Vermont mammals

Big Brown Bat in Vermont

Eptesicus fuscus

Native to Vermont S4 Apparently Secure in Vermont

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

Occasional in Vermont 26th most recorded of 65 mammals logged in Vermont

173 occurrence records
154 with iNaturalist photos
May 26, 2026 Last seen in Vermont

Records from 2000–2026.

173 total records count every Vermont occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 167; the monthly chart covers the 165 records with a full observation date.

When to look for the Big Brown Bat in Vermont

Most sightings fall in July to August.

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

Monthly Vermont records (table)
MonthRecords
January6
February4
March6
April12
May14
June16
July33
August47
September8
October9
November4
December6

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

Seasonality

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

Occurrence map

Where Big Brown Bat has been recorded in Vermont

167 records mapped · zoom and drag to explore

165 Vermont records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Green Mountain National Forest 13
Green Mountains 3
Marsh-Billings-Rockefeller National Historical Park 2
Dead Creek Wildlife Management Area 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 Vermont

CountyRecords
Chittenden County 41
Windsor County 28
Rutland County 23
Bennington County 12
Windham County 12
Addison County 12
Washington County 12
Grand Isle County 7
Orange County 5
Franklin County 4
Caledonia County 4
Orleans County 2
2 other counties 11

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

Big brown bats forage over Vermont ponds, forest openings, streets, and farm fields, often roosting in buildings or large hollow trees. Summer evenings near water in the Champlain Valley or at places such as Marsh-Billings-Rockefeller National Historical Park provide good opportunities to watch their steady flight.

Reports peak in July and August; winter animals usually remain hidden in hibernation sites. Observe emerging bats without blocking a roost entrance, and never touch a grounded bat. Contact a wildlife professional if one needs help.

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 Vermont 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"