Pennsylvania mammals

Eastern Red Bat in Pennsylvania

Lasiurus borealis

Native to Pennsylvania S4 Apparently Secure in Pennsylvania

Not listed as nonindigenous in Pennsylvania by USGS NAS; native to its Pennsylvania 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 roosting among green leaves, disguised as a dead leafEastern red bat in flight against blue skyEastern red bat roosting on a pine branchEastern red bat hanging under tree leavesEastern red bat tucked among white apple blossoms
Photo: NPS Photo · Public DomainEastern red bat roosting among green leaves, disguised as a dead leafPhoto: Chrissy McClarren and Andy Reago · CC0Eastern red bat in flight against blue skyPhoto: Christina Butler · CC BY 2.0Eastern red bat roosting on a pine branchPhoto: Summit Metro Parks · CC-BYEastern red bat hanging under tree leavesPhoto: Rev. Lee A. Payne, Jr. · CC-BYEastern red bat tucked among white apple blossoms

Eastern Red Bat in Pennsylvania, by the numbers

Occasional in Pennsylvania 30th most recorded of 77 mammals logged in Pennsylvania

188 occurrence records
178 with iNaturalist photos

Records from 2000–2026.

188 total records count every Pennsylvania occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 187; the monthly chart covers the 186 records with a full observation date.

When to look for the Eastern Red Bat in Pennsylvania

Most sightings fall in July to August.

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

Monthly Pennsylvania records (table)
MonthRecords
January3
February3
March22
April23
May24
June16
July25
August29
September13
October14
November12
December2

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

Seasonality

Year-round in Pennsylvania, with recorded sightings peaking in July–August, with a smaller rise in March–May.

Occurrence map

Where Eastern Red Bat has been recorded in Pennsylvania

187 records mapped · zoom and drag to explore

186 Pennsylvania records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Gettysburg National Military Park 5
State Game Land #157 3
Beltzville State Park 2
Cook Forest State Park 2
State Game Land #121 2
Washington Crossing Historic Park 1
Codorus State Park 1
Glade Run Lake 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 Pennsylvania

CountyRecords
Philadelphia County 44
Montgomery County 16
Allegheny County 11
Bucks County 11
Centre County 10
Chester County 10
Lancaster County 8
Adams County 8
Cumberland County 6
Delaware County 4
Greene County 4
Berks County 3
29 other counties 53

The complete county distribution, spread across 41 Pennsylvania counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

For Pennsylvania’s eastern red bats, trees beside open hunting space matter more than the name of the waterbody. Leafy roost cover borders open water at Pymatuning and Presque Isle, while Delaware Water Gap supplies forested slopes broken by river clearings.

Records rise in April and May and again in August. Seasonal movement and activity can improve detection, but observer presence changes too, making those peaks a report pattern rather than a count of bats overhead.

Occurrence data from iNaturalist and GBIF.

Eastern red bat roosting among green leaves, disguised as a dead leaf
Full species profile Eastern Red Bat Lasiurus borealis Size 9.3–11.7 cm3.7–4.6 in Weight 7–13 g0.2–0.5 oz Lifespan Up to 2.6 yr View the full profile

More mammals in Pennsylvania 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"