California mammals

Arizona Cotton Rat in California

Sigmodon arizonae

Native to California SNR Unranked in California

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

IUCN Red List status

LC – Least Concern

Widespread and abundant; not at risk.

Photo: mattyfelp · CC BY 4.0Arizona cotton rat standing in dry grassPhoto: Francisco Farriols Sarabia · CC BY 4.0Arizona Cotton Rat (Sigmodon arizonae)Photo: Francisco Farriols Sarabia · CC BY 4.0Arizona Cotton Rat (Sigmodon arizonae)Photo: Matt Felperin · CC BY 4.0Arizona Cotton Rat (Sigmodon arizonae)

Photo: mattyfelp · CC BY 4.0Arizona cotton rat standing in dry grassPhoto: Francisco Farriols Sarabia · CC BY 4.0Arizona Cotton Rat (Sigmodon arizonae)Photo: Francisco Farriols Sarabia · CC BY 4.0Arizona Cotton Rat (Sigmodon arizonae)Photo: Matt Felperin · CC BY 4.0Arizona Cotton Rat (Sigmodon arizonae)

Arizona Cotton Rat in California, by the numbers

Occasional in California 155th most recorded of 241 mammals logged in California

52 occurrence records

1 with iNaturalist photos

Records from 2000–2026.

52 total records count every California occurrence from GBIF and iNaturalist; the map plots a georeferenced sample of 45; the monthly chart covers the 45 records with a full observation date.

When to look for the Arizona Cotton Rat in California

Most sightings fall in February.

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

Monthly California records (table)

Month	Records
January	0
February	33
March	3
April	0
May	0
June	0
July	0
August	0
September	0
October	5
November	2
December	2

Monthly arizona cotton rat occurrence records (iNaturalist and GBIF) in California, 2000–2026.

Seasonality

Year-round in California, with recorded sightings peaking in February.

Occurrence map

Where Arizona Cotton Rat has been recorded in California

45 records mapped · zoom and drag to explore

45 California records mapped

Notable places to look

Park, forest, or monument	iNaturalist records
Palo Verde Ecological Reserve	1

Protected places with the most arizona cotton 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 California

County	Records
San Bernardino County	32
Riverside County	13
Other localities	7

The complete county distribution, spread across 2 California counties. Every occurrence record falls in one county, so these sum to the total. Counties from GBIF and US Census boundaries.

Arizona Cotton Rat records in California fit dry scrub, rocky canyons, and sandy or gravelly ground.

Reports center on the Mojave and Colorado deserts, including Death Valley and the Joshua Tree region. They show where people have documented the species, and they don’t rank California’s best habitat.

California records span more than one season. Gaps and clusters in reports can reflect when and where people looked, not true absence or abundance.

Occurrence data from iNaturalist and GBIF.

Full species profile Arizona Cotton Rat Sigmodon arizonae Size 24.9–36.1 cm9.8–14.2 in Weight 172 g6.1 oz Lifespan Up to 5.2 yr View the full profile

More mammals in California 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"