While most folks settled into bed on a warm night in July, a team of wildlife biologists with headlamps and blue latex gloves sat around a table in the middle of the Mashpee National Wildlife Refuge and waited.
“Bat!” one biologist, stationed about 200 yards away, exclaimed.
The rest of the team snapped on their headlamps, rose out of their camping chairs and marched through the tall grass of the forest to a large suspended net. A big brown bat nestled in the middle of the net. Work began.
US Fish and Wildlife hired the Biodiversity Research Institute team, a nonprofit out of Portland, Maine, to trap bats six nights this week in Mashpee to study and tag bat species in the national refuge.
While most of the bats caught and tagged were big brown bats, there was also an exciting confirmation this week: a juvenile Northern Long-Eared Bat, a threatened species, was trapped in the Mashpee woods on Tuesday night, July 12.
“It’s not a shock that one was found but it is nice to have confirmation of one,” said Eileen McGourty, Wildlife and Fisheries Biologist with US Fish and Wildlife.
The federal agency listed the species as threatened last spring after white nose syndrome, a fungus, decimated an estimated 98 percent of the Northern Long-Eared population since 2007. The species has mostly disappeared in the northeast except for a few locations: Martha’s Vineyard, Long Island, and Cape Cod, specifically the Mashpee refuge and the Cape Cod National Seashore.
Researchers have little information on Northern Long-Eared Bats prior to white nose syndrome because they had been a common species at that time. And one big question yet unanswered is why the bat has survived on the Cape and these other locations.
Ms. McGourty has conducted acoustic bat surveys in the refuge since 2012 to begin to answer that question. US Fish & Wildlife started a national program to study bat habitats in over 50 wildlife refuges in 13 states on the East Coast as the bat species declined rapidly.
Ms. McGourty placed microphones throughout the forest to record bat calls. The Northerns make a high pitch noise as high as 110 kilohertz. Humans can typically hear frequencies at 20 kilohertz. Software then printed out the different bat frequencies; in 2014 and last year, Ms. McGourty found likely matches of the Northern Long-Eared.
While the evidence was mostly conclusive that Northerns were in the refuge, the federal entity still wanted a physical confirmation. And when the bat was announced as threatened, federal money arrived.
Ms. McGourty has hopes to place a transmitter on a caught Northern Long-Eared so that they can track where the bats roost.
With confirmed roosting spots in the Mashpee refuge, Ms. McGourty and US Fish & Wildlife can learn how to better manage their forests for the bat; for example, where and when not to burn or cut down vegetation.
They can also use the roost to better estimate the size of the population. Jonathan Reichard, US Fish & Wildlife’s white-nose syndrome national assistant coordinator, said that mothers colonize while giving birth, some colonies as big as 10 to 12 bats.
So every night this week starting at sunset, or about 8:30, Caroline M. Byrne, a wildlife biologist with Biodiversity Research Institute, along with volunteers, an assistant and US Fish & Wildlife personnel took to the woods to catch bats. Northerns, as well as other bat species, give birth between May and August.
They set up a station on a dirt road marked as Great Hay Road off Red Brook Road in southern Mashpee. About 200 yards on either side of the station, the team set up two large nets called mist nets. The nets are barely visible even up close and both stretch about 100 feet wide and 20 feet tall. Both traps were suspended over the dirt road as bats typically travel through open areas, preferring the open road to woods.
As the bats come out to feed at night, they travel along the path and into the net before falling into little pockets that line the net. Every 10 minutes, the crew checks the nets. Among the sounds of flies, peepers and wind, a “bat here” or “bat” or “got one” riddle the evening, followed by a distinct high-pitched bat noise. The crew typically stays out for five hours each night.
When a bat does fall in the net, the crew can lower and raise the netting to work at an appropriate level. Ms. Byrne untangled bats carefully with a new pair of purple latex gloves for each (a new pair for each bat ensures that no white nose syndrome will spread), places the bat in a brown paper bag and then returns to camp. Over a lighted table, and with headlamps, the team measures and records the bat’s wing span, its length, weight, sex, species; they inspect it for potential damages caused by white nose or other predators; set aside any droppings for another researcher’s project; and often talk to the bat.
Ms. Byrne, like many biologists who study the mammal, says the bat is a misunderstood creature. While waiting for bats to fall into the mist nets, she often talks about how cute they actually appear. She noted the bats’ feisty character and showed how resilient the creature can be. One big brown bat captured Wednesday night, July 13, showed signs of severely broken fingers that had healed. “I am amazed at how much these guys deal with,” she said.
Bats can also improve a human’s experience outdoors. According to US Fish & Wildlife a colony of 100 bats feeding for 200 days will consume more than 2,200 pounds of insects or approximately 600 million bugs.
Each bat that has not already been tagged from past surveys receives a band with a tag number before it is set free.
As of Wednesday night, no adult Northern Long-Eared Bat had been caught but about 30 bats which had never been tagged fell into the net. They caught 18 big browns on Wednesday night. The juvenile Northern, Ms. Byrne said, was too small for a radio transmitter. The transmitter, if a large enough Northern were caught, would send off a signal to researchers to track. The transmitter, about the size of an ant, is attached with a long, flimsy antenna.
Still, Ms. McGourty said that even without an adult Northern caught, the mist netting has been a success with Tuesday’s confirmation. Now they know that mothers are in the area and birthing their pups.
Not too far from the refuge, personnel on Joint Base Cape Cod recently concluded an extensive similar surveying process. Jacob C. McCumber, the Natural Resources and Integrated Training Area Management program manager for the Massachusetts Army National Guard, concluded a 27-night mist netting survey on the base on Wednesday night. Of the 27 days, their department trapped two adult Northerns and were able to put transmitters on both.
One of the transmitters was lost, but the other bat led the department to two roosting spots close by. One was nestled in the space between cedar shingles and trim board; the other was up in a tree where Mr. McCumber said five other Northerns were found, which he assumed were females. The program manager said they can take the results of their effort and learn to better manage to protect the species.
Equally exciting, Mr. McCumber said, his department will try to monitor where the bats winter. He said there has been evidence, while minimal, that bats have wintered on Martha’s Vineyard; he has also recorded acoustics of the bat on Cape Cod in the winter, but hopes to track them in the fall to find a potential hibernation spot.
“We are trying to see if they hibernate here,” he said. “It’s a big question.”
Mr. Reichard, the national assistant coordinator for white nose, said there has been evidence to support hope that the Northern Long-Eared Bats are surviving the fatal disease, although still limited.
“We are seeing adults surviving and reproducing,” he said, albeit in select areas and for unknown reasons. “The hope is that their offspring will survive.”