A big brown bat caught during the 2022 Bat Blitz. While bigger than other area cave bats, it is tiny at less than two inches long.
CAMP MCDOWELL - Last week, the bats of the Bankhead National Forest had their moment in the sun—or rather, the moonlight.
Nearly a hundred bat experts and others from at least ten states, plus Norway, converged at Camp McDowell for the 2022 Bat Blitz, an intensive survey of the bat population. Bat Blitzes are organized every year by the Southeastern Bat Diversity Network (SBDN) and a state group, in this case, the Alabama Bat Working Group (ABWG).
This year, between Tuesday, Aug. 2, and Thursday, Aug. 4, the 65 or more registered participants and the twenty U.S. Forest Service personnel working with them set up more bat traps in more areas of the Bankhead than two biologists could have managed in a whole summer, according to Allison Cochran, USFS wildlife biologist for the Bankhead. Cochran and fellow Bankhead wildlife biologist Rollins Jolly collaborated with SBDN and ABWG to host the event.
Participants came from Georgia, Tennessee, Florida, South Carolina, North Carolina, Virginia, Kentucky, Missouri and Idaho and included biologists, professors, students and employees of federal and state agencies, power companies, environmental consulting firms and non-profit organizations.
Previously the site of a 2008 blitz, the Bankhead was selected again because, since then, white-nose syndrome (WNS), a devastatingly deadly bat disease caused by the fungus Pseudogymnoascus destructans, has spread to the forest. Ninety to one hundred percent of bats in colonies infected with WNS die. By April 2021, WNS was estimated to have killed more than 90 percent of the northern long-eared, little brown and tricolored bat populations in North America, according to one study, available online at doi.org/10.1111/cobi.13739.
This year’s goal was to trap bats at all 2008 sites, plus a few others added by the USFS, to get a sense of the impact of WNS on Bankhead bats, according to Nicholas Sharp, the Alabama Department of Conservation and Natural Resources nongame wildlife biologist for north Alabama.
During the survey, ten teams set out in the late afternoons for sites deep in the Bankhead where they would try to trap bats.
The survey included twenty-six sites in all, two of which were trapped on two nights.Before dusk, ten teams set up either mist nets or harp traps at that night’s sites. Mist nets, fine mesh nets that are stretched out between poles and then raised into the air using pulleys, are set up in likely flight corridors or near features that bats might want to access, such as fresh water. These nets have built-in mesh pouches to catch any bats that fly into the net. Harp traps, roughly harp-shaped traps featuring a frame containing offset rows of thin strings, usually of fishing line, which bats fly into before dropping into a collection bag beneath, are usually placed outside caves, in which several species of bats, collectively called cave bats, hibernate during winter.
“Bats can see these nets. (. . .) They also have echolocation on their side,” said team leader Emily Ferrall, a wildlife biologist with the Georgia Department of Natural Resources, while setting up a mist net across an overgrown one-lane road, essentially two narrow tracks through the weeds, near Slick Ford. “They can just go around,” she noted.
At the point where she was setting up the net, trees and thick vegetation crowded close to either side of the road. “This is a corridor that we think they could be traveling down,” Ferrall said, “because it’s easier to fly down this than the middle of the woods. It’s a much simpler pathway for them to navigate.”
She added, “We try and think about ways to try and almost trick them or make them not have enough time to change their mind or go around (the net)."
Ferrall’s team set up two more nets across parts of the road that lacked enough surrounding vegetation to form corridors but did offer water—in mudholes that had formed in the ruts of the road.
With the nets in place, the team settled in to wait some distance away, where they had set up an examination station. Once bats appeared against the darkening sky, the first one spotted by Bankhead District Ranger Andy Scott, team members took turns checking the nets every 10-12 minutes—for the next five hours. The survey was scheduled to continue until around 1 a.m.
“Last night, I was in a creek,” Ferrall said. “I had two nets inside of the creek—I wore waders—and then I had a net on the road above the creek where there’s a bridge.” Despite her teams’ efforts and the relatively large source of fresh water, on Tuesday, Ferrall’s team “got skunked”; it didn’t catch a single bat.
The teams’ composition changed every night, allowing each participant to work with a greater number of colleagues. That meant that other members of Ferrall’s Wednesday night team reported having more luck on Tuesday. Michaela Bass, biodiversity surveys manager for the Tennessee Wildlife Resources Agency, said her team caught six bats on Tuesday. Another team caught four, including two big browns, a red and a tricolor.
Big brown bats are the second largest of the 15 or 16 bat species found in Alabama, after the hoary bat. Experts differ on whether Alabama has 15 or 16 species. “There’s one bat called the eastern small-footed bat that should be here in Alabama but has never been documented in Alabama,” Sharp said, explaining that the eastern small-footed has been documented in the areas of Tennessee and Georgia that surround Alabama’s Jackson County in the northeast corner of the state. “I’m sure they don’t know the state boundary and purposefully avoid the corner, so they gotta be here, but we’ve never documented that bat, so I don’t count it.”
The tricolor bat, formerly called the eastern pipistrelle before DNA testing revealed it is not part of the Pipistrelles genus, is the smallest.
Survey methods
The experts who handled the bats were required to wear gloves and have up-to-date rabies pre-exposure vaccines. (Members of the public are reminded not to handle bats, a very small percentage of which carry rabies.) Additionally, everyone who came within six feet of the bats was required to wear an N-95 mask to protect the bats from possible exposure to COVID.
Once removed from the traps, the bats were examined to determine their species, which can sometimes be obvious because of distinct coloration or the size of certain features but which sometimes requires measuring features such as the ears or even toe hair. The surveyors also measured and weighed the bats and determined their sex, their reproductive status and whether they were juveniles or adults.
That last is determined by examining the joints in the bones of the bats’ wings, Ferrall explained. A gap at the joint means the bones aren’t fully formed and indicates the bat is still a juvenile, born this year. Bats grow so quickly that, by winter, it will already be difficult to tell if those born between April and June are juveniles or adults, Ferrall added. By next summer, she said, it will be impossible to tell the difference.
Dr. Chris Burns, a plant and soil scientist who graduated from Alabama A&M in 2021 and who has been working with bats for seven years, said that she would be testing the bats for COVID, too.
“If it’s one of our more rare species, we may put a band on it,” Ferrall added, noting that the bands, which can reveal when a bat was first captured, have shown some bats to be at least forty years old when recaptured. She said that bats of certain species would also be fitted with transmitters so Kelsie Eshler of Copperhead Environmental Consulting could track them the next day, either on the ground or by plane.
Eshler, who had one of Copperhead’s two planes hangared in Jasper for aerial tracking during the Blitz, said that daytime tracking would lead her to roost trees, whereas nighttime tracking would reveal where the bats eat.
“We tagged four tricolored bats and are actively trying to radio track them,” Cochran said after the survey, adding that knowing bats’ location could inform the USFS’s forest management. Already declared endangered in Canada, tricolor bats are among the species most impacted by WNS and have been submitted for endangered status in the U.S.
Around 8:30 p.m. on Wednesday, Aug. 3, Ferrall’s team caught its first bat of the night in one of the road rut nets. It was carried to the examination station in a small brown paper bag.
Bass examined, weighed and measured the bat, an adult male big brown, 48 millimeters (roughly 1.89 inches) long and weighing 16 grams (just over half an ounce).
Burns swabbed his mouth.
Then it was time to release him.
“My favorite part of the night is letting them go,” said Vicky Smith, A-Z Animals wildlife educator and caretaker of three rescued native cave bats and two Egyptian fruit bats. “The researchers always laugh at me because I get to work with bats every day and can hold a bat any time I want to, but my bats are injured. I don’t get to see (a bat in flight).”
“The nicest thing about this is we get to go out and learn new things,” said Dr. William Stone, Alabama A&M associate professor of wildlife and ABWG coordinator, who has participated in Bat Blitzes since the first one in 2002, including all three held in Alabama. (The 2016 Bat Blitz was held in the Talladega National Forest.) He also spent ten years trapping bats in the Bankhead for his own longterm, low-intensity study, which was shut down in 2020 by the COVID pandemic.
“I learned how to do a bat wing punch at one of these (blitzes),” Stone noted. A wing punch is a method of obtaining a DNA sample; the wing heals from the procedure. “I’m a seasoned veteran of this, but still I’m learning new things,” he continued. He noted that he sometimes learns the most about new technologies relevant to his work in particular from the younger participants of the blitzes.
After releasing the big brown bat, Ferrall’s team disposed of the bag that had held him and sanitized the station and their tools and gloves. According to Stone, before WNS, researchers typically placed bats in reusable cotton bags, but the risk of cross-contamination is now too high.
The survey teams were to return to Camp McDowell by 2 a.m. for decontamination, which included boiling the nets and the outer layers of their clothing at an outdoor decon station set up by the camp.
Survey results
In 2008, the survey collected 395 bats in the Bankhead, including northern long-eared, red, big brown, tricolor and evening bats and several members of two endangered species—one gray and 16 Indiana bats. Both species were on the endangered list even before WNS struck. This year, with even more sites included in the survey, only 192 bats were collected. Fewer species were caught as well: red, big brown, evening, tricolor and Seminole bats (in order of most caught to least).
There was some good news, however. “As far as I know, all bats appeared healthy and free of signs of white-nose syndrome,” Cochran said. She noted that the bats trapped were a variety of ages and sexes.
In addition to the survey itself, the Bat Blitz also included a child-friendly educational event for the public on Monday afternoon in Camp McDowell’s Randall Commons. It was there that Smith spoke.
During her presentation, “Batty about Bats,” Smith debunked bat myths, explained the structure of bats’ wings and feet, illustrated the differences in species using preserved specimens, shared many other interesting bat facts and introduced the audience to five live bats.
One of the most interesting facts Smith shared about bats is that their feet are already full-sized at birth. Those relatively big feet help a baby bat, called a pup, to hang on to its mother when she’s flying. “Mom has her hands in her wings, and she can’t fly around and hold the bat at the same time,” Smith pointed out.
She noted that bat moms usually have one pup a year, but twins are occasionally born.
A bat’s feet are rotated, appearing to face backward from a human point of view, so that a bat can hang upside down with its stomach facing a cave wall or tree instead of its back, allowing it room to sweep its wings back in order to fly as it lets go.
Bat myths debunked
As noted earlier, bats are not blind; some species just have very small eyes. Bats are not rodents, which are part of the order Rodentia; bats are part of the order Chiroptera, which means “winged hand.” Not all bats have rabies; in fact, only half of one percent of bats have the disease, according to Smith. Bats don’t attack humans; Smith said encounters described as attacks are really instances when bats flew close to people’s heads while hunting the large concentrations of insects that humans attract.
Finally, only three species of bats drink blood, and they are found only in South and Central America. Most bats, including all Alabama species, eat insects. A few in the southwest drink nectar, and some in other countries eat fruit.
Bats’ role in the ecosystem
“A substantial portion of what (bats) eat are insects that are crop pests,” Sharp said later, adding that one study found that bats save the U.S. agriculture industry a minimum of $4 billion a year in pest control. “If you like to eat food, you should thank a bat,” he said.
According to Smith, bats are also important pollinators and dispersers of seeds.
The highlight of Smith’s engaging presentation was, inevitably, the rare chance to see live bats up close. First, Smith introduced the audience to her three rescued cave bats: Merlin, a Mexican free-tailed bat, whose wrist and ulna were broken and didn’t heal properly; Covid, a big brown bat, whose wing was shredded by a cat and had to be amputated; and Peri, a tricolored bat, who had one wing ripped off by a cat.
“Cats kill and injure more bats than any other animal in the United States,” Smith said.
People, too, can be a danger to bats. Locally, the biggest threat humans could pose to bats might be to disturb them in their caves during their winter hibernation. If bats come out of hibernation early, they will not be able to find enough insects to eat to survive. “Be careful if you’re in caves with hibernating bats,” Smith warned.
To help bats, Smith recommends installing bat houses (not where there are outdoor cats, of course), sharing your bat knowledge, and carefully evicting any bats that are roosting where you don’t want them—without harming them. For more information on evicting bats, visit www.humanesociety.org/resources/eviction-notice-roosting-bats. Remember that some bats are protected by law.
Last but not least, Smith brought out her Egyptian fruit bat Aurora and her pup, Orie. Born on June 6, Orie was nursing enthusiastically while clinging to his mother, oblivious to his audience.
The educational event also included several exhibits. South provided a display of specimens and equipment to be used in the survey, including a net, measuring tools, a bat detector, transmitters and a receiver.
Maggie Wade Johnston, executive director of Wild Alabama, was present to share information about the non-profit organization's programs.
Izzy Carbonell, representing both ABWG and the Jacksonville Zoo and Gardens in Florida, offered bat origami and stickers to visitors. Chad Fitch of Alabama Power invited them to design their own bat-themed art using scratch paper.
Shon Tatum-Mendes from the USFS’s National Forests in Alabama Supervisor’s Office in Montgomery gave out bat coloring books. Benjamin Blair, a seasonal USFS employee on the Bankhead, applied temporary bat tattoos, and Lauren Wright, a USFS summer intern from Auburn, helped children decorate colorful cut-out bats.
Outdoors, Randall Blackwood, naturalist for Cathedral Caverns State Park, offered an explanation and hands-on demonstration of how sonar works.
Sponsors of the 2022 Bat Blitz included the U.S. Forest Service, TVA, the Alabama Wildlife and Freshwater Fisheries Division of the Alabama Department of Conservation and Natural Resources, Copperhead Environmental Consulting, the Wildlife Society, the Northwest Alabama RC&D Council, Alabama Power, the U.S. Fish and Wildlife Service, Vanasse Hangen Brustlin Inc. and the Alabama Conservation Enforcement Officer Association.
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