The Birds of Wyoming. 67 



their breakfast of grasshoppers. They were scattered over a 

 larger area than when we saw them the previous evening. Be- 

 fore 8 o'clock most of them had left the hills and settled down 

 for the day in the poplar trees along the river bottom. Here 

 I found the trees literally full of hawks, and counted as many 

 as thirteen in one tree. Two of the three whose stomachs were 

 examined contained grasshoppers and no other food. The 

 third contained, in addition to grasshoppers, the head of a 

 meadow mouse of the genus Arvicola (subgenus Chilotus). 

 One contained 88 grasshoppers, another 96, and the third 106. 

 Most of the grasshoppers were a large species of Oedipoda, 

 though a few belonged to the genus Caloptenus. 



' 'Assuming that each hawk captured 200 grasshoppers 

 a day and that there were 200 hawks, the daily catch would 

 be 40,000 grasshoppers. At this rate these hawks would de- 

 stroy 280,000 grasshoppers in a week and 1 ,200,000 in a month. 

 I have no means of knowing how long the hawks remained in 

 the neighborhood of Pendleton, but was told that they had 

 been there before our visit. When in southern California, 

 about a month later, I was told by Mr. Edward Merriam that 

 on three occasions he had noticed similar gatherings of hawks 

 in San Diego county. Once he saw a flock of several hun- 

 dred large hawks catching crickets in cracked adobe soil in 

 the San Marcos valley. At night the hawks came into the 

 live oaks at the head of the valley to rest. He shot one and 

 found its stomach packed full of large black crickets. On 

 two other occasions he saw large flocks of these hawks similar- 

 ly engaged in catching the same species of cricket. The time 

 was during the latter part of September." 



"Mr. A. S. Bennet, writing to the U. S. Department of 

 Agriculture from Lay, Colo., states that on July 10, 1889, he 

 saw flocks of large hawks, some of which were circling near 

 the ground, while others were perched on it. The mass con- 

 tained at least 500 individuals, and were feeding upon species 

 of cricket (Anabrus purpurasccns), which covered over fully 



