This milk snake captured in New York
shows signs of fungal and bacterial infections. Could this become a major risk
to snake populations across the United States? Photo: D.E. Green, USGS National
Wildlife Health Center
By Matt Miller, senior science
writer
While studying timber rattlesnake movement patterns and habitat
use in Vermont, researchers made a surprising discovery:
snakes covered in lesions, particularly around their faces.
Called snake fungal disease, it’s a disease showing up
with increasing frequency in snakes around the eastern and midwestern United
States. Conservationists fear it could pose a similar threat to snakes as
white-nose syndrome in bats. That’s a scary comparison: white-nose syndrome was first documented in 2007
in New York and has since spread widely, killing millions of bats as far
west as Oklahoma. It has recently been raging through caves in the Smoky
Mountains and has been verified in Kentucky’s Mammoth Cave National Park. So
far, despite many efforts at controlling the spread, the disease rages on.
Could snakes face a similar menace?
Timber rattlesnakes don’t move as
widely as bats, but they do share some habits. They too hibernate
underground in communal dens—often with other snake species. During
hibernation, immune systems are suppressed. This combination can create a
fertile ground for fungal disease growth and spread.“There has been a lot of money
spent on white-nose syndrome, and a lot of educational outreach, but so far
they’ve been unable to stop the spread in bats,” says Emily Boedecker, acting
state director for The Nature Conservancy in Vermont. “Snakes are even less
appreciated by the public than bats. An emerging disease is a significant
concern.” The research partnership between the
Vermont
Department of Fish and Wildlife, the Orianne Society
and The Nature Conservancy captured snakes to monitor
their movements through radio telemetry. But they also weighed and measured
snakes, and assessed their health. That’s when researchers found snake fungal
disease. It has never been documented in Vermont before, but now it was turning
up on numerous snakes.
Snake fungal disease has been
documented sporadically in the past, but it began showing up with increasing
frequency beginning in 2006. While it has been known to cause mortality,
the effects on snake populations is yet unknown – in large part due to the
secretive nature of snakes.
“We have more questions than
answers,” says Dr. Chris Jenkins, executive director of the Orianne
Society. “We don’t know if it’s a big deal yet, but we need to look into it
closely.”
Jenkins notes that the disease does
not appear to be spreading like white-nose syndrome; it is appearing in
different parts of the country at the same time. It’s possible that snake
fungal disease is not new but is only now being recognized. “Maybe we just
weren’t looking for it,” he says.
When they emerge from hibernation, timber
rattlesnakes bask in the sun, which appears to help control the lesions.
Another possibility is that the
disease has always been present, but now has been exacerbated by a change in
environmental conditions, including climate change.
In Vermont, researchers found that
the timber rattlesnake population had relatively low genetic diversity, not
surprising given its isolation. “Low genetic diversity and a fungal disease
is a combination I find very disconcerting,” says Doug Blodgett, a wildlife
biologist for the Vermont Department of Fish and Wildlife.
Biologist Doug Blodgett captures a
timber rattlesnake in Vermont. While the research is aimed at tracking snake
movements for conservation purposes, it also assesses snake health. Photo: Matt
Miller/TNC
The problem with wildlife diseases –
indeed, any threats to wildlife – is that they are not considered serious
threats until it’s too late. It is difficult to predict what will be a minor
issue and what will devastate millions of animals – as has turned out to be the
case with white-nose syndrome, and fungal diseases impacting amphibians.
While snake fungal disease was not a
focus of the Vermont research, it may be one of the most important findings.
Hopefully this time conservationists can gather necessary information and develop
strategies to stop the disease before it devastates snake populations.
“We know so little about this
disease, but now we know it’s here and we can start addressing the issue,”
says Blodgett. “We know we can’t ignore it. The past should teach us that.”
Matt Miller is a senior science writer for the Conservancy. He writes
features and blogs about the conservation research being conducted by the
Conservancy’s 550 scientists. Matt previously worked for nearly 11 years as
director of communications for the Conservancy’s Idaho program. He has served on the national
board of directors of the Outdoor Writers Association of America, and has
published widely on conservation, nature and outdoor sports. He has held two
Coda fellowships, assisting conservation programs in Colombia and Micronesia.
An avid naturalist and outdoorsman, Matt has traveled the world in search of
wildlife and stories.
- See more at:
http://blog.nature.org/science/2013/06/11/snake-fungal-disease-the-white-nose-syndrome-for-reptiles/#sthash.jt9LtP7q.dpuf
- See more at:
http://blog.nature.org/science/2013/06/11/snake-fungal-disease-the-white-nose-syndrome-for-reptiles/#sthash.jt9LtP7q.dpuf
- See more at:
http://blog.nature.org/science/2013/06/11/snake-fungal-disease-the-white-nose-syndrome-for-reptiles/#sthash.jt9LtP7q.dpuf
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