SEEDS EATEN BY GRAY GROSBEAK. 



29 



WEEDS. 



Grass seeds constitute an average of 53.09 percent of the total food 

 of the birds examined, or more than five-sevenths of the vegetable 

 food alone. Most important among them are foxtail (Chcetocholoa, 

 fig. 17) and bur grass (Cenchrus, Plate II, fig. 10), which together 

 amount to 43.59 percent of all the bird's food. Since these grasses 

 are among the most pernicious weeds, the 

 parrot-bill is more than welcome to all of 

 their seeds it desires. 



The seeds of other grasses also are im- 

 portant, furnishing 9.51 percent of the 

 bird's subsistence. Among them are seeds 

 of witch and crab grasses, most species of 

 which are weeds. Yard or wire grass 

 {Eleusine indica) also is eaten. Seeds of a 

 spurge {Croton sp.) contribute 9.81 percent 



to this grosbeak's fare, and other weeds, in- 



Fig. 17. — Seeds of yellow fox- 

 tail (Chwtochloa glauca). 

 (From Hillman, Nevada Ex- 

 periment Station.) 



eluding bindweed (fig. 21), lambs' quarters, 



tumbleweed (fig. 18), sunflower, carpet weed, nightshade, vervain 



(fig. 3), mallow, etc., compose 6.13 percent. 



Thus the gray grosbeak is a great consumer of weed seeds, and it is 

 remarkable that seeds form practically seven-tenths of the food in 

 August and September, when insects are superabundant. The bird's 

 habit of feeding upon weeds is undoubtedly beneficial, especially be- 

 cause it eats so many seeds of foxtail and bur grass, pests with which 

 every farmer in the South has to contend. 



GRAIN. 



The only grain found in stomachs of this species is sorghum. Six 

 birds had eaten it in quantity sufficient to make an average of 2.03 

 percent of the total food. Ignoring even the fact that sorghum is 



• d 



Fig. 18. 



-Seeds of rough tumbleweed (Amaranth us retroflexus) . 

 Experiment Station. ) 



• • 



(From Hillman, Nevad? 



usually grown for fodder, not for grain, the amount consumed is so 

 small that there need be no fear of damage by this shy and uncom- 

 mon bird. 



Animal Food. 



While the parrot-bill consumes a smaller proportion of animal 

 matter than other grosbeaks, it selects about the same things, the 

 principal items being grasshoppers, caterpillars, and beetles. . 



