Big Fires, Bad for Spotted Owls

News of a study in a press release today from the U. of Wisconsin-Madison:

Giant forest fires exterminate spotted owls, long-term study finds

“We had this long-term demographic study, we knew all the owls in the 137 square mile study area,” says Peery. “The fire burned almost half the study area. On one side was the treatment, a large, high severity fire, and on the other side was the control, with little or no fire. Almost all the owl territories within the megafire went from occupied to unoccupied. We can now say that megafires have a significant impact on the spotted owl, and so we think that forest restoration through fuel reduction benefits both the forest ecosystem and the spotted owl.”

I hesitate to think that the researchers were surprised that the owls had left the burned area….

The study, “Megafires: an emerging threat to old-forest species,” is (behind a pay wall).

Exterminated? Well, maybe, but all they know is that the burned area is unoccupied — the owls likely flew off. Some chicks may have been killed — but I speculate.

Some folks will point out that the fire area studied, the King Fire in Calif., burned in 2014, so it’s too soon to say that those owls won’t come back at some point. They will come back, eventually. But that doesn’t mean that “mega fires” are desirable. The researchers got one thing right: “…forest restoration through fuel reduction benefits both the forest ecosystem and the spotted owl.” We have plenty of snag forest habitat.


  1. We are seeing just the opposite with Mexican spotted owls in “mega fires” in AZ and NM. Not only are the owls returning immediately to their nest sites but reproduction increases in the years subsequent to fire. We don’t yet know the long term effects on fidelity and population, but fires are giving the birds a boost.

    • Fires on the low- to moderate-severity spectrum, even large ones, are not bad for owls – they can even be beneficial. After all spotted owls are adapted to live in forests that burn. Large, uniform patches of high severity like in the King Fire are not good – that’s what this study showed. It represents an enduring loss of nesting habitat that will not regenerate in our lifetimes.

  2. I also understand at least some of these nest sites were salvage logged, so it may not be a valid conclusion that it was the fire that drove off the owls. Was that disclosed in the paper?

  3. To clarify above, I have been told by someone familiar with the circumstances, that in the King Fire area, overall CASPO occupancy went up from 50% before the fire to 58% one year post fire, although it is true that in their study sites, which burned very hot and some of which had territories which overlapped with private lands which were clearcut almost immediately after the fire, did loose occupancy. But this is not because the owls burned up in the fire or all died, they simply shifted, and probably would have used, (and may actually be using) the high intensity areas for foraging. They did not log the study sites, but they did log in almost every other occupied owl territory.

    • Occupancy doesn’t mean they are nesting. If the nests are destroyed, the “occupancy” only means they are foraging. Remember, the owls are territorial, and defend their nesting habitat. The owls without nests may not find unclaimed nesting habitat, and they are notorious for using old established nests. Owls are seen in many places, including the WUI. In my experience, the Forest Service doesn’t salvage log the known nest stands.

      • That is technically true Larry. I think what is interesting though is increased occupancy/foraging indicates that burned forest habitat is very important in owl ecology. The down and dead wood and early successional growth is likely very good for owl prey populations. The bottom line though is that fire is not the threat to owl sit was once considered to be, in fact its probably good for owls in some fairly large portion of the landscape.

        • When the nests are burned, there is a longterm period of decreased reproduction. In some parts of the Rim Fire, even in the National Park, nesting won’t be happening for decades, if even at all. When a burned stand re-burns (something the preservationists never talk about), seed sources become quite scarce. Remember, pines have their own cycles of good cone years, too. The fires we have today are extremely bad for the California Spotted Owl. It’s all about the lack of available nesting habitat, and how very long it takes to grow it.

          • Larry, would you mind providing your citations for your statement that for “When the nests are burned, there is a longterm period of decreased reproduction.” I’ve not seen the research to demonstrate that is true. I also thought the reburn hypothesis was disproven a number of years ago. Where did you get that from? I think it is very useful to have solid information to back up such sweeping and important conclusions in a public forum.

            • In the central Sierra Nevada, reburns are a constant. Some older tree rings indicated a fire every 13 years. The local Indians were experts at maintaining their forests. Just look at how little old growth now remains on the lower half of the Stanislaus NF. Without definitive studies, either way, we do have to address current conditions, utilizing the “anecdotal evidence” to support the right decisions. We cannot just wait for the inadequate “anecdotal science” that is so common, these days. Look at how short of a time the Forest Service has been using the modern styles of salvage logging that are merely snag thinning projects, with multi-sized “leave snags” and large chunks of the fire ‘left for wildlife’. Why not study THAT style of salvage logging, instead of the “industrial” style of private industry?

              It’s all about the lack of available nesting habitat, and how very long it takes to grow it.

              • Did you have citations for your assertion Larry? Just curious.

                It would seem native american ignitions would not have any significant affect on fire return intervals in frequent fire systems like the lower elevation forests of the Sierra Nevada.

                  • Hi Bryan, I think Larry’s *smirk* is meant to meant that, no, he doesn’t have any actual citations to back up his assertions. Which has been a point of contention here on this blog for as long as Larry’s been on it….then off it…then on it…then….

                  • I am sorry, I was not clear, I am asking for your citations for your statement that for “When the nests are burned, there is a longterm period of decreased reproduction.” This is a pretty meaningful assertion if true, it would be great to see the science, please.

                    • Logic says that if there is less habitat and fewer nests, with the same amount of breeding pairs, reproduction levels will drop. I learned what I know from actual field scientists, working directly with the birds. Logic takes it from there… for me. I care very little if people here disbelieve. I have access to other people, whose minds are more open.

                      There are no citations for ‘doing nothing’, instead of modern salvage projects. There are plenty of modern salvage projects to actually study but, no scientists want to, apparently.

              • Larry “ReBurn” Harrell.
                Fire frequency in the era before fire suppression does not mean that forest sitll burns with that frequency. In most cases, reburn is a rare occurrence that affects a subset of the fire-affected landscape.

                • I have many examples of re-burn happening within 20 years. It is more normal for my part of the Sierra Nevada. The study was done in the Sierra Nevada, where re-burns are quite common. The Groveland RD of the Stanislaus National Forest shows how often these re-burns happen. Yosemite National Park shows the same thing, with no logging history.

        • “The down and dead wood and early successional growth is likely very good for owl prey populations.”

          Therefore, thinning and fuel reduction in old-growth stands, including leaving “skips and gaps,” as Jerry Franklin and Norm Johnson propose, and leaving downed woody debris and early seal habitat, would likely very good for owl prey populations, and thus for owls.

            • 2ndLaw, this probably isn’t the thread for a comparison of the effects of fire and logging, but logging, even clear cutting, does mimic important effects of fire. There are pros and cons of both, to put it one way. For example, after logging, much downed woody debris, litter, and duff remains that would be consumed in a hot fire, leaving soils exposed. Fire is both good and bad, sometimes, and the same goes for logging — it depends on where, when, how much, etc.

    • The increase from 50 to 58% you refer to is erroneous – the folks who produced that statistic did not use the same sites in their before/after comparison. Further, the King Fire study showed that in the year right after the fire, owls did not use high-severity burned area for foraging, although they suggest this may change through time as succession occurs in those areas and prey species move back in.

  4. This excerpt from “Bruce and Chas Vincent: Losing Our Forests to Litigation,” at Evergreen Magazine, is appropriate here:

    Evergreen: Tell us about the guidelines and management principles Common Ground has developed.

    Chas Vincent: Our guidelines and principles are all based on ecosystem management practices that restore natural resiliency in forests. Dr. Chad Oliver, who is the director of Yale University’s Global Institute for Sustainable Forestry, first described the principles and practices we have embraced when he was at the University of Washington, maybe 20 years ago. Our goal is to increase biological diversity by altering structural diversity in ways that create habitat niches for early seral species – songbirds, deer, elk, rodents and sun loving plant and tree species that have lost their places in our forest.

    Evergreen: You describe a problem we are seeing all over the West, the downstream result of forest canopy closure, and the need for disturbance – natural or human – that creates openings in which early seral species can again prosper.

    Chas Vincent: That’s pretty much it – except that we have so much dead and dying timber on the Kootenai that prescribed fire can’t be safely applied without first thinning our overstocked stands.

  5. The other big problem with this study is that is takes a giant logical leap form “fire is bad” to “logging is good.” The article concluded: “megafires have a significant impact on the spotted owl, and so we think that forest restoration through fuel reduction benefits both the forest ecosystem and the spotted owl.”

    It does not necessarily follow that because fire is bad, logging is therefore good. It depends critically on the probability of harm by fire and the probability of harm (or benefit) caused by logging. Spotted owls tend to live in dense, fuel-rich forests with relatively infrequent stand replacing fire regimes, so the probability harm by fire is low. On the other hand, the extent and frequency of logging necessary to moderate fire behavior at a landscape scale would likely require significant degradation of owl habitat.

    Many scientists have taken a critical look at this and realized that it is unlikely that fire will interact with most fuel reduction projects. Many acres of habitat must be degraded by logging in order to moderate fire behavior on just one acre, so logging for fuel reduction does not provide net benefits to owls.

    In early 2012, FWS released their proposed rules for spotted owl critical habitat and an announcement of their intention to encourage widespread “active management” within suitable, critical habitat. Fed. Reg. March 8, 2012. This brought out critics in the scientific community who call for more rigorous analysis of the consequences before widespread adoption of logging as a means of habitat management.

    [W]e are concerned that the decision to move forward with untested “active management” of federally owned forest lands at the landscape level prior to validation through the scientific peer-review process represents a potentially serious lapse in the application of the scientific process. This decision may conflict with the DOI’s scientific integrity policy as well as the mandates of several environmental laws …

    The Department of the Interior’s Fish and Wildlife Service (FWS) considers active forest management as including those techniques that involve aggressive forest thinning and associated forest canopy reductions in dry forests and modified regeneration harvests in mature moist forests. Given that the primary driver of the spotted owl’s decline has been the destruction of old-growth forest habitat by logging, which will be the means used to achieve the anticipated forest thinning and regeneration harvests, we are especially concerned about the potential habitat impacts of adopting untested “active management” forestry technique. Accordingly, we request that the DOI prepare an Environmental Impact Statement (EIS) under NEPA to provide a rational, scientific approach for the testing of active management forestry in order to ensure that such techniques are validated through the peer-review process prior to their utilization at any commercial or landscape scale in the spotted owl’s critical habitat.

    The Presidential Memorandum accompanying the proposed critical habitat designation also noted: “on the basis of extensive scientific analysis, areas identified as critical habitat should be subject to active management, including logging in order to produce the variety of stands of trees required for healthy forests. The proposal rejects the more conservative view among conservation biologists that land managers should take a ‘hands off’ approach to such forest habitat in order to promote this species’ health.” We are concerned that this memorandum overstates the quality and quantity of scientific research on the potential benefits of active forest management, especially in the Pacific Northwest on a federally threatened species. In particular, we are unaware of any substantial or significant scientific literature that demonstrates that active forest management enhances the recovery of spotted owls.

    after a full scientific peer-review of the data collected, the FWS and DOI would be able to make a fully informed decision regarding short- and long-term management of critical habitat. We believe that such an approach is clearly warranted given that the spotted owl is a closed canopy dependent species and active management may degrade habitat for the owl and encourage further expansion of the barred owl. Notably, recent evidence has shown spotted owl extirpation rates related to barred owl invasions are highest for spotted owls with low levels of old growth habitat in nesting areas or high levels of forest fragmentation[fn]. Scaling up logging activities throughout the Pacific Northwest, particularly on BLM lands in western Oregon where “active management” is ostensibly going to be integral to pending resource management plan revisions, is therefore premature and not representative of the best available science.

    Society for Conservation Biology, The Wildlife Society, American Ornithologists Union. 4-2-2012 letter to Secretary of Interior Salazar.

    • In the Sierra Nevada, the core nesting habitats are the lands most at-risk to stand-replacing firestorms. Currently, those “Protected Activity Centers” are protected with a hands-off policy, unless a decision is made to improve a portion of that habitat through thinning. I have been involved with just that, which allowed trees between 10-14.9″ in diameter to be “thinned from below”. All trees 15″ dbh and bigger are absolutely protected.

      Another thing that is confusing is that foraging habitat is not part of the owl’s “critical habitat”. That seems to be an issue with some people opposing active forest management. In the Sierra Nevada National Forests, logging really isn’t a threat to the California Spotted Owl.

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