Tennessee mammals

Northwestern Marsh Rice Rat in Tennessee

Oryzomys texensis

Native to Tennessee SNR Unranked in Tennessee

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

IUCN Red List status

NE – Not Evaluated

Not yet assessed against IUCN Red List criteria.

Northwestern Marsh Rice Rat in Tennessee, by the numbers

Common in Tennessee 23rd most recorded of 86 mammals logged in Tennessee

103 occurrence records

Records from 2000–2026.

103 total records count every Tennessee occurrence from GBIF and iNaturalist; the monthly chart covers the 102 records with a full observation date.

When to look for the Northwestern Marsh Rice Rat in Tennessee

Most sightings fall in October to November.

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

Monthly Tennessee records (table)
MonthRecords
January9
February1
March7
April5
May5
June7
July5
August0
September8
October21
November22
December12

Monthly northwestern marsh rice rat occurrence records (iNaturalist and GBIF) in Tennessee, 2000–2026.

Seasonality

Year-round in Tennessee, with recorded sightings peaking in October–November.

Occurrence map

Where Northwestern Marsh Rice Rat has been recorded in Tennessee

103 records mapped · zoom and drag to explore

103 Tennessee records mapped

Notable places to look

Park, forest, or monumentiNaturalist records
Wolf River Wildlife Management Area Unit 1 9
Eagle Lake Refuge 7
Shiloh National Military Park 1

Protected places with the most northwestern marsh rice rat 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 Tennessee

CountyRecords
Shelby County 40
Fayette County 36
Haywood County 13
Tipton County 8
Gibson County 3
Hardin County 2
Hardeman County 1

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

Northwestern marsh rice rat reports fit Tennessee’s low, wet western edge better than its uplands. Reelfoot Lake State Park and the Hatchie and Tennessee national wildlife refuges provide marsh, flooded grass, river margins, and ditches where this strong-swimming mouse can move beneath dense cover.

The Tennessee record is strongest in autumn and early winter, with October and November leading the pattern, not January and March. Reports appear in most months but disappear in August, which may say more about when wetland surveys occurred than where the rat was absent. NatureServe leaves the state rank unresolved, so the records shouldn’t be turned into a population estimate.

More mammals in Tennessee 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"