The bat detector sputtered and crackled from its post along Middle Cove Loop at Long Point Wildlife Refuge. It hadn’t yet made the telltale repeating noises that occur when an echolocating bat flies by, but by the time wildlife monitor Luke Elder returned to collect the device in the morning, numerous sonar squeaks had been recorded. The squeaks were then processed by software to determine which bat species called Long Point home.

Luke Elder, a recent Middlebury College graduate, has been working since June to monitor the Island bat population, the first population survey since Kendra Buresch first studied Island bats in 1997. Mr. Elder is interning with local wildlife monitoring group BiodiversityWorks, which in turn is working with the United States Fish and Wildlife Service on the project. The local initiative could lend insight into a regional bat crisis.

Molly Peach led a group of 15 people on an evening hike at Long Point. — Ivy Ashe

More than 5.5 million bats have died off since 2006 as a result of white-nose syndrome, a viral infection caused by the fungus Geomyces destructan. In addition to causing lesions in bat skin and holes in bat wings, it also causes infected bats to wake up during hibernation.

“If you see a bat flying around in the winter, there’s something wrong,” Mr. Elder said. The insect food supply is low in the winter, so a bat out and about cannot feed, and its metabolism is thrown off, causing weight loss, dehydration and death. The disease originated in European caves, where bats have acclimated to the fungus and do not get the viral infection. It was observed in a cave in New York state in 2006 and has since spread throughout the Northeast region.

But one place where white-nose syndrome has not been documented is here on Martha’s Vineyard. The Vineyard is also a documented home of the Northern long-eared bat, one of the species most affected by white-nose syndrome. The Northern long-eared bat is being considered for listing on the endangered species list, which requires careful study of its current population and habitats.

Luanne Johnson of BiodiversityWorks said that she was approached by the Fish and Wildlife Service about doing bat surveys on the Island as part of the effort to learn more about the Northern long-earned bat.

The Vineyard has already provided new data for the Fish and Wildlife Service. In both 2012 and 2013, Nature Conservancy land steward Liz Loucks observed the Northern long-eared bat roosting in bluebird boxes. Ms. Johnson said this had never been documented before.

Mr. Elder’s project builds on the data from Kendra Buresch’s original 1997 report, which she completed as part of a master’s thesis. Ms. Buresch looked at bat habitats across the Island and documented population abundance. Seven different species were observed here.

White-nose syndrome has not been detected on the Vineyard. — Ivy Ashe

“A lot has changed [since 1997] and nobody has since studied bat populations,” Mr. Elder said.

On Wednesday Mr. Elder and Trustees of Reservations educator Molly Peach led a group of 15 people on an evening hike at Long Point, to a site where Mr. Elder had not yet collected bat data. He brought along two detectors, which were ensconced in waterproof containers to be left overnight, when bats are active. The chosen site was near a small pond and a grove of oak trees. Oaks are a preferred roosting site for bats.

“They hang upside down and look like leaves,” Mr. Elder said. The next morning, when he processed the data, he determined that the area was home to Eastern red bats, the most common species observed so far in the bat study.

Wednesday’s walk included one bat expert — Gwen Domas hinski, a high school sophomore from Pennsylvania who has been studying bats with researcher DeeAnn Reader at Bucknell University since she was in fifth grade. Back home, Gwen assists with summer roost colony checks, bat tagging and general survey work.

“The fact that white nose isn’t here yet is interesting,” she said after the walk. “And it’s interesting knowing about how the bats [themselves] got here.” Bats, even those species that are not migratory, often have large home ranges, so a mainland bat could easily make its way to the Vineyard on a regular flight in search of food.

Other explorers came to learn more about making their own backyards more bat friendly. Mr. Elder explained the details of constructing a bat box and placing it high in a tree, where bats can easily find it. A good box should provide tight quarters for a potential colony, as bats like to nest close together for warmth, and be made with rough wood so bats can climb and cling.

“Having a bat on your private property is an indication that your property is a healthy, functioning environment,” Mr. Elder said.

Martha Reston, who made the trip from Chappaquiddick with two neighbors, said that she once had a colony of more than 40 bats living under the outdoor trim of her house. She had to evacuate them by spraying water under the eaves.

“My grandkids saw it; they thought it was the greatest thing in the world,” Mrs. Reston said. She still wanted the bats around, she said, but hoped they would roost in a bat box.

Mr. Elder said one of the reasons for the evening bat walk was to increase awareness of the project and involve the public in data collection. He is relying largely on the original 1997 survey for data collection sites, but encouraged anyone with a large bat population on their property to contact BiodiversityWorks about placing a bat detector onsite. Next summer the project will expand to include mist-netting, a practice of trapping bats for identification and, if funding is available, tagging for future study. Bat detectors can tell what species are in the area, but they cannot help with population counts.

Mr. Elder said that so far he had detected just four of the seven species originally found here, but that he had a late start on the project and “peak bat season” had already passed. Still, he was encouraged that the Northern long-eared bat was still around.

“It’s a positive picture in some dire circumstances,” he said.