74 Wyoming Experiment Station. 



common at Douglas ; Coues, "very numerous in Wyoming, 

 where it is the characteristic species of its genus;" Grinnell, 

 "this species was very abundant throughout the plains and 

 mountain regions about Como and breeds." Fisher reports one 

 specimen taken at Cheyenne and one from the Laramie moun- 

 tains, both of which had been feeding upon ground squirrels. 

 There are three specimens in the University collection. One 

 nest has been found and Gilmore made the following note : 

 Nest taken with four eggs, had built in a crevice in the weath- 

 ered rocks at Sand creek, Albany county. The nest was built 

 of small branches, lined with grass and a few feathers. Eggs 

 fresh, and the nest was about 15 feet from the ground. May 

 9, 1899. 



356. Falco peregrinus anatum (Bonap.). 



Duck Hawk. 



Summer resident ; very rare. This vicious falcon has 

 been observed by only two collectors in Wyoming, and these 

 observations were made over a quarter of a century ago. 

 While this is probably the greatest destroyer of birds of any 

 of the hawks or falcons, yet it is not worthy of considera- 

 tion here on account of its scarcity. Although I have traveled 

 extensively over the state I have never seen one of these 

 birds. 



Allen found them on the plains in Wyoming, 1871. Grin- 

 nell makes the following note : "This species was abundant 

 in the vallev of the Yellowstone above Emigrant peak, and had 

 no doubt been breeding there, as I took a very young bird." 



357. Falco columbarius Linn. 



Pigeon Hawk. 

 Migratory ; rare ; possibly may breed in the alpine districts. 

 We know nothing of this blood-thirsty hawk. None of the 

 collectors in recent years have reported them. Hayden in 

 his annual report of 1870 mentions six specimens that were 

 taken on La Bonte creek and Green river and Coues notes that 



