South Dakota mammals

Big Brown Bat in South Dakota

Eptesicus fuscus

Native to South Dakota S5 Secure in South Dakota

Not listed as nonindigenous in South Dakota by USGS NAS; native to its South 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 Bats (Eptesicus fuscus)Big brown bat flying in daylight with wings spreadBig brown bat flying at night with wings spreadBig brown bat roosting on lichen-covered tree barkBig brown bat roosting on a wooden structure
Photo: Connor Long · CC BY-SA 4.0Big Brown Bats (Eptesicus fuscus)Photo: rhododendrites · CC-BY-SABig brown bat flying in daylight with wings spreadPhoto: Dan Riskin · CC-BYBig brown bat flying at night with wings spreadPhoto: Rita Clare · CC0Big brown bat roosting on lichen-covered tree barkPhoto: Bonnie Isaac · CC0Big brown bat roosting on a wooden structure

Big Brown Bat in South Dakota, by the numbers

Common in South Dakota 34th most recorded of 100 mammals logged in South Dakota

32 occurrence records
32 with iNaturalist photos
Apr 2, 2025 Last seen in South Dakota

Records from 2000–2026.

32 total records count every South Dakota occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 29; the monthly chart covers the 29 records with a full observation date.

When to look for the Big Brown Bat in South Dakota

Most sightings fall in July to August.

29 South Dakota occurrence records (iNaturalist and GBIF) by month of year, 2000–2026. Shows when the species is recorded, not a guarantee of presence. Based on a small number of dated records; the seasonal pattern may not be representative.

Monthly South Dakota records (table)
MonthRecords
January1
February1
March2
April3
May3
June2
July8
August5
September2
October1
November1
December0

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

Seasonality

Year-round in South Dakota, with recorded sightings peaking in July–August.

Occurrence map

Where Big Brown Bat has been recorded in South Dakota

29 records mapped · zoom and drag to explore

29 South Dakota records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Big Sioux 1
Laframboise Island Nature Area 1
Missouri National Recreational River 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 South Dakota

CountyRecords
Brookings County 7
Minnehaha County 7
Clay County 3
Lincoln County 2
Brown County 2
Sanborn County 2
Davison County 2
Day County 1
Lawrence County 1
Stanley County 1
Gregory County 1
Other localities 3

The complete county distribution, spread across 11 South Dakota counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Big brown bats have 32 South Dakota records since 2000, every one an iNaturalist observation, with 21 of them also carried in GBIF, so casual photographs, not specimen or survey data, document this widespread, building-roosting bat here. Brookings and Minnehaha counties lead with 7 each, in the state’s more settled east. NatureServe rates the state population S5, secure, fitting a species that adapts readily to human structures across South Dakota.

July is the busiest month, with 8 of the dated sightings, tracking peak summer activity when maternity colonies are active and insects are plentiful; December is the only month with no record at all.

Occurrence data from iNaturalist and GBIF.

Big Brown Bats (Eptesicus fuscus)
Full species profile Big Brown Bat Eptesicus fuscus Size 7.5 cm3 in Weight 17 g0.6 oz Lifespan 19 yr View the full profile

More mammals in South 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"