BARRED OWL

Katie Dugger, David Wiens, and Ryan Baumbusch

Latin name: Strix varia

The Barred Owl is native to the U.S. east of the Great Plains but has recently invaded the Pacific Northwest, now occurring at very high densities from British Columbia down to central California. Our previous research has shown that Barred owl presence and increasing densities throughout the range of the Northern Spotted Owl has detrimental effects on spotted owl demography and is associated with continued declines of spotted owl populations. However, the impacts this novel predator might have on other species in Pacific North West (PNW) forests has not yet been studied. In conjunction with FWS collaborators, we are exploring diet composition and body condition of Barred owls in Washington and Oregon relative to habitat characteristics and Barred Owl population densities. In addition, within an experimental framework that allows sampling from areas where Barred owls are present vs. areas where Barred owls are absent, we are investigating the effects this novel predator is having on small mammal populations, the primary source of dietary overlap with Northern Spotted owls. This research will inform resource managers and policy-makers as they strive to maintain biodiversity and conserve native PNW species in the face of this very successful invasive species.  

Publications: 

Transient dynamics of invasive competition: Barred Owls, Spotted Owls, habitat, and the demons of competition present

The effects of habitat, climate, and Barred Owls on long-term demography of Northern Spotted Owls