Michigan mammals

Western Little Brown Myotis in Michigan

Myotis lucifugus

Native to Michigan S1 Critically Imperiled in Michigan

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

IUCN Red List status

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

EN – Endangered

Very high risk of extinction in the wild.

Little brown myotis roosting alertly on a wooden beamLittle brown myotis roosting in the corner of an attic beamLittle brown myotis roosting on painted wood sidingLittle brown myotis resting among blue spruce branches
Photo: Steph Brulot-Sawchyn · CC0Little brown myotis roosting alertly on a wooden beamPhoto: LeeAnn Latremouille · CC BY 4.0Little brown myotis roosting in the corner of an attic beamPhoto: Tom Romeo · CC BY 4.0Little brown myotis roosting on painted wood sidingPhoto: Patrick Jackson · CC BY 4.0Little brown myotis resting among blue spruce branches

Western Little Brown Myotis in Michigan, by the numbers

Occasional in Michigan 48th most recorded of 75 mammals logged in Michigan

43 occurrence records
32 with iNaturalist photos
Jun 6, 2026 Last seen in Michigan

Records from 2000–2026.

43 total records count every Michigan occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 41; the monthly chart covers the 41 records with a full observation date.

When to look for the Western Little Brown Myotis in Michigan

Most sightings fall in June to August.

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

Monthly Michigan records (table)
MonthRecords
January0
February0
March0
April0
May2
June9
July11
August11
September5
October0
November0
December3

Monthly western little brown myotis occurrence records (iNaturalist and GBIF) in Michigan, 2000–2026.

Seasonality

Year-round in Michigan, with recorded sightings peaking in June–August.

Occurrence map

Where Western Little Brown Myotis has been recorded in Michigan

41 records mapped · zoom and drag to explore

41 Michigan records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
University of Michigan Biological Station 5
Ottawa National Forest 2
Baraga State Forest Area 1
Wells State Park 1

Protected places with the most western little brown myotis 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 Michigan

CountyRecords
Cheboygan County 8
Houghton County 3
Kalkaska County 3
Gogebic County 2
Mackinac County 2
Grand Traverse County 2
Ontonagon County 2
Isabella County 2
Leelanau County 1
Allegan County 1
Manistee County 1
Chippewa County 1
12 other counties 15

The complete county distribution, spread across 24 Michigan counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Michigan holds 43 little brown myotis records, 32 of them iNaturalist observations, and the University of Michigan Biological Station in Cheboygan County is the most often named site, with 5. That’s a thin file for this small, fast-flying bat.

That thinness matters here: NatureServe ranks the species S1, Critically Imperiled, in Michigan, and the IUCN lists it Endangered globally, both driven by white-nose syndrome, the fungal disease that has collapsed hibernating bat colonies across the Great Lakes since the 2010s. Reports cluster from June through August, tracking summer activity outside the winter hibernacula where the real population crash is measured.

Occurrence data from iNaturalist and GBIF.

Little brown myotis roosting alertly on a wooden beam
Full species profile Western Little Brown Myotis Myotis lucifugus Size 8–9.5 cm3.1–3.7 in Weight 6–13 g0.2–0.5 oz Lifespan 35 yr View the full profile

More mammals in Michigan 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"