48 BULLETIN 621, U. S. DEPARTMENT OF AGRICULTURE. 



this, the first being most often eaten, Tabulation of the monthly 

 percentages of these grains reveals two periods of great consumption. 

 The high tide of one is reached in March, when they formed over a 

 third (34.22 per cent) of the diet. From this point a decrease 

 through April (20.90 per cent) to May (8.43 per cent) was noted, 

 after which the monthly averages again increase. In June small 

 grains formed 10.20 per cent of the food ; in July, 20.22 ; and in 

 August, 22.80, the second period of great consumption. A marked 

 decrease occurs in September (8.33 per cent) ; October is represented 

 by 7.08; November, 2.67; and December, 0.89, the minimum monthly 

 quantity recorded. In January and February these grains formed 

 7.00 and 9.74 per cent, respectively, of the food. Inasmuch as wheat 

 predominated among the smaller grains, it is possible that the two 

 maximum periods (March- April and July-August) are indicative 

 of the sowing and sprouting season in spring, and of the harvest 

 of the crop late in summer. 



Wheat. 



Wheat was present in 227 of the 1,340 stomachs of adult crows, 

 an average of about 1 in every 6. Local influences, especially the 

 absence of corn, appear to determine the extent of the crow's depre- 

 dations on this crop. Stomachs collected in the Northwest illustrate 

 this point. Four crows collected at Corvallis, Oreg., in January, 

 had fed on wheat exclusively, over 237 kernels being counted in their 

 stomachs. Three of five stomachs secured in Saskatchewan in April 

 were practically filled with this grain. All of a series of 10 crows 

 from Manitoba, also taken in April, had fed on wheat, which com- 

 prised over two-thirds (68.9 per cent) of their food. In the stomachs 

 of six others, secured in Manitoba in the month following, it formed 

 over 40 per cent of the contents. 



When attacks upon wheat are made in sowing or sprouting time, 

 the depredations of even a single crow, limited only by a most ample 

 gizzard, may be of considerable consequence. Two birds collected in 

 Manitoba in April had eaten 140 and 133 kernels, respectively. 

 Another taken in the same place in May had devoured 86, while one 

 collected in British Columbia, in March, had made away with 54 

 kernels of wheat and 7 of oats. At harvest time and after, a large 

 part of the wheat eaten by crows may well be classed as waste, in- 

 volving no loss to the farmer. Birds collected in wheat-raising areas 

 at this time of year usually were well fed. Six stomachs contained 

 135, 120, 91, 90, 65, and 60 kernels respectively, and in several others 

 over 25 kernels were noted. 



Evidence of the wheat-eating habits of the crow revealed by 

 stomach analysis has been corroborated by field observation. Dr. 



