151 



order to determine to what extent they feed upon the weevil, it has 

 been necessary to make an extensive study of the stomach contents of 

 a large number and variet}^ of birds. To make the work as successful 

 as possible, collections have been made in numerous localities and at 

 intervals during- two seasons. 



Nearly all of the stom.achs of birds shot in cotton fields by agents 

 of the Bureau of Entomology during the seasons of 1903 and 1901 

 were examined by Mr. E. A. Schwarz, who was assisted in the work 

 by Mr. J. C. Crawford. The investigation was conducted primarily 

 to ascertain to what extent the birds that frequent cotton fields in Texas 

 feed upon the Mexican cotton boll weevil, but while no attempt was 

 made to identify the seeds on which these birds largel}^ feed, the insect 

 contents of each stomach were determined by Mr. Schwarz as fully 

 as the minuteness of the fragments would allow. The complete results 

 of these examinations would form a contribution of no inconsiderable 

 importance to our knowledge of the food habits of these birds, and 

 should, by all means, be published at some time. The following 

 results refer only to the cotton boll weevil and are as stated by Mr. 

 Schvv^arz : 



The stomachs submitted came from the following localities: 



Three hundred and forty stomachs obtained at Calvert between 

 September 1 and December 10. These with few exceptions are those 

 of turtle dove and quail. 



One hundred and twenty-four stomachs of quail from Franklin, 

 Robertson County, November 22 to November 26, 1901. 



Five hundred and sixteen stomachs obtained at Victoria, represent- 

 ing 17 species of birds. Of these, 100 were obtained during the last 

 week of February, 7 during June, 3 during July, 26 during August, 

 and 380 between September and December. 



The birds obtained in February plainly showed that they were fol- 

 lowing the plowmen through the cotton fields, because at this season 

 the stomachs contain an element not found in any other season, namel}^, 

 the white grubs (larvee of Lachnosterna). That so few birds were 

 obtained in the months from March to August is explained b}^ the 

 following, written by Mr. J. C. Crawford: 



Summer collecting shows the futility of depending on birds for keeping the weevil 

 in check, for almost no birds are seen in the cotton fields during the early summer 

 months, the individuals being exceptionally rare. Mr. Harris reports that for entire 

 days he saw no birds in the cotton fields. 



Arranging the birds according to the number of stomachs available, 

 we arrive at the following results: 



Mourning dove, ^'turtle dove'^ [Zenaidura macroura)y 225 stomachs. — No insect 

 remains whatever found ; stomach contents consisted entirely of seeds and pebbles. 

 (Several hundred more stomachs of the same birds shot in Texas have not been 

 examined, as the result obtained from the examination of the 225 stomachs seemed 

 to be conclusive. ) 



