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Big-brown Bat, Eptesicus fuscus fuscus & E.f. osceolus


Echolocation: Steady 25-30k. fish-hook shaped slope.  Sometimes confused with TABR

Florida Distribution:  Peninsular FL

Roosting Behavior: Colonial.  Males sometimes solitary.  Documented in buildings, bridges, culverts, and other structures, Often associated with TABR.  Also tree cavities, beneath loose bark & snags.  Documented in buildings in SW peninsula & NW panhandle; radio-tracked to pine snags   in central FL.  (Finn, unpublished). Intolerant of disturbance   A common nuisance bat N of FL,  less common in FL structures; seems to prefer trees.  

Foraging Behavior: Urban areas & pine forests, Prefer beetles (Coleoptera), also wasps, ants, flies & moths.

Reproduction: Mate in fall & winter; Twins born May - June.

Management and Conservation Recommendations:  EPFU acoustic files were recorded during surveys in FL, GA and SC.    Education programs aimed at the public, management that preserves pine and other snag trees and installation of bat houses & IPM practices that focused on management will contribute to the conservation of this and other bat species. (see also TABR below)

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Urban Bat Status





Mass g

FA mm


Total length



16 – 19*

42 - 51

325 - 350

99 -129

Curved, blunt


Dark brown - reddish brown, hairs dark at base, Very similar in a to the smaller NYHU

 (* as high as ~30g if pregnant or preparing for hibernation)




Rare, S3