|Waiting for sunset, Missouri State University graduate
students (from left) Ben Hale, Josh Parris and Larisa
Bishop-Boros set up a net at the opening of a cave at
Sequiota Park. Photo by Bob Linder
Using a fine-mesh net stretched across the cave entrance, Missouri State University biology professor Lynn Robbins and several graduate students carefully captured 44 bats — including the rare grays — for a close-up look at the flying mammals’ health.
“For the most part the bats were clear of White Nose Syndrome,” Robbins said, referring to the fungus that has killed more than a million bats in eastern states. “But we are sending tissue samples from some gray bat wings that showed some discoloration. If there is an infection, it didn’t start here.”
The bats were released unharmed, and samples were sent to the U.S. Geological Survey’s disease laboratory in Madison, Wis.
Robbins said he should know within a few weeks whether the fungus has reached Springfield.
Confirmation of the disease in this part of Missouri would be big news in the bat world. “Oh, definitely,” Robbins said.
The protected gray bats fluttered into Sequiota Cave this weekend — more than a week ahead of schedule — prompting park officials to end boat cave tours early and close the cave to public use. It’s primarily a “bachelor” bat cave, home mainly to adult male bats, although Robbins said a few female gray bats were caught Monday night.
“We may check the cave later to see if any females are raising babies,” he said.
His team attached tiny identifying bands on the bat’s wings, in part because no one really knows where the gray bats come from on their way to Sequiota Cave.
“We hope these bands show up elsewhere, so we’ll know more about this group of gray bats,” Robbins said.
Melvin Johnson, Outdoor Initiatives Community Recreation Supervisor for the Springfield-Greene County Park Department, said the unusually warm winter triggered the bats’ early arrival.
By summer, up to 6,000 gray bats will call Sequiota Cave home during the day. They’ll cling to the roof in two or three colonies before emerging at dusk to devour mosquitoes, flies, mayflies and other bugs and insects.
Before 2006, gray bats typically arrived in mid-April, Johnson said. But as the environment continues to get warmer, the bats fly in earlier each year. Two years ago they arrived the first week of April. Last year they entered the cave on March 31.
|A gray bat is examined after being netted by Missouri
State University grad students at Sequiota Cave.
Johnson said gray bats are sensitive to human intrusion into their cave living areas, which is one reason the cave is closed. The cave entrance also has been posted to prevent people from possibly tracking White Nose Syndrome fungus spores into the cave.
White Nose Syndrome is the newest potential threat to the Sequiota bats and others in the Ozarks. The fungus causes bats to come out of hibernation early, depleting their stores of energy as they move about trying to find insects that haven’t yet emerged. Without a food source, the bats starve or die from exposure to the cold.
The fungus so far has only been suspected in two areas in Missouri, in Pike County north of St. Louis and Shannon County in the southeast part of the state. So far there’s been no indication the fungus affects humans, although people can transport fungus spores from cave to cave on shoes and clothing.
Robbins said Missouri wildlife officials have found fungus DNA on two kinds of bats, though the bats weren’t considered infected with the disease. The presence of the fungus in Missouri is “not confirmed but suspected,” according to Robbins.
At dusk Monday, Robbins’ team captured gray bats, tri-colored bats and one big brown bat to assess their health and determine the ratio of males to females in the cave.
The bats hibernate in caves elsewhere during the winter, but use the Sequiota Cave during warm summer months.
A few years ago, one of Robbins’ graduate students put a radio tracking collar on a Sequiota Cave bat to see where it went after it left the cave. The result was surprising.
“It went to the mall and foraged on bugs flying around the lights in the parking lot,” Robbins said. “When the weather turned bad or the wind picked up, it foraged closer to the cave, around the stream and pond.”