Tri-colored Bat

Scientific Name
Perimyotis subflavus
Also Known As
Tricolored Bat, Eastern Pipistrelle
All of Florida
Bmosquitoes, Beetles, Ants, Moths
Life Expectancy
12 - 13 Year
The Tri-colored Bat

Photo 133405235 © stephen_buckingham, CC BY-NC

Tri-colored Bat conservation status - Endangered

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The Tri-colored Bat in Central Florida

The tri-colored bat (Perimyotis subflavus) is a small vesper bat species found throughout much of eastern North America. As its name suggests, the fur of tri-colored bats displays three different colors: dark shoulders contrasting with brown back fur and olive to tan fur on the underside.

This unique looking bat plays an important role in controlling insect pests, yet also faces conservation threats from human disturbance and white-nose syndrome fungus. Read on to learn identification tips, biology, ideal habitat conditions, and prevention methods for the tri-colored bat in Central Florida.

Appearance and Identification

Tri-colored bats can be identified by their distinctive tricolored fur and small size compared to other Florida bat species

Adult Tri-colored Bat

Photo 190752500 © Robby Deans, CC BY-NC

Adult Tri-colored Bats

  • Size: Adults reach a total body length of 3 to 3.5 inches and weigh 4 to 8 g. Wingspan is 8 to 9 inches.
  • Fur: Shoulders are brown to reddish-brown. Back is dark brown. Underside is olive to tan.
  • Head: Blunt tragus ear shape. Pink fleshy nose and lips.
  • Wings: Dark wing membranes with dark veins contrasting pale fur. Calcar lacking erect keel.
Juvenile Tri-colored Bat

Photo 135791332 © leannemontana, CC BY-NC

Juvenile Tri-colored Bats

  • Size: Newborns weigh approximately 0.25 g and have a forearm length of 26 to 29 mm. Wingspan reaches about 8 inches at maturity.
  • Fur: Fur color on back and shoulders is grayish overall. The wings are pinkish and nearly furless.
  • Features: Juveniles have a dark facial mask and relatively large feet like adults.

The tri-colored bat is smaller than the big brown bat (Eptesicus fuscus) and Seminole bat (Lasiurus seminolus) with less red-toned fur than the evening bat (Nycticeius humeralis). Identifying key features like the tri-colored fur and blunt tragus helps distinguish them.

Maturation Rate

Newborns open their eyes at around 6 to 8 days old. Nursing continues for 4 to 5 weeks until weaning, when the pup becomes independent. Sexual maturity is reached by their first autumn around 2 to 3 months old. Most adult body mass is achieved by 60 days after birth. The fast maturation enables a single litter each year.

Habits and Behavior

Tri-colored bats roost in clusters up to hundreds of individuals in tree cavities, Spanish moss, and under loose bark. They emerge at dusk to forage around forest edges and open wetlands. Tri-colored bats have slow, maneuverable flight less than 30 feet above ground as they pursue small insects like moths, mosquitoes, beetles and flies.

Sounds are also important for orientation and social communication. Colonies produce a constant low-intensity vocalization audible to humans. Their echolocation frequencies range from 25 to 50 kHz, often modulated. Tri-colored bats normally roost apart from other bat species.

Reproduction and Lifespan

Reproduction and Lifespan

Mating occurs in autumn near hibernacula as tri-colored bats swarm before entering winter dormancy. After delayed fertilization, adult females then migrate to summer grounds in April and May. Just one young per year is born any time from late May through mid July.

Tri-colored bats have a longer gestation than other small Myotis bats, averaging 60 days. The single pup remains flightless for 18 to 21 days. Maximum lifespan in wild tri-colored bats is estimated around 12 to 13 years based on banding studies.