CONSIDERING CONTROL OF INVASIVE BARRED OWLS TO BENEFIT CALIFORNIA SPOTTED OWLS: POSSIBLE JUSTIFICATION AND DRAFT METHODS

Barred owls (Strix varia) recently expanded their range from eastern to western North America and are negatively affecting site occupancy, reproduction, and survival of federally threatened northern spotted owls (Strix occidentalis caurina), thereby confounding the land-based conservation strategy for northern spotted owls. Barred owls are moving southward into the range of non-federally listed California spotted owls (S. o. occidentalis), but are not, at this time or in the foreseeable future, a threat to the California spotted owl population. We recommend consideration of barred owl control in the northern Sierra Nevada Mountains while barred owl numbers are low enough to efficiently eliminate the possibility that they negatively affect California spotted owls outside of the foreseeable future.