SOME INSI-CTS AND OTIIl-R AkTIIR()l»()I)S IN 



THE DIET OF TlU: WESTERN 



MEADOW EAR K 



IIAKol.D C. ItUV ANT 



In L'onncition with tlu' iiiv<sti(;iiti(iii into the cuonoinif status of certain 

 liiiils, now heintr carried on l»y the Ciilil'ornia State Fish and (iaino Coni- 

 rnission and the rniversity of California, many interesting things reg^arding 

 their food-hahits are l)eing diseovereil. For some time we iiave known that 

 certain birds destroy <|iiantities of insects. It lias only heen of late, however, 

 that we have attempted to determine the real kind and nuantity taken. 

 Kvidenco furnisheil hy the V. S. Uiological Survey and economic ornitholo- 

 gists have revealed some facts of unusual interest. The present investigation 

 is not only substantiating some of these facts but has furnished some interi'St- 

 ing new evidence. 



The (piantity of food reiiuired by birds necessitates that the numbers of 

 in.sects taken be very great. Stomach examination of the western meadow- 

 lark {SlunnUa iitylala) has shown that this bird often takes as many as 

 twenty large cutworms, thirty to forty ground beetles, ten to twenty crickets 

 or grasshoppers, and fifty or more ants to a meal. As the time of digestion 

 is between two and four hours the amount of fooil found in a mcadowlark's 

 stomach re|)resents the amount taken during the four hours before the bird 

 was killed. Si.xy-six mcadowlarks taken in the vicinity of Kl Toro, Orange 

 County, California, averaged ten gras.shoppers per stomach during the six 

 months, June to Xovend)cr. IJIll. Seventy-three and twenty-three hundredths 

 per cent of all the food taken by these sixty-six birds during these six months 

 was made up of grasshoppi-rs. Individual birds must have averaged over 

 thirty grasshoppers a day during this tinu*. 



But pcrhajis of more interest than the ([uanlily of life destroyed by this 

 liird is some of the pe<'uliariti<'s of its diet. The ordinary articles of diet are 

 ground beetles (Carabidu", Tencbrionida-), grasshoppers, crickets, cutworms, 

 wireworms, plant bugs ( Pentatomidae), certain bees, wasps and ichneumon 

 Hies, and ants. The extraordinary articles of diet can be summed up a.s, 

 centipedes, millii)cdes, scorpions, certain crustacca, snails, spiders, and pro- 

 tected and stinging insects. 



(iround l)eetles arc taken each mimth of the year. The following are 

 those most often taken: I'lt rostirlnis sp., Ciilatlnis nifudllis, AnisoilarU/liis 

 sp., ('laitiiiis sp., Kit odes sp., lilapsliniis sp., and Cotnoiilis subpubesccns. 

 Among the other beetles identified are Silpha sp., Drdstiriiis .sp., Mxjapniflus 

 alliriiniis. Limoiiiiis rolifoniiciix, Liminiiiix canis. Cardiophonis tiiifhrosus, 

 Sapriinis sp., Sphi nophtirus sp., and Pinhrolira sorni: Weevils and snout 

 beetles including nuMnbers of the family Curculionidae form a considerable 

 l>ercentagc of the bei'tlcs taken as food. 



