Evening Bat

Scientific Name
Nycticeius humeralis
Also Known As
North American Evening Bat
All of Florida
Beetles, Moths, Flies, Winged Ants
Life Expectancy
5 Years

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The Evening Bat in Central Florida

The evening bat (Nycticeius humeralis) is a small, insectivorous bat species found throughout the southeastern United States, including central Florida. As its name suggests, the evening bat is active at dusk and forages for insects at night. This guide provides identification tips, biology facts, potential health risks, and prevention methods for the evening bat in central Florida.

Appearance and Identification

The evening bat can be identified by the following physical characteristics in juveniles and adults

Adult Evening Bat

Adult Evening Bats

  • Size: Adults reach an average body length of 9 cm and weight of 6-13 grams. Wingspan is around 22-27 cm.
  • Fur: Adults have tricolored fur – dark shoulders and back blended into medium brown and tipped with white. The underside is lighter.
  • Head: Blunt tragus, small eyes, and short rounded ears.
  • Wings: Broad wings with short, rounded tips to enable slow flight maneuverability.
Juvenile Evening Bat

Photo 218363783 © keith_lott, CC BY-NC

Juvenile Evening Bats

  • Size: Newborns weigh approximately 1.5-2 grams with a forearm length of 26-29 mm. They reach adult size by approximately 6 weeks old.
  • Fur: Juvenile fur is grayish in color. The fur is short and soft as they grow.
  • Features: Younger evening bats have disproportionately large feet to aid in clinging to mothers. The face is pink and eyes closed at birth.

The evening bat can be distinguished from other Vespertilionidae bats by size, tricolored fur pattern, blunt tragus shape, and habit of roosting in foliage instead of buildings or caves.

Maturation Rate

Evening bat pups grow rapidly after birth, reaching full adult size by 20-30 days old. They are able to fly by 18-21 days. Weaning occurs by 3-4 weeks old. Sexual maturity is reached within the first year. The fast maturation enables evening bats to contribute to reproduction.

Habits and Behavior

The evening bat is aptly named for its early evening activity patterns. It emerges from roosts around dusk to forage. Evening bats have slow, maneuverable flight as they chase insects. This species uses echolocation calls to navigate and hunt within dense foliage.

Evening bats roost in the leaves of deciduous trees and shrubs. They are also found in Spanish moss. The bats change roosts frequently. These bats are migratory and travel south for winter. Evening bats hibernate in hollow trees or under loose bark. They are more solitary than colonial.

Reproduction and Lifespan

Female evening bats reach sexual maturity in their first year. Mating takes place in autumn. Females give birth to one pup per year in May-July. The gestation period is 60-90 days. Pups are weaned by 3-4 weeks old.