Maryland mammals

Tricolored Bat in Maryland

Perimyotis subflavus

Native to Maryland S1 Critically Imperiled in Maryland

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

IUCN Red List status

  1. LC
  2. NT
  3. VU
  4. EN
  5. CR
  6. EW
  7. EX

VU – Vulnerable

High risk of extinction in the wild.

Tricolored Bat hibernating on a limestone mine wallTricolored Bat hanging from a cave ceiling with pale belly fur visibleTricolored Bat roosting in a shallow concrete creviceTricolored Bat tucked against a pale cave wallTricolored Bat roosting under a dark cave overhang
Photo: Krynak Tim, U.S. Fish and Wildlife Service · Public domainTricolored Bat hibernating on a limestone mine wallPhoto: Ann Froschauer/USFWS · CC-BYTricolored Bat hanging from a cave ceiling with pale belly fur visiblePhoto: aispinsects · CC-BYTricolored Bat roosting in a shallow concrete crevicePhoto: cigazze · CC-BYTricolored Bat tucked against a pale cave wallPhoto: Matt D'Agrosa · CC-BYTricolored Bat roosting under a dark cave overhang

Tricolored Bat in Maryland, by the numbers

Occasional in Maryland 36th most recorded of 100 mammals logged in Maryland

39 occurrence records

Records from 2000–2026.

39 total records count every Maryland occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 31; the monthly chart covers the 31 records with a full observation date.

When to look for the Tricolored Bat in Maryland

Most sightings fall in February.

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

Monthly Maryland records (table)
MonthRecords
January1
February13
March1
April1
May3
June0
July2
August1
September1
October8
November0
December0

Monthly tricolored bat occurrence records (iNaturalist and GBIF) in Maryland, 2000–2026.

Seasonality

Year-round in Maryland, with recorded sightings peaking in February, with a smaller rise in October.

Occurrence map

Where Tricolored Bat has been recorded in Maryland

31 records mapped · zoom and drag to explore

31 Maryland records mapped

Where it's recorded in Maryland

CountyRecords
Garrett County 15
Washington County 10
Calvert County 2
Anne Arundel County 2
St. Mary's County 1
Howard County 1
Other localities 8

The complete county distribution, spread across 6 Maryland counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Tricolored bat is among the smallest bats in North America and has been devastated by white-nose syndrome, a fungal disease that has collapsed cave-hibernating bat colonies across the East, which likely explains why the state’s record count around Savage River and Green Ridge state forests stays low even in suitable habitat. The IUCN lists the species globally Vulnerable, and NatureServe ranks it S1, Critically Imperiled, in Maryland, a real conservation signal, not just sparse survey coverage.

Records show three modest peaks in March, May, and July, roughly tracking spring emergence from hibernation, breeding season, and summer foraging before bats begin seeking winter roosts again.

Tricolored Bat hibernating on a limestone mine wall
Full species profile Tricolored Bat Perimyotis subflavus Size 7.7–8.9 cm3–3.5 in Weight 5–8 g0.2–0.3 oz Lifespan Up to 14.8 yr View the full profile

More mammals in Maryland 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