OBSERVATIONS IN 1905. 19 



is significant also that the adult orioles, naturally having a better 

 idea of where to hunt for weevils, consumed a much larger number 

 of them than the young ones. 



In addition to the four species of sparrows and two species of orioles 

 found feeding on the weevils, there were also two species of flycatchers 

 which captured them in small numbers. The scissor-tailed flycatcher 

 ( Muscivoraforjicata) , though quite numerous in the pastures and along 

 roadsides, visited the cotton plants very infrequently. Eleven indi- 

 viduals were collected, one of which had taken two boll weevils, and 

 this one, strangely enough, was taken in a mesquite pasture at some 

 distance from the cotton fields. The least flycatcher (Empidonax 

 minimus), which was present in small numbers as a migrant, was 

 occasionally seen to visit the cotton stalks, and of the three individuals 

 collected two had taken boll weevils, one having eaten four, the other, 

 one. 



In addition to the birds already mentioned, the following species were 

 more or less numerous in the cotton fields: Mockingbird, quail, yel- 

 low warbler, great-tailed grackle, cardinal, and curve-billed thrasher. 



Runge, August 23-September 5; September 11-23. — During the first 

 half of this period the grosvth of cotton had practically ceased, as 

 the result of protracted drought. During the latter half, after a 

 few light showers, the cotton plants began to put forth new buds and 

 leaves. The cotton leaf -worms were very abundant at this locality; 

 nearly all the fields had been attacked by them, and over large areas 

 the plants had been entirely denuded of leaves and buds. 



Weevils were quite abundant, but by reason of the ravages of cotton 

 worms they had been forced to concentrate on the small patches of 

 cotton containing leaves and buds. In such places they averaged 

 about 2 weevils to a hill, the greatest number found in one spot 

 being 19 on 5 hills. In the fields where cotton worms were still at 

 work the weevils averaged about one to every two hills. 



Birds were abundant in and about the cotton fields, and in the mes- 

 quite thickets. Cotton worms furnished a much more attractive and 

 easily obtained food supply for the birds than weevils, as was shown 

 both by field observations and by stomach examinations. Birds 

 were much more numerous in fields infested with the cotton worms 

 than in those wliich were uninfested, and in the case of certain species 

 their presence or absence in a given locality was largely determined 

 by the abundance of these insects. Tliis was notably true of the 

 yellow-billed cuckoos, which on August 23 were found in large num- 

 bers about an isolated field where cotton worms were abundant; but 

 on September 2, after this brood had all pupated, not a single cuckoo 

 could be found there, although they were still numerous in fields a few 

 miles away. 



Cotton worms were contained in the stomachs of nearly every 

 species of bird collected at Runge, and they formed a large percentage 



