VALUE OF BIRDS TO MAN. 45 



have eaten, during the day, a quantity one and five-sixths 

 times its own weight. 1 



Three young Robins, about ten days old, fed by their 

 parents, were watched by Weed and Dearborn. By an in- 

 genious method of weighing and calculating, the observers 

 arrived at the conclusion that apparently there was eaten a 

 daily amount equal to more than half the birds' own weight. 2 



Mr. Daniel E. Owen kept a young Hermit Thrush, which 

 ate regularly half its weight of raw steak daily, and would, 

 he says, probably have eaten as much more had it been fed 

 often er. 3 



In 1895 two young Crows were kept and fed by Messrs. 

 A. H. Kirkland and H. A. Ballou, then my assistants, from 

 August 7 to September 2, when one bird was killed by 

 accident. The survivor was kept until September 14, when 

 it was killed to determine some points regarding digestion. 

 These birds were confined in a large cage or enclosure in an 

 insectary, and were also allowed access during the day to 

 an enclosed yard, which they reached through the window. 

 This gave them considerable exercise. 



A careful record was kept of most of their food. Never- 

 theless, they occasionally picked up some sprouted grain in 

 the yard, and probably a few insects that could not be re- 

 corded or weighed. For this reason the quantity of the daily 

 food supply recorded is probably, on the average, too low, 

 or, in other words, on the safe side. Some of the smaller 

 animals fed to the birds (toads, frogs, and salamanders) were 

 not always weighed, but they were measured and could be 

 compared with others of known weight, so that the weight 

 was approximated closely. 



The birds were well grown when they were first received ; 

 but the amount of food at first given them probably was not 

 sufficient for their needs, as their weight did not increase, 

 although they were fed a variety of both vegetal and animal 



1 Birds of Ontario in their Relation to Agriculture, by Charles W. Nash. 

 Toronto, Department of Agriculture, 1898, p. 22. 



2 Birds in their Relations to Man, by Clarence M. Weed and Ned Dearborn, 

 1903, p. 65. 



3 Notes on a Captive Hermit Thrush, by Daniel E. Owen. The Auk, Vol. 

 XIV, No. 1, January, 1897, pp. 1-8. 



