SPOTTED OWL Stirix occidentalis (Xantus) 



Order: STRIGIFORMES Family: STRIGIDAE 



Distinguishing characteristics : A large, white-spotted, dark brown owl with brown eyes 

 and without ear-tufts . Differs from the similar appearing barred owl of eastern North 

 America in being much more heavily spotted with white all over and particularly on the 

 posterior underparts where the barred owl lacks these markings . 



Present distribution : (Divided into three subspecies) . Resident in Pacific coastal and 

 Cascade Mountains forests from southwestern British Columbia south to northwestern 

 California; also Sierra Nevada and mountains of southern California; also southern 

 Rocky Mountains from central Colorado, south through eastern Arizona and New Mexico; 

 and mountains of Mexico in Sonora, Michoacan, Guanajuato, and Nuevo Leon. 



Former distribution : The same as at present but including some localities from which it 

 is apparently now extirpated in western Texas and Utah . 



Status : All three subspecies very uncommon and vulnerable. Widely scattered pairs. 

 Known to be seriously declining in numbers in the heavy forests of western Oregon, 

 Washington, and northwestern California which comprise the range of S. o. caurina . 



Estimated numbers : Total population unknown. 



Breeding rate in the wild : Two or three (usually two) eggs per set. 



Reasons for decline : Removal of old-growth timber — its required habitat, in the 

 Cascades and coast range of the Northwest; disturbance of limited areas of habitat in 

 mountain canyons by recreational and construction activities . Extremely sedentary 

 nature retards movement of birds to new and more favorable habitat when old sites are 

 destroyed. 



Protective measures already taken : Some habitat is preserved at lower altitudes in 

 Olympic and Mt. Rainier National Parks. Forest management agencies have been alerted 

 to the incompatability of this species with present forest management practices in the 

 Northwest. A study of the ecology and populations was begun at the Oregon Cooperative 

 Wildlife Research Unit in spring of 1972 in cooperation with the U.S. Forest Service. 



Measures proposed : Locate existing breeding pairs . Absolute protection of the 

 environment of known nesting sites in all parts of its range . Preliminary information 

 indicates each pair of S. o. caurina occupies and requires 300 to 600 acres of old-growth 

 timber. Thorough study of-its ecological requirements and limiting factors. 



Number in captivity : Unknown. One at Oregon State University . 



Breeding potential in captivity : Unknown . 



159 



