is 1917 | Recent Literature. 495 
and are the result of inexperience. The facts are: that nestlings do not 
thoroughly digest their food (apparently taking only the most available 
nourishment), so that identification is easier in corresponding cases than 
in adults; and that not only stomach analysis, but even examination of 
excrement, gives results that far surpass in definiteness and accuracy, 
anything that can usually be learned by field observation. 
For instance contrast the following statements of the results (from the 
paper reviewed) of 16 hours watching the feeding of brown thrasher 
nestlings and the analysis of a few droppings of nestling cardinals. 
Brown Thrasher Cardinal 
150 cutworms 17 rose-beetles (Macrodactylus subspinosus) 
9 “worms” 2 other Scarabzidze 
5 earthworms 1 click beetle (Limonius sp.) 
11 dragonflies 1 caterpillar hunter (Calosoma scrutator) 
10 beetles 1 leaf-hopper (Jassidz) 
50 ants 3 grasshoppers 
1 grasshopper 1 spider 
72 or more other insects. 1 dragonfly 
many bits of snail 
17 blackberry seeds (Rubus sp.) 
221 mulberry seeds (Morus rubra) 
Is it not obvious that the examination of excrement if carried on to an 
equal extent would surpass field observations in every way? Stomach 
examination would be still more definite as to composition of food; but 
would not yield so much information on quantity. The greatest defect 
of this method however, is that only one batch of data is obtained from a 
single individual. 
The foregoing notes on the cardinal are quoted from the reviewers’ 
paper on the grosbeaks,! where the method of studying the food of nest- 
lings by analysis of the excrement was urged. The method used was to 
tie a bag with a distinctly colored tape, over the breastbone and under wings 
of each nestling. The excrement can be gathered from such bags at any 
intervals desired and preserved as separate castings or in mass for analysis. 
The observer need not remain at the nest but can carry on similar opera- 
tions at several nests if desired. This work could be carried on by the 
same class of observers who now publish data on the frequency of feeding 
and the material if analyzed by competent scientists, would yield a vast 
amount of definite and therefore valuable information.— W. L. M. 
Effect of Poisoning Operations on Birds; Value of Carrion 
Feeders.— These interesting topics are further illuminated by data 
presented by W. W. and J. L. Froggatt in their third report on sheep- 
1 Bull. 32, U.S. Biol. Survey, 1908, pp. 23-24. 
