THE COWBIRD. 



27 



other substances are also eaten, but they are mostly of the same gen- 

 eral character, such as hard seeds of grasses or weeds, with but little 

 indication of fruit pulp or other soft vegetable matter. The following 

 table shows the_ various grains and seeds identified, with the number 

 of stomachs in which they were contained: 



Vegetable substances found in stomachs of cowbirds. 



Stomachs. 



.... 56 



.... 20 



.... 102 



.... 1 



.... 1 



.... 4 



Weeds — Continued. stomachs. 



Pennyroyal [Trichostema dicho- 



tomum) 2 



Mouse-ear chickweed ( Ceras- 



tium) 2 



Plantain {Plantacjo) 1 



Sunflower (Helianthus) 8 



Gromwell (Lithospermum) 4 



Blue-eyed grass {Sisyrinchium 



bermudiana) • 1 



Barngrass ( Chcetochloa) 265 



Panic-grass {Panicum) 133 



Joint-grass ( Paspalum) 22 



Yard-grass {Eleusine indica) . 2 



Unidentified (mostly unknown 



grass seeds) 57 



Miscellaneous: 



Mast 1 



Leaf gall 2 



Rubbish 5 



Grain: 



Corn - , 



Wheat 



Oats 



Buckwheat 



Fruit: 



Blueberry ( Vuccinium 



Easpberry {Eubus) ... 

 Forage: 



Clover ( Trifolium) 8 



Timothy {PMeum) 8 



Sorghum {Andropogon sorghum) . 2 

 Weeds: 



Ragweed (Ambrosia) 176 



Knotweed {Polygonum) 49 



Sorrel {Rumex) 37 



Thistle ( Carduus) 1 



Amaranth (Amaranthus) 11 



Mustard {JBrassica nigra) 4 



Chickweed (Alsi^ie) 9 



Oats are apparently the favorite grain with the cowbird, as they 

 were found in 102 stomachs, a record which exceeds the total of those 

 containing either wheat or corn. They first appear in March, when 

 12.9 per cent are eaten, evidentl}^ waste grain picked up in the stubble- 

 fields, highways, and barnyards, except in the southern part of the 

 country, where sowing may take place as early as this month. Oats 

 constitute less than 2 per cent in April, nearly 8 percent in May 

 (probably partly made up of grain from newly sown fields), 3.7 in 

 June, 25.1 in July, 31.5 in August, 19.1 in September, and after that 

 decrease rapidly and reach zero before the 1st of November. The 

 average consumption for all the months of the year is 8.6 percent. 

 Corn was found in 50 stomachs, but the irregular manner in which it 

 is distributed through the food of the year indicates that it is not a 

 favored diet. The record for January, which shows a little more than 

 33 per cent, is based on only 3 stomachs, and so can not be considered 

 very reliable. In any case the corn eaten must have been scattered 

 grain, unless it was some that had been left in the shock over winter. 

 Even in October, when corn is abundant everywhere, it is scarcely 

 touched. Only 1 bird out of 70 taken in that month had eaten any, 

 and in this single instance it amounted to only 6 percent of the entire 

 food. In the other months the quantitj'^ ranges downward to zero, but 

 in such an erratic manner as to indicate that it is never sought, but 

 merely eaten when found and when better food is not at hand. The 



