Wildfire is a paramount issue for Sierra Nevada land managers. Historical logging and fire exclusion has likely contributed to declines in old-forest dependent species, including California Spotted Owl. More recently, concern has grown that high-severity, stand-replacing fires, which appear to have become more common, may constitute another threat to the species.

Research is needed to better understand how Spotted Owls respond to wildfire so that post-fire landscapes can be managed to give the species the best chance of persisting. In past work, we radio-tracked adult owls in territories that were burned by a large wildfire. The owls continued to occupy partially burned territories several years after fire and preferentially forage in severely burned patches. We also assessed daytime roosts during the non-breeding season to study how ranges and habitat use by birds with partially burned territories shifted during the winter.

A third component of this project was examining whether breeding-season diet and home-range size of California Spotted Owls differed between our burned study site and other unburned study sites in the Sierra Nevada. We collected and analyzed regurgitated pellets at roosting locations in our burned site to quantify the diet of owls whose territories were affected by forest fire. Finally, we also conducted an analysis of data from across large swaths of the Sierra Nevada to assess patterns in Spotted Owl occupancy after fire.

More recently we have teamed up with Yosemite National Park biologists to study occupancy patterns in recently burned forests.

For more information about IBP’s work with Spotted Owls and post-fire landscapes, please contact Rodney Siegel.