4 
voodpecker and warbler, in the tree tops, select still others. It is thus 
apparent that a bird’s diet is likely to be quite varied, and to differ at 
different seasons of the year. 
In investigating the food habits of birds, field observation can be 
relied on only to a limited extent, for it is not always easy to determine 
what a bird really eats by watching it. In order to be positive on this 
point, it is necessary to examine the stomach contents. When birds are 
suspected of doing injury to field crops or fruit trees, a few individuals 
should be shot and their stomachs examined. This will show unmis- 
takably whether or not the birds are guilty. 
In response to a general demand for definite information regarding 
the food habits of our native birds, the Biological Survey of the Depart- 
ment of Agriculture has for some years past been conducting a system- 
atic investigation of the food of species which are believed to be of 
economic importance. Thousands of birds’ stomachs have been care- 
fully examined in the laboratory, and all the available data respect- 
ing the food brought together. The results of the investigations 
relating to birds of prey, based on an examination of nearly 3,000 
stomachs, were published in 1893, in a special bulletin entitled The 
Hawks and Owls of the United States. Many other species have been 
similarly studied and the results published, either in special bulletins 
or as articles in the yearbooks. The present bulletin contains brief 
abstracts of the results of tood studies of about 30 grain and insect 
eating birds belonging to 10 different families.! 
These species comprise among others the crow blackbirds and rice- 
birds, against which serious complaints have been made on account of 
the damage they do to corn, wheat, rice, and other crops; and also the 
cuckoos, grosbeaks, and thrashers, which are generally admitted to be 
beneficial, but whose true value as insect destroyers has not been fully 
appreciated. The practical value of birds in controlling insect pests 
should be more generally recognized. It may be an easy matter to 
exterminate the birds in an orchard or grain field, but it is an extremely 
difficult one to control the insect pests. It is certain, too, that the 
value of our native sparrows as weed destroyers is not appreciated. 
Weed seed forms an importantitem of the winter food of many of these 
birds, and it is impossible to estimate the iumense numbers of voxious 
*veeds which are thus annually destroyed. 
'The limits of this bulletin preclnde giving more than a very brief statement 
regarding the food of each bird, but more detailed accounts of some of the species 
will be found in the following reports of the Biological Survey (formerly Division 
of Ornithology and Mammalogy): The Cuckoos—Bulletin No. 9, 1898, pp. 1-14; 
Crow—Bullotin No. 6, 1895, pp. 1-98; Woodpeckers—Bulletin No. 7, 1895, pp. 1-39; 
Kinghird—Annual Report Secrotary of Agriculture for 1893, pp. 233-234 ; Redwingel 
Blackhird—Yearhook for 1897, pp. 349-351; Baltimore Oriole—Yearbook for 1895, PP. 
126-420; Grackles—Yearbook for 1804, pp. 233-248; Moadowlark—Yearbook for 1895, 
pp. 420-426; Cedarbird—Annual Report Socretary of Agriculture for 1892, pp. 197- 
200; Catbird, Brown Thrasher, and Wren—Yearbook for 1895, pp. 405-418. 
