 times its own weight, or about .05 ounce of grass a day, then 

 100,000,000 grasshoppers would destroy about 156 tons daily. 

 The price of hay during the summer of 1918 was about $30 a 

 ton; therefore the dickcissels of Illinois during the active pejiod 

 of the nesting season saved the people of the State about $4,680 

 daily by the destruction of grasshoppers alone. 2 



Mr. W. L. McAtee, the eminent economic ornithologist of 

 the Bureau of Biological Survey, United States Department of 

 Agriculture, says that investigation has shown that most birds 

 are beneficial, although in varying degrees, and that only four 

 or five species in the United States are consistently injurious. 



1 Iowa Conservation, January-March, 1917, Vol. I, No. 1, p. 12. 



Gross, Alfred O.: Auk, Vol. XXXVIII, No. 2, April, 1921, p. 166. 



