Project

Since its first appearance in New York in 2007, White Nose Syndrome (WNS) has quickly spread across the United States and Canada. By 2012, the US Fish and Wildlife Service estimated at least 6 million bats had already succumbed to the disease, while state and federal agencies have scrambled to close off caves and protect unaffected bat populations. North American bats hibernate over the winter for upwards of four months. During this torpor, they awaken every few weeks, but infrequently enough to conserve energy in the form of fat. Current understanding of WNS suggests the psychrophilic fungus, Pseudogymnoascus destructans, kills bats in two ways as their body temperature drops during hibernation. Infected bats arouse from torpor more frequently and for longer periods, using more energy without food available to replenish it. Additionally, damage to the thin wing membranes hinders flight while inducing a variety of physiological changes and inflammation.

For an interactive map of the spread of White-Nose Syndrome, visit the USGS tool.

There is hope for infected bats, despite mortality rates in excess of 90% for some cave populations. Bats with the fungus that survive until arousal in the spring have demonstrated an ability to recover from the disease. It is likely that bats with a mild-enough infection to subsist until the end of hibernation can mount a stronger immune response as energy use is no longer suppressed.

Traditionally, efforts to kill the fungus using antifungal agents would be the intuitive response to a goal of reducing the severity of disease. A developing understanding of microbes’ roles in ecosystems and the lack of knowledge about caves, however, mean that methods which indiscriminately kill fungi could severely impact cave ecology. Antifungals could kill fungi which compete with P. destructans on the bats’ skin, or disrupt cave function. Handling and treating bats as they are affected during hibernation is also counterproductive, as disturbing bats wastes their valuable energy reserves. We instead began our plan for defending bats from White Nose Syndrome with the volatile compound ocimene. Potentially effective without contact with the bats, ocimene has demonstrated an ability to delay the growth of fungi, thus giving bats a better chance at fighting the infection when they arouse.

Design files for amplification of leupA, amplification of leupB, ocimene part 1, ocimene part 2-1, ocimene part 2-2, and ocimene part 3.

WNS map credit: U.S. Fish & Wildlife Service
Bat photo credit: Wayne National Forest
Lab photo credit: Bob Phelan, SDELC