In the days of coal mining, workers would take canaries down to the tunnels with them to detect carbon monoxide. Canaries would warn miners of the impending danger in their surroundings.
Some environmentalists say Northern spotted owls in the forests of the Pacific Northwest are like the canaries in the coal mines. As an indicator of forest health, the spotted owl population also serves as a warning signal for the condition of its environment.
But there’s bad news.
“[The spotted owl] is on a trajectory to be functionally extinct, probably within this century,” says Dan Donato, a scientist with the Washington Department of Natural Resources.
So what does that mean for the forests the spotted owl frequents?
A GOLDILOCKS HABITAT DILEMMA
According to Donato, if you define forest health by a landscape’s ability to sustain populations of all its native species, then the decline of the spotted owl shows the forests it inhabits may be in trouble.
Donato specializes in the research and monitoring of northern spotted owl habitats, which are dependent on old-growth forests to survive. The U.S. Department of Agriculture has varying definitions for what constitutes old-growth forests, but they all typically include old, mature trees with large trunk diameters and dense canopy layers.
This specific type of forest is becoming increasingly rare after decades of harvesting, disease, and insect infestation. The Arbor Day Foundation partnered with the Washington Department of Natural Resources to plant a dense tree canopy over thousands of acres to help spotted owls survive. The plantings of Douglas fir, Western hemlock and Western redcedar mimic a similar structure of old-growth forests and serve to help owls nest, roost, and forage.
The destruction of old-growth forests caught the attention of the White House in 2022. The Biden Administration issued an executive order that requires the U.S. Departments of Agriculture and the Interior to develop policies to address threats to old-growth forests.
A majority of the Northern spotted owl’s range is in old-growth forests on the coastal side of the Cascade Mountain Range. Unfortunately, within this wetter region, old-growth has been logged and the forests have been converted to new growth. Donato says this conversion of the land and habitat fragmentation has had a drastic impact on the species and are the most critical threats to the owl’s survival.
Though the owl can mostly be found on the moist side of the mountains, there are also some dry forests within their range standing east of the Cascade Mountain Range crest. But the lack of moisture, coupled with the typical characteristics of old-growth, makes conserving the forest difficult.
“Many structural features of spotted owl habitat, like dense multi-layered canopies, are all the exact same things that you might describe as fuel buildup,” Donato warns, referring to the plant material wildfires use to tear through forests.
To help prevent wildfires — a dire issue in the American West — dense trees need to be thinned as part of fuel management.
“But if you thin it too much and make it open so it’s fire-resistant, you’ve made it not-spotted owl habitat anymore,” Donato cautions. “It’s just this constant tension, and it’s actually one of the big active areas of both research and management: ‘How do we provide both?’”
Still, Donato notes that shrinking habitat is not the sole issue facing the northern spotted owl. There’s also a different adversary at play:
THE BARRED OWL
On top of losing its preferred habitat, the spotted owl faces another challenge: a larger, aggressive cousin. The barred owl is native to Eastern North America but has now set up camp in the spotted owl’s West Coast territory. And scientists aren’t sure why.
“It wasn’t brought here as far as anyone can tell. It just immigrated across the continent,” Donato says.
No matter why barred owls came to the region, the changing landscape of the American West is making it easy for them to stick around. While spotted owls need old-growth forests to survive, barred owls can thrive in both young and old forests. That means the current landscape now favors the barred owl.