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Bats in Vermont

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Vermont is home to nine species of bats:

A little brown bat in a Vermont cave during the summer

Cave Bats hibernate in caves and mines during the winter. In Vermont, we have records of:

  • Big brown bats
  • Little brown bats – state endangered
  • Indiana bats – federally endangered and state endangered
  • Tri-colored bats – state endangered
  • Northern long-eared bats – federally threatened and state endangered
  • Eastern small-footed bats – state threatened

The little brown and big brown bat also are known as house bats because they are often found roosting in buildings during the summer.​

Migratory Bats migrate south to warmer climates for the winter and roost in trees during the summer. In Vermont during the summer, we have records of:

  • Silver-haired bats
  • Hoary bats
  • Eastern red bats

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Why are the bats dying?

White-nose Syndrome (WNS) is a newly identified fungal disease that causes hibernating bats to arouse too frequently over the winter, resulting in the rapid depletion of stored body fat and often death. The disease was first documented in New York in 2006 and soon spread to Vermont. By 2012, WNS was found in 16 states and four Canadian provinces and the death toll from this disease had already resulted in the loss of an estimated 5.7 to 6.7 million bats. As of March, 2016 the disease is now in 27 states and five Canadian provinces and continues to spread each winter. This disease has affected all six of Vermont’s cave bat species.

In Vermont, populations of cave bats have declined dramatically since the disease was first observed in the state. In particular, populations of Vermont’s two most common bat species, the little brown bat and the northern long-eared bat have declined over 90 percent.


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Bats in the winter:

A hibernating bat can be disturbed by noises, light, and even body heat of a passing caver. If a hibernating bat is disturbed, it can take upwards of 10 minutes for the bat to become mobile, so a passing cave visitor may not notice the effects of their disturbance immediately and a bat knocked off the wall would fall to the ground before being able to take flight. A little brown bat typically burns through 4-5% of its stored body fat during each arousal from hibernation and may have just enough fat to make it through the winter without additional disturbance.

There are about 40 known major sites where bats overwinter in Vermont, and there are likely many minor sites with only a few individuals. Entering any sites in the winter that contain threatened or endangered bats is considered a “take” under Vermont Endangered Species law and could result in fines up to $2,000 per bat. A “take” of federally listed species can result in even greater fines.

Some of Vermont’s significant bat hibernacula have been gated to protect the bats from disturbance including Aeolus Cave, Nickwackett Cave, Plymouth Cave, Bridgewater Mine, and Greeley Mine. Surveys demonstrate that gated caves/mines show greater bat population increases than ungated sites, likely due to the added protection from human and/or predator disturbance.

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When to stay out of hibernacula:

Due to the drastic declines in bat numbers, all caves or mines that harbor bats during the winter should be avoided from October 1 thru May 1. Hibernating bats are most concentrated and vulnerable during this time, and disturbance could be fatal.

Decontamination: The fungus that causes White-nose Syndrome, Pseudogymnoascus destructans, can survive in dirt on clothing, footwear, and equipment. It is possible that, under some circumstances, transmission of dirt from infected to uninfected sites could also spread the fungus. The VCA and the NSS recommend that effective decontamination procedures be used to reduce any risk of transmission of the fungus to other bats and/or habitats. The latest decontamination protocols can be found at

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Rabies in bats:

Less than half of one percent of bats are infected with the rabies virus. Even though that number is low, people should never handle live or dead bats. Rabies is incurable. If you think that you may have been exposed contact your doctor and call the Vermont rabies hotline at 1-800-4RABIES. If you have other questions about rabies, visit the Centers for Disease Control webpage on bats and rabies:

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