Identification

Visual: Large owl with rounded head, dark eyes, and white spotting on head, back, and underparts. Strictlynocturnal.

Vocal: Territorial call is three or four low-pitched, cadenced hoots, lasting nearly 2 seconds: who; who-whoo; whooo. This call sounds a little like the who-cooks-for-you of barred owls. Contact call is a hollow, upslurred whistle.

Nesting Habitat

Deep, rocky canyons containing old-growth coniferous forest or scattered conifers. These reclusive owls may require the shade of these canyons to help them regulate body heat. They lay their eggs in crevices of cliffs and in stumps or on limbs of tall conifers. They may use nests of other raptors, clumps of mistletoe or debris, or lay their eggs directly onto a stump or rock ledge.

Nesting Dates

Courtship: probably February through early March

Incubation: probably March through May

Dependent nestlings: probably May through August

Incubation of 2-4 eggs requires 28-32 days. The young fledge about 32-36 days after hatching.

Statewide Distribution and Population

Charles Johnson (1997) found 12 occupied territories in deep canyons south and west of Colorado Springs. Smaller populations inhabit slickrock canyons of Mesa Verde National Park in southwestern Colorado and remote river canyons in Dinosaur National Monument.

Federal and State Status

Federal threatened and state threatened (Mexican spotted owl--our subspecies). Colorado State Wildlife Action Plan Tier 1 species.

Search and Nest Monitoring Protocol

Walk through appropriate habitat shortly after sunset or before sunrise, February-June. Listen for territorial calls. If you find an active territory, immediately notify State Parks or Colorado Division of Wildlife personnel.

Recommended Nest Buffer Area

To be determined on a case-by-case basis by Colorado Division of Parks and Wildlife personnel.

References

Ganey, J. L., and R. P. Balda. 1994. Habitat selection by Mexican Spotted Owls in Northern Arizona. Auk 111: 162-169.

Johnsgard, P. A. 1988. Owls of North America. Smithsonian Institution Press, Washington, D.C.

Johnson, C. L. 1997. Distribution, habitat, and ecology of the Mexican spotted owl in Colorado. M. A. thesis, University of Northern Colorado.

Kingery, H. E., ed. 1998. Colorado breeding bird atlas. Colorado Bird Atlas Partnership, Denver.

Vroos, K. 1988. Owls of the Northern Hemisphere. MIT Press, Cambridge.

Walker, L. W. 1974. The book of owls. Alfred Knopf, New York.

Wickersham, L.E. 2016. The Second Colorado Breeding Bird Atlas. Colorado Bird Atlas Partnership, Denver.