2 L'nivcrsUij of CaUfoniia I'uhUvaiions in Zooloijy. [Vol. 7 



Characters. — Most like Otus asio cineraeeus (Ridgway), 

 from which it differs chiefly in slightly smaller size, paler color- 

 ation and greater restriction of dark markings. Above pale 

 ashy, darkest on crown, each feather faintly vermiculated with 

 dusky, and with a narrow dark median stripe. Underparts 

 somewhat darker, but still with- dark markings much restricted. 

 Legs and toes white, sparsely marked with duslvy. 



Remarks. — The plumage of owls is notoriously difficult to 

 describe in set terms, and the present form is no exception to 

 the general rule. However, although the differences distin- 

 guishing gilmani from ciiieraceiis are not easy to translate into 

 words, they are none the less clearly apparent upon the com- 

 parison of specimens. I recognized these distinctions some years 

 ago (Swarth, 1904, p. 8), but hesitated to name the new race, 

 mainly through lack of material. vSince that time, whenever I 

 have had an opportunity of handling screech owls from Arizona, 

 I have tested the supposed characters, and found no difficulty 

 in distinguishing the races. Gilmani has a peculiar earthy cast 

 to the gray of the dorsum and wings which is quite different 

 from the clear gray upper parts of cincraccus, and this alone 

 is sufficient to distinguish the two forms. The latter is heavily 

 2narked and blotched with black, so much so as to give it a strik- 

 ing general resemblance to 0. trichopsis, occurring in the same 

 region in Arizona. 



Although the two subspecies are found in about the same 

 region geographically (in part at least), they occupy different 

 life zones, cineraceus being a bird of the upper Sonoran and 

 lower Transition, while gilmani is purely lower Sonoran in its 

 distribution. A somewhat parallel case appears to exist in Colo- 

 rado, as illustrated by Otus a. maxwclUae and 0. a. aikeni, also 

 inhabiting different life zones. Gilmani is a common resident of 

 the giant cactus country, valleys and mesas which are subject to 

 extremes of heat and aridity, while cineraceus is at home along 

 the shaded cafion streams and on densely timbered hillsides, 

 regions so entirely ditt'erent faunally that T cannot now recall 

 a single bird common to both places during the breeding season. 

 I have seen examples of gilmani from the Santa Cruz valley 

 near Tucson, from Blackwater, from Fort IMojave. and I'l-om 



