What does the history of barred owls mean for spotted owls in the Pacific Northwest?

Backyard wildlife evokes different emotions, awe and concern chief among them. When it comes to owls in Gig Harbor, fascination is also added to the list. If they are in our area, we usually hear owls before seeing them; a solo hoot or exchanged screeches in the night. Growing up, I was lucky enough to have a mated pair of barred owls nest in the towering trees of our backyard every year. They seemed equally curious about us, and it wasn’t uncommon to spot them around dawn and dusk.

However, barred owls are considered invasive in many areas of the Pacific Northwest due to their fierce habitat competition with the spotted owl, which are native to this region and federally listed as threatened under the Endangered Species Act (ESA).

Barred owls showed up on Washington’s landscape around 1965. They migrated from the eastern United States, bridged the sparsely treed landscape of the Great Plains, and settled into the Pacific Northwest’s dense forests. While they prefer old-growth forests, they have adapted to lowland forests, city parks, and residential areas. Similarly, spotted owls inhabit mature forests, usually dominated by Douglas Firs, and their diet consists of small mammals: mice, shrews, moles, and — particularly in the Pacific Northwest — flying squirrels. (Yes, we have flying squirrels!)

The two species of owls look similar: both are brown and white in color with no ear tufts. Barred owls are slightly larger and their white markings are more streaks than spots.

Normally, owls in the same genus — like barred and spotted owls — are separated by geographic range. Those who share a region use different habitats and have contrasting behaviors (hunting methods, diet selection, etc). In their shared landscape, barred owls have the upper hand. They are more aggressive, a bit larger, require less acreage per established territory, and take a wider variety of species for food (including species that are active during the day, like snakes).

The lower elevations of spotted owl habitat were “logged out” in timber harvesting, causing the initial decline of this species. Despite their ESA listing in 1990, the owl is not showing signs of recovery and barred owls have worsened its decline.

Gig Harbor residents can keep an eye — and an ear — out for barred owls in their neighborhoods, but are unlikely to see spotted owls close to home (they are more common near the forests of the Cascade Mountains).

Today, protections for spotted owls are primarily seen in the NW Forest Plan. According to the Washington Forest Protection Association, this plan “developed a forest management strategy to protect more than 1,000 late-successional and old-growth dependent species across 19 National Forests and 7 Bureau of Land Management districts” across Washington, Oregon, and California. (Late-successional species, also called “climax-species,” are plant species that can germinate and grow with limited resources, such as water or sunlight.)

Simply put, spotted owls and their habitat of old growth forest are being monitored and protected.

Protections become trickier with the competition of barred owls. Lethal removal studies have been conducted. Researchers at Oregon State University published a paper in July 2021 showing that lethal removal of barred owls stabilized spotted owl populations in a shared landscape. However, the 17-year study is not without controversy and — as with many difficult wildlife management decisions — presents a question of ethical responsibility.