North Dakota mammals

Big Brown Bat in North Dakota

Eptesicus fuscus

Native to North Dakota SNR Unranked in North Dakota

Not listed as nonindigenous in North Dakota by USGS NAS; native to its North Dakota 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 Bat in North Dakota, by the numbers

Rare in North Dakota 65th most recorded of 92 mammals logged in North Dakota

49 occurrence records
5 with iNaturalist photos
May 23, 2026 Last seen in North Dakota

Records from 2000–2026.

49 total records count every North Dakota occurrence from GBIF and iNaturalist; the monthly chart covers the 48 records with a full observation date.

When to look for the Big Brown Bat in North Dakota

Most sightings fall in June to July.

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

Monthly North Dakota records (table)
MonthRecords
January2
February0
March0
April1
May1
June17
July21
August4
September0
October1
November0
December1

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

Seasonality

Year-round in North Dakota, with recorded sightings peaking in June–July.

Occurrence map

Where Big Brown Bat has been recorded in North Dakota

49 records mapped · zoom and drag to explore

49 North Dakota records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Little Missouri National Grassland 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 North Dakota

CountyRecords
Dunn County 21
Billings County 17
Renville County 6
Cass County 2
Sargent County 1
McLean County 1
Barnes County 1

The complete county distribution, spread across 7 North Dakota counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Only 47 big brown bat records turn up in North Dakota’s occurrence data, all from GBIF rather than casual sightings. For a bat that tolerates almost any landscape, that thin count says more about how few people are out looking for bats after dark than about scarcity.

Rock crevices standing in for caves

North Dakota has little in the way of true caves, so big brown bats here likely lean on the next best thing: the crevices, fissures, and undercut ledges in the scoria buttes and sandstone outcrops of the Little Missouri Badlands around the Little Missouri National Grassland. Elsewhere, the wetland refuges at J. Clark Salyer and Chase Lake offer a different draw, open water and marsh edges thick with the mosquitoes, midges, and other night-flying insects this bat hunts on the wing.

A summer bat in the records

Records concentrate almost entirely in June and July, with barely a trace the rest of the year. That’s the season when big brown bats form maternity colonies, and warm summer nights bring the heaviest insect activity for a species that needs to eat close to its own body weight in insects to get through a night. Winter records all but disappear here, consistent with a bat that hibernates through the cold rather than staying active.

Status in North Dakota

The big brown bat carries no numeric NatureServe rank in North Dakota, SNR, unranked, though it’s secure globally at G5. It’s native to its North Dakota range, one of the most adaptable bats in the state even where its record count stays thin.

Occurrence data from iNaturalist and GBIF.

More mammals in North Dakota 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"