48 USEFUL BIRDS. 
seems quite probable- that a young bird at liberty, depend- 
ing largely on its own exertions to procure food, and thus 
exercising more than in confinement, would require still 
more food to repair the consequent extra waste of the 
tissues. 
Others have made similar experiments with Crows in con- 
finement. Samuels says that he has kept specimens in cap- 
tivity, and has proved by observation that at least eight 
ounces of such food as frogs, fish, etc., are eaten daily by 
our common Crow. He says that a Crow can live on a very 
limited allowance, but believes eight ounces to be a reasonable 
amount. He leaves us to infer that he is speaking of adult 
Crows, which undoubtedly require less food than their grow- 
ing young. 
Weed and Dearborn kept a wounded adult Crow in a small 
box, twelve by thirteen by twenty inches. In these cramped 
quarters, where the bird could hardly stretch its wings, it 
ate fish for three days in succession at the rate of four and 
eighty-three hundredths ounces per day,—more than a 
quarter of its own weight, or about half what our young 
Crows ordinarily required.” 
Probably the amount of food eaten by this captive bears 
about the same proportion to the quantity eaten by a vigor- 
ous Crow at liberty that the food taken by a prisoner in 
solitary confinement, or that consumed by a sedentary clerk, 
bears to the amount required by a strong man at hard labor, 
or by a prize-fighter in training. 
The amount of food taken by young birds could not be 
disposed of by such limited powers of digestion as are given 
to other animals. What a wonderful contrast is presented 
between the quantity of food required by the hot-blooded, 
quick-pulsing, active bird, and that needed by the cold- 
blooded vertebrates. Many reptiles can live for months 
without food. Even some of the mammals do not eat at 
all during their hibernation. 
' Birds of New England, by Edward A. Samuels, 1870, p. 359. 
? Birds.in their Relations to Man, by Clarence M. Weed and Ned Dearborn, 
1903, p. 61. 
