Minnesota mammals

Big Brown Bat in Minnesota

Eptesicus fuscus

Native to Minnesota S3 Vulnerable in Minnesota

Not listed as nonindigenous in Minnesota by USGS NAS; native to its Minnesota 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 Minnesota, by the numbers

Occasional in Minnesota 35th most recorded of 88 mammals logged in Minnesota

228 occurrence records
207 with iNaturalist photos
May 29, 2026 Last seen in Minnesota

Records from 2000–2026.

228 total records count every Minnesota occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 224; the monthly chart covers the 223 records with a full observation date.

When to look for the Big Brown Bat in Minnesota

Most sightings fall in July to August.

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

Monthly Minnesota records (table)
MonthRecords
January2
February2
March7
April22
May21
June18
July49
August42
September26
October12
November12
December10

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

Seasonality

Year-round in Minnesota, with recorded sightings peaking in July–August.

Occurrence map

Where Big Brown Bat has been recorded in Minnesota

224 records mapped · zoom and drag to explore

224 Minnesota records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Mississippi National River and Recreation Area 14
Miscellaneous 4
Pipestone National Monument 3
Chippewa National Forest 1
Superior National 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 Minnesota

CountyRecords
Hennepin County 29
Lac qui Parle County 27
Ramsey County 19
Dakota County 11
Rice County 10
Crow Wing County 9
Cass County 8
Olmsted County 8
St. Louis County 8
Chippewa County 7
Washington County 6
Anoka County 5
37 other counties 81

The complete county distribution, spread across 49 Minnesota counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Big brown bat records in Minnesota stretch from the Mississippi National River and Recreation Area through the Twin Cities to Itasca State Park and Minneopa State Park farther out, reflecting a bat that roosts as readily in buildings and bridges as in natural cavities. With 207 iNaturalist and 171 GBIF records nearly balanced, this is one of the state’s better-documented bats.

Reports climb steadily from June and peak July through September, when maternity colonies are most active and juveniles start flying. NatureServe ranks the species S3, Vulnerable, in Minnesota, a more cautious grade than its wide reporting might suggest, one that tracks the statewide toll white-nose syndrome has taken on hibernating bat colonies.

Occurrence data from iNaturalist and 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 Minnesota 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"