A fungus that causes “white nose syndrome” has devastated the northern long-eared bat population in some eastern states and was discovered in two places in Minnesota in 2012. The bat was recently placed on the “threatened status” list by the U.S. Fish & Wildlife Service which will give researchers time to find a cure while still allowing construction and logging to take place in the summer months.
On Wednesday, April 1 the U.S. Fish & Wildlife Service (FWS) designated the northern long-eared bat as a threatened species under the federal Endangered Species Act.
Since 2006 bats in the eastern part of the country have been infected from a fungus called the white-nose syndrome (WNS). Hibernating have died by the millions after being infected with the fungus that turns their noses white and causes them to wake up prematurely. The bats often freeze or starve to death because there are no insects to catch. The fungus also causes dehydration and wounds on wing tissue. To date the disease has been discovered in 28 of 37 states.
By enacting the threatened status, the FWS will be able to seek a cure for the disease and implement protections for the bat habitat; efforts they hope will help the bat make a comeback.
Over the last eight years the federal government has spent $20 million in an effort to find a cure for white-nose syndrome. The state of Minnesota recently announced that it was giving $1.25 million from the state conservation fund to help with the fight. Recipients of that money include the University of Minnesota-Duluth’s Natural Resources Research Institute (NRRI), which will work in cooperation with the Minnesota Department of Natural Resources and the U.S. Forest Service to study the bats as they come out of hibernation and find trees to use as maternity roosts.
Wildlife biologist Ron Moen is the lead researcher on the threeyear project. The NRRI biologist said in statement, “Right now we don’t know which trees they use or how long they use them.”
Moen and his team will try to capture more than 140 female bats and attach tiny VHS radio transmitters on them, then track them to their roosting trees. The team will capture bats using fine-mesh nets strung between trees. Once researchers can establish where bats roost and in what kinds of trees they choose to raise their young, researchers can make a plan to protect those areas for that two-month roosting period.
Moen’s work will piggyback on a 2013 project by the U.S. Forest Service. Susan Catton, Superior National Forest Service wildlife biologist, said the Forest Service captured bats with mist nets similar to the ones used to capture songbirds, banded them and put VHS transmitters on female northern long-eared bats, which guided researchers to roost trees. Five bats were outfitted with radio transmitters in 2013 and 15 in 2014. Ten of those bats were located in the Superior National Forest and five at Camp Ripley.
“We were the first ones in the state to put transmitters on bats,” said Catton.
Forty sets of wing punches and swabs were taken from captured northern long-eared bats and sent to the Forest Service Research Station’s lab in Rhinelander, Wisconsin, where tests were done to see if they had WNS, said Catton.
“In the Arrowhead Region we found that bats roost in large aspen and a mix of other trees.”
Once a tree is selected and pups are born, the real adventure begins for the bats. Mothers, who typically give birth to one pup a summer, form large maternity colonies and spend the next six weeks taking care of them. As many as 30 bats may roost in one tree.
Catton said they have learned that the first nest site is often not the last home for the pups. “The mothers will move their pups from tree to tree for unknown reasons,” she said, “Maybe it’s to find a warmer site, find a tree with a lot more thermal energy going into it, or maybe they are seeking safety from predators.”
In 2009 the Forest Service began an acoustic bat monitoring survey in the Superior National Forest that runs from May to September, recording bat activity. In 2010, 8,554 bat calls and 3,184 unidentifiable or non-bat signals were recorded during the 930 detector hours. Catton said data is being compiled and a report will soon be issued.
Minnesota DNR Endangered Species Coordinator Rich Baker explained that the FWS has issued an interim rule that eliminates unnecessary regulatory requirements for loggers, landholders, government agencies and land managers as long as they abide by three conservation methods: Stay one quarter mile away from a hibernacula (a place where bats hibernate); no one can knowingly cause harm to a roosting tree; and, no one can clear cut within one-quarter mile of a roosting nest.
However, Cook County loggers could face some obstacles if a bat hibernation area is discovered on a logging site. The proposed rule could make it illegal to harvest a known roosting tree from June 1 to July 31 when the pups are growing in the nest. During that time all logging will be prohibited within a quarter of a mile of the tree. But if the bats move from tree to tree, will the quarter mile no-cut zone expand?
Amber Ellering, a forestry policy analyst, said not every tree on a logging site is going to be searched for cracks and crevasses that might contain a roosting site.
“However, when we do get information about bats we will use it. We will know more next year after more information has been collected. I think the researchers were hedging their bets on the quarter mile no-cut zone. I don’t know for sure, but I think they figured that when the bats move their pups, they can only carry them for a certain period of time and distance, and I think they factored that in there when they came up with the quarter-mile zone.”
Paul Lungren from the Minnesota DNR regional office in Grand Rapids said right now because the rule is so new, there isn’t a lot of information for DNR foresters to work with. “All I can say is that we are getting more information daily.”
DNR’s Baker said, “As it now stands, we know of about 100 roost trees in the state. I’m sure there are thousands but we don’t know where they are. We will get that information over the next three years from the joint study.”
Baker said in 2012 the fungus that causes the white-nosed syndrome (WNS) was found in the underground mine in Soudan near Tower and in the Forestville/ Mystery Cave State Park in southern Minnesota. However, he said, researchers haven’t found any fungus in 2013 or 2014 and no northern long-eared bat has been found to have the WNS disease in Minnesota. Results of testing for 2015 aren’t in yet.
“But out east, especially in Vermont, 99 percent of the bats have died,” Baker said, adding that northern long-eared bats in Thunder Bay have been found to have WNS.
Baker praised the efforts of the FWS for finding a middle ground that minimizes the impacts to the forest industry while striving to find a cure for white nose syndrome.
Wayne Brandt, editor in chief of the Timber Bulletin and a member of the Minnesota Forest Resources Council said, “The proposed rule is certainly not perfect and includes some troubling aspects, including quarter-mile buffers around known roost trees during periods of time when bat pups are most vulnerable. … Finding methods to kill the fungus or cure white nose syndrome is what is needed to save the bat. What isn’t needed are restrictions for forest management.”
On May 4, the threatened status for the northern long-eared bat will become effective. Because this is an interim rule, and given the number of comments received in response, the Fish & Wildlife Service has opened a 90-day public comment period that will run until July 1, 2015.
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