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WHEELER:

Welcome to the Econews Report. I'm your host this week, Tom Wheeler, executive director of EPIC, the Environmental Protection Information Center, and I am joined by three friends who are great birders and spotted owl biologists. First, we have Peter Carlson, a long time spotted owl biologist who is from the area. Hey, Peter. Next, we have Dave Wiens, who is a research wildlife biologist at USGS. Hey Dave.

WIENS:

Tom, thanks for having me today.

WHEELER:

And lastly, but not leastly, we have Ken Burton, local bird nerd. Hey, Ken. Hi.

BURTON:

Tom and Pete and Dave, thanks for including me in the conversation.

WHEELER:

And it's a treat for our listeners because we get Ken on two shows this month, which is wonderful. All right. Yeah. All right. So we are talking about barred owls today, and their impacts not just on northern spotted owls, which are huge, but also just on West Coast forest ecosystems. Dave, so we talk about the barred owl as invasive or non-native to the West Coast. How is it here in the first place? How do we come to have barred owls across the West Coast? Where do they come from?

WIENS:

That's a great question. It's actually really interesting because barred owls are a native species to eastern North America. And for millennia, their expansion, they were limited to eastern North America. And that was largely because of the Great Plains region, a large region of treeless expanse that barred owls could not get across. However, along with European settlement came some pretty major ecological changes to the Great Plains region, including fire suppression and extirpation of bison and beaver, which allowed shelter beds of trees to grow. And essentially we think those allowed barred owls to move westward and impact native species on the west coast.

WHEELER:

So, we began to see barred owls in Washington, I believe, in the early 1960s. The first report in California was in the second half of the 1970s. Peter, you ran for a long time a spotted owl research station outside of Hoopa. When did you start seeing barred owls popping up in your spotted owl surveys?

CARLSON:

study, we had just two or three random detections of barred owls in the early 90s, and that included a hybrid that showed up in 1994. I would say by about 1996 or so, we were starting to get more consistent detections just in a few spots, historic spotted owl sites that started having a pair of barred owls, and that stayed at low numbers, just a few of those for a number of years.

WHEELER:

And it seems that somewhere around 2010, things flipped and we saw just very considerable barred owl invasion here in Northern California and the pronounced impacts from barred owl invasion on spotted owls. Ken, as a local birder, when did you start noticing barred owls?

BURTON:

Well, I remember even before I moved up here, this would have been mid to late nineties, Bardowl in California was still something of a big deal. And it was actually something that, that birders would go out and look for to add to their state bird lists. And I was one of those people. And I came up here, not just for that, but that was one of my, one of my goals up here. And I don't even remember where I was when I finally came cross paths with one, but probably somewhere up in the, up in Redwood National Park. And yeah, I, since then, I, I mean, I moved here in 2005 and since then it's just gradually become the expected forest owl in most places and, and I certainly hear them, I don't hear them all that often, but certainly more than spotted owls now and places where there used to be spotted simply don't have them anymore. So occasionally Bardowls, I mean, they're still pioneering. They're still dispersing into new areas. And recently there've been some that have shown up in some pretty unexpected places. There was one way out on the, on the North spit recently by the coast guard station, and there's been one at the Arcata Marsh lately, and those kind of cause a little bit of a stir among the local birding community, just because they're in unexpected spots, but yeah, it's just one of those gradual insidious things that you don't even really notice happening until suddenly it's in your face and everywhere.

WHEELER:

And I think that that speaks to one of the ways that the barred owl is, is becoming so prolific in our region is that it is, it is much more of a generalist when it comes to habitat. It certainly likes the habitat that the Northern spotted owl has always enjoyed the older mature forest, the closed canopy, the kind of mature forest ecosystems, but it also can exist in much more urbanized areas, much younger forests as well. So it exists across a greater diversity of the landscape, Dave. So the, the barred owl, I know that it is like bigger, better, faster, stronger than the Northern spotted owl in some sense, but they're also cousins. Can you talk about the kind of biological features of a barred owl that allow it to out-compete its cousin, the Northern spotted owl?

WIENS:

Yeah, well, first of all, barred owls are, as you alluded to closely, are related to spot owls. So, they're in the same genus of strix owls. But barred owls tend to be a little bit more aggressive in defending their territories. They're also a little bit larger. And so, as an apex predator that's coming into these areas, they're basically exploiting this untapped niche that they have available to them, being this new top-level apex predator in the system. And in terms of spot owls, they really hone in on the forest conditions that spot owls also like for nesting in older, tall trees. And so, barred owls are able to get into those areas. They're able to reach higher densities. Multiple pairs of barred owls can use a territory the size of a territory that only one pair of spot owls can use, for example. And so, they basically overwhelm the spot owls with their numbers and their aggressiveness. And the spot owls are relegated to suboptimal habitats where they may have reduced survival and also disrupted nesting. And so, over time, you can see this pattern as we have more and more barred owls. This has resulted in some very steep, dramatic population declines of northern spot owls.

WHEELER:

So densities on the landscape, one of the things that facilitates that density is a more widely varied diet. Can you talk about what we know about the diet of barred owls versus the diet of spotted owls?

WIENS:

Yeah, just quickly, they are a generalist, opportunistic, top-level predator, and in comparison, spotted owls are a specialist predator, and so spotted owls specialize on tree bulls, wood rats, and northern flying squirrels, largely. Barred owls love to eat those things, plus anything else that moves in the forest, essentially, including insects, earthworms, just basically anything that moves that will fit in their mouth, they will eat, and so that allows them to use much smaller areas than spotted owls require and attain much higher densities as well.

WHEELER:

Peter, I think that you had a point.

CARLSON:

Yeah, I fully agree with Dave on their broad diet, allowing them to use a wider range of resources. I want to point out another reason that they've been able to outcompete and have their populations increase so rapidly is, on average, they will nest earlier than spotted owls do, and they have more young. Spotted owls typically will have one or two fledglings, whereas barred owls will have often three and sometimes even four fledglings. And so that just allows their population to increase in a localized area much more quickly.

WHEELER:

And Ken, I believe that you've seen the effect of this more varied diet in our forest ecosystems. Can you talk about that?

BURTON:

Well, I have circumstantial evidence. Very recently on a hike up in Prairie Creek Redwoods, I, it wasn't that long a hike, but I came across no fewer than five giant salamanders, coastal giant salamanders, on the trails that had either missing or mangled front ends. And not all of them were dead. They were just mutilated. And several of them were just like the rear half of the animal lying on the trail. And I shopped that observation around among some local biologists and with the idea that maybe barred owls were behind that mayhem. And I got some support for that idea. They've definitely been documented to eat amphibians. And these are both, the salamander and the owl are both nocturnal animals. And again, it's circumstantial, but it seems to several of us that that's the likeliest candidate. And I want to point out that these salamanders have been hammered just as hard as spotted owls have by loss of old growth habitat.

WHEELER:

Absolutely. Well, well, thank you for that. So as far as I can understand it, I tried to go back in time and look at when did we first become aware of the impact of, of barred owls on spotted owls? The first paper I could come across was from I believe 1976 and that was a master's thesis out of Western Washington University where someone theorized because of all of these things that we've talked about, the preference for the same habitat, the more aggressive nature of barred owls, the, the, the more widely varied diet, allowing them to exist at greater densities that that barred owl invasion was likely going to have a significant impact on spotted owls. And that was proved true, right? Dave, can you talk about the most recent demographic information that we have for spotted owls and how we can kind of try to tease apart the impact of barred owls on spotted owl populations?

WIENS:

Well, yeah, there's a couple of ways that that's happened over time. And the first is these long-term, spot-out demographic studies that Pete mentioned that he works on that have been in place across the range of the northern spot-out since the late 80s, early 90s. And so, there are currently, or recently, there have been as many as 11 of these long-term study areas where they do intensive demographic works on northern spot-outs over close to 30 years, where they individually mark and recapture individual birds and enable to track their survival and reproduction over time and estimate their population trends. And so, every five years, a large group of scientists get together and they analyze all the data from these study areas and look at population trends. And so, the most recent analyses where we did that, we found that all populations that have been monitored of spot-outs since the early 90s are in decline now. Not only that, but the rate of decline was accelerating in recent times within the past 5 to 10 years. And so, based on the data from those studies, we can see that there's a strong association with decline in spot-outs with a concurrent rise of barred owls in those areas. Just briefly, the second way and the more powerful approach that's been used more recently are large-scale removal experiments involving barred owls, where we set up these carefully controlled removal experiments in several study areas in Washington, Oregon, and northern California, and then we systematically remove barred owls from areas while monitoring the population response of spot owls to that removal. Those experiments have provided some very powerful results in terms of how not only barred owls are affecting spot owls, but also that once you do remove barred owls, that you're able to stabilize these long-term population declines that I mentioned that we've been observing over the past 30 years for spot owls. Those declines are essentially arrested and halted in areas where barred owl removal has occurred.

WHEELER:

That's wonderful. Peter, maybe you could talk about your experience running a long-term study area and having kind of seen this decline of northern spotted owls in your own study area over time and what it kind of looked like on the ground to go out and hoot and find fewer and fewer owls.

CARLSON:

Yeah, like I said earlier, we started picking up some barred owls in the mid to late 90s, but they seem to stay, in our area, they seem to stay at a fairly low level. We were hearing stories from other areas like Hoopa and some of the areas on the coast where they were starting to see more barred owls, but we did start seeing an increase, and after a while, our study area seemed to be about five years behind the trend on Hoopa, and so we could kind of foresee what to expect, and sure enough, like you alluded to before, it was around 2009-2010 when we really started seeing more of an increase in barred owls, and that was year after year for quite a while seeing an increase in the number of detections, and that seemed to start leveling off by around 2017-2018, not seeing as much of an increase, but they were still there prevalent, and yeah, it got to the point where we realized we were monitoring more barred owls than spotted owls just with our nighttime calling. I mean, it's kind of a surreal thing for me having started work on spotted owls in 1992 to see that change.

WHEELER:

Absolutely. The EcoNews, we're talking about barred owl removal. So Dave, you've mentioned these removal experiments, which occurred across the range of the Northern Spotted Owl, but some of our earliest successes were in Northern California. We had Green Diamond and Hoopa engaging in these removal experiments. And our region showed the most dramatic response to barred owl removal. That is, we get rid of the barred owls, the spotted owls suddenly kind of reappear on the landscape and appear to do quite well. Can you talk about the dynamics of why California might experience such a rapid rebound, whereas other areas where barred owl invasion had occurred for a longer period of time, where barred owls were more densely present, why it took longer for positive results to be shown in Oregon and Washington?

WIENS:

Yeah, that's a great question. As the range expansion of barred owls moves southward into the Pacific Northwest from Washington and Oregon into Northern California, then those impacts basically followed that. And so we see in, for example, by the time we began removal experiments in Washington and Oregon, populations of spotted owls have been severely impacted in those areas, and we actually didn't have that many spotted owls left in these study areas where we were doing the removals. Whereas in Northern California, the impacts didn't have as long to be as realized because barred owls hadn't been there as long. And so there was still more spotted owls on the landscape when those removals happened, and that allowed their spotted owls to respond to the removal. When you have much fewer spotted owls and a high, high abundance of barred owls, you have a much tougher time not only keeping the barred owls from recolonizing those areas, as soon as you remove the territorial pairs, the new ones will come right back. And these high-density areas, that's a repeated process that happens with removal and recolonization. And when you have very low numbers of spotted owls, you can see how that process then would take a while to take hold. It did. We did see positive effects in the spotted owl populations, even in those areas with high densities of barred owls. However, like you said, in areas with lower densities of barred owls and still substantial populations of spotted owls, we can see very rapid response in barred owl removals, simply because the spotted owls are still around to respond so quickly.

WHEELER:

But it's not to say that Bardowl removal won't be impactful for Washington and Oregon, right? We have a proposed Bardowl management strategy that has been championed by the U.S. Fish and Wildlife Service in conjunction or in relation with multiple other state and federal agencies that is out for public review right now. And the strategy also proposes removals in these areas. It's not too late, is I guess my point. Or is it too late for Northern Spotted Owls in Washington and Oregon where Bardowls have been present on the landscape for so long? Is it too late to save Spotted Owls for these two areas?

WIENS:

I'll let the other two talk a little bit. But first, I don't think it is our experiment, even though it ended about three years ago now. The experiment in Washington and Western Oregon, where densities of spotted owls are by far the highest in that region, we did see a positive effect. We did see a positive response of spotted owls. We did see the population declines come to a halt in those areas where we removed barred owls. And so essentially, what we're doing is the spotted owls that were already there in the landscape, once we began doing removals, it allowed the spotted owls to retain their territories and hold on to them and begin nesting. And if you do that, that experiment was only for five years. And so over a prolonged, longer period, as more spotted owls nest and begin producing more young, we might see a stronger response in that case.

WHEELER:

I want to do some myth busting. So I have been one of the few vocal proponents of barred owl removal. And so I get to hear from a lot of folks who are skeptical about this as an idea. And one of the persistent things I hear is that it's too late for the spotted owls and their best hope is to interbreed. And then they can continue on in some sense by contributing their genetics to barred owls. And that's going to be the future of owls. Ken or Peter, do you have any thoughts on this idea of interbreeding as some way of species preservation?

CARLSON:

Sure. I can say that over three decades of doing spotted owl surveys and work, I've seen a handful of hybrid owls. They're not that common. The spotted owl genetics would just get swamped by the barred owl genetics because there's just so many more barred owls. Looking into the future, if that's what was going to happen. Yeah, I would totally disagree with that idea that that's beneficial to the spotted owl genome.

WHEELER:

So one of the things I use as an example to talk about this is my own genetics, right? I did one of the 23 and me genetic tests and I got a report back that, Hey, lo and behold, I have more Neanderthal DNA in me than the average person, which is very cool and exciting, right? Not very surprising, really. It's not very surprising, right? Big heavy brow. I dragged my knuckles on the ground, right? We all know that humans interbred with Neanderthals and other hominids early in our evolutionary history, but there's not a whole lot of Neanderthal left in us, right? Like it, it, it doesn't, it doesn't make up a very large component of our DNA. It doesn't seem to have really impacted me and makes me different than my other less Neanderthal friends and relatives. It, it, it is, it's gone. It is an extinct species and, and homo sapien is left in here too. We'll see barred owls continue if we don't do barred owl removal and spotted owls will, will virtually be, be gone from, from the, from their genome. There's not a lot of back-crossing. It's a lot of first generation hybrids that don't really contribute much to the overall genetic pool here. So it doesn't seem like this is really any sort of a strategy. I think that there's also something important in what is likely to be lost in, in practical terms. The Northern spotted owl has been an umbrella species for our mature and old growth forest ecosystems, right? Through the protection of the, of the spotted owl, which has resulted in the Northwest forest plan protecting most of the old growth habitat left on federal lands, protecting lands on private industrial timberlands across Pacific Northwest. We are then protecting the myriad of species that also depend on those same forest types that may not warrant protection or may not have enough information to warrant production under federal and state endangered species acts. When we lose the Northern spotted owl, we also are losing that. We're losing our ability to utilize the ESA, the endangered species act to protect this wide variety of habitat. And then very, very pragmatically it can get logged again. We have a lot of acreage that has been protected from destruction or modification because the Northern spotted owl that may be gone if we, if we don't do something about the decline of the Northern spotted owl. So this story about what's one owl versus another, it's not quite true. It's one owl versus perhaps a whole ecosystem of protections. And when we think about barred owls and their more diverse diet, it's one owl versus West coast ecosystems. We have these forests that did not evolve together with barred owls are now trying to contend with barred owls. Oh goodness. All right, I'll get off my soapbox. So Dave, I alluded to the fact that there is a barred owl management strategy under development. If you could give us some of the broad strokes of what is being proposed here that that'd be fantastic.

WIENS:

Really, the Bardal Management Strategy was developed by the Fish and Wildlife Service, and I'm with the United States Geological Survey. And so, basically, we've provided the science background that then has informed the management strategy itself. And so, I think very broadly, I think I'm not intimately familiar with the strategy. I'm becoming more so, as it's out for comment right now. But I think that this is a broad-scale strategy that allows landowners, individual landowners, a lot of flexibility to participate in this program that's developing for Bardal Management, a very important program where my understanding is that there would be focal areas where Bardals would be intensively managed, and then more generalized areas where it would be more site-specific, where the squad owls are in the landscape is where the management might occur. I think it's right now under development still, and out for comment. And so, I don't know if I want to say too much about it.

WHEELER:

else, any other comments on the, the Bartow mansion strategy? All right. I think that this is going to be one of those things that's absolutely necessary to preserve the Northern spotted owl. As Dave said, it is a broad landscape level strategy, allowing landowners to participate in Bartow removal. If they are interested, it also looks at the science of where Bartow management would have the most bang for its buck. So can we arrest the further spread of Bartow owls into the Sierras where they might be impacting California spotted owls? That seems like a good priority. If we can stop them there, then we won't have to, in the future, contend with this fight that we're now having to deal with, with Northern spotted owls, or can we stop them around Sonoma where Bartow invasion has is at its leading edge. So if we can stop at Sonoma, then the Sonoma Marin Northern spotted owls will be doing a lot better. And I think that the thing that I'm interested in as an environmental organization is trying to provide support for this because we know it's going to be controversial. Already animal rights organizations have flooded the public comment portal with over 10,000 comments against Bartow removal, and they're coming at it from a different perspective, right? They don't want to see precious individual lives be lost. And I think that they're kind of missing the larger ecosystemic impact that Bartow owls are going to have. Yeah, Ken.

BURTON:

Yeah, well, I think you're absolutely right, Tom, that the objections are mostly at the individual level. I don't think anybody wants barred owls to replace spotted owls. And nobody, including the people who would be out there shooting the barred owls, wants to destroy those lives. But the situation, I think, has gotten to the level where we have to place ecosystem-level concerns ahead of individual animal concerns. We have to, just for the integrity of the planet. I mean, I wish we had an Endangered Ecosystem Act instead of an Endangered Species Act, but we don't. Some species, I mean, saving them is so, so intractable. How are we gonna save the polar bear, for example? But with something like the spotted owl, there are some very concrete, doable things that can be done to make a huge difference. I'm not claiming that barred owl removal is gonna be the be-all and end-all for the spotted owl, but it's gonna make a huge difference. And the only thing getting in the way is the politics, really, at this point. If the Endangered Species Act means anything at all, I think it has to be employed where it can do some real good.

WHEELER:

I agree around this Christmas season in Humboldt County in Blue Lake, somebody always puts out a banner with a quote from John Lennon, war is over if we want it. And I think with Barda owls and spotted owls, we have perhaps a new adaptation of those lyrics, which is extinction is preventable if we want it right. This is one of the necessary things that we have to do to prevent the extinction of the Northern spotted owl. And I feel like it's a moral imperative for us, the environmental community who have been fighting for the Northern spotted owl for 30 plus years to, to do the thing that's hard. And the thing that's hard is Barda owl removal. They're very cute, but we, we do species removals for all sorts of different reasons, including other cases where we are trying to save other species, even in our own homes, we put out mice traps, right? I don't, I don't necessarily see the difference besides Barda owls just being extremely charismatic. So I hope that doesn't get in the way. But anyways, I, I learned a lot in today's show and I hope that y'all did too. And I hope that you give the idea of Barda owl removal more, more thought. If you are skeptical, I hope that that's what folks listening to today's show arrive at is that maybe there's more doubt about it, or maybe there's more excitement for Barda owl removal. If you were, if you're on the fence to begin with, because this is going to be something necessary to save the Northern spotted owl. Well, I want to thank my, my wonderful guests, Peter Carlson. Thank you so much. Ken Burton, Dave Weins had a wonderful show. Thank you so much for joining the EcoNews Report.

BURTON:

Thanks.

WHEELER:

Join us again next week on this time channel for more environmental news from the north coast of California.