Have you got bats in your home in South Florida?  Check out our information sheet to help you know what to do: (English version) (Spanish version)

Little is known about our largest and most endangered bat in Florida, the Florida bonneted bat (Eumops floridanus).  Its total population is believed to only be in the hundreds.  It gained federal protection under the Endangered Species Act in late 2013 and is listed as critically endangered by the IUCN.  Its range is very limited to the southern tip of Florida and mostly concentrated on the coastal ridges.

There are still many basic questions about the Florida bonneted bat that need further research to answer.  Florida bonneted bats have long narrow wings designed for very fast flight but not adapted for tight turning.  A comparison would be that all other native bats tend to be acrobatic in flight like moths while Florida bonneted bats could be compared to jet airplanes flying fast in a straight line.  This also means they tend to fly higher than other native bats and tend not to forage in areas where there are tight flyways or abundant obstacles.  It is estimated that they could fly dozens of miles very night to forage.  These characteristics make studying these species challenging for researchers since they tend to travel above traditional mist netting set ups they use to capture bats.  In Miami-Dade County, Florida bonneted bats then must forage for food every night in a very limited number of open spaces that remain in the urban landscape.  Areas in the Miami-Dade County that they have been shown to utilize are golf courses, very large unlit parking lots, open fields in parks, airports, and large freshwater lakes.

These are two large chamber bat houses occupied by Florida bonneted bats in a preserve near Punta Gorda.

These are two large chamber bat houses occupied by Florida bonneted bats in a preserve near Punta Gorda.

Florida bonneted bats tend to form small colonies with numbers ranging from just a few individuals to dozens.  They appear to prefer to roost in cavities, whether natural or artificial.  As of early 2016, there are a very few known roosts for the species.  Known roosts are in specially made bat boxes in Ft. Myers and near the Punta Gorda area, natural roosts in tree cavities at the Florida Panther National Wildlife Refuge, Big Cypress National Preserve, and the Avon Park Air Force Range, and in roof-lines of homes in Coral Gables and Kendall.

Florida bonneted bat roost under Spanish tile in Coral Gables

Florida bonneted bat roost under Spanish tile in Coral Gables

In Miami-Dade County, frequent hurricanes and habitat loss has eliminated most natural roost options of a large cavity in a dead tree.  Therefore, it is likely that most of these highly endangered bats are residing in artificial structures like multistory buildings with gaps in wooden roofing or openings in Spanish tile roofs.

Watch this clip below to see a video of a Florida bonneted bat colony in a red-cockaded woodpecker cavity in a slash pine.

This map shows the detection density of the Florida bonneted bat in three connected county parks.

This map shows the detection density of the Florida bonneted bat in three connected county parks.

Zoo Miami’s Conservation and Research Department assists wildlife agencies in furthering the scientific knowledge of this special species.  Staff conducted a year long acoustic study of the Zoo, Larry and Penny Thompson Memorial Park, and Martinez Pineland to determine if the Florida bonneted bat was present and possibly learn more about their use of these mixed use properties.  The results from the study showed that it is utilizing these county owned properties and this map shows where it was most frequently detected.

Zoo Miami staff has also helped in the rehabilitation and release of an injured sub-adult male “Clyde” and an orphaned male pup “Bruce”.

"Bruce" the Florida bonneted bat pup. Photo by Dustin Smith

“Bruce” the Florida bonneted bat pup. Photo by Dustin Smith

Did you know that all bats are protected under wildlife laws?  If you discover bats in your home, it is illegal to kill them.  You can hire a pest control company to humanely exclude them from your home  they will put devices on the roost location entrance which will allow them to leave but not get back inside.  Most colony bats in this area have multiple roost sites that they will switch between.  That way they can safely leave your home and go to one of their other sites. In Florida, exclusion cannot be done between April 16th and August 14th because this is the maternity season and laws protect young from being separated from their mothers and dying of starvation.  Unfortunately, these laws do not fully protect the Florida bonneted bat since they are believed to be able to give birth at any time during the year like is common with tropical species.  So, if you discover bats in your home, make sure that someone correctly identifies the species present to prevent Florida bonneted bat pups from being harmed.

Did you know Zoo Miami has over 30 bat houses on its grounds?  They provide homes to hundreds of Brazilian free-tail and evening bats.  One house has the potential to hold up to 800 bats.   That single group could eat up to 21 lbs of insects in a single night!

If you live in the greater Miami area where this endangered species has lost most of its natural habitat and roosts and want to help, consider putting up a specially designed bat house in a protected area for the Florida bonneted bat. These houses need to likely be placed >25ft high, with no obstructions nearby, facing north or south with sun exposure, and no access for predators.  We recommend the use of a pivot pole support to enable easier installation and allow for maintenance, if needed.  The area needs to be protected from potential disturbance and vandalism but might provide a refuge outside of homes where they could unknowingly be harmed from remodeling/construction of other structures.  Plans for the house can be downloaded at the following link: Florida Bonneted Bat House Plans

Discuss this Project

  1. John Williams

    Hello,

    I live in the West Kendall area of Miami-Dade County. I usually go for a morning run around 5:30am along 142nd Avenue between SW 88th street and 104th street. Lately, my girlfriend and I have noticed a bat flying near 104th street. I was wondering if you would be able to identify which bat species this could be?

    Also, if I were to build a bat house, what type of risks are involved in encouraging bats to roost near my home. Are they dangerous to children and pets? Hope you can help and answer some of my questions.

    Best Regards,
    John Williams

    • Frank Ridgley DVM

      Hi John,

      There are 7 species of bats that call Miami-Dade County home. The bat you are seeing could be any one of them but it would be difficult to tell the difference without using some equipment. Each species has a distinct vocal pattern and frequency range that we can see using ultrasonic recording equipment. There are no risks that I can think of having bats near your home, only benefits. All our native bats are insectivores and can almost consume up to their own body weight in insects every night. Bats should be treated like any wildlife. If you were to find one on the ground or perched somewhere, avoid harassing or touching it as it may act defensively. But, bats are shy and elusive animals by nature. If you were to put up a bat house, you would expect the bat guano to fall to the ground below it. So, make sure and place it where you don’t mind this happening and kids or dogs wouldn’t be getting into the feces.
      The species that would be most likely to roost in regular bat boxes around your area would be the Brazilian Free-tailed or Evening bats. They can form large colonies that people enjoy watching emerge every night at dusk and these colonies can end up eating pounds of insects every night. If you want to try and put up boxes for the endangered Florida Bonneted Bat, they require larger chambers than our other native bats. Plans for those houses can be found here and advice and plans for more common species in the area can be found at the Florida Bat Conservancy’s website here

      I hope that answers your questions! Thanks for thinking about our native bats.

      Dr. Frank Ridgley
      Conservation and Research Department
      Zoo Miami

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