174 Bryant, Birds as Grasshopper Destroyers. [April 



shore birds and one of the herons had turned their attention to the 

 grasshoppers. One hundred per cent of the food of a Killdeer was 

 made up of grasshoppers, eleven having been eaten. The Killdeer 

 being a common bird in the locality and having a greater capacity 

 than smaller birds must be considered an effective destroyer. 

 An Anthony's Green Heron collected along a canal contained 

 fourteen grasshoppers. 



Such then, are the conditions to be expected during an outbreak 

 of grasshoppers. Birds flock to infested areas and also change 

 their food habits to meet the abundance of a particular kind of 

 food, thus doubly increasing their efficiency in helping to bring 

 back normal conditions. 



Let us now compare conditions to be expected in localities 

 where grasshoppers exist in more nearly normal numbers. Since 

 birds which forage on the ground feed to an especially large extent 

 upon grasshoppers, we will depend upon the analysis of the food of 

 such a bird for evidence. As an illustration of this type there is 

 no better bird than the Western Meadowlark. 



The Eastern Meadowlark is noted as a bird which feeds exten- 

 sively on grasshoppers, 29 per cent of the food for the year being 

 made up of these insects. Beal (U. S. Dept. Agric, Div. Biol. 

 Surv., Bull. 34, p. 66) has pointed out that the eastern bird sur- 

 passes the western in the number of grasshoppers destroyed. He 

 further states that nearly every species of bird in the east eats a 

 larger percentage of these insects than does the related species on 

 the Pacific coast in spite of the fact that in the west grasshoppers 

 are available for a longer period each year. 



Further evidence furnished by the examination of nearly two 

 thousand stomachs of Western Meadowlarks taken in all parts of 

 California and in every month of the year has shown that the 

 western bird, although not equaling the record of the eastern bird, 

 in reality takes larger quantities of grasshoppers than was at first 

 supposed. 



Fourteen and two tenths per cent of the total food of the Western 

 Meadowlark for the year in California is made up of grasshoppers. 

 An additional 5.2 per cent is made up of crickets (Gryllus) and an 

 additional .9 per cent of Jerusalem crickets (Stenopelmafus). Five 

 hundred and eighty-seven or 30.5 per cent of the nineteen hundred 



