Conserving the Nature of America
Press Release
Research Collaboration Forms After Rare Bat Roost Found on Florida Panther Refuge

October 15, 2015


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A small bat with large ears held by a biologist with a blue piece of fabric.

Florida bonneted bat Credit: Gary Morse, FWC
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FLORIDA PANTHER NATIONAL WILDLIFE REFUGE, Immokalee, FL -- History was made at Florida Panther National Wildlife Refuge on  July 7, when Dr. Elizabeth Braun de Torrez and her University of Florida research team found only the second known active natural roost of one of North America’s rarest mammals, the Florida bonneted bat.

Afterwards, a collaboration of bat conservation partners formed, and the Friends of the Florida Panther Refuge won a grant for bat monitoring equipment. Now, exciting work is underway to better understand this imperiled bat.

The Florida bonneted bat, only found in South Florida, was federally listed as endangered in November 2013, due to a wide array of large and imminent threats facing the species. The bonneted bat is thought to have the most limited geographic distribution of any bat species in the United States.  However, more information is needed to better understand the bat’s natural history and habitat requirements. Some evidence suggests they roost in pine tree cavities within fire dependent pineland communities. However, this is based upon only two other documented natural roost sites identified over the past 35 years. Only one other active natural roost is currently known for this bat; that roost was discovered by a crew of red-cockaded woodpecker technicians at Avon Park Air Force Range in late 2013. The last documented natural roost prior to this was found in 1979, and no longer exists.

The University of Florida research team is headed by Dr. Holly Ober and Dr. Robert McCleery with assistance from field technicians Kirk Silas, Megan Wallrichs, Tara Rambo, Amy Hammesfahr, and Rebecca Sensor. Braun de Torrez’s team has been investigating the relationship between fire activity and Florida bonneted bat activity at the Florida Panther National Wildlife Refuge.   Efforts included the daunting task of finding where these elusive bats were roosting in order to monitor their response to fire and to gain insight into what types of roosts the bats use.

A single snag emerges from a slash pine forest.
Active Florida bonneted bat roost in a slash pine snag on Florida Panther NWR. Credit: Mark Danaher, USFWS

Two weeks before finding the roost, the team intensified their efforts on the refuge. Using acoustics monitoring equipment, they documented times and locations of Florida bonneted bats using the area and narrowed down the region from which the bats were coming.

“One night, we heard two bonneted bats fly overhead very early in the evening, about 30 minutes after sunset. Using our ultrasonic bat detectors, we were picking up high levels of bonneted bat activity and what appeared to be social calls in the area,” Braun de Torrez recalled.

After five nights of spreading out a crew of people, including refuge staff, to watch and listen at potential cavities, the roost was found in a cavity of a slash pine snag. The elated team observed 12 bonneted bats emerge while more bat vocalizations came from within the roost.

“This colony size seems typical of the species. In bat houses on Babcock-Webb Wildlife Management Area, the average colony size is nine bats,” Braun de Torrez said.

With the discovery of a natural roost and active colony, the refuge and its partners gained an invaluable opportunity to learn from these rare mammals and contribute to recovery efforts. However, the logistics of properly monitoring this roost weren’t going to be feasible without the equipment and people to make it happen. 

This is when collaboration for targeted Florida bonneted bat research on the refuge ignited. Long-time refuge volunteer, zoologist, professional writer, and bat enthusiast Leah Miller found a grant application for $5,000 of product-in-kind from Wildlife Acoustics, whose mission is to advance the conservation of animals through bioacoustics recording technology, offers this opportunity on a quarterly basis. While the refuge itself could not apply for the grant, Miller contacted the Friends of the Florida Panther Refuge, a non-profit group with the primary mission of supporting goals of Florida Panther National Wildlife Refuge. In line with their mission, the Friends group previously purchased an ultrasonic recorder for refuge bat studies in December 2014.  With the Friends’ significant interest in obtaining more equipment for bat research, Miller began working with their board, Braun de Torrez, the Service’s South Florida Ecological Services Office, and Bat Conservation International. After more than 40 hours of volunteer research and writing, Miller submitted the grant for the Friends of the Florida Panther Refuge. Shortly after submission, the Friends group learned they were one of only two recipients of the Wildlife Acoustics grant, out of a pool of 84 applicants covering 10 countries.

With more acoustic equipment now in hand, refuge staff, the South Florida Ecological Services’ staff, Friends board members, and Miller are monitoring the roost, complementing Braun de Torrez’s research. Those cooperative efforts include bimonthly emergence counts at the roost, regular pre- and post-prescribed burning emergence counts, and acoustics monitoring of the active roost and other randomized locations throughout the refuge with hopes of locating additional roost sites. Thanks to the efforts of interested stakeholders and partners, much has been learned about Florida bonneted bat ecology over the past few years.  Yet, more information is needed.  Any new information about distribution, abundance, roosting preferences, habitat use, or foraging behavior will greatly advance conservation efforts for the species.

“The Friends of the Florida Panther Refuge have been partners in threatened and endangered species recovery for many years, said Roxanna Hinzman, field supervisor of the South Florida Ecological Services Office. “We look forward to ongoing cooperative efforts to work with them on recovery of the Florida bonneted bat.”

 As collaborators monitor the roost and its inhabitants, Wildlife Acoustics and the Friends of the Florida Panther Refuge invite the public to follow their work via Facebook updates at and

Additionally, the public can learn more about these organizations at their respective websites: and   Those interested in the University of Florida’s bonneted bat research are encouraged to visit Dr. Bob McCleery’s and Dr. Holly Ober’s lab websites at and

Florida Panther National Wildlife Refuge would like to thank the many partners who are making this project possible, including: the University of Florida Department of Wildlife Ecology and Conservation; Friends of the Florida Panther Refuge; Leah Miller; Wildlife Acoustics; Paula Halupa, Marilyn Knight, Daryl Thomas, and Roxanna Hinzman of the South Florida Ecological Services Office; and Bat Conservation International.

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