Massachusetts mammals

Eastern Red Bat in Massachusetts

Lasiurus borealis

Native to Massachusetts S3 Vulnerable in Massachusetts

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

Eastern Red Bat in Massachusetts, by the numbers

Occasional in Massachusetts 52nd most recorded of 93 mammals logged in Massachusetts

122 occurrence records
44 with iNaturalist photos
Mar 12, 2026 Last seen in Massachusetts

Records from 2000–2026.

122 total records count every Massachusetts occurrence from GBIF and iNaturalist; the monthly chart covers the 85 records with a full observation date.

When to look for the Eastern Red Bat in Massachusetts

Most sightings fall in August.

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

Monthly Massachusetts records (table)
MonthRecords
January0
February0
March5
April4
May1
June4
July6
August30
September15
October14
November4
December2

Monthly eastern red bat occurrence records (iNaturalist and GBIF) in Massachusetts, 2000–2026.

Seasonality

Year-round in Massachusetts, with recorded sightings peaking in August.

Occurrence map

Where Eastern Red Bat has been recorded in Massachusetts

122 records mapped · zoom and drag to explore

111 Massachusetts records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Franklin Park Zoo 1

Protected places with the most eastern red 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 Massachusetts

CountyRecords
Middlesex County 38
Bristol County 26
Suffolk County 11
Worcester County 11
Essex County 9
Dukes County 8
Norfolk County 4
Barnstable County 3
Plymouth County 3
Franklin County 2
Berkshire County 2
Hampshire County 1
Other localities 4

The complete county distribution, spread across 12 Massachusetts counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Eastern red bats don’t roost in caves or buildings like most Massachusetts bats. They hang alone in leaf clusters at the edge of tree canopy, wrapped in a furred tail membrane that makes them look like a dead leaf to a passing predator, which is why records near the wooded edges of Blue Hills Reservation and Massasoit National Wildlife Refuge likely trace to daytime roosts in nearby foliage rather than caves.

Records carry three bumps, April, July, and a stronger one across September and October, tracking spring arrival, summer roosting, and the fall migration when red bats move south in large numbers rather than hibernating locally. NatureServe ranks the species S3, vulnerable, in Massachusetts, notably more precarious than most of the state’s other bats, in part because it migrates instead of overwintering in protected hibernacula.

Occurrence data from iNaturalist and GBIF.

More mammals in Massachusetts 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"