230 UNIVERSITY OF COLORADO STUDIES 



360. Falco sparverius — American Sparrow Hawk. 



Our most common summer hawk from plains to timberline, a few sometimes remain- 

 ing through the winter. 

 [365. Aluco pratincola — American Barn Owl. 



The evidence does not warrant the retention of this record.] 



366. Asio wiLonianus — American Long-eared Owl. 



Common resident of plains and mountains. Eleven sets of eggs in the Gale collection 

 in University Museum. 



367. Asio flammeus — Short-eared Owl. 



One in University collection taken by Bragg at Boulder in 1903. Noted by Rockwell 

 near Niwot, March 26, 1904, and at Longmont, December 30, 1906. 



368. Strix varia — Barred Owl. 



Gale noted the species on plains near Boulder in 1886. 

 372. Glaux acadicus — Saw-whet Owl. 



Found by Gale nesting up to 8,500 feet. He recorded it at various points in 1889 

 -and 1890. Sprague also reported it from the mountains. 

 373c Otus asio maxwelliae — Rocky Mountain Screech Owl. 



One of our most common owls, named in honor of Mrs. Maxwell, who prepared the 

 collection of birds and mammals of Colorado for the Centennial Exposition at Philadelphia. 

 Gale reported it nesting both in the lower mountain region and on the plains. Of 14 

 nests in the University cabinets collected by him, unfortunately the altitude and locality 

 are missing from all the labels. The eggs run 4, 5 and 6 to the set and the dates run 

 from April 13 to May 19. Cooke reports it at Lamb's ranch in Estes Park, 9,000 feet, 

 which is near the north line of Boulder County. 

 374. Otus flammeola — Flammulated Screech Owl. 



Our rarest owl. Of the first 14 specimens taken in Colorado (being the first 23 for 

 the United States), 7 were taken in Boulder County. The Sprague specimen is now the 

 property of Hon. R. H. Whiteley, of Boulder. Apparently a bird of the mountains here. 

 No actual nesting records, but no reason to doubt that it nests in the county. Dille records 

 two nests from Estes Park, just north of Boulder County. 

 375a. Bubo virginianus pallescens — Western Horned Owl. 



Our largest owl, rather common resident of plains and mountains. 

 376. Nyctea nyctea — Snowy Owl. 



Very rare winter visitor. 



378. Speotyto cunicularia hypogaea — Burrowing Owl. 



Our most abundant owl on the plains, perhaps less common in the winter. Have not 

 seen it in the mountains. Gale found in its nests remains of small rodents and one shore 

 lark. 



379. Glaucidium gnoma — Pygmy Owl. 



Rare resident of mountains and plains. Gale had at least two specimens (perhaps 

 the two now in Felger's collection, taken near Boulder, altitude 7,500 feet, January 20, 

 1891), and in dissecting them found in one a mouse and in the other a mouse and a 

 shrew. One collected by Bragg near Boulder is in the University cabinets. 



