388 University of California Publications in Zoology [Vol. li 



here presented can easily be verified. A determination of the 

 status of a bird must include a study of the bird from every 

 point of view. To many city folk the esthetic and educational 

 value of a bird is the more important, for they never see it from 

 any other point of view. Perhaps the rancher is an extremist 

 on one side and the city resident on the other. A modification 

 of the views on both sides is very desirable to a sane appreciation 

 of the value of birds in general and the western meadowlark in 

 particular. 



The advance made in investigations of the economic relations 

 of birds since Professor Aughey (1878) studied the relation of 

 birds to the locust ravages in Nebraska up to the present, when 

 government experts give the whole of their time to such inquiries, 

 demonstrates the growth of the science of economic ornithology. 



A study of this advance, however, shows that only a beginning 

 has been made. Although we know in general the food habits 

 of our common birds, yet conditions vary so greatly that we 

 cannot definitely predict the food in any given locality. The 

 work thus far has afforded us a general survey of the food habits 

 of birds and in some few instances has given lis definite knowl- 

 edge as to the u.sual food of certain birds. The thing that eco- 

 nomic ornithology has not afforded us as yet is a detailed study 

 of the food of a particular bird in a given locality throughout the 

 whole year. 



The importance, then, of a thorough knowledge of the eco- 

 nomic relations of a bird in addition to its life-history is evident. 

 It has been left to one of the new sciences, economic ornithology, 

 to tell us of these economic relations and to explain the real status 

 of birds. The agitation coincident with the establishment of 

 this science had made known at least five facts : 



1. Birds are very largely insectivorous, and as a result are 

 important in keeping the numbers of insects in check. 



2. The amount of food required by birds is enormoiLS. 



3. Birds often considered injurious are really beneficial, and 

 vice versa. 



4. Birds change their food habits and feed on the kind ol 

 food most easily obtained. 



