The University of Florida faces the unique challenge of relocating thousands of campus residents: its beloved bat colony.
The university is home to the world’s largest occupied bat house, a trio of raised structures in the Field and Fork Gardens across Ellis Lake on Museum Road. Together, the two of these homes shelter an estimated 500,000 bats—possibly the largest bat colony east of the Mississippi River. Crowds regularly gather to witness the twilight spectacle of bats coming out of houses to hunt insects under cover of darkness.
Now, with the oldest and most densely occupied Bat House dilapidated beyond repair, UF staff will attempt to lure its residents to the latest Bat Barn, which has been devoid of bats since its construction in 2017. Employees can begin to limit the access of bats. Old house in mid-August, which will be old enough for this year’s bat pups to fly. Then, they would tear down the old house and eventually rebuild.
This is no easy task: once settled, bats can prove very reluctant to move.
“They are loyal to a perch,” Fly By Night, Inc. Laura Sackback Finn, of bat expert, a non-profit organization that works in bat conservation research, bat management and public education.
Given the size of the colony, UF scientists and environmental health and safety workers are moving into largely uncharted waters. Their goal is to remove the bats before the old house collapses and prevent the colony from moving to other structures on the premises. EH&S staff estimate that excluding bats will cost between $5,000 and $10,000, which the university will fund. Estimates are still being developed to repair and rebuild the old bat house. Donations are being accepted at UFgive.to/BatHouse22 to fund student research at the colony and help grow the Bat House, which is visited by a number of groups on campus and related to the UF community .
Celebrating bats in a new bat house, however, is more of an art than a science. Why do bats choose a particular perch?
“It’s the million-dollar question,” said Shelley Johnson, state special agent in natural resources with UF/IFAS Extension and joint faculty in the Department of Wildlife Ecology and Conservation. “UF bats belong to a maternity colony. Females are looking for a place that provides security and the right conditions in which to raise their pups. This can include things like warm temperatures and ready access to food and water. ,
The Finn recently visited homes to help a team of UF bat-movers, which includes Johnson, determine the next steps to move the bat safely. After inspecting the latest bat barn, Finn said it may have been empty because its plywood roasting slats are too smooth to hold bats. The internal temperature can also be too cold for puppies.
“It’s like Goldilocks and the three bears. It has to be perfect,” Finn said.
History of UF’s Bat House
The UF’s original bat house was built in 1991 as a solution to an unsightly problem—a mess of pee and guano at the UF Percy Beard Track and Field Stadium, then home to some 5,000 bats. When the stadium hosted the state track relay in the late 1980s, the bats emerged collectively To eat insects drawn towards bright light. Seeing this, some onlookers got scared.
UF officials made a compromise: Bats could live on the premises, but they needed their own living quarters. The University Athletic Association funded the construction of the first bat house. Bradley Files, pest management coordinator for UF Environmental Health and Safety, said it took several attempts to successfully relocate the colony.
“We will capture thousands of bats and house them,” Files recalled. “And the next day, they’ll all be gone.”
As the colony grew, so did their living space. A bat barn 20 feet from the original home was finished in 2010, with the bats moving in a year later. Another barn was built nearby in 2017. Until Finn’s recent visit, UF scientists and staff were puzzled as to why the bats had turned down the new barn. EH&S employees recently attached four tiny houses outside the barn to entice the bats to begin the relocation process on their own.
Now, based on Finn’s counsel, Chris Carlson, associate director of EH&S’s Facility Support Services, has devised a game plan to make the barn more hospitable. Possible modifications include roughing up the plywood slats, adding a strip of paint with grit to help bats land more easily, increasing the landing pad, and painting the barn’s exterior a darker color.
“Then it just takes patience,” said the Finn.
Carlson said that if the bats don’t move by mid-August, staff will gradually begin the exclusion process in the old home and physically move the bats to the new home.
“This is much more desirable than a one-time extermination on a large scale, which would scatter bats throughout the complex, leaving them vulnerable to prey,” he said.
bats are winged wonders
While no one wants bats in their attic – or a track stadium – bats provide vital services and help maintain a balanced ecosystem. They are the primary predators of nocturnal flying insects, providing a natural form of pest control. Scientists estimate that the UF’s bat colony sends 2.5 billion insects every night. That’s about 2,500 pounds of moths, mosquitoes, flies and beetles.
Most of the bats in the UF are Brazilian free-tailed bats, Tadarida brasiliensis. Brazilian free-tailed bats are one of the most common bat species in North America and the most common bats in Florida. They often build their homes under bridges and Spanish tile roofs, in attics and concrete block walls or expansion joints.
Brazilian free-tailed bats are excellent fliers and can reach speeds of up to 100 miles per hour in level flight, according to Verity Mathis, mammal collection manager at the Florida Museum of Natural History. They are also capable of flying long distances. Their nocturnal forage for insects can extend up to 30 miles, and they have been documented at altitudes of about 9,000 feet.
“The Brazilian free-tailed bat is truly remarkable,” Mathis said. “When they are migrating, they can actually show up on weather radar. This one species is capable of just that.”
Mathis spends most of his time dispelling common bat myths. Bats are not blind, and are unlikely to tangle in people’s hair while they fly. Of the more than 1,400 known species of bats, only three drink blood.
Bats are the only true flying mammals and are more closely related to humans than to rodents.
“They probably get the worst rap of any mammal and that’s highly undesirable,” Mathis said. “They’re just trying to coexist peacefully and keep up with the ecosystem services they provide.”
While very few bats have rabies, you should never handle a bat with your bare hands, Mathis said. If you see an injured bat on UF’s campus, whether in a building or on the ground, contact EH&S at 352-392-1591 during normal business hours or the University Police Department at 352-392-1111 after hours.
In the meantime, don’t miss the UF’s nightly bat show, which starts about 15 minutes after sunset.
“Our bat houses are completely unique,” Mathis said. “They make Gainesville one of the best places in America to see bats.”
Hear Mathis talk about UF’s bat facts »from florida” podcast. learn how to build your own bat houseWith the help of UF/IFAS experts.
11 August 2022