Brazilian Free-Tailed Bat

Scientific Name
Tadarida brasiliensis
Also Known As
Mexican Free-tailed Bat
All of Florida
Moths, Beetles, Dragonflies, Flies, Ants, Wasps
Life Expectancy
8 - 10 Years
The Brazilian Free-Tailed Bat

Photo 152370587 © lisaeiselin, CC BY-NC

Brazilian Free-Tailed Bat conservation status - Least Concern

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Brazilian Free-Tailed Bats in Central Florida

The Brazilian free-tailed bat (Tadarida brasiliensis) is a highly adaptable bat species found across the southern United States, including central Florida. As the name suggests, this bat has a distinctive tail that extends beyond the tail membrane, giving it greater agility in flight. This comprehensive guide provides detailed identification tips, biology facts, and control methods for Brazilian free-tailed bats in central Florida.

Read on to learn about their habits, reproduction, diet, health risks, signs of infestation, and professional exclusion options if you suspect an invasion on your property.

Appearance and Identification

Brazilian free-tailed bats can be identified by their physical characteristics

Adult Brazilian Free-Tailed Bat

Photo 198385062 © Lara Brenner, CC BY-NC

Adult Brazilian Free-Tailed Bats

  • Size: Adults have a wingspan of 11-13 inches (28-33 cm) and weigh 0.5 to 0.75 ounces (14 to 21 grams). Their bodies reach 3-3.5 inches (8-9 cm) in length.
  • Fur: Adults have dense, short, velvety fur that is dark gray to brownish-black on the back and lighter gray underside.
  • Wings: Narrow, pointed wings adapted for fast, sustained flight.
  • Tail: Distinctive free tail that protrudes 1-1.5 inches (2.5-4 cm) beyond the tail membrane.
  • Head: Small, flattened head with large eyes and short, rounded ears.
Juvenile Brazilian Free-Tailed Bat

Photo 94999305 © Jaime Cedeño Nicolás, CC BY-NC

Juvenile Brazilian Free-Tailed Bats

  • Size: Newborns weigh approximately 0.25 ounces (7 grams) at birth with a wingspan of 8 inches (20 cm). They reach adult size at around 6 weeks old.
  • Fur: Juvenile fur is gray to black in color. The fur is short and thin.
  • Features: Younger bats have large feet and protruding pink lips. Their tails extend just beyond the tail membrane.

Maturation Rate

Pups grow rapidly after birth, reaching full adult size in 6 weeks. They are sexually mature at 1 year old. The average maturation rate allows populations to rebound quickly after pest control efforts. Diligent, ongoing management is key.

Habits and Behavior

Brazilian free-tailed bats roost in very large colonies of up to 1 million individuals in caves, under bridges, and in building attics and roofs. They emerge at dusk in spiraling clusters to feed. Their flight can reach speeds over 60 mph aided by their aerodynamic tails.

Brazilian free-tailed bats are highly social. Hundreds to thousands cluster together when roosting. They groom each other frequently. Their large colonies provide protection through shared body heat and humidity.

Reproduction and Lifespan

Mating occurs in flight. Females give birth to a single pup in May through July after ~3 month gestation. Pups cannot fly for 3-4 weeks. Maximum lifespan in the wild is about 8-10 years.

Ideal Habitat and Range

Central Florida’s humid subtropical climate offers ideal roosting and foraging conditions for Brazilian free-tailed bats. Average temperatures range from 60sF to 90sF (15-32C) with moderate rainfall. Urban centers provide roost sites under bridges, in parks with palm trees, and on high-rise buildings. Rural areas offer foraging over wetlands, pastures, and citrus groves.

The abundance of flying insects sustains large colonies. Brazilian free-tailed bats exploit these rich insect populations, with access to plentiful roosts and warmth needed to rear young. Their high reproductive rate allows Brazilian free-tailed bats to thrive in central Florida.

Diet and Feeding

Brazilian free-tailed bats are insetivores and feed almost exclusively on insects. They eat:

  • Moths
  • Beetles
  • Dragonflies
  • True flies
  • Wasps
  • Mayflies

They use echolocation to hunt insects on the wing at night. A single bat can consume over half its body weight in insects each night. Large colonies require massive insect populations, migrating seasonally to track emerging hatches.

Female Brazilian Free-Tailed Bat

Photo 423714 © Juan Ramirez, CC BY-NC

An ambulance showing the common health risks

Common Health Risks

Brazilian free-tailed bats pose some health risks through accumulation of guano and contact with people:

  • Histoplasmosis – Fungal infection from spores in guano accumulated in attics and walls. Causes flu-like illness.
  • Rabies – Rare but bats could spread through bites if handled. Nearly always fatal viral disease.
  • Ectoparasites – Bats share roosts with bat bugs, mites, fleas, and ticks which can bite people.

Preventing Brazilian Free-Tailed Bat Colonies

The key is bat-proofing potential roost sites by sealing openings to make buildings inhospitable. This may involve:

  • Installing one-way exclusion devices on vents and chimneys.
  • Sealing gaps under eaves, fascia boards, and soffits using steel wool or caulk.
  • Covering vent openings with fine mesh Screens.
  • Trimming back trees and vegetation touching the building.

Trapping and relocation of smaller colonies is also an option using professional bat control methods. Prevent contact with guano accumulations found in attics and walls by wearing PPE. Seek medical attention for flu symptoms after exposure.

Brazilian Free-Tailed Bats in Central Florida – Conclusion

With their high reproductive potential and ability to exploit urban areas, Brazilian free-tailed bats readily colonize central Florida. However, through active monitoring and exclusion efforts focused on sealing potential roost sites, large infestations can be prevented. Their preference for building crevices means bat-proofing measures are highly effective deterrents when applied properly. Continued vigilance is key to detecting and addressing small colonies before they expand. With early intervention, Brazilian free-tailed bats can be managed in central Florida.