This week, the feds announced some really bad news for bats in 16 Eastern states. They're now dying by the millions from a disease caused by an invasive fungus that's only been known in the U.S. since 2006. (See this Oregon Field Guide episode for great footage and background.)
In five years, white nose syndrome has killed an estimated 5.5 million to 6.7 million bats. And if scientists can't find a way to stop it, several eastern bat species are certain to go extinct.
This is terrible news. But what does it mean for bats in the Pacific Northwest, where neither the disease nor the related fungus has been detected? To answer that, I talked to Pat Ormsbee, the Northwest bat specialist for the U.S. Forest Service and Bureau of Land Management.
Several important highlights from our conversation:
- Experts don't know for sure the fungus that causes white nose syndrome, geomyces destructans, doesn't exist in the Northwest.
- Bat colonies in the Northwest are smaller than the Eastern colonies, and they're hard to find. So, if they were dying from the disease and spreading the fungus, it would be less obvious.
- There are some reasons to hope the fungus won't spread as quickly out West as it has back East, but the science underpinning those hopes is scant.
- The Northwest has a lot of caves on public land. That increases the risk of people spreading the disease. Don't bring caving gear from other regions to the Northwest!
- Bats play a really valuable role in managing pests for us. They're worth an estimated $22 million in crop management – and that figure doesn't even include forestry.
Here's our interview in full:
What's your reaction to the new estimates of bat deaths from white nose syndrome?
It's depressing. It's worse than I and others anticipated. It really makes it clear that this is a devastating invasive disease that at this point we really don't really have any control over.
This is a new infection in the U.S. We know this fungus is in Europe, but somehow it doesn't kill the bats in Europe. Are we to presume it came from Europe or do we even know that much?
Well, we'll never know for sure how it got here, but the scientific world feels it probably was brought over most likely by a human tourist. The original epicenter for white nose syndrome is site called Howe Caverns. That's a tourist cave that sees over 200,000 visitors a year. The popular hypothesis is that it was probably brought over on a tourist's shoe or pants or whatever and was introduced into the bats that also roost at that site.
Is it understood that people are helping to spread it from that initial introduction or is it spreading on its own?
The primary means of spreading white nose syndrome is bat-to-bat or environment-to-bat, and that's because bats are colonial roosters and they move to different locations throughout a region between seasons. They are going to be the primary mode of spreading this disease as far as we know.
But, again, we think this probably came from Europe originally and, in this case, the asexual spores of this fungus are very good at attaching to surfaces and getting moved to other areas. That's one of the ways they disperse and persist in the landscape.
So, it would be naive to think humans visiting a site that had this fungus at it could not pick it up and take it to a new site. That's a very reasonable assumption, and there is some evidence that this fungus has been found on equipment and clothing within the affected zone in the Northeast. It's been found on those things that have been taken into infected sites.
Does that affect how we might prevent it from spreading out to the West? And are some things being done on that front already?
Yes, and this is the big issue for us. First off, look at a map of the United States. Look at the public land in the West compared to the East. This is our big concern. We have got a lot of public land out here – especially in Oregon – and there are a lot of holes in the ground on that public land that people can wander into.
Our concern is that this would get picked up somewhere in the East and be brought here and be deposited in one of our sites by a human. That we would have a new epicenter here in the West, that's our biggest fear.
We have begun doing our educational efforts to let people know there is a decontamination protocol that needs to be followed if you're going underground to prevent the potential spread. We are also asking people not to bring gear that might have been exposed to white nose into the Northwest.
A lot of the stories I've read on this have said the disease has only reached as far as western Oklahoma. Does that mean this fungus does not exist in caves in the Northwest?
"For us, the big fear is that we will have a human introduction and a new epicenter."We have no idea. We know very little about the fungal ecology or general ecology of our subterranean habitats – particularly caves. It's one of the things on our list we'd love to know is what species within the geomyces destructans genus are here in the West, if any. We're assuming it's not here.
One of the other differences, however, between the East and the West is so far we have not documented large colonies of bats in the West like they have in the East. Most of our wintering bat colonies are fairly small.
One of the fears is this stuff could show up, these smaller colonies could die and spread this stuff around, and we might never know because we aren't getting reports of hundreds to thousands of bats flying out in winter.
The speed at which it spread to the 16 states out East is part of the startling element of this. I guess I'm wondering why wouldn't it spread farther?
There are reasons - and we can always stay hopeful. There maybe reasons why the spread could slow and possibly not occur, but I sure wouldn't hang my hat on that with something this aggressive and invasive.
One reason is that we may have species in the West – other fungal species or bacterial species – that out-compete this species – that might prevent it from getting a foothold. We would love for that to be true, but we certainly can't make that assumption given that we know nothing about the fungal ecology of our caves.
The other hope, even more slight, is that perhaps our species have some sort of resiliency to white nose that the Eastern species don't have. There are two species in the East that have succumbed to white nose. One, in particular, is the little brown bat, which has had the highest level of mortality from white nose syndrome of any other species. [Their range spans] the entire United States and portions of Canada and Mexico. There's no break, really, in their distribution. So, that's unfortunate. And the species overlap, of course, with Eastern and Western species.
The things that might slow it down could be geographic features like the Great Plains, where there are fewer caves where bats can hibernate in winter. So there may be some pieces to the puzzle that may allow us some comfort in knowing the bat-to-bat spread could be slowed somewhat in the hopes that they find a cure that we can apply before it gets out here. For us, the big fear is that we will have a human introduction and a new epicenter.
What do you know about whether the westward spread of the disease has slowed?
The things that might be on our side are things like the expanse of the Great Plains might be false security. There aren't as many holes in the ground there, and we might not have as many hibernating bats. But frankly we aren't convinced because of some of the leaps we've seen with white nose and the distance it's traveled.
I don't think it's slowed. I think that we saw a big jump in the detection of the fungus itself, geomyces destructans, in 2010 where it showed up in western Oklahoma. We did not see an equally big jump in 2011, but our ability to do surveillance for this disease diminishes as you move West. And there are these smaller colonies where we can't get into the back country to find these animals, or we just don't know where they are. So what we've documented and what is really happening may not necessarily align. We hope it does.
I read there are some real problems a lack of bats could cause not just in the ecosystem but for insect control and things our economy really depends on too.
Yeah, the average estimate from research done [last year] is that nationwide bats are worth somewhere over $22 billion a year just in crop management for things like not having to use pesticides and in fewer lost crops from pest infestations. Those estimates did not include the benefits to forests. Of course, in the Northwest, in Oregon, that's a very big deal. We do know a number of our forest insect pests are moths that are typically nocturnal, so the primary predator for those would be bats since they are nocturnal and they feed on moths and beetles.
The other thing is there's so much we don't know about bats – let alone how they fit completely into the environment and the ecosystems. They're very difficult to study, being nocturnal. They fly, they echolocate. They're just strange – wonderfully strange – little animals and hard to study. And I think that's important to keep in mind because there could be delayed ramifications from this loss. It could be a domino effect where the losses don't become apparent until it's too late. We're all very nervous about that, too.
Some scientists say they're looking at the real threat of extinction and realizing this could be a widespread and large-scale extinction event that we don't see very often.
Yes, all that is true. But at this point the modeling for the extinctions – particularly of the little brown bat – have been done in the Northeast region. They're drastic. There's no good news there. If the decline continues, which so far it looks like its going to in that particular region, extinction is inevitable.
Even with regional extinctions, if other regions are somehow buffered from this situation, these species are long-lived, they have a low reproductive rate, they have specific environmental needs, and they are colony roosters. Given their whole life history and those components, it could take a very long time to recolonize those areas. It will easily be decades – and potentially centuries – before we'd see recolonization of these species – even if we have source populations to recolonize from.
Is this disease directly affecting the work that you do?
Oh yes. Fortunately, in the Northwest we like to think we have a little breathing room. Our big push right now is to do the education, to get the public aware that they have the potential to contribute to the problem by going into these sites. We're asking people to stay out of abandoned mines altogether, just for safety reasons. And now with white nose on the horizon there's another good reason to stay out of those. But for folks going into caves, there are decontamination protocols that are available on the Fish and Wildlife Service website. We're also telling people if you're coming in from another area, just don't bring your gear into the Northwest.
We have an inter-agency White Nose Syndrome Response Team that's made up of most of the federal agencies and our state wildlife agencies in Washington and Oregon, and we are just finishing up our Draft White Nose Syndrome Response Plan, which we hope to get signed by all of these agencies and then get out to our people to implement. There are recommendations in there that would be apropos for private landowners and citizens who are interested in knowing more and getting involved.
We've also attempted to step up our surveillance. We're assuming (white nose syndrome) isn't here. But, again, it's very difficult do to surveillance in the Northwest. We've got a lot of holes in the ground, and we really don't know where our bats go in the winter. That's not an invitation for people to go out and help us find them. Bats are so susceptible [to potential mortality] just from being disturbed in winter, so we don't really want the public out there looking for these winter bats for us. But we are developing an orchestrated effort to do surveillance.
So the surveillance - that means you're watching the bats to see where they go and what they do?
Yes, in winter, and in summer we've been doing some population monitoring since we really don't know where our bats go in the winter, and bats are more active in summer. We feel like keeping a finger on the pulse of what bats are doing in summer, and what the populations look like in general, could be an indicator for us to be aware of if things start to go south.
Anything else you want to mention that I didn't ask you about?
The only thing I would add for folks to keep in mind is that bats really are good insect eaters, and they go about their job quietly. They're fairly shy and gentle animals they really aren't trying to get in our hair and be problematic.
I just think it may take a paradigm shift for people – a social, cultural shift – to rewire their impression or their attitude toward bats as being vicious or bad and to be more bat friendly in their lifestyles. Particularly in places where people have bats move in with them, to not kill them when they find them. They have been kind of demonized in our culture, and I don't think we can afford to hang onto that attitude about bats.