Roost habitat of Mexican Spotted Owls (Strix occidentalis lucida) in the canyonlands of Utah

Wilson Journal of Ornithology
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Abstract

In large portions of their geographic range, Mexican Spotted Owls (Strix occidentalis lucida) roost in forest-dominated environments, but in some areas the owls use relatively arid rocky canyonlands. We measured habitat characteristics at 133 male roosts (n = 20 males) during 1992-95, and 56 female roosts (n = 13 females) during 1994-95. Across all years and study areas, 44% of Mexican Spotted Owl roosts occurred in mixed-conifer forest patches, 30% in desert scrub habitat, 16% in pinyon-juniper woodlands, and 10% of roosts occurred in riparian vegetation. Two basic substrates were used as perches by owls, including rock ledges or various trees, where roost height averaged 9 m (0.54 SD), and average height of cliffs above perched owls was 50 m (58 SD). For both males and females, trees types used most frequently included various firs (51%), followed by pinyon pine (18%), Utah juniper (15%), and big-tooth maple or box elder combined (15%). Roost sites were located in canyons composed of cliff-forming geologic formations, primarily oriented north-west to south-east. The width of canyons measured at roosts averaged 68 m (105 SD), but ranged from 1-500 m. Canopy cover at roosts used by owls ranged from 44% to 71%, mean tree height of all trees present was 9.5 m and mean diameter of trees was 25.4 cm. Non-roost habitat was warmer, not as steep, and possessed fewer caves and ledges than roost habitat. Trees present in roost plots were taller, and thus showed greater average diameter than trees present in non-roost habitat.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Roost habitat of Mexican Spotted Owls (Strix occidentalis lucida) in the canyonlands of Utah
Series title Wilson Journal of Ornithology
DOI 10.1676/14-021.1
Volume 127
Issue 4
Year Published 2015
Language English
Publisher The Wilson Ornithological Society
Contributing office(s) Southwest Biological Science Center, Contaminant Biology Program
Description 7 p.
First page 690
Last page 696
Country United States
State Utah
Other Geospatial Zion National Park; Capitol Reef National Park; Manti La Sal National Forest; Canyonlands National Park
Online Only (Y/N) N
Additional Online Files (Y/N) N
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