64 BIRDS IN THEIR RELATIONS TO- MAN. 



Mr. Daniel E. Owen has recorded ' some interesting obser- 

 vations on the food of a young hermit thrush recently from 

 the nest. It ate regularly half its weight of raw beefsteak 

 each day, and probably would have taken as much more had 

 it been fed at sufficiently frequent intervals. Perhaps the 

 most interesting point brought out was a method of deter- 

 mining the rapidity of digestion in young birds. Having 

 noticed that the blueberries eaten dyed the excrement, it oc- 

 curred to Mr. Owen that " this fact furnished a ready method 

 of finding the length of time required by the thrush to digest 

 blueberries. The test was made July 26. At 12.56 p.m. of 

 that day, the bird voided white excrement and was fed at 

 once with blueberries. At 2.28 p.m., one hour and thirty- 

 two minutes later, it dropped blue excrement mingled with 

 berry seeds. If this experiment was trustworthy, and I see 

 no reason to doubt the accuracy of the method, the time re- 

 quired for a blueberry to traverse the digestive tract was, 

 practically, one hour and a half." 



A brood of young cedar-birds confined by Mr. Frank Bolles 2 

 and fed by the old birds were supplied with eight thousand 

 four hundred cherries in twelve days. 



Three robins about ten days old observed by us were fed 

 in two hours one bird-cherry (P. pennsyleanica), one large 

 cricket (Gryllus), one smooth caterpillar an inch and a half 

 long, one moth (Noctuid), one harvest-man (Phalanyiida:), 

 one tumble-bug (Copris), two earthworms (Lumbricus), two 

 carabid beetles, twenty-nine grasshoppers (Acridiidce), and 

 eight small creatures thought to be spiders but which could not 

 be made out with certainty. These forty-seven items were 

 brought at thirty visits between 4.04 and 6.03 a.m. During 

 the middle of the day the old birds came less often. Be- 

 tween 10 and 10.30 there were four visits, from 1.25 to 1.51 



1 The Auk, vol. xiv. pp. 1-8. 



2 Id., 1890, vol. vii. p. 290. 



