Louisiana mammals

Northwestern Marsh Rice Rat in Louisiana

Oryzomys texensis

Native to Louisiana S5 Secure in Louisiana

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

IUCN Red List status

NE – Not Evaluated

Not yet assessed against IUCN Red List criteria.

Northwestern marsh rice rat on a bare soil bank, unrestrainedAI-generated image: Northwestern marsh rice rat foraging among sedges at dusk. No additional license-safe photograph of this species exists. This image was generated with AI from verified reference material and reviewed by our editorial team for accuracyAI-generated image: Northwestern marsh rice rat grooming on a muddy bank. No additional license-safe photograph of this species exists. This image was generated with AI from verified reference material and reviewed by our editorial team for accuracy
Photo: Rich Sommer · CC BY 4.0Northwestern marsh rice rat on a bare soil bank, unrestrainedAI-generated image No additional license-safe photograph of this species exists. This image was generated with AI from verified reference material and reviewed by our editorial team for accuracyNorthwestern marsh rice rat foraging among sedges at duskAI-generated image No additional license-safe photograph of this species exists. This image was generated with AI from verified reference material and reviewed by our editorial team for accuracyNorthwestern marsh rice rat grooming on a muddy bank

Northwestern Marsh Rice Rat in Louisiana, by the numbers

Occasional in Louisiana 48th most recorded of 72 mammals logged in Louisiana

9 occurrence records
9 with iNaturalist photos
Oct 30, 2022 Last seen in Louisiana

Records from 2000–2026.

When to look for the Northwestern Marsh Rice Rat in Louisiana

Most sightings fall in March.

9 Louisiana 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 Louisiana records (table)
MonthRecords
January0
February1
March4
April0
May0
June2
July0
August0
September0
October2
November0
December0

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

Seasonality

Sparse observation record in Louisiana; presence confirmed but timing of activity not well documented.

Occurrence map

Where Northwestern Marsh Rice Rat has been recorded in Louisiana

9 records mapped · zoom and drag to explore

9 Louisiana records mapped

Where it's recorded in Louisiana

CountyRecords
Lafourche County 2
Jefferson Davis County 2
East Baton Rouge County 1
Terrebonne County 1
Tangipahoa County 1
Lafayette County 1
Other localities 1

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

Northwestern marsh rice rats carry a NatureServe S5 secure rank in Louisiana despite a global rank that’s still unresolved, GNR, reflecting recent taxonomic splitting of the marsh rice rat complex. All 9 of the state’s records from 2000 onward come from iNaturalist, scattered across six parishes, and Lafourche Parish, with 2, takes in the kind of coastal marsh this semi-aquatic rodent depends on.

March carries 4 of the 9 records, and June and October have 2 each, but a sample this small can’t show any true seasonal shift in this marsh-dwelling rat’s activity.

Occurrence data from iNaturalist and GBIF.

Northwestern marsh rice rat on a bare soil bank, unrestrained
Full species profile Northwestern Marsh Rice Rat Oryzomys texensis Size 22.6–30.5 cm8.9–12 in Weight 40–80 g1.4–2.8 oz View the full profile

More mammals in Louisiana 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