WEEDS EATEN BY CAKDINAL. 11 



is noteworthy that the cardinal appears to be the only one of the 

 grosbeaks which uses its massive beak for the purpose for which it 

 seems especially designed, namely, the cracking and grinding of hard 

 seeds. The samaras of maple were found in a few stomachs, and in 

 Florida Mr. C. J. Maynard a observed more than 20 cardinals feeding 

 on the seeds of a single maple. The somewhat similar winged seeds 

 of the tulip tree also serve as food, and, according to the experience 

 of the writer, are a favorite winter diet of the redbird around Wash- 

 ington. Galls were eaten by 4 birds, and buds, which often have been 

 stated to be especially sought after by grosbeaks, by only 2. 



The seeds of bindweeds, grasses, sedges, etc., form 36.38 percent of 

 the entire food — more than half of the vegetable diet of the species. 

 They were eaten by 361 of the birds examined, and range from 6 to 49 

 percent of the fare in different months, the 

 greatest quantity being consumed in winter. 

 The seeds of the various smart weeds (fig. 1) 

 and bindweeds (fig. 21) are of most impor- 

 tance, .having been ^consumed by 81 cardinals 

 and constituting 5.57 percent of the annual 

 food. Six species were identified, and it is fig. i.— seeds of smart- 

 probable that the seeds of all members of this p^oSTr^From 

 large genus are eaten indiscriminately. They Hiiiman, Nevada Ex- 

 are among the commonest and worst weeds of periment station) 

 both dooryards and cultivated fields. Besides being notorious crop 

 chokers and seed adulterants, smartweeds are the main support of the 

 disastrous corn-root aphids before the latter are transferred to the 

 corn bv their ant guardians. Hence the cardinal's habit of devouring 

 smartweed seeds is beneficial, not only in abating direct injury by 

 these pernicious weeds but also in tending to diminish the number of 

 aphids by destroying their most important host plants. 



The seeds of foxtail grasses (figs. IT and 37) are next in impor- 

 tance. Foxtail is only too well known for its keen competition with 

 cultivated crops, and is to be classed among the most troublesome 

 weeds. Its seeds compose 3.21 percent of the cardinal's food, 51 out 

 of 498 birds examined having eaten them. Bur grass (Cenchrus 

 trihuloides, PI. II, fig. 10) should be mentioned here, as it is pos- 

 sible some of its seeds were wrongly classed with those of foxtail, 

 the shelled kernels of which they greatly resemble. They liave been 

 positively identified in several stomachs. Henry Nehrling b says car- 

 dinals " are very fond of bur grass seeds or sand spurs * * * 

 s . . 



"Birds of E. N. A., 1881, p. 109. 



b Our Native Birds of Song and Beauty, II, 1896, p. 196. 



