204 Birds of Colorado 



Genus OTUS. 



Small Owls with wings under 7*5 ; facial disk not well developed, 

 hardly noticeable ; ear-tiifts well developed ; skull and ear-openings 

 symmetrical, the latter small and normal ; wing rounded, but long and 

 about twice the short, rounded tail ; tarsus feathered, toes bristly or 

 naked ; plumage with marked dichromatic phases. 



A large cosmopolitan genus with only two North American species, 

 but separated into a great many subspecies difficult to discriminate. 



A. Larger ; wing over 6 ; toes bristly or partly feathered. 



a. Paler and less heavily streaked. 0. a. maxwelliae, p. 204. 



b. Darker and more heavily streaked. O. a. aikeni, p. 205. 



B. Smaller; wing under 6; toes naked. O. flammeola, p. 207: 



Rocky Mountain Screech Owl. Otus asio maxwellim. 



A.O.U. CheckUst no 373e — Colorado Records — Ridgway 77» pp- 210, 

 213 ; 79, pp. 232, 235 ; Morrison 89, p. 66 ; Kellogg 90, p. 90 ; Bendire 

 90, p. 298 ; 91, p. 91 ; 92, p. 263 ; Hasbrouck 93, p. 256; Cooke 97, 

 pp. 78, 160 ; Biu-nett 03, p. 156 ; Dille 03, p. 74 ; Henderson 03, p. 235 ; 

 09, p. 230 ; RockweU 07, p. 140 ; 08, p. 207 ; H. G. Smith 08, p. 185. 



Description. — Very closely resembling O. a. aikeni, but very distinctly 

 paler, the ground-colour much lighter, and the black streaking much 

 less heavy, both above and below ; white on the wings and scapulars 

 more conspicuous, and a tawny wash across the back, showing rather 

 plainly. Measurements average a little larger ; wing 7-0, tail 3-5 (see 

 Plate 5). 



Distribution. — North-east Colorado, chiefly north of the Arkansas 

 Platte Divide, but occasionally in winter south to Colorado Springs ; 

 extending northwards along the foothills as far as Fort Custer in south 

 Montana. 



This Owl is a resident in north-east Colorado, and is found chiefly 

 along the foothills and river valleys from Denver northwards. Kellogg 

 reports it as rare in Estes Park, and it has been taken out on the plains 

 as far as Dry Willow Creek in Yuma co., in June by H. G. Smith. 



Habits. — ^This Owl is an inhabitant of the cotton-wood 

 groves along the Platte and its tributaries in north-east 

 Colorado. It is chiefly abroad at night, spending the 

 day in a hollow tree, or sitting quietly on a horizontal 

 branch close to the trunk, which it closely resembles. Its 

 home is generally betrayed by disgorged pellets lying below. 



The nest and eggs were first taken by Anthony on 

 the Platte River, six miles from Denver, May 4th, 1884 ; 



