Montana mammals

Western Little Brown Myotis in Montana

Myotis lucifugus

Native to Montana S2 Imperiled in Montana

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

Occasional in Montana 74th most recorded of 122 mammals logged in Montana

19 occurrence records
14 with iNaturalist photos

Records from 2000–2026.

When to look for the Western Little Brown Myotis in Montana

Most sightings fall in July to August.

19 Montana occurrence records (iNaturalist and GBIF) by month of year, 2000–2026. Shows when the species is recorded, not a guarantee of presence. Based on a small number of dated records; the seasonal pattern may not be representative.

Monthly Montana records (table)
MonthRecords
January0
February0
March0
April2
May1
June3
July6
August4
September3
October0
November0
December0

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

Seasonality

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

Occurrence map

Where Western Little Brown Myotis has been recorded in Montana

19 records mapped · zoom and drag to explore

19 Montana records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Glacier National Park 1
Lewis and Clark Caverns State Park 1
Montana University System 1
Lolo National Forest 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 Montana

CountyRecords
Missoula County 2
Fergus County 2
Gallatin County 2
Carbon County 2
Valley County 2
Flathead County 1
Carter County 1
Jefferson County 1
Lake County 1
Mineral County 1
Wheatland County 1
Beaverhead County 1
2 other counties 2

The complete county distribution, spread across 14 Montana counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Montana holds just 19 records of the little brown myotis, 14 of them iNaturalist observations, spread thinly across 14 counties with no more than 2 in any one.

Records run from April through September and peak at 6 in July, too few to carry a real seasonal signal. NatureServe ranks the species S2, Imperiled, in Montana, and the IUCN lists it Endangered globally, both driven by white-nose syndrome, the fungal disease that has collapsed hibernating bat colonies across North America since the 2010s.

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 Montana 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"