Bats swoop in for Delta Forest research
Published 12:00 am Monday, August 13, 2001
In the top photo, Tony Reed, left, and Ed Moody untangle a bat caught in a research net in the Delta National Forest about 30 miles north of Vicksburg. In the lower photo, A cantankerous and banded Evening bat is checked before being released again into the dark. (The Vicksburg Post/C. TODD SHERMAN)
[08/13/01] CLARK LAKE Deep in the south end of Delta National Forest, on a trail they’ve dubbed “Cottonmouth Road,” Tony Reed and Lann Wils gently untangle a bat from a mist net, using the light of their headlamps to quell the darkness.
The tiny creature, no larger than a chicken egg, screeched and wiggled to free itself from the netting and hands that held it captive.
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“It’s like holding a mouse or a hamster, just a lot more nippy,” said Reed, 29, eager to show off the ends of his thumbs, covered in small, red nicks.
“The Evening bat is the most cantankerous bat we get,” he said, as the two swatted mosquitoes under the constant drone of katydids. The night’s catch was no exception. “It’s about like sticking your thumb under a sewing machine.”
After a few minutes of careful maneuvering, the flying mammal was pocketed in a large, cotton sack for measuring, banding and weighing. If it were a species of special concern, Wils and Reed would use surgical glue to attach a tiny transmitter to its back to track it by radio frequency during the day. But this Evening bat was a recapture; a yellow band was already clipped to its tiny forearm, so it was recorded in the bat log, then allowed to return to the pitch black night.
“Anytime you get to play in the woods and get paid for it, it’s an excellent situation,” said Wils, 25, who has spent his last two summers catching bats in the Delta as part of a cost-sharing project between the forest and Arkansas State University, where he and Reed are students. “The last (bat) survey was in the ’60s and ’70s out of Auburn. The only thing they had for a field guide for Mississippi was a pamphlet there was not a lot of work done in the state.”
So Wils teamed up with forest officials to provide them more information on the mammal considered to be a good indicator of species of forest health while using the study as the basis for his master’s thesis. “They’re really sensitive on a ecological scale. That’s why we look at bats and how they are doing,” Wils said.
Reed assists him for work on his bachelor’s degree in wildlife management.
On one evening last week, the pair worked near Clark Lake, about 30 miles north of Vicksburg, on an ATV trail pock-marked with enormous mud puddles. Two mist nets were placed over large water holes to catch bats when they swooped down to drink. The tiny creatures work fast; once caught, they can chew their way out of a net in minutes, so every quarter of an hour, from dark until 1 a.m., Wils and Reed turn on their headlamps and make the short walk from their vehicle to check the nets.
Tromping through the muck and water in knee-high rubber boots and waders, they caught the eye of a curious armadillo who had wandered in for a drink. “You name the critter, we’ve just about spotted it out here,” Reed said, reeling off a list of animals that includes bobcats, rattlesnakes, coyotes, gray foxes and even a recent alligator spotting. “We’ve been fighting cottonmouths all summer,” Wils said. But this evening, only Evening bats are netted despite a few gaping holes torn by the unfortunate bard owls or flying squirrels that have, too, swooped into the nets.
Initially, when they began the project in the fall of 1999, the two didn’t expect to catch anything.
“Last summer, it busted loose,” Wils said. “We’ve done pretty well.”
They have netted eight species of bats Evening, Southeastern, Little Brown, Red, Seminole, Northern long-eared, Eastern Pipistrel and the Big Brown. “That’s pretty decent species diversity,” Wils said. Yet a few species have eluded them the Indiana and the Gray bat, both endangered, as well as Rafinesque’s big-eared bat. “The Indiana was a long shot, since it’s more of an upland bat,” Wils said. And the gray prefers caves, a feature not common in the Delta. “The thing that’s surprised us is that we haven’t caught the big-eared bat, the Rafinesque. This project won’t help their case,” he said, explaining that the bat is a species of special concern, meaning it is not considered threatened though it may be proposed for listing. “There’s not enough data to list it.” He said that the species may still be in the forest but it’s avoided the nets because of its huge ears and extra-sensitive hearing.
Wils said he is surprised they have caught so many Southeasterns, also known as myotis austroriparius, or austros for short. “We’ve netted 590 bats over the last two summers. Out of that, I’d say 150 are austros,” he said. “A lot of species, we don’t know much about. The Southeastern bat is one of them. And it seems to be fairly common here,” he said.
Ultimately, however, it’s not catching bats they seek to do, but to find their homes among the hollow trees in the forest. If researchers can better understand how bats choose their roost trees, forest-resource managers would know how to protect their habitat “It’s just like a house. They have certain trees for certain species of bats,” Wils said, and it usually takes an enormous sweetgum, hickory or red oak, all common trees on the Delta. “That’s their biggest problem; their roost trees are being cut,” Wils said. “It’s not a big problem with the Forest Service because of the thinning and selective cuts they do. They leave trees that can get to this stage.”
So while Reed and Wils spend their nights catching bats, they spend their days searching for roost trees. To date, they have found four. Once they find a roost, they conduct an exit count, which entails watching a tree for hours at dusk, when the bats leave for a night of feasting on insects and mosquitoes. They’ve counted as many as 620 from one tree in one evening.
This is the last week the pair will be on the forest before returning to Arkansas and the indoor classroom. In the fall, Wils will present his findings at the North American Bat Research Symposium in Vancouver, British Columbia.
But in their absence, bat monitoring in the Delta will go on. Over the summer, two Delta National Forest employees were trained on capturing and releasing the bats, and have had their required series of rabies shots. “I’m learning from the pros,” said Ed Moody, wildlife technician for Delta National Forest, as he struggled to untangle the second bat caught that evening, shifting it from hand to hand as the tiny Evening bat lived up to its reputation continually biting him until getting free.