A Turning Point in Saving Bats from white-nose syndrome - White-nose syndrome (WNS) is caused by a fungus, Pseudogymnoascus destructans (formerly known as Geomyces destructans). Given the extent and rate of spread of the fungus (Pseudogymnoascus destructans), which causes WNS in North America, it is time to admit that it can’t be stopped.
A Turning Point in Saving Bats from WNS | Merlin Tuttle
June 7, 2016
A Turning Point in Saving Bats from White-Nose Syndrome
By Merlin Tuttle
Given the extent and rate of spread of the fungus (Pseudogymnoascus destructans), which causes WNS in
North America, it is time to admit that it can’t be stopped. It is here to stay, and further attempts to document
or prevent its spread are more likely to exacerbate than alleviate bat mortality. The last thing that the
relatively small numbers of survivors need now is more human disturbance during a period of critical stress.
An unknown portion of the WNS die-off has almost certainly been caused by well-intended human efforts to
help bats in hibernation sites. Human entry typically causes bats to raise their metabolism and burn up extra
energy, even if they do not visibly arouse. A single ill-timed disturbance can force a bat to waste a month’s
supply of stored fat. In bats whose energy has already been depleted by WNS this could be the straw that
broke the proverbial camel’s back.
Bats are highly mobile, able to spread WNS with almost unbelievable speed, as they’ve already proven. They
also know and visit thousands of roosting places unknown to us, making effective control impractical, if not
impossible, even if a safe and effective cure could be found.
Hibernating little brown myotis (Myotis lucifugus) in a Michigan mine. Hundreds of miles of passages in this
state’s abandoned mines have been protected, but are unreachable for status surveys, making accurate counts
impossible. Summer monitoring of feeding habitat with bat detectors likely would give more reliable year-to-
year evidence of status trends.
Suggestions of treating caves to eliminate or suppress WNS, pose risks of unintended consequences.
Mycologists have warned that “Attempts to eradicate specific cave microorganisms may lead to undesired
fungal or bacterial outbreaks since intact communities may interact as biological control agents.”
Federal and state agencies are currently considering a proposal to test fogging with an apparently nontoxic
chemical suppressant in an abandoned railway tunnel in Georgia this winter. The tunnel’s former hibernating
bat population has fallen from 5,000 to just 220 since the arrival of WNS.
Because remaining bats likely have the highest natural resistance, they may be ready to begin rebuilding on
their own, as appears to have happened in other locations. Even if the proposed experiment caused half of the
remainder to die needlessly, the experiment could be mistaken as successful because 110 “were saved.”
Such treatment is impractical on a large scale and would neither eliminate the fungus nor prevent reinfection
of bats. It also could have unintended consequences. It could trigger costly bat arousals caused by ultrasonic
sounds, odors or air movement during pressurized release. And, even if nonlethal, it could suppress non-target
organisms, disrupting unique cave ecosystems of potentially great value.
Huge expanses of hibernating gray myotis in Fern Cave,
Alabama. This cave shelters America’s largest hibernating bat
populations, mostly gray myotis. Because of its miles of
extremely complex passages, hundreds of thousands of bats at a
time may be overlooked during winter surveys, again making
acurate status trend determinations impossible.
At this point I believe we should pursue two primary goals to
deal with WNS: 1) improve protection at key hibernation sites
for all bats (not just for species already listed as endangered)
and 2) expand standardized monitoring of status trends in
summer habitats, based on ultrasonic detection. In some cases
entry/exit counters in protected cave or mine entrances may
also prove helpful. It is imperative that we accurately monitor
status trends to credibly defend threatened and endangered
listings and to measure the efficacy of conservation actions,
including improvements in summer habitat and restoration and
protection of hibernation sites.
bat . bat conservation . bats . conservation . disease . merlin tuttle . merlin tuttle's bat conservation . White-
nose syndrome . wns
Article Source: www.merlintuttle.com/2016/06/07/a-turning-point-in-saving-bats-from-wns
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