South Dakota mammals

Least Weasel in South Dakota

Mustela nivalis

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.

Least Weasel in South Dakota, by the numbers

Rare in South Dakota 68th most recorded of 100 mammals logged in South Dakota

20 occurrence records
8 with iNaturalist photos
Sep 8, 2025 Last seen in South Dakota

Records from 2000–2026.

20 total records count every South Dakota occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 19; the monthly chart covers the 19 records with a full observation date.

When to look for the Least Weasel in South Dakota

Most sightings fall in April.

19 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
January0
February4
March1
April6
May1
June3
July1
August1
September1
October0
November1
December0

Monthly least weasel occurrence records (iNaturalist and GBIF) in South Dakota, 2000–2026.

Seasonality

Year-round in South Dakota, with recorded sightings peaking in April, with a smaller rise in February.

Occurrence map

Where Least Weasel has been recorded in South Dakota

19 records mapped · zoom and drag to explore

19 South Dakota records mapped

Where it's recorded in South Dakota

CountyRecords
Bennett County 3
Brown County 3
Hand County 2
Custer County 2
Union County 2
Sanborn County 1
Minnehaha County 1
Haakon County 1
Hamlin County 1
Meade County 1
Shannon County 1
Gregory County 1
Other localities 1

The complete county distribution, spread across 12 South Dakota counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Least weasels are North America’s smallest carnivore, and South Dakota’s record for the species leans toward GBIF (16 records) over iNaturalist (8), since an animal this small and fast is more likely to turn up in a trap than in a photograph. NatureServe rates the state population S5, secure, despite the genuinely thin record.

Records scatter one at a time across four separate months, February, April, June, and November, too sparse a pattern to describe any real seasonal trend beyond confirming occasional detection through the year.

Occurrence data from iNaturalist and GBIF.

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