Delaware mammals

Eastern Red Bat in Delaware

Lasiurus borealis

Native to Delaware S5 Secure in Delaware

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

Occasional in Delaware 22nd most recorded of 62 mammals logged in Delaware

34 occurrence records
30 with iNaturalist photos
Apr 2, 2026 Last seen in Delaware

Records from 2000–2026.

When to look for the Eastern Red Bat in Delaware

Most sightings fall in July.

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

Monthly Delaware records (table)
MonthRecords
January0
February2
March1
April7
May1
June2
July10
August4
September1
October1
November5
December0

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

Seasonality

Year-round in Delaware, with recorded sightings peaking in July, with a smaller rise in April.

Occurrence map

Where Eastern Red Bat has been recorded in Delaware

34 records mapped · zoom and drag to explore

34 Delaware records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Killens Pond State Park 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 Delaware

CountyRecords
New Castle County 19
Sussex County 11
Kent County 4

The complete county distribution, spread across 3 Delaware counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Eastern Red Bats roost alone among leaves, where reddish fur and a tucked posture resemble dead foliage. Delaware’s wooded parks and forest edges at Killens Pond, White Clay Creek, and Redden State Forest provide roosting and feeding habitat; at dusk, watch openings beside trees rather than searching roosts by day.

Records are scattered from spring through fall, with small peaks in April, July–August, and November that may include migrants. Never handle a grounded bat bare-handed.

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 Delaware in the atlas

Data & sources

The data and visualizations on this page draw on these open sources: