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Posts Tagged ‘cave’

Halloween is on its way and with it comes the festive images of black bats flittering through a leafless forest. While this iconography may have contributed to bats’ unfortunate public image, the fear of losing our bats is something truly scary. Will our cave hibernating bats go the way of the American chestnut, victim to a foreign fungus, preserved in memory through holiday traditions? Now that’s a frightful thought.

 

Cory Holliday, cave and karst program coordinator for TNC, tracking bats

Cory Holliday tracking bats

White-Nose Syndrome (WNS) is still an emerging pathogen. Although we continue to research, monitor, track, acquire background data, etc., we are far from having enough information to battle WNS on a meaningful scale. Further complicating the conservation and recovery is the sensitive environment in which WNS attacks our cave dwelling bats: complex ecological systems void of sunlight and plants in which fungi are a major component. Almost any environmental treatment option will likely upset these unique ecological systems. The rate of WNS transmission and geographic spread has been incredible. Due to the seasonality of WNS and the nature of modern scientific research, it is easy to feel overwhelmed and nearly helpless when considering bat conservation in the face of WNS.

 

 

Any conservation effort designed to mitigate the effects of WNS right now would be very risky. We have very little information about how Geomyces destructans (G.d. – the fungus which causes WNS) interacts with the cave environment, what environmental fungal loads are and how/if they influence WNS severity, etc. I’ll stop because if I was to create a list of things we don’t know about G.d. and WNS, it would overcome the limits of my computer storage capacity.

 

But can we really sit by—watching, recording, gathering information— while this horrifying disease sweeps through our caves killing millions of bats? All the while our bats are disappearing from our landscape. The Nature Conservancy is a scientific conservation organization that does not back down from a challenge of this magnitude and we are taking action.

 

Risky? Yes. Desperate? Yes. Worthwhile? You bet. In 2009 when WNS made its big leap down the Virginias, it became apparent to many of us batty Nature Conservancy folks that WNS had terrifying potential. We began immediately looking for conservation opportunities. We made calls, participated in workshops, and gathered as much information as we could and came up with a very, very short list of WNS conservation ideas which could be applied with the information and technologies we have at hand. Our search required that the projects be environmentally benign and they not increase risks to even individual bats, which are under enough pressure already. One strategy seemed to really fit the bill: an artificial cave.

 

In an artificial cave, you can manipulate the environment and kill the fungus with anti-fungal agents or heat while the bats are absent, without fear of impacting a natural ecosystem. You can manipulate the environment to attract a variety of bat species. Ideally, the bats can come and go seasonally, with no disruptions to their natural behaviors, and the fungus can be eliminated during the summer while the bats are absent.

 

Beginning in 2010 we began to talk about this concept internally at The Nature Conservancy. At first we talked quietly as it’s a big, risky project which sounded a little crazy to our deeply scientific sensibilities. Fortunately the more experts we engaged and solicited opinions from, the more confidence we had that we were on the right track, and we could begin talking about it louder.

TNC Artificial Cave diagram

The Nature Conservancy Artificial Cave diagram

Now here we sit in 2011. We’ve had official science advisory feedback. We’re very near to finalizing the design and soliciting bids for construction. We’re developing MOUs and partnerships around the construction, management, and research related to the project. We’re on schedule to have the artificial cave in the ground and ready to go before hibernation season 2012-13.

 

The cave is designed to be largely a cold air trap to attract the colonial bat species which typically congregate in cold winter caves. We have made accommodations for a range of micro-climates within the cave to attract a diversity of species and in meaningful numbers. We’re locating the cave very near a major fall swarming site in efforts to reduce the colonization time, which is typically quite long at 5-7 years. The cave is designed to regulate its temperatures passively, not requiring artificial temperature enhancements which could be subject to mechanical or electrical failures. The entire structure will be underground and is truly designed to function like a natural cave; however, ours is waterproof and sealed from the natural environment, excepting the entrances which will allow bats and air to move in and out freely. Although the artificial cave is still under development, the accompanying sketch is likely very near what our final design will look like.

 

To us, this project really has no down sides. If the project is a complete success, bats will colonize the cave, and we will be able to protect bats from acquiring and succumbing to WNS. Bats will be saved, and the artificial cave can become a model that can be replicated across the nation. If it is a partial success and bats colonize the cave, but we are unable to control WNS, we still have a large facility that acts exactly like a natural bat cave, and we can use it as a field laboratory without fears of impacting a natural ecosystem. If the mitigation project is a complete failure and bats never colonize in meaningful numbers, we still have a cave-like environment in which to study Geomyces destructans and potential WNS control agents at scale. More importantly, however, we won’t be sitting in a post-WNS world wondering if this could have worked.

 

And that is ultimately what our decision-making process came down to. We did not feel that WNS mitigation projects shouldn’t be attempted because they are expensive and there is no guarantee of success. With the appalling risk of losing entire species of bats we felt it would be irresponsible to allow money to limit our best opportunity at gaining ground against the horrifying effects caused by White Nose Syndrome. The Nature Conservancy has been fundraising to build this artificial cave and more and more, people are signing on to support this hopeful prospect which is a rarity in the world of White Nose Syndrome. And with that spirit, we are building this cave. We have high hopes for success and are taking great measures to enhance our chances. And if this strategy fails as a mitigation project, we will hold our heads high knowing that we gave it our best shot.

 

Cory Holliday, cave and karst program director for The Nature Conservancy

Cory Holliday, cave and karst program director, TNC

Cory Holliday is the cave and karst program director for The Tennessee Chapter of The Nature Conservancy. He is the chairman of the Tennessee Bat Working Group and co-founder of the Tennessee Cave and Karst Working Group.

Cory’s work has been focused on WNS since his home state of TN became a border state in 2009. The TN Chapter of The Nature Conservancy has been a contributor to the national WNS effort by supporting and participating in workshops and symposia, and by supporting research and contributing data, and logging many hours underground.

TNC has developed a partnership with Bat Conservation International (BCI) to develop a science advisory group for the project to ensure the highest chance of success. Plans are well underway for the project and TNC is planning to break ground in the spring of 2012. This project is designed as a pilot project which can be replicated anywhere. Future projects will benefit from the intense design planning process which is being undertaken by TNC and BCI to develop an efficient and effective hibernacula which will require very little maintenance and will passively maintain optimum hibernacula conditions.

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Lava Beds National Monument in northern California is a hotspot for bats, with both high diversity (14 bat species) and abundance (thousands of individuals) of bats making use of the monument.  The presence of so many bats is due to the wealth of habitat – with hundreds of caves to choose from, bats can be selective and find specific caves that suit differing maternal (summer) and hibernacula (winter) needs. 

Researcher holding a Townsend's big-eared bat. Photo credit: Ann Froschauer/USFWS

For years, Lava Beds staff have searched for Townsend’s big-eared bat (Corynorhinus townsendii) colonies in the summer and counted these bats as they hibernate in the winter.  Recently, though, we have begun augmenting these efforts with the use of acoustic bat monitoring technology which will allow us to learn about other bat species in the monument.  Acoustic monitoring has become a leading method for the study of bats due it being a highly efficient and non-intrusive means of collecting data on bat activity.  As bats forage at night, they use echolocation for navigation and hunting, and we are using bat detectors which record these ultrasound frequencies that are not audible to the human ear.  Specialized software can be used to view the bat calls, and in some cases, the characteristic shapes and frequencies of the calls can be used to identify bats to the species level. 

We are hoping that by implementing long-term acoustic monitoring we will be able to characterize the occurrence and activity levels of our bats on a park-wide scale.  In the process, we will also gain new knowledge on bat species that are present in Lava Beds but which we rarely encounter in caves, such as the little brown bat (Myotis lucifugus) and other species of the Myotis genus.  This knowledge could serve as a baseline for determining the impact of white-nose syndrome in the event that it reaches the western United States.  Additionally, this acoustic data can be analyzed to determine seasonal patterns in bat activity, which may reveal the timing of when bats go into and out of hibernation and contribute to understanding how the life cycles of bats may be influenced by environmental triggers.  We are also collecting acoustic data from our migratory Brazilian free-tailed bat (Tadarida brasiliensis) colony to learn about the timing of the spring arrival and fall departure of the colony.  Our acoustic monitoring efforts are largely in a pilot phase this year, and we are still refining our protocols, but we hope to fully implement our acoustic program in 2012.

Shawn Thomas works as a Physical Science Technician at Lava Beds National Monument in northern California, where he has been stationed since 2009. He is part of the cave management program at Lava Beds and supports a variety of projects in the Resource Management Division. Shawn’s primary focus is on bat monitoring and bat management, and he serves as the monument’s representative in collaborating with agencies and researchers on white-nose syndrome and bat research.

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In the middle of a tough hibernation season for bats, it is great to hear some good news. With several new states and a third Canadian province confirming a number of new WNS sites in 2011, Missouri remains hopeful that the disease will not take hold. I was fortunate enough to be invited to assist in some Indiana bat and WNS surveys with Missouri Department of Conservation resource scientist Tony Elliot and cave biology assistant Shelly Colatskie earlier this year. Tony was kind enough to offer this update after MDC’s winter survey season.



Tony Elliott (MDC) surveying bats for WNS, credit Ann Froschauer/USFWS

We have wrapped a busy winter of cave survey efforts here in Missouri. Our focus this winter has been on conducting bat counts at our main Indiana bat hibernation sites and surveillance for signs of white-nose syndrome.

I look forward to these surveys because they are a chance to get out in the field, visit different caves throughout the state, and (best of all) see a bunch of bats. However, the need to conduct WNS surveillance added a sense of trepidation to my outlook heading into this year’s surveys. We documented the presence of the fungus associated with WNS at a couple of locations in Missouri last spring and therefore expected to see some signs of the disease this winter. We adjusted the timing of our surveys a bit to give ourselves the best chance of seeing signs of WNS if it was present, stocked up decontamination supplies, and slowly began surveys in mid-December hitting full stride in early February.

Despite quite a bit of snowfall for this part of the country, we were able to conduct all of our surveys as planned with no major problems (yes – that means there were some minor problems, but no need to go into details here). We soon tired of the smell of bleach and other decontamination cleansers, but were encouraged by seemingly stable bat numbers and no signs of WNS. We did send a few samples in to the lab for testing, but they all came back negative for both the disease and presence of the fungus. Also, we have not received any reports of bats dying outside of caves in Missouri.

hibernating little brown and Indiana bats, credit Ann Froschauer/USFWS

So, for now, the news out of Missouri is good. We could still pick up signs of the fungus again this spring, but “our” bats are becoming active and we would be very surprised to see any WNS mortality this spring. Also, the preliminary results of our bat counts indicate that bat numbers are probably stable compared to surveys conducted two years ago.

MDC and USFWS scientists prepare to survey a site for WNS

Earlier I mentioned looking forward to these surveys for several reasons; the other big reason is the people that I get to interact with during this work. I get to go out into the field with land managers from within my own agency and partner agencies throughout the state. I also work with private land owners and citizens who are involved in cave conservation and protection. All of these individuals are a tremendous help during the surveys, whether allowing us access to or guiding us through a site we could not do this work without them. Additionally, the folks that go into the field with us consistently provide different perspectives, good challenging questions, and good humor to our work. We appreciate all of the assistance and look forward to the next survey period, hoping against hope that WNS continues to spare Missouri’s bats.

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The U.S. Fish and Wildlife Service has posted new white-nose syndrome decontamination protocols and supporting documentation for cavers.

While bat-to-bat transmission is believed to be the primary method for the spread of the fungus likely responsible for WNS (Geomyces destructans), recent research and long-distance jumps in WNS affected sites suggests that human-assisted transmission does pose a threat to bat populations.

Recent pilot studies have determined that fungal spores can be transferred from cave sediment to cave gear, including equipment and clothing, then transported to an uninfected cave. Bats can develop WNS directly from affected cave environments, even in the absence of infected bats.

In addition to decontaminating gear, the USFWS recommends that cavers observe cave closures and advisories on all State, Federal, tribal and private lands. If cavers choose to disregard cave closures, it is imperative to follow decontamination protocols to prevent further spread of WNS.

For more information, check out:

Human Spread of White-Nose Syndrome: Why Decontamination is Important (pdf – 1.20MB)

White-Nose Syndrome Decontamination Protocol (pdf – 20KB)

Supporting decontamination documentation for cavers (pdf – 38KB)

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