Connecticut mammals

Western Little Brown Myotis in Connecticut

Myotis lucifugus

Native to Connecticut S1 Critically Imperiled in Connecticut

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

Rare in Connecticut 50th most recorded of 70 mammals logged in Connecticut

3 occurrence records
3 with iNaturalist photos
Jan 19, 2026 Last seen in Connecticut

Records from 2000–2026.

When to look for the Western Little Brown Myotis in Connecticut

Most sightings fall in January.

3 Connecticut 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 Connecticut records (table)
MonthRecords
January1
February0
March0
April0
May0
June0
July0
August1
September1
October0
November0
December0

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

Seasonality

Sparse observation record in Connecticut; presence confirmed but timing of activity not well documented.

Occurrence map

Where Western Little Brown Myotis has been recorded in Connecticut

3 records mapped · zoom and drag to explore

3 Connecticut records mapped

Where it's recorded in Connecticut

CountyRecords
New Haven County 2
Fairfield County 1

The complete county distribution, spread across 2 Connecticut counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Connecticut’s open databases hold just 3 records of the little brown myotis since 2000, all of them iNaturalist observations. That’s a strikingly thin tally for a bat that was once one of the most familiar in barns and attics across the Northeast.

A collapse that started close to home

The fungus behind white-nose syndrome was first found on hibernating bats near Albany, New York, in the winter of 2006, and it moved through New England’s hibernation sites within a few years. Connecticut sat squarely in that early wave, and the state’s current S1 ranking, critically imperiled, reflects just how hard this bat was hit here compared with its broader global standing.

Three records, two coastal counties

The three Connecticut records fall in January, August, and September, two in New Haven County and one in Fairfield, both counties on Long Island Sound. That’s far too few to show a season or a stronghold, and it fits a bat now scarce enough that few people encounter one by chance. When it does forage, it hunts insects low over open water, wetlands, and shorelines.

Status in Connecticut

NatureServe ranks the little brown myotis S1, critically imperiled, in Connecticut, far below its G3 global rank, and it’s still native to the state even though white-nose syndrome has left it one of the rarest bats here.

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 Connecticut 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