THE BIRD BOOK 
374— 375a 
373f. Mexican Screech Owl. Otus asio ctneraceus. 
Range. — Western Mexico and southwestern border of 
the United States. A gray form with little or no buff, and 
more numerously barred below. 
373g. Aiken’s Screech Owl. Otus asio aikeni. 
Range. — El Paso County, Colorado. A gray form, with 
the dark markings coarser and more numerous than in any 
other. 
373h. MacFarlane’s Screech Owl. 
Otus asio macf arlanei. 
Range. — Northern border of the United States from 
Washington to Montana. 
373.1. Spotted Screech Owl. Otus trichopsis. 
Range. — Mountains of southern Arizona, south into 
Mexico. 
A grayish species, similar to asio, but paler and more 
finely barred beneath, and with whitish spots on the 
feathers of the foreback. The nesting habits and eggs are 
probably the same as those of the Screech Owl. 
373.2. Xantus’s Screech Owl. Otus xantusi. 
Range. — Southern Lower California. 
A grayish species with the back and underparts finely vermiculated with red- 
dish brown, and with streaks of darker. It is not likely that the habits or eggs 
of this species will be found to differ from those of the Screech Owl. 
374. Flammulated Screech Owl. Otus flammeolus flammeolus. 
Range. — Mountain ranges of Mexico, north to Colorado and west to California. 
This species is smaller than asio, has shorter ear tufts, the plumage is much 
streaked and edged with rusty, and the toes are unfeathered to their base. They 
nest in hollow trees, generally using deserted Woodpecker holes. Their three 
or four eggs are white. Size 1.15 x .95. This species is uncommon in all parts 
of its range. 
371a. Dwarf Screech Owl. Otus flammeolus idahoensis. 
Range. — Local in Idaho, eastern Washington and California. 
This rare variety is smaller than the preceding and is considerably paler. Its 
eggs have not been described, but should be a trifle smaller than the last. 
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