874 



SCIENCE 



[N. S. Vol. XXXVI. No. 938 



The western meadowlark (Sturnella ne- 

 glecta) has been the subject of considerable 

 complaint from the ranchers of the state, 

 owing to its habit of pulling sprouting grain. 

 The investigation has shown that this bird is 

 guilty of destroying sprouting grain; but the 

 evidence as to its value as a destroyer of in- 

 sects is of greater interest. Some idea of the 

 remarkable change of food habits during the 

 year can be obtained from the following table. 



COMPABISON OF THE FOOD HABITS OP THE MEADOW- 

 LARK FOR DIFFERENT MONTHS OF THE YEAR, 1911 



Birds Collected in Grain Fields in the Vicinity of 



Sed Bluff, Tehama County, Cal. Average 



of Six Birds for Each Month 



TABLE SHOWING NUMBERS AND PERCENTAGES OF CUT- 

 WORMS CONSUMED BY MEADOWLARKS TAKEN IN 

 THE VICINITY OP RED BLUFF, CAL. 



Grain appears to be resorted to when insects 

 are not available. Beetles are taken the year 

 round. Cutworms in the food reach a maxi- 

 mum in May, whereas grasshoppers reach a 

 maximum in July, in this particular locality. 

 A table showing the numbers of cutworms 

 actually counted in the stomachs of meadow- 

 larks taken at Red BlufP in February, March, 

 April, May and June, and their per cent, of 

 volume demonstrates the quantities of these 

 pests destroyed by this species of bird. It will 

 be noted that the numbers of cutworms con- 

 sumed is greater when the worms are still of 

 small size. The percentages represent the 

 comparative volume of the difPerent kinds of 

 food found in the stomach. A few larvse not 

 typical cutworms, taken by the birds, are 

 nevertheless classified under this heading. 



The value of meadowlarks as checks on the 

 increase of grasshoppers is also attested by 

 the accompanying table. 



TABLE SHOWING NUMBERS AND PERCENTAGES OF 



GRASSHOPPERS CONSUMED BY MEADOWLARKS 



TAKEN IN THE VICINITY OP EL TORO, CAL. 



The numbers of grasshoppers were esti- 

 mated by counting paired mandibles. Man- 

 dibles pass through the alimentary tract with- 

 out being digested, as can be shown by an 

 examination of the feces. Experiments with 

 young meadowlarks has shown the time of 

 digestion of grasshoppers to be between three 

 and four hours. The numbers found in stom- 

 ach examination doubtless represent, there- 

 fore, those which have been eaten during the 

 preceding three or four hours, before the birds 

 were killed. In order to ascertain some idea 

 of the numbers consumed in a day, the aver- 

 age number per bird needs to be multiplied by 

 four. It seems safe to conclude that the par- 

 ticular meadowlarks examined were averag- 

 ing almost fifty grasshoppers a day. As many 

 as twenty-eight pairs of mandibles were found 

 in a single stomach. 



Of course not all of the grasshoppers de- 

 stroyed can be considered injurious, for only 

 certain species become abundant enough to 

 destroy crops. The main point to be noted 



