White nose syndrome: control and prevention

I have been listening to a lot of webinars lately. Last week I posted about Ecohealth’s Zika virus webinar, and this week I want to talk about a White Nose Syndrome webinar that was hosted by the U.S. Forest Service and the Association of Fish and Wildlife Agencies. [I’ve already introduced the fungus (Pseudogymnoascus destructans, or Pd for short) that causes white nose syndrome in several North American bat species in some previous posts; you might want to read those before reading this.] The speakers were Drs. Sybill Amelon, Christopher Cornelison, Dan Linder, and SarahHooper. Note that this post is not organized in the way that the webinar was.

Government agencies have two major goals when it comes it to WNS: (1) help affected bat populations to recover, and (2) protect bat populations that have not yet been affected by WNS.

How can we help affected bat populations to recover?

Eliminating the causative agent of a population decline is an important first step in helping a species to recover – in this case, Pd is the causative agent. Therefore, many people are working on many different possible ways to reduce the prevalence of Pd-infection in affected colonies or to reduce Pd-infection intensities in infected bats. The goal here is to have an integrated disease management system, where many complimentary methods are used in tandem. These methods fall into two categories: those that directly tackle the pathogen, and those that try to make the environment less suitable for Pd (or more suitable for bat survival). Promising methods include the potential application of probiotic bacteria that produce anti-Pd volatile compounds to bats or the environment, using gene silencing to control Pd, and using UV light to kill the very UV-sensitive Pd spores.

When bats are infected with Pd, they have abnormal hibernation behaviors, including rousing from torpor more frequently than uninfected bats. Arousal from torpor burns fat reserves, and this ends up being the main cause of mortality in Pd-infected bats – they run out of fat stores before the end of the winter. So, to help bat populations recover in areas affected by WNS, we should avoid disturbing hibernating bats. We should also work to conserve important bat foraging habitats, so that bats can get big and fat before they start hibernating in the fall.

How can we protect bat populations that have not yet been infected by WNS?

As I posted about a few weeks ago, we’ve recently had some very bad WNS news: Pd reached the West Coast already, and way before we expected it to. Hopefully that’s some kind of crazy fluke and WNS hasn’t established on the West Coast. Regardless, we can play a big role in protecting WNS-free populations by delaying the spread of Pd to those colonies and practicing good early detection and eradication procedures when Pd turns up in new areas, whether we talking about the East or West Coasts. Scientists and cavers play particularly important roles here. We can’t really prevent infected bats from visiting uninfected hibernacula, but we can use good decontamination procedures to ensure that humans aren’t tracking Pd spores from uninfected to infected caves.

One big, looming question:

On the West Coast, bats don’t tend to huddle together in huge hibernacula during the winter, like they do on the East Coast. This complicates monitoring for WNS on the West Coast immensely, because it’s hard to find a lot of hibernating bats to check on them. It’s also unclear how the different hibernation strategies used by West Coast bats will affect the spread of Pd. There’s a lot of important data that needs to be collected here – and fast.

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