Guest blog: cave and karst program director Cory Holliday discusses TNC's artificial cave project

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 HollidayWhite-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.

The Nature Conservancy artificial cave diagramNow 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, TNCCory 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.