24 ' FOOD HABITS OP THE GROSBEAKS. 



• 



. For instance, a single casting of a young cardiiial, covered with 

 its thick, chalky, and gelatinous layers, was preserved, and from it 

 were taken the following : One insect egg, the leg and scutellum of a 

 scarabseid beetle, head and other remains of a leaf -hopper, bits of a 

 snail, and 11 seeds and the core of a mulberry. From the remainder 

 of tlie total quantity the following were identified: Seventeen rose- 

 beetles {Macrodactylus subspinosus, fig. 14), 2 other scarabseids, 1 

 click beetle {Limonius sp.), 1 caterpillar hunter {Calosoma scru- 

 tator, fig. 7), 1 leaf -hopper (Jassidse), 3 grasshoppers, 1 spider, 1 

 dragon fly, many bits of snail, 17 blackberry seeds {Rubus sp-.), and 

 221 seeds of mulberry {Moms rubra) . The only beneficial species in 

 the above list is the caterpillar hunter, while among the injurious 

 forms, four in number, the rose-beetle is very important. This in- 

 sect's habits, as well as its occasional overwhelming abundance, have 

 been described on a preceding page. 



The infestation of the insect about the District of Columbia in 1906 

 was especially severe. Not only roses were attacked by the insects, 

 but elder blossoms were covered, and around the basswoods their 

 humming was as loud as of a swarm of bees. Frequent attempts were 

 made to discover whether the cardinal feeds upon them, but no oppor- 

 tunity was afforded until the above-mentioned nestlings were discov- 

 ered at the extreme end of the rose-beetle season. The fact that so 

 many were taken at that time is good evidence that special search 

 was made for them. 



f 



Among the food given to the inmates of a nest under observation in 

 1907, the following were identified by sight : A chrysalis, a caterpillar 

 or sawfly larvae, a horsefly, and a grasshopper. From a small quan- 

 tity of excrement were recovered bits of snail, grass seed, a small 

 caterpillar, ground and click beetles, and 3 rose-beetles. The cap- 

 ture of the latter is again significant, as they -v^ere very scarce up to 

 that time. This fondness for rose-beetles distinguishes the bird as 

 an important guardian of the plants the insects attacks. 



SUMMABY. 



Examination of nearly 500 stomachs of cardinals shows that the 

 bird's diet is about three-tenths animal and seven-tenths vegetable. 



The cardinal has been accused of pilfering certain grains, notably 

 corn, to an injurious extent, which charge the evidence from stomach 

 examination neither proves nor disproves. But in view of the fact 

 that only §.73 percent of the total food is grain, and that more than 

 half of that amount is waste, the loss is greatly overbalanced by the 

 destruction of weed seeds alone, which compose more than half of the 

 vegetable food. Moreover, some of the weeds consumed are espe- 

 cially destructive to grain crops. 



In securing its insect food the cardinal injures us in 1 case and 

 benefits us in 15. In other words, considering the animal food alone, 



