410 University of California Publications in Zoology IT L - U 



to the young by the parents may be observed ; second, the stomach 

 contents may be examined and the quantity estimated; third, 

 experimental feeding of caged birds may be used; and fourth, 

 the quantity of food may be determined by a daily weighing of 

 nestling birds and of their excreta. 



The first method, owing to the difficulty of observing in the 

 field the feeding of the young of so shy a bird as the western 

 meadowlark, has been largely neglected in the interest of the 

 other more practical methods. However, some observations as 

 to the number of trips to the nest made with food have been made. 

 In one instance a female western meadowlark carried food to 

 the nest three times in twenty minutes (6:15-6:45 A.M.). As 

 the presence of the observer caused some nervousness on the part 

 of the parent birds, this cannot be considered the normal rate. 

 AMOUNT OF FOOD REQUIRED BY WESTERN MEADOWLARKS 

 Stomachs of nestling western meadowlarks examined con- 

 tained as high as two grams of insect food. Maxima of seven 

 large cutworms, of twelve grasshoppers (three-quarters of an inch 

 in length), and of eight beetles have been found in the stomachs 

 of nestlings. One stomach contained twenty-four ants and parts 

 of a ground beetle. The volume of nestling stomachs and of 

 their capacity in terms of the common elements of food follows : 



Volume of average cutworm 5 c.c. 



Volume of average ground beetle 3 



Volume of average grasshopper 75 



Volume of average stomach of $ western meadowlark 3.00 



Volume of average stomach of $ western meadowlark 2.50 



Capacity of average <$ stomach in cutworms 6 



Capacity of average $ stomach in cutworms 5 



Capacity of average stomach in ground beetles 10 



Capacity of average $ stomach in ground beetles 8 



Capacity of average $ stomach in grasshoppers 4 



Capacity of average $ stomach in grasshoppers 3 



A nestling western meadowlark after obtaining no food for 

 three hours was fed twenty-eight small grasshoppers (one-half 

 inch in length), equal in volume to about three cubic centimeters. 

 Another one was fed four grasshoppers (one inch in length), 

 twelve small grasshoppers (one-half inch in length), one robber 



