468 Umversitij of California Publications in Zoologij [Vol. 11 



perimental feeding has substantiated this fact. The larger the 

 amount of food consumed tlie larger must be the toll taken. As 

 experiment showed that insects are digested more rapidly than 

 grain, proportionately larger amounts of insect food than vege- 

 table food may be consumed daily. 



6. Stomach examination has demonstrated the following facts : 

 (1) A much larger percentage of animal food (sixty per cent) 

 is taken during the year than vegetable food (forty per cent). 

 The meadowlark feeds on grain to a considerable extent during 

 the winter months. A very small proportion of tliat found in 

 the stomachs was sprouted grain. A large proportion of the 

 grain taken was made up of wild oats and had evidently not 

 been gathered in grain fields. If meadowlarks by their depre- 

 dations can drive many of the ranchers of the state to drill their 

 grain and plant it more deeply the.y will be performing a service 

 by increasing the yield. The increased yield so produced would 

 doubtless more than cover the loss sustained from the birds. 



(2) Western meadowlarks destroy large numbers of insects 

 which are injurious to the same crop damaged by the birds 

 themselves. 



(3) The kind of food varies with time of year, locality, and 

 abundance of available food. This correlation of food habits 

 with the environmental conditions increases the bird's value as 

 a balancer. If the meadowlark did not change its food with a 

 change in supply, its value as an insect destroyer would be slight. 

 In turning its attention to the food most abundant it becomes 

 an important factor in maintaining a balance. Its survival as 

 a destroyer of insects is dependent on its being able to obtain a 

 supply of food when animal food is not available. 



(4) The quantity of injurious insects taken daily is large 

 enough to make this bird of at least some importance as a de- 

 stroyer of insect pests. The cumulative effect of such destruction 

 enhances the bird's value. Few beneficial insects are destroyed. 



(5) The meadowlark destroys quantities of seeds of serious 

 weed pests. 



The service which birds render to agriculture has been over- 

 emphasized by those appreciating the esthetic value of birds. 



