191-t] Bryant: Economic Status of the Western 3IcadotrIarl- 381 



The investigation has consisted primarily of field investiga- 

 tion, experimentation, and stomach examination. A large part 

 of the field work has been carried on at Lathrop, San Joaquin 

 County, California, a place admirably suited for the work in 

 hand. Duties on tlie agricultural and horticultural demonstra- 

 tion train, which toured the .state in 1911 and 1912 under the 

 auspices of the Department of Agriculture of the University of 

 California and the Southern Pacific Railway Company, have 

 afforded additional opportunit.v to study conditions from one 

 end of the state to the other. 



Economic ornitholog.y is a new science and has hardly pro- 

 gressed further than the stage of preliminary interest and stud.v. 

 As a result practically all of the work attempted thus far 

 has been of the extensive rather than of the intensive sort, and 

 has been made up largely of a study of the food of birds. In 

 this investigation the attempt has been made to improve on past 

 methods and, by determining the food of birds taken in the same 

 localit.v each month, or twice each month, to furnish reliable 

 evidence as to their food throughout the whole year. A study 

 of the l)ird in the field, its depredations, and its life-history, has 

 also been made in order that all available evidence might l)e 

 obtained. 



Considerable difficulty has been experienced in that there 

 has been, and now is, a difference of opinion as to the criteria 

 to be used in the determination of the economic status of a bird. 

 The ideas which have been advanced in the past, and even those 

 of the present day, appear to be unsatisfactory, or at least un- 

 trustworthy. It seemed, therefore, that a review of past methods, 

 with the addition of such new ones as appeared to be valuable, 

 might prove not only interesting but of considerable value to 

 future workers in the field. A similar lack of information re- 

 garding methods of stomach examination has been evident. A 

 detailed account of the method used in this investigation, there- 

 fore, seems jiistified. 



The service which birds render to agriculture has doubtless 

 been overemphasized. On the other hand, the position taken 

 by some that birds are of no value as insect and weed-seed de- 

 stroyers hardly seems .justified by the facts. If there be a mis- 



