Strix occidentalis occidentalis

Scientific Name:Strix occidentalis occidentalis
Common name:California Spotted Owl
Rank and Status   
Global Rank:G3G4T3 Native Status:Native
Subnational (State) Rank:S1 Endemic:No
US ESA Status:None Sand Dunes:No
NNHP Tracking Status:At-Risk List Wetland:No
Other Agency Status Status Last Updated Status Comments
Bureau of Land Management - California Dropped, no longer of concern 2011 BLM List
US Forest Service - Region 4 (Intermountain) Sensitive USFS list, Jan 2015 update
US Forest Service - Region 5 (California) Sensitive USDA Forest Service, Pacific Southwest Region [R5], Sensitive Animal Species by Forest, updated 09/09/2013
US Forest Service - Lake Tahoe Basin Management Unit Sensitive USDA Forest Service, Pacific Southwest Region [R5], Sensitive Animal Species by Forest, updated 09/09/2013
Nevada Wildlife Action Plan - 2012 Species of Conservation Priority
Nevada Wildlife Action Plan - 2005 Species of Conservation Priority
CCVI Score Moderately Vulnerable Conf. VH; Factors contributing to increased vulnerability are dispersal/movement, historical hydrological niche, and disturbance.
Distribution (NV Counties)

Status: Predicted or probable


Status: Confident or certain

Carson City Lyon Washoe
Summary Occurrence Data
Occurrence Count:6
Total Observed Area (hectares):Not Available
Maximum Known Elevation (m):2219
Minimum Known Elevation (m):1539
Strix occidentalis occidentalis data at NatureServe
Strix occidentalis occidentalis photos and data at Encyclopedia of Life
Character Abstract
Identification Comments:
Subspecies Comments:
Food Habits:Small mammals, particularly nocturnal arboreal or semi-arboreal species, predominate in diet; mostly Glaucomys, Neotoma, and Sciurus. Breeders take larger rodent prey than do nonbreeders (Thrailkill and Bias 1989). Generally hunts from perch at dusk and at night. May cache prey.
Phenology Comments:
Reproduction Comments:Nesting confirmed in the Carson Range in 2009 (P12AMM01NVUS).
Migration Mobility:
Habitat Comments:Typical habitat is dense, multi-layered evergreen forest that includes a diversity of tree species, large trees (some greater than 83 cm DBH), some trees with evidence of decadence, and open areas under the canopy; most often on lower, north-facing slopes of canyons, usually within 0.3 km of water (Gould 1977, Bias and Gutiérrez. 1992). Commonly inhabited plant associations include: mixed conifer forest, usually dominated by ponderosa pine (southern Sierra Nevada); ponderosa pine, Douglas-fir, and/or white fir (northern Sierra Nevada) (Gould 1977). In the central Sierra Nevada, 97 percent of the habitat patches in which owls roosted were characterized by the presence of residual trees (greater than 100 cm dbh); owl roost and nest sites were also characterized by residual trees and high structural diversity (Moen and Gutiérrez 1997). Nests are on broken tree tops, cliff ledges, in natural tree cavities, or in tree on stick platforms, often the abandoned nest of hawk or mammal; sometimes in caves. This owl exhibits a high level of nest site fidelity.
Ecology comments:Adults may migrate downslope in fall, return to higher elevation in spring; fall (mid-October to mid-November) movements averaged 31 km (19 miles) with a change in elevation averaging 754 m (2,473 ft) in the Sierra Nevada, CA (Dawson et al. 1987, Laymon 1989).
Version Date:

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