THE COWBIED. 



29 



stomachs, which shows that the birds relish them. Knotweed, smart- 

 weed, and other species of the genus Polygonum^ all noted weeds, were 

 found in 49 stomachs. The other items of the weed -seed food are eaten 

 to a greater or less extent, but not by so many birds as are those 

 specifically mentioned. Of the 544 stomachs only 2 were filled with 

 grain alone, while 94 contained nothing but weed seed. The amount 

 of weed seed destroyed by birds in a single year in the United States 

 is immense, and it is evident that the cowbird is one of the noteworthy 

 agents by which the already overflowing tide of noxious weeds is kept 

 within its present limits. 



SUMMARY. 



In summing up the results of the investigation, the following points 

 may be considered as fairly established: (1) Twenty per cent of the 

 cowbirds' food consists of insects, which are either harmful or annoy- 

 ing. (2) Sixteen per cent is grain, the consumption of which may 

 be considered a loss, though it is practically certain that half of this 

 is waste. (3) More than 50 per cent consists of the seeds of noxious 

 weeds, whose destruction is a positive benefit to the farmer. (4) Fruit 

 is practically not eaten. 



The following table shows the percentage of each of the principal 

 kinds of food for every month in the year: 



Food of the coivhird. 



[Number of stomachs examined: January, 3; February, 10; March, 18; April, 83; May, 99; June, 53; 

 July, 57; August, 38; September, 79; October, 70; November, 23; December, 11. Total, 544.] 



Food. 



i 

 1 



1 

 1 





< 



1 







1 

 < 



1 

 1 



1 

 1 



1 



a 



1 



i 

 i 

 ft 



1 



ANIMAL. 



I'redaceou.s bee- 

 tles 



Per- 

 cent. 



pa- 



cent. 



Per- 

 cent. 



Per- 

 cent. 



1.1 

 10.2 

 5.8 

 5.2 

 0.8 



2.5 

 0.1 



Per- 

 cent. 



3.9 

 12.3 

 10.7 

 10.3 



2.4 



2.2 

 0.9 



Per- 

 cent. 



1.6 



16.5 

 20.3 

 3.8 

 9.8 



4.8 

 2.3 



Per- 

 cent. 



1.5 

 8.1 

 29.7 



7.2 



2.9 

 0.5 



Per- 

 cent. 



Per- 

 cent. 



Per- 

 cent. 



Per- 

 cent. 



Per- 

 cent. 



0.4 



Per- 

 cent. 



0.7 

 4.6 

 11.0 



2.3 



1.1 

 0.4 



other beetles 



0.3 



2.4 



2.4 

 2.9 

 2.1 

 1.0 



0.2 



1.7 

 45.1 

 0.3 

 2.4 



0.9 

 0.1 



0.8 

 0.3 



0.3 

 iTr. 



0.1 

 1.8 



iTr. 



iTr. 



iTr. 



ITr. 

 6.2 



Caterpillars 



other insects 



Spiders and myr- 



1.3 



0.7 



1.3 

 O.G 



0.2 



0.1 



0.3 



Other animal food 



Total animal 



food 



VEGETABLE. 



















2.3 



4.5 



8.6 



25.7 



42.7 



59.1 



51.9 



50.5 



13.0 



1.9 



6.3 



0.7 



22.3 



33.3 



64.4 



95.5 



31.3 

 49.1 



11.0 



7.1 

 60. 1 



1.1 



15.7 

 41.5 



0.1 



12.9 

 28.0 



27.2 

 19.2 



1.7 



31.7 

 16.6 



1.2 



58.1 



1.1 

 97.0 



6.1 

 87.6 



2.5 

 96.8 



16.5 

 60.0 



1.2 



Weed seeds 



other vegetable 

 food 



Total vegeta- 

 ble food.... 















97.7 



95. 5 



91.4 



74.3 



57.3 



40.9 



48.1 



49.6 



87.0 



98.1 



93.7 



99.3 



77.7 



