CAKDINALS AS WEED DBSTEOYERS. 



13 



seed-eating birds, and their great value to the farmer consists in 

 the service they render in this direction. The warfare against 

 seeds, so costly to him, is waged by the whole body of sparrows and 

 other seed-eating birds year in and year out without cessation. "Were 

 it not for them the 

 number of weeds 

 would be vastly 

 greater and the re- 

 sulting damage cor- 

 respondingly larger. 

 How great this dam- 

 age is will appear 

 from the statement 

 that the loss to the 

 wheat interests of 

 Minnesota from dockage, largely due to the presence of weed seed, is 

 about $2,500,000 annually." Moreover, conditions in Minnesota are 

 not exceptional, and in eyery State the total annual loss from weed 

 seeds is very great. So far, then, as farmers can protect and increase 

 the number of , weed-seed eating birds to that extent will they reap the 

 benefit of increased service from these faithful servants. The redbird 

 eats the seeds of many of the most harmful weeds, making more than 

 a third of its subsistence upon them. Hence it occupies a very impor- 

 tant place among the weed-destroying birds, and should be prized 



accordingly. 



Animal Food 



% 



^ 



Fig. 5. — Seeds of corn gromwell (hMM%ve,mi^m arven,»e). 

 (E'rom Hillman, Nevada Experiment Station.) 



\ 



Though in quantity much less than the vegetable food, the animal 

 , portion of the cardinal's diet is much more diverse and is comprised in 



no less than six 

 of the natural 

 classes. These are 

 myriapods, centi- 

 pedes, insects, 

 spiders, bivalves, 

 and univalves. 



t'^ i^k ^ ^ ^ Insects are vastly 



J^^S^ <^^ ^& more important 



*'*''* ^^^ ^^t ^iQ ^ than the others 



and constitute 

 26.25 out of 28.99 

 percent, the total 

 proportion of animal matter consumed. The percentage is appor- 

 tioned among the orders of insects as follows : Wasps 0.92, bugs 3.72, 

 butterflies (and caterpillars) 5.1, grasshoppers 6.42, and beetles 10.48. 



Fig. 6.- 



-Seeds of ragweed (Ambrosia artemlslaefolia) . 

 Hillman, Nevada Experiment Station.) 



(From 



"Bull. 95, Mmn.,Agr. Exp. Sta., 1906, p. 195. 



