WAYNE, N.J. (AP) - In the face of a potent fungus that has wiped out 90 percent of New Jersey’s hibernating bat population in recent years, a William Paterson University biology professor and his student netted a glimmer of hope recently.
The Record reported (https://bit.ly/2eJIGzi ) they captured and released two healthy northern long-eared bats in High Mountain Park Preserve in Wayne - the first time the species has been documented to be living in the preserve.
The discovery is noteworthy because of the dramatic declines in the number of bats from white-nose syndrome, which has prompted the federal government to list the northern long-eared species as threatened.
As part of their research, William Paterson biology Professor Lance Risley and senior Julia MacDonald were able to track the bats using radio transmitters to determine the kinds of trees they preferred to roost in. Such information can be used to protect and enhance the bats’ preferred habitat, thus help the species survive.
“This most recent sighting of long-eared bats gives us another indication why it’s important to protect these habitats wherever they exist,” said Eric Olsen, director of land programs at The Nature Conservancy, which purchased the 1,200-acre High Mountain preserve in the 1990s with several partners.
While some New Jersey bat species migrate south in fall, others - including little brown bats and northern long-eared bats - hibernate in caves and old mine shafts.
Experts think that makes them more susceptible to the fungus that causes white-nose syndrome, since the bats often huddle together in the caves and can easily spread diseases.
One of New Jersey’s largest hibernation sites is the Hibernia Mine in Rockaway Township, which attracted as many as 30,000 little brown bats before white-nose syndrome struck. A count in March 2015 found fewer than 500.
The New Jersey numbers echo precipitous declines nationally. Federal officials have estimated that since white-nose syndrome was first detected in a cave near Albany, New York, in the winter of 2006-07, as many as 6 million bats among seven species have died in the United States. The disease has spread to 29 states, from Maine to Oklahoma, and five Canadian provinces.
The losses affect humans, since bats eat vast quantities of insects that can carry West Nile virus and other diseases. Bats also feed on insects that cause substantial crop damage, enabling farmers to use less insecticide and saving them up to $4 billion annually. A million bats can consume up to 8,000 pounds of mosquitoes, moths and other flying insects in one night.
Northern long-earned bats are a little more than 3 inches long, with a wingspan of 9 to 10 inches. Compared to little brown bats, long-eared bats are more secretive when hibernating, using spots that are difficult for researchers to get to, Risley said. That makes it harder to get a good population count in winter.
“As a result,” Risley said, “our summer work counting them becomes that much more important.”
Risley and MacDonald first scouted High Mountain preserve to identify likely habitat areas for the bats. Northern long-eared bats typically fly through a forest’s understory, feeding on insects.
Then the two researchers placed acoustic equipment in promising areas. Their machinery can record the high-pitched sounds that humans can’t hear but that bats emit to hunt, using echolocation. The researchers set the device so it would not pick up competing noise, such as the sound of crickets, katydids and flying squirrels.
“We got a lot of long-eared bat calls,” said MacDonald, a Vernon native who conducted the research as part of her senior honors thesis.
Next, they set up a net one night in the flyways where they had recorded the bat calls. Within 20 minutes, they had captured two long-eared bats.
Wearing protective gloves, Risley and MacDonald disentangled the bats from the net, took measurements, then shone the beam of a flashlight through the wings to detect scarring from white-nose syndrome. Surprisingly, these bats appeared healthy.
Before releasing the bats, Risley and MacDonald used surgical cement to attach tiny radio transmitters to the bats’ backs, so the researchers could track them and learn what kinds of trees they preferred for roosting.
To track the bats, they walked through the forest with a 3-foot-long antenna. “Sometimes we ran into hikers who were curious to know what we were doing,” MacDonald said.
White-nose syndrome is caused by a fungus, Pseudogymnoascus destructans, which leaves a whitish powder on bats’ noses, ears and wing membranes and destroys the tissue crucial to their ability to avoid dehydration and maintain body temperature.
The fungus causes the bats to move around during hibernation, which burns up vital body fat. Researchers think the fungus was brought within the past decade to the United States from Europe.
The Nature Conservancy has spent more than $500,000 over the past five years financing researchers looking for ways to combat the fungus, said Cory Holliday, the cave program director for The Nature Conservancy in Tennessee.
For instance, they are backing Georgia State University researchers who have identified a bacterium, Rhodococcus rhodochrous, which emits a compound that can halt the spread of the fungus. The appeal is that it could be applied generally to a cave where bats are hibernating, rather than individually to each bat. The Nature Conservancy has helped pay for construction of an artificial cave in Tennessee so researchers can determine potential unintended consequences before actually introducing promising methods into natural caves, Holliday said.
Working with Wayne Township and the Natural Lands Trust, The Nature Conservancy bought High Mountain Park Preserve in 1993 to protect habitat of Torrey’s mountain-mint, an endangered plant that grows on the ridge.
High Mountain is among more than 30 preserves The Nature Conservancy owns and manages in New Jersey. The conservancy plans to promote public use of its preserves and improve accessibility. At High Mountain, the non-profit will add kiosks for hikers to learn more about the habitats protected within the preserve, Olsen said.
The Nature Conservancy also wants to encourage the use of its preserves as laboratories for environmental research, he said.
Risley and MacDonald’s work fits right into their plans, especially since part of the William Paterson campus abuts the preserve. “It’s beautiful forested and protected property,” Risley said. “We’re lucky we have it as an outdoor laboratory.”
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Information from: The Record (Woodland Park, N.J.), https://www.northjersey.com
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