Most people are familiar with bats, but a particularly rare species of bat endemic to Florida is one of the least known and seen mammals in North America. The Florida bonneted bat, the largest species of bat found in the state, is critically endangered and only found in a handful of counties in south Florida. It has one of the most restrictive ranges of any bat species in the United States, which has made it difficult for biologists to collect important data on this imperiled species.
Colony size, breeding season, breeding behavior and social structure are just a few unknowns when it comes to the Florida bonneted bat. The lack of information has inhibited conservation efforts, and with limited data on the species it’s difficult to modify management or regulatory activities to benefit this bat.
In January 2014, the FWC and University of Florida began a study to better understand the roosting and reproduction patterns of the Florida bonneted bat. Specifically, researchers are trying to determine the size and composition of roosting colonies, environmental factors affecting roosting activity, breeding season dates and patterns of movements of bats between roosts.
Biologists first needed to identify a roosting site where the bat could be studied. The bat houses at the Babcock-Webb Wildlife Management Area in Charlotte County represent the largest number of roosts of Florida bonneted bats, and this site provided a unique opportunity to study the species roosting behavior and learn how to better conserve or encourage roosting colonies at Babcock-Webb as well as other locations throughout south Florida.
The team is investigating the bats roosting on Babcock-Webb to determine patterns in roosting activities, identify the social structure and relatedness of bats in individual roosts and confirm the seasonal chronology of reproduction.
Researchers capture bats three times per year (August, December and April) as they leave the bat houses. The bats are marked with very small microchips called Passive Integrated Transponder (PIT) tags. Each bat house in the study area is fitted with an automatic PIT reader that detects the tags as a bat enters or leaves the house. It also records the individual identification number of the bat.
During the capture sessions, bats are caught in mist nets so researchers can determine their age and sex, record body measurements and assess the overall health of the colony. Researchers also regularly count the bats as they exit the houses in the evening and then count any flightless young remaining in the houses.
After completing the first year of the two-year study, researchers have learned that the Florida bonneted bat has an extended breeding season. Their colonies are relatively small, and roosts are dominated by a single male. Temperature, particularly low temperatures, influence the activity of the bats.
Information gained will help staff at the Babcock-Webb WMA better manage the bats, including identifying locations for new bat houses. The FWC and U.S. Fish and Wildlife Service may use information obtained about breeding seasons and roost composition to refine restrictions on excluding Florida bonneted bats from roosts in buildings, or educating pest control operators about roosting bonneted bats.