Kentucky mammals

Big Brown Bat in Kentucky

Eptesicus fuscus

Native to Kentucky S5 Secure in Kentucky

Not listed as nonindigenous in Kentucky by USGS NAS; native to its Kentucky range.

IUCN Red List status

  1. LC
  2. NT
  3. VU
  4. EN
  5. CR
  6. EW
  7. EX

LC – Least Concern

Widespread and abundant; not at risk.

Big Brown Bats (Eptesicus fuscus)Big brown bat flying in daylight with wings spreadBig brown bat flying at night with wings spreadBig brown bat roosting on lichen-covered tree barkBig brown bat roosting on a wooden structure
Photo: Connor Long · CC BY-SA 4.0Big Brown Bats (Eptesicus fuscus)Photo: rhododendrites · CC-BY-SABig brown bat flying in daylight with wings spreadPhoto: Dan Riskin · CC-BYBig brown bat flying at night with wings spreadPhoto: Rita Clare · CC0Big brown bat roosting on lichen-covered tree barkPhoto: Bonnie Isaac · CC0Big brown bat roosting on a wooden structure

Big Brown Bat in Kentucky, by the numbers

Common in Kentucky 23rd most recorded of 77 mammals logged in Kentucky

169 occurrence records
128 with iNaturalist photos

Records from 2000–2026.

169 total records count every Kentucky occurrence from GBIF and iNaturalist; the monthly chart covers the 168 records with a full observation date.

When to look for the Big Brown Bat in Kentucky

Most sightings fall in July to August.

168 Kentucky occurrence records (iNaturalist and GBIF) by month of year, 2000–2026. Shows when the species is recorded, not a guarantee of presence.

Monthly Kentucky records (table)
MonthRecords
January13
February17
March14
April17
May8
June12
July22
August18
September8
October13
November19
December7

Monthly big brown bat occurrence records (iNaturalist and GBIF) in Kentucky, 2000–2026.

Seasonality

Year-round in Kentucky, with recorded sightings peaking in July–August, with a smaller rise in November and February–April.

Occurrence map

Where Big Brown Bat has been recorded in Kentucky

169 records mapped · zoom and drag to explore

168 Kentucky records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Carter Caves State Resort Park 10
Daniel Boone National Forest 9
Land Between the Lakes Other 8
Mammoth Cave National Park 7
Land Between the Lakes National Recreation Area 3
John James Audubon State Park 2
Dale Hollow State Resort Park 2
Clay Hill Memorial Forest 1

Protected places with the most big brown bat sightings, from the USGS Protected Areas Database plus named mountain ranges, good spots to look, not a full breakdown, so they don't sum to the total.

Where it's recorded in Kentucky

CountyRecords
Carter County 16
Jefferson County 10
Daviess County 10
Harlan County 10
Trigg County 9
Edmonson County 8
Franklin County 8
Madison County 6
Bell County 6
Breckinridge County 5
Kenton County 5
Warren County 5
38 other counties 71

The complete county distribution, spread across 50 Kentucky counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

The refreshed Kentucky snapshot contains 169 deduplicated big brown bat records, drawing on 128 iNaturalist and 125 GBIF records with overlap between the sources. February and November stand out in the monthly series, suggesting that cave and seasonal survey work contributes heavily to the pattern.

Mammoth Cave and Pennyrile Forest sit within Kentucky’s broad karst belt, where roost and hibernation searches can concentrate documentation. The bat is treated as native, and its record total shouldn’t be used as an estimate of how many animals occupy those landscapes.

Occurrence data from GBIF.

Big Brown Bats (Eptesicus fuscus)
Full species profile Big Brown Bat Eptesicus fuscus Size 7.5 cm3 in Weight 17 g0.6 oz Lifespan 19 yr View the full profile

More mammals in Kentucky in the atlas

Data & sources

The data and visualizations on this page draw on these open sources:

  • GBIFCC-BY 4.0occurrence records behind the range map, elevation, and record counts
  • iNaturalistCC0 / CC-BY / CC-BY-SAobservations, photos, and audio recordings
  • NatureServe ExplorerCC-BYthe state conservation rank
  • IUCN Red Listattributed factthe global conservation status
  • USGS NASpublic domainnative / introduced status
  • Natural Earthpublic domainthe relief basemap
  • USFSpublic domainnational-forest boundaries
  • USGS Protected Areas Databasepublic domainthe named parks, forests, and refuges behind "notable places to look"