The barred OWL has expanded its range into western north american over the past century, and the species is now almost ubiquitously distributed from southeast alaska to california, threatening…

The Department of the Interior Fish and Wildlife Service Region 8 awarded a $299,985 Cooperative Agreement under the Endangered Species Recovery Implementation (CFDA 15.657) program to the University of Wisconsin System for a 3-year study on managing the invasive Barred Owl to protect threatened native species such as the Northern and California Spotted Owls. The study will involve the continued lethal removal of Barred Owls in California to prevent the extinction of the native Spotted Owl subspecies, which have experienced population declines due to competition with the larger and more aggressive Barred Owl. The findings from this study will assist the U.S. Fish and Wildlife Service in developing a broader Barred Owl management strategy across California.

The barred OWL has expanded its range into western north american over the past century, and the species is now almost ubiquitously distributed from southeast alaska to california, threatening native species and forest ecosystems. The larger and competitively dominant barred OWL has functionally extirpated the northern spotted OWL subspecies from the state of washington and caused precipitous population declines in many areas of oregon and california. More recently, the barred OWL has expanded in range into the sierra nevada where IT poses a major threat to california spotted owls. Without continuing and expanding our currently limited lethal removal studies, barred owls will soon cause the extinction of northern spotted owls and ultimately california spotted owls as well. Thus, our study represented a rare and substantial conservation success in invasive species management in continental systems. However, barred owls continue to immigrate into the sierra nevada from the pacific northwest such that approximately five individuals need to be removed across the bioregional annually to prevent the reestablishment of a breeding population. Barred owls will be removed using field protocols established by diller ET AL. (2014) or as described in the barred OWL management strategy once complete. Current removals could buy time to develop alternative management approaches and ensure that some spotted owls remain on the landscape until the USFWS barred OWL management strategy is implemented. This study will assist the US fish and wildlife service in managing barred owls across large areas of california, and will will occur from january 1, 2024 to december 31, 2026.