Scientists studying the California spotted owl are trying to figure out which calamity is worse for the rare birds: burning trees or cutting them down after a fire.That’s the issue at the heart of competing studies in California, the most recent of which suggests post-fire logging — not severe fire — is the real threat to the spotted owl.
In a study published this week in the scientific journal Nature Conservation, research ecologists said they found that owl populations suffered after the so-called King Fire in 2014 in the Eldorado National Forest because of post-fire logging.
Furthermore, the authors said, previous research by scientists missed that point and blamed a loss of owls in some areas on the fire itself, even though those areas hadn’t been occupied by owls in the first place.
“Most studies of spotted owls and fires in California found little to no effect of fires on owl site occupancy, but the King Fire study results contradicted these. Now we have a better idea where the King Fire results came from — it was post-fire logging and pre-fire abandonment,” said Monica Bond, a wildlife biologist with the Wild Nature Institute and co-author of the study.
The researchers said they found that in fire-damaged sites that had owls prior to the fire, where less than 5 percent of the area was logged, 12 of 15 spotted owl sites were occupied after the fire.
In sites where 5 percent or more of the area was logged, two out of six owl sites were occupied, they said.
The most recent study, conducted by researchers critical of logging, adds to a debate with policy implications; Congress is weighing legislation to change forest management activities and speed the approval of logging operations in areas damaged by wildfire, which some lawmakers say will reduce chances of subsequent fire.
The owl, too, is under federal review, as the Forest Service pursues a conservation strategy to protect the population. California spotted owl numbers have declined in the past 20 years, according to the agency, due to threats to habitat and competition from the barred owl, which has invaded the spotted owl’s territory.
California spotted owl isn’t listed as endangered, but the authors of the study are leading an effort to have it listed by the Fish and Wildlife Service.
The study’s lead author, Chad Hanson, is a research ecologist with the John Muir Project of the Earth Island Institute, which opposes such legislation and is critical of logging on federal lands generally.
Recently burned forests — called snags for the dead trees left standing — are beneficial to spotted owls as hunting territory, Hanson said. Owls nest in deep woods and hunt in more open areas.
“We call this the bed-and-breakfast effect,” Hanson told E&E News.
In a news release, Hanson said of the study, “This is good news for declining California spotted owls because this is something that we can control — we can make policy decisions to stop post-fire logging operations in spotted owl habitat.”
A researcher whose work was questioned in the new study, Gavin Jones, took issue with some of the findings.
Jones, a graduate research assistant at the University of Wisconsin, Madison, told E&E News that his studies showed without a doubt that high-severity fire negatively affected spotted owls.
Those findings from the King Fire were “entirely unambiguous,” Jones said.
Jones said he doesn’t rule out that post-fire logging could be detrimental to spotted owls and that research in that area has been limited.
And while Jones said he’s more of a scientist than a policy advocate, he added that campaigners for less logging sometimes take the view that all wildfire is good and all logging is bad — when the truth is somewhere in the middle.
Even severe wildfire is good in patches, Jones said.
“Is all severe fire good? We’ve found it’s not good,” Jones said. “I think there’s this basic problem of missing the nuance.”