The state is asking residents and pest control experts to give bats a break between June 1 and Aug. 15 to help preserve the population in the wake of a deadly disease first discovered in Maine last year.
White-nose syndrome was first detected in eastern North America in 2006, and federal fish and wildlife experts estimate the disease has claimed at least 5.5 million bats since then. Bats with the obvious white-nose fungal infection weren’t discovered in Maine until May 2011, when some were discovered at two sites in Oxford County. Earlier this year, the National Park Service confirmed the infection had been detected in Acadia National Park.
Last week, the state Department of Inland Fisheries and Wildlife sent a letter to animal control professionals around the state informing them they cannot prevent bats from returning to their roosting sites, even within buildings, from June 1 through Aug. 15. The exclusion of bats is accomplished using a device that lets the animals leave a roosting area, such as an attic, but won’t let them back in, explained John Pratte, animal damage control program coordinator at IF&W. Think of it like a reverse lobster trap — bats can get out, but can’t get back in.
“This is the time of year when bats are roosting, and you have the maternity roost,” said Pratte. “It’s important to try to avoid disturbing those; we’re trying to minimize additional mortality on the bat population, and this is one mechanism.”
The department notes that if bats must be removed in that time frame, approval must be granted from an IF&W regional biologist. And bats may be removed from a living space at any time, the department notes, and may be “lethally removed” if human or pet exposure is suspected.
That new rule doesn’t apply to landowners, the state said. However, the state asks that property owners try to avoid excluding roosting bats during the same time period.
If a property owner finds bats in an attic, IF&W added, the animals likely have been roosting there in the summer for many years, so waiting a few more months before removing them might not hurt.
After Aug. 15, any young bats should be able to fly and survive on their own, said Pratte.
As white-nose syndrome creeps into the state, scientists are looking for any means to preserve the population and avoid putting extra stress on it.
“It’s getting a lot of attention from us and other agencies and groups,” said Pratte. “We’re all working together to try to understand what’s happening with the bat population, but also to reduce mortality factors,” said Pratte.
State officials were meeting with pest professionals about the change, as well.
“We’re meeting with the state this week to learn more about this change in policy and, of course, we’ll work with them in any way we can to help manage this situation,” said Modern Pest Services’ wildlife manager, Mike Gaumont. “This year alone, we’ve dealt with over 30 bat cases so both the bat population and issues surrounding our clients’ health and safety are our greatest concerns. If anyone has a bat issue, we highly recommend they contact a licensed nuisance wildlife professional for more information.”
In the letter to professionals, IF&W noted that bats in the genus Myotis, commonly known as the little brown bat, have been hit particularly hard by white-nose syndrome.
“Models predict that the little brown bat may face extinction by 2026 if current trends continue, prompting the U.S. Fish and Wildlife Service to consider emergency listing of little brown bats to the endangered species list,” the state wrote.
Ann Froschauer, communications leader for the U.S. Fish and Wildlife Service’s white-nose syndrome program, said wildlife officials didn’t have a good handle on exactly how big the overall bat population was in the Eastern United States, and what sort of percentage 5.5 million dead bats might be out of the whole. She explained that while officials closely watched endangered bat species, the more common bat species, such as the little brown bat, weren’t closely tracked. Federal and state officials are looking to get a handle on those numbers, she said.
Canadian researchers recording little brown bat “echolocation” calls along New York’s Hudson River during spring and summer from 2007 to 2009 reported a 78 percent decline in bat activity since the disease first appeared locally, according to a research paper published in the June 2011 edition of the journal Biology Letters.
And an August 2010 study published in the journal Science suggested a 99 percent probability of “regional extinction” of little brown bats within the next 15 years. With more than 1 million bat deaths reported already, the U.S. Fish and Wildlife Service is calling white-nose syndrome “the worst wildlife health crisis in memory.”
The white-nose fungus is harmless to humans, but deadly to bats. On its white-nose site, Maine IF&W notes that bats play a critical role in maintaining healthy ecosystems.
“A recent study published in Science estimates that insect-eating bats provide a significant pest-control service, saving the U.S. agricultural industry at least $3 billion a year,” the state wrote. “For example, the 1 million little brown bats that have already died equates to between 660 and 1,320 metric tons of insects that are not being eaten each year.”